Nuevas Perspectivas en la Efficiencia del Uso Nirogeno en Vaca Lecheras

USDA-ARS?s Scientific Manuscript database

Dairy cows utilize feed crude protein (CP) with greater efficiency than other ruminants, but still excrete about 2 to 3 times more nitrogen (N) in manure than they secrete in milk. This increases milk production costs plus environmental N pollution. Optimizing microbial protein formation in the rume...

Pesticide Safety for Farmworkers = Uso Seguro de Pesticidas para los Trabajadores del Campo.

ERIC Educational Resources Information Center

Poli, Bonnie; Fluker, Sam S.

A booklet for farmworkers and employers uses illustrations and simple text in English and Spanish to inform about the dangers, precautions, and use of pesticides. Topics covered include methods of pesticide absorption; signs/symptoms of pesticide poisoning; first aid; residues; appropriate work clothes; safe and unsafe pesticide practices; how to…

Factores que Influencian la Adquisición de Infecciones de Transmisión Sexual y VIH en Mujeres Jóvenes Chilenas que Participaron en la Intervención Online I-STIPI

PubMed Central

Villegas, Natalia; Cianelli, Rosina; Santisteban, Daniel; Lara, Loreto; Vargas, Jessica

2017-01-01

Resumen El objetivo de este estudio descriptivo de corte transversal fue investigar los siguientes factores asociados a la prevención de las infecciones de transmisión sexual (ITS) y el virus de la inmunodeficiencia humana (VIH): (a) conocimientos, (b) actitudes, (c) autoeficacia, (d) vulnerabilidad, (e) conductas de riesgo, (f) conductas de prevención, y (g) uso de internet en mujeres chilenas entre 18 y 24 años. Se utilizó un cuestionario estructurado disponible en un sitio web seguro para la recolección de datos que incluyó preguntas relacionadas con la prevención de ITS/VIH. Los resultados del estudio indicaron que las mujeres jóvenes están en riesgo de adquirir ITS/VIH y tienen necesidades especiales para la prevención. La familiaridad y frecuencia del uso de internet en esta población puede ser utilizado para la prevención de ITS/VIH. PMID:27257190

Expresiones de afecto de madres bilingües, Bilingual mothers' expressions of affect

PubMed Central

Shiro, Martha

2015-01-01

En la interacción de 10 madres bilingües con sus hijos de 30 meses se analiza la expresión de afectividad en L1 y en L2. Se identificaron las expresiones de emoción, volición y actitud epistémica en 30 interacciones espontáneas: i. 10 madres (español L1) hablando en L1; ii. 10 madres (español L1) hablando en inglés L2; y iii. 10 madres (inglés L1) hablando en L1. Los resultados sugieren que los usos de L2 difieren de los de L1 (inglés o español): la expresión de volición y actitud epistémica se asemeja al inglés L1, mientras que la expresión de las emociones se acerca al español L1. Estos hallazgos permiten explicar los usos del lenguaje expresivo de los bilingües y ayudan a determinar sus efectos en el desarrollo del lenguaje PMID:25844004

[Trattamento del disturbo da uso di alcol da un punto di vista psicologico].

PubMed

Coriale, Giovanna; Fiorentino, Daniela; De Rosa, Francesca; Solombrino, Simona; Scalese, Bruna; Ciccarelli, Rosaria; Attilia, Fabio; Vitali, Mario; Musetti, Alessia; Fiore, Marco; Ceccanti, Mauro

2018-01-01

RIASSUNTO. L'elaborazione del piano di trattamento rappresenta un momento molto delicato e complesso del processo terapeutico del disturbo da abuso di alcol (DUA). È la fase in cui le informazioni raccolte da un'équipe di professionisti (medici, psicologi e assistenti sociali) (modello bio-psico-sociale del DUA) vengono messe insieme per decidere il percorso terapeutico più adatto. Per quanto riguarda la parte psicologica, è di notevole importanza scegliere un trattamento clinico in grado di ridurre al minimo la mancata adesione al trattamento e, per i soggetti che rimangono in trattamento, di garantirne l'efficacia. Se da una parte, le tecniche psicoanalitiche e comportamentali hanno fornito le basi della terapia psicologica dell'alcolismo, dall'altra, gli approcci basati sull'evidenza scientifica sono stati elaborati a partire dai principi del colloquio motivazionale e della terapia cognitivo-comportamentale. In questo articolo viene fornita una panoramica dei trattamenti che sono risultati più efficaci nel trattare il DUA e delle modalità temporali più adeguate per monitorare l'efficacia del trattamento.

TECNOLOGÍAS DE INFORMACIÓN Y COMUNICACIÓN PARA LA PREVENCIÓN Y CONTROL DE LA INFECCIÓN POR EL VIH Y OTRAS ITS*

PubMed Central

Curioso, Walter H.; Blas, Magaly M.; Kurth, Ann E.; Klausner, Jeffrey D.

2010-01-01

Avances tecnológicos innovadores como Internet, computadoras personales de bolsillo, teléfonos celulares y otros equipos son un arsenal en crecimiento en el esfuerzo de impedir y controlar el VIH y otras infecciones de transmisión sexual (ITS). A pesar que existe una diversidad de tecnologías de información y comunicación en diferentes etapas de desarrollo para la prevención del VIH e ITS, la investigación en esta área se encuentra aún en crecimiento, y el impacto en la incidencia de enfermedad, las evaluaciones con diseños rigurosos y los estudios económicos todavía son muy limitados. Sin embargo, algunas de estas evidencias son prometedoras y poseen un gran potencial para su uso en nuestro medio. En este artículo hemos realizado una revisión sistemática de la literatura relacionada con el uso de la tecnología aplicada a la prevención y control del VIH e ITS. De ser usada apropiadamente, esta tecnología podría mejorar la vigilancia del VIH y otras ITS, diagnóstico, notificación de parejas, prevención, manejo clínico, y capacitación de profesionales de la salud. PMID:26339254

Modos de produccion cientifica: Culturas y metodologias de investigacion en la Universidad de Cadiz

NASA Astrophysics Data System (ADS)

Gonzalez Ramos, Ana M.

2004-12-01

Este trabajo de investigacion supone un modelo teorico de caracter aplicado, que proporciona la oportunidad de evaluar la produccion cientifica de los investigadores. Se encuadra dentro de la tradiccion de la estadistica aplicada y la sociologia del conocimiento. Atiende especialmente a dos conjuntos de temas de interes, por una parte, las caracteristicas principales que determinan el nivel y tipo de produccion academica producida por las unidades de investigacion y por los propios investigadores; por otra, la utilizacion que se hace de los metodos y tecnicas de investigacion puesto que de ello tambien depende el modo de produccion cientifica. Los puntos novedosos de esta tesis son: la medicion cuantitativa del objeto de estudio, la suma de los productos y las condiciones externas a la produccion del conocimiento mas otros elementos internos como las caracteristicas de los investigadores y la metodologia utilizada para desarrollar sus trabajos; y, finalmente, el uso de las nuevas tecnologias. El aprovechamiento de los recursos estadisticos y las fuentes de informacion secundarias se complementan con el diseno propio de una encuesta donde se implementa las caracteristicas descritas en un capitulo anterior sobre los metodos cientificos mas idoneos descritos en los principales manuales y articulos cientificos desde distintas disciplinas de conocimiento. Dicha encuesta ha sido desarrollada como un programa propio y en base a los mas innovadores usos de la tecnologia en la metodologia de encuestas.

Muscle dysmorphia: detection of the use-abuse of anabolic adrogenic steroids in a Spanish sample.

PubMed

González-Martí, Irene; Fernández-Bustos, Juan Gregorio; Contreras Jordán, Onofre Ricardo; Sokolova, Marina

2017-07-14

Debido a una distorsión en la imagen corporal, las personas que padecen Dismorfia Muscular se perciben menos musculosas de lo que son en realidad. Con el fin de aumentar su musculatura, algunas de estas personas hacen uso de hormonas cuya función principal es la del aumento del tamaño muscular. Por lo que el objetivo de este estudio es conocer la prevalencia del uso de hormonas en personas afectadas por Dismorfia Muscular. 562 hombres y 172 mujeres fisicoculturistas y levantadores de pesas, a los que se le administraron diferentes cuestionarios para conocer, primero si padecían el trastorno, y después en qué porcentaje usaban hormonas la muestra afectada. Para la creación de los modelos de regresión de la dismorfia muscular fueron empleadas las técnicas estadísticas de árboles de decisión (R = 0.78 y R2 = 0.62). Los resultados indican que casi un 50% de participantes, afectados por este trastorno, hacen uso de estas drogas. Due to a distortion in the body image, the people who suffer from muscle dysmorphia have the self-perception of being less muscular than they currently are. With the aim of increasing their muscular development, they resort to the use of AAS. The purpose of the present study is to know the prevalence of the use of AAS in a Spanish sample affected by muscle dysmorphia. 562 male and 172 female bodybuilders and weightlifters were provided with different questionnaires in order to know, firstly, if they suffered from this disorder and, secondly, the percentage of the participants affected who use these substances. Decision trees and regression was applied to create explanatory models for muscle dysmorphia (R = 0.78 and R2 = 0.62). The results show that almost 50% of the participants, male and female, affected by this disorder use this kind of drugs.

Estudio multifrecuencia del medio interestelar cercano a HD 192281

NASA Astrophysics Data System (ADS)

Arnal, E. M.; Cappa, C.; Cichowolski, S.; Pineault, S.; St-Louis, N.

Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de 21-cm del Hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100 micrones, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5 Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

Estudio multifrecuencia del medio interestelar cercano a HD 192281

NASA Astrophysics Data System (ADS)

Arnal, E. M.; Cappa, C. E.; Cichowolski, S.; Pineault, S.; St-Louis, N.

Una de las causas que modifica la estructura y dinámica del medio interestelar es la acción que los vientos de las estrellas de gran masa ejercen sobre el mismo. En este trabajo, mediante el uso de datos interferométricos obtenidos en la banda de radio en la transición de λ˜21-cm del hidrógeno neutro y de imágenes de la emisión de continuo en las bandas de 408 y 1420 MHz, de imágenes HIRES del satélite IRAS en 60 y 100μm, y de observaciones de continuo obtenidas con radiotelescopios de disco simple en 2695, 4850 y 8350 MHz se ha realizado un estudio multifrecuencia de los efectos que los vientos estelares de HD 192281, una estrella de tipo espectral O5,Vn((f))p, han tenido sobre el medio interestelar que rodea a la misma.

Meningococco B: controllo di due focolai epidemici mediante vaccinazione

PubMed Central

2014-01-01

Riassunto La problematica di un efficace approccio vaccinale nei confronti del Meningococco B (MenB) è stata superata identificando con la metodica della "reverse vaccinology" alcuni antigeni capaci di indurre una risposta verso la maggior parte dei ceppi di MenB circolanti nel mondo. Il nuovo vaccino MenB a 4 componenti (4CMenB) è stato autorizzato in Europa, Australia e Canada, ed è entrato nei calendari di immunizzazione pediatrica internazionali: Australia, Canada, UK. In Italia, le prime regioni che hanno raccomandato la vaccinazione contro il MenB sono state Basilicata e Puglia. La gestione di epidemie/focolai epidemici richiede la messa in atto di una risposta rapida da parte delle autorità sanitarie nei confronti di una emergenza sanitaria ad elevato impatto, anche emotivo, sulla popolazione, come recentemente dimostrato in due università americane. Alla dichiarazione di focolaio epidemico in atto, in entrambi i contesti si è attivata una procedura per l'uso del vaccino 4CMenB non ancora autorizzato negli USA. È stato così possibile organizzare gli interventi di profilassi attiva nei due campus universitari, adottando il primo impiego su larga scala del nuovo vaccino 4CMenB e conseguendo, in tempi relativamente brevi, elevati tassi di copertura vaccinale. A fronte di circa 14000 studenti immunizzati con almeno una dose, non è stata segnalata alcuna problematica di eventi avversi conseguenti all'immunizzazione; ad oggi non si sono verificati casi nei soggetti che hanno ricevuto il vaccino. Come conseguenza dei due focolai descritti, è oggi in corso la valutazione da parte dell'FDA per l'estensione dell'uso del vaccino 4CMenB negli Stati Uniti negli adolescenti e giovani adulti. PMID:25916017

Relaciones entre el sueño y la adicción

PubMed Central

Cañellas, Francesca; de Lecea, Luis

2016-01-01

Resumen La interacción entre los trastornos del sueño y el abuso de sustancias es ya conocida, pero seguramente más compleja de lo que se pensaba. Existe tanto una relación positiva entre tener un trastorno por uso de substancias y sufrir un trastorno de sueño, como viceversa. Los efectos sobre el sueño dependen de la substancia utilizada, pero se ha demostrado que tanto durante su uso como en período de abstinencia los consumidores tienen diferentes problemas de sueño y fundamentalmente un sueño más fragmentado. Sabemos que hay que tener en cuenta los problemas de sueño para evitar recaídas en la adicción. Investigaciones recientes indican que el sistema hipocretinérgico definido por el neuropéptido hipocretina/orexina (Hcrt/ox), localizado en el hipotálamo lateral e implicado entre otros en la regulación del ciclo sueño-vigilia, jugaría un papel importante en las conductas adictivas. Diferentes estudios han demostrado interacciones entre el sistema hipocretinérgico, los circuitos de respuesta aguda al estrés y los sistemas de recompensa. También sabemos que la activación optogenética selectiva del sistema hipocretinérgico incrementa la probabilidad de la transición del sueño a la vigilia, y también es suficiente para iniciar un comportamiento compulsivo de recaída adictiva. La activación del sistema hipocretinérgico podría explicar la hipervigilia asociada al estrés y a la adicción. El mayor conocimiento de esta interacción permitiría entender mejor los mecanismos de la adicción y encontrar nuevas estrategias para el tratamiento de las adicciones. PMID:23241715

Análisis de costo de la enfermedad, del tratamiento, las complicaciones e intervenciones de la hipercolesterolemia en México en 2016.

PubMed

Baeza-Cruz, German; Peniche-Otero, Gustavo; Alva-Esqueda, Mónica E; Naranjo-Muedano, Mariana; Soria-Suárez, Noé; Morales-Flores, Héctor J

2018-04-20

Describir los costos y el impacto económico de la atención de pacientes diagnosticados con hipercolesterolemia en México en el año 2016. METODOLOGíA: Se desarrolla una evaluación económica del tipo análisis de costo de la enfermedad donde se cuantifican los recursos médicos utilizados para el tratamiento de la hipercolesterolemia así como para sus complicaciones. Los costos de los recursos médicos utilizados son obtenidos de los costos unitarios por nivel de atención del Instituto Mexicano del Seguro Social (IMSS) así como de las licitaciones publicadas en el portal de compras del IMSS. El uso de recursos se obtiene mediante un panel de expertos y para el porcentaje de presencia de las complicaciones se efectúa una revisión de literatura. Los costos médicos directos son estimados multiplicando la frecuencia de uso por el costo unitario, agrupándolos y obteniendo así los costos individuales de cada recurso médico. Los casos de hipercolesterolemia en prevención secundaria con enfermedad coronaria y enfermedad cardiovascular representan un mayor costo promedio anual ($111,835.19, D.E. $84,276.37), seguido de la hipercolesterolemia en prevención secundaria con enfermedad coronaria sin enfermedad cardiovascular ($56,352.13, D.E. $29,004.04), los cuales no incluyen los costos generados por las complicaciones. El resto de los grupos de hipercolesterolemia representan una carga económica menor. La carga económica de la hipercolesterolemia representa en promedio por caso al año $258,761.37, esto traducido a los aproximadamente 445,075 de casos diagnosticados y tratados al año representaría un impacto económico en el sistema de salud de más de ciento quince mil millones ($115,168,331,355.11). Copyright © 2018. Published by Elsevier Inc.

Understanding differences in access and use of healthcare between international immigrants to Chile and the Chilean-born: a repeated cross-sectional population-based study in Chile

PubMed Central

2012-01-01

Introduction International evidence indicates consistently lower rates of access and use of healthcare by international immigrants. Factors associated with this phenomenon vary significantly depending on the context. Some research into the health of immigrants has been conducted in Latin America, mostly from a qualitative perspective. This population-based study is the first quantitative study to explore healthcare provision entitlement and use of healthcare services by immigrants in Chile and compare them to the Chilean-born. Methods Data come from the nationally representative CASEN (Socioeconomic characterization of the population in Chile) surveys, conducted in 2006 and 2009. Self-reported immigrants were compared to the Chilean-born, by demographic characteristics (age, sex, urban/rural, household composition, ethnicity), socioeconomic status (SES: education, household income, contractual status), healthcare provision entitlement (public, private, other, none), and use of primary services. Weighted descriptive, stratified and adjusted regression models were used to analyse factors associated with access to and use of healthcare. Results There was an increase in self-reported immigrant status and in household income inequality among immigrants between 2006 and 2009. Over time there was a decrease in the rate of immigrants reporting no healthcare provision and an increase in reporting of private healthcare provision entitlement. Compared to the Chilean-born, immigrants reported higher rates of use of antenatal and gynaecological care, lower use of well-baby care, and no difference in the use of Pap smears or the number of attentions received in the last three months. Immigrants in the bottom income quintile were four times more likely to report no healthcare provision than their equivalent Chilean-born group (with different health needs, i.e. vertical inequity). Disabled immigrants were more likely to have no healthcare provision compared to the disabled Chilean-born (with similar health needs, i.e. horizontal inequity). Factors associated with immigrants’ access to, and use of, healthcare were sex, urban/rural status, education and country of origin. Conclusion There were significant associations between SES, and access to and use of healthcare among immigrants in Chile and a higher prevalence of no health care provision entitlement among poor and disabled immigrants compared to the Chilean-born. Changing associations between access and use of healthcare and SES among immigrants in Chile over time may reflect changes in their socio-demographic composition or in the survey methodology between 2006 and 2009. Resumen Introducción La evidencia internacional indica menor acceso y uso de servicios de salud por parte de inmigrantes, pero sus factores desencadenantes varían significativamente dependiendo del contexto. Algunas investigaciones se han desarrollado en este tema en América Latina, desde una perspectiva cualitativa. Este estudio cuantitativo exploró el auto-reporte de acceso y uso de servicios de salud de inmigrantes en Chile y los comparó con la población chilena. Métodos Análisis secundario de datos de encuesta nacional CASEN 2006 y 2009. Inmigrantes fueron comparados con chilenos en características demográficas (edad, sexo, urbano/rural, composición del hogar, etnia), estatus socioeconómico (educación, ingreso, situación contractual), tipo de previsión (pública, privada, otra, ninguna), y uso de varios servicios de atención primaria. Análisis descriptivo, estratificado, y modelos de regresión ponderados para entender factores asociados al acceso y uso de servicios de salud en STATA 11.0. Resultados Se observó un aumento de reporte de inmigrantes y de la desigualdad en el ingreso de inmigrantes entre 2006 y 2009. Hubo una disminución en la tasa de inmigrantes sin previsión y un aumento en el acceso al sistema privado. Los inmigrantes usaron más frecuentemente la atención prenatal y ginecológica, y menos la atención del niño sano. No hubo diferencia en el uso de citología vaginal o el número total de atenciones recibidas en comparación con los chilenos. Los inmigrantes en el quintil inferior de ingresos reportaron 4 veces más la ausencia de prestación de salud que los chilenos (inequidad vertical). Similares resultados se observaron al comparar inmigrantes con discapacidad con chilenos con discapacidad (inequidad horizontal). Los factores asociados con el acceso y uso del servicio de salud por parte de los inmigrantes fueron el sexo, urbano/rural, educación y país de origen. Conclusión Se observó una asociación significativa entre estatus socioeconomico, migración y acceso y uso de asistencia sanitaria. Los resultados de este estudio pueden deberse a verdaderos cambios en la composición de los inmigrantes y sus patrones de uso del sistema de salud chileno, pero también pueden deberse a cambios en la metodología y recolección de datos entre encuestas 2006 y 2009. Este aspecto requiere mayor análisis y debate en la región. PMID:23158113

GEONETCast Americas

Science.gov Websites

-channel CIIFEN Centro Internacional para la Investigación del Fenómeno de El Niño / International Conocimiento y Uso de la Biodiversidad / National Commission for Knowledge and Use of Biodiversity Sub-channel Center for the Investigation of the El Niño Phenomenon Sub-channel CMACast Regional GEOENTCast Component

The impact of the use of different types of gloves and bare hands for preparation of clean surgical instruments.

PubMed

Bruna, Camila Quartim de Moraes; Souza, Rafael Queiroz de; Massaia, Irineu Francisco Silva; Cruz, Áurea Silveira; Graziano, Kazuko Uchikawa

2016-10-10

to determine if there are differences on the safety of the preparation of clean surgical instruments using different types of gloves and bare hands and evaluate the microbiological load of these preparations without gloves. laboratory procedure with a pragmatic approach, in which the samples were handled with different types of gloves and bare hands. In addition, cytotoxicity assays were carried out by means of the agar diffusion method. Further samples were subjected to microbiological analysis after being handled without gloves. none of the samples showed cytotoxic effect. All microbiological cultures showed growth of microorganisms, but no microorganism has been recovered after autoclaving. there were no differences in the cytotoxic responses regarding the use of different types of gloves and bare hands in the handling of clean surgical instruments, which could entail iatrogenic risk. It is noteworthy that the use of gloves involves increase in the costs of process and waste generation, and the potential allergenic risk to latex. determinar se existe diferenças na segurança do preparo de instrumentais cirúrgicos relacionada ao uso de distintos tipos de luvas e das mãos nuas no preparo, e avaliar a carga microbiológica destes preparados sem luvas. experimento laboratorial com abordagem pragmática, onde amostras foram manipuladas com diferentes tipos de luvas e com as mãos nuas, elaborado teste de citotoxicidade por meio da difusão em ágar. Outras Amostras sofreram análise microbiológica após serem manipuladas sem luvas. nenhuma das amostras apresentou efeito citotóxico. Todas as culturas microbiológicas apresentaram crescimento de microrganismos, embora nenhum microrganismo tenha sido recuperado após a autoclavação. não houve diferenças nas respostas citotóxicas relacionadas ao uso de diferentes tipos de luvas e das mãos nuas na manipulação do instrumental cirúrgico limpo que sinalizasse risco de iatrogenia. Ressalta-se que o uso de luvas implica em aumento dos custos do processo e da geração de resíduos, além do potencial risco alergênico ao látex. determinar si existen diferencias en la seguridad de la preparación del instrumental quirúrgico relacionadas con el uso de diferentes tipos de guantes y de las manos desnudas y evaluar la carga microbiológica de estos preparados sin guantes. experimento de laboratorio con enfoque pragmático, en el que las muestras fueron manejadas con diferentes tipos de guantes y las manos desnudas. Además, un ensayo de citotoxicidad se llevó a cabo mediante el método de difusión en agar. Otras muestras fueron sometidas a análisis microbiológico después de haber sido manipuladas sin guantes. ninguna de las muestras presentó efecto citotóxico. Todos los cultivos microbiológicos mostraron crecimiento de microorganismos, pero ningún microorganismo ha sido recuperado después de la esterilización en autoclave. no hubo diferencias en las respuestas citotóxicas con respecto al uso de diferentes tipos de guantes y de las manos desnudas en el manejo del instrumental quirúrgico limpio, lo que podría conllevar riesgo de yatrogenia. Es de destacar que el uso de guantes implica un aumento de los costos del proceso y la generación de residuos, además del potencial riesgo alergénico al látex.

Three Dimensional Modeling of Breaking

DTIC Science & Technology

2005-09-30

Three Dimensional Modeling of Breaking Robert A. Dalrymple Dept of Civil Engineering The Johns Hopkins University 3400 North Charles Street...University,Dept of Civil Engineering,3400 North Charles Street,Baltimore,MD,21218 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING...R.A. Dalrymple, A.J.C. Crespo, and D. Cerquiero, "Uso de la Tecnica SPH para el Estudio de la Interaccion entre Olas y Estructuras," Ingenieria del

Estereotipos Sexuales y su Relación con Conductas Sexuales Riesgosas1,2,3

PubMed Central

Pérez-Jiménez, David; Orengo-Aguayo, Rosaura E.

2012-01-01

Resumen Los estereotipos sexuales son creencias generalmente aceptadas y poco cuestionadas que podrían contribuir a cómo los hombres y las mujeres debemos expresar nuestra sexualidad. Los objetivos de este estudio eran identificar cuántos hombres y mujeres heterosexuales en Puerto Rico endosaban ciertos estereotipos acerca de la sexualidad masculina y femenina y explorar la relación entre el endoso de estos estereotipos sexuales y las actitudes hacia el condón masculino y su uso en relaciones sexuales vaginales Llevamos a cabo un estudio descriptivo-correlacional mediante el cual le administramos dos escalas, una sobre sexualidad masculina y otra sobre sexualidad femenina a un grupo de 429 personas heterosexuales. Encontramos que los hombres endosaron estereotipos sexuales masculinos y femeninos más que las mujeres y que estos tienden a tener una visión más conservadora respecto a la sexualidad femenina que la que tienen sobre su propia sexualidad. Las mujeres, por otra parte, tienden a ver su propia sexualidad y la sexualidad masculina en términos menos estereotipados y más equitativos. También encontramos que a mayor endoso de creencias tradicionales sobre la sexualidad masculina y femenina, peor la actitud hacia el uso del condón masculino. Sin embargo, el endosar estereotipos sexuales masculinos y/o femeninos no se relacionó con el uso del condón. Estos hallazgos contradicen la literatura que sugiere que estos estereotipos sexuales y de género resultan en conductas sexuales de alto riesgo, lo cual tiene implicaciones importantes para el desarrollo e implementación de programas de prevención. PMID:24575164

[Not Available].

PubMed

Sendrós Madroño, José M

2016-06-03

La atención nutricional en el paciente oncohematológico debe formar parte del tratamiento global del paciente. Las alteraciones debidas a la localización de la neoplasia y los efectos secundarios del tratamiento oncoespecífico muchas veces dificultan o impiden la alimentación oral. Esto puede dar lugar a una desnutrición y es de gran importancia su detección, valoración e intervención temprana. El primer paso en la intervención nutricional es el consejo dietético. Este artículo muestra qué aspectos deben tenerse en cuenta para poder elaborar un consejo dietético y la importancia de que este sea individualizado. Se describen como ejemplo cuatro situaciones especiales, donde es necesario trasladar las recomendaciones nutricionales a un plan dietético. También se incide en el uso de los probióticos en pacientes inmunocomprometidos.

Aves hormigueras en bosque seco del Pacífico de Nicaragua: uso de hábitat y comportamiento parasítico

Treesearch

Marvin A. Tórrez; Wayne Arendt; Pomares Salmeron

2009-01-01

Sixteen species of ant-following birds belonging to eight taxonomic families were observed parasitizing army ants (Formicidae: Ecitoninae) in dry forest on the Pacifi c slope of Nicaragua. The birds used all three habitats previously selected as part of a broader biodiversity study: secondary forest, forest fallow, and coffee plantation. Species known to follow army...

Are probiotics effective to prevent traveler’s diarrhea?

PubMed

Pinos, Yazmín; Castro-Gutiérrez, Victoria; Rada, Gabriel

2016-12-23

La diarrea aguda es la enfermedad más común que afecta a los viajeros, principalmente aquellos que se dirigen a regiones de alto riesgo. El uso de probióticos podría prevenir su aparición, sin embargo, los datos que apoyan su uso no son consistentes y no se recomiendan en las guías clínicas actuales. Utilizando la base de datos Epistemonikos, la cual es mantenida mediante búsquedas en múltiples bases de datos, identificamos cuatro revisiones sistemáticas que en conjunto incluyen siete estudios aleatorizados pertinentes a esta pregunta. Realizamos un metanálisis y tablas de resumen de los resultados utilizando el método GRADE. Concluimos que los probióticos podrían prevenir la diarrea del viajero, pero la certeza de la evidencia es baja.

Acceptability of an Embodied Conversational Agent-based Computer Application for Hispanic Women

PubMed Central

Wells, Kristen J.; Vázquez-Otero, Coralia; Bredice, Marissa; Meade, Cathy D.; Chaet, Alexis; Rivera, Maria I.; Arroyo, Gloria; Proctor, Sara K.; Barnes, Laura E.

2015-01-01

There are few Spanish language interactive, technology-driven health education programs. Objectives of this feasibility study were to: 1) learn more about computer and technology usage among Hispanic women living in a rural community; and 2) evaluate acceptability of the concept of using an embodied conversational agent (ECA) computer application among this population. A survey about computer usage history and interest in computers was administered to a convenience sample of 26 women. A sample video prototype of a hospital discharge ECA was administered followed by questions to gauge opinion about the ECA. Data indicate women exhibited both a high level of computer experience and enthusiasm for the ECA. Feedback from community is essential to ensure equity in state of the art dissemination of health information. Hay algunos programas interactivos en español que usan la tecnología para educar sobre la salud. Los objetivos de este estudio fueron: 1) aprender más sobre el uso de computadoras y tecnología entre mujeres Hispanas que viven en comunidades rurales y 2) evaluar la aceptabilidad del concepto de usar un programa de computadora utilizando un agente de conversación encarnado (ECA) en esta población. Se administro una encuesta sobre el historial de uso y del interés de aprender sobre computadoras fue a 26 mujeres por muestreo de conveniencia. Un ejemplo del prototipo ECA en forma de video de un alta hospitalaria fue administrado y fue seguido por preguntas sobre la opinión que tenían del ECA. Los datos indican que las mujeres mostraron un alto nivel de experiencia con las computadoras y un alto nivel de entusiasmo sobre el ECA. La retroalimentación de la comunidad es esencial para asegurar equidad en la diseminación de información sobre la salud con tecnología de punta. PMID:26671558

JPRS Report, Reference Aid: Glossary of Acronyms and Abbreviations of Spain

DTIC Science & Technology

1988-12-01

Emigraciön INSS Instituto Nacional de la Seguridad Social INTA Instituto Nacional de Tecnica Aeroespacial INTUSA Industrias Turisticas, S. A. INUR...Marconi Espafiola, S. A. META (plan de) Modernizaciön del Ejercito de Tierra MFCS Medidas destinadas a Fomentar la Confianza y Seguridad MIL...Favored-Nations System S/R (S/Ref.) su referenda your reference SS Seguridad Social SSUPC Sistema de Seguimiento de Uso de la Celula Social

When Students Say Far Too Much: Examining Gushing in the ELT Classroom (Cuando los alumnos dicen demasiado: análisis del uso excesivo de palabras en clases de inglés como lengua extranjera)

ERIC Educational Resources Information Center

Mugford, Gerrard; Cuevas, Oscar Ramírez

2015-01-01

English foreign-language users often overuse words when faced with difficult situations. Called gushing, such excessive use of words is often legitimately employed by native speakers to express, for instance, gratitude and apologies when a simple "thank you" or "sorry" does not sufficiently convey an interlocutor's feelings.…

Positive Prevention: Successful Approaches To Preventing Youthful Drug and Alcohol Use [and] La Prevencion Positiva: Metodos que han tenido exito en la prevencion del uso de drogas y alcohol entre la juventud.

ERIC Educational Resources Information Center

American Association of School Administrators, Arlington, VA.

The United States has the highest rate of youthful drug abuse of any industrialized country in the world. There is a growing awareness that drug and alcohol use are closely connected to other problems such as teenage suicide, adolescent pregnancy, traffic fatalities, juvenile delinquency, poor school performance, runaways, and dropouts. Youthful…

Pedagogia artistica: la conceptualizacion y la creatividad en estudiantes de ciencias de sexto grado

NASA Astrophysics Data System (ADS)

Ortiz Colon, Edwin A.

Se realizo un estudio fenomenologico sobre la conceptualizacion, la creatividad y el valor del dibujo en propiciar un contexto creativo para el aprendizaje de ciencias de sexto grado. La conceptualizacion se interpreto como un proceso que ocurre en las relaciones que los estudiantes establecen entre los temas de estudio y las ideas principales, las experiencias previas, las creencias personales, el tiempo y el valor de la conservacion ambiental. La esencia de la creatividad se definio en funcion de la imaginacion, las destrezas, la intencion, la libertad de pensamiento y expresion y el contexto. El dibujo propicio un ambiente creativo de aprendizaje en las ciencias al facilitar el uso del pensamiento cientifico profundo, el inquirir artistico y la expresion libre.

Using the Dictionary for Improving Adolescents' Reading Comprehension of Short Scientific Texts (Uso del diccionario para mejorar la comprensión lectora de textos científicos cortos en inglés con adolescentes)

ERIC Educational Resources Information Center

Becerra Cortés, Ximena

2013-01-01

This paper reports on an innovative and action research project which focused on the use of the dictionary and the prior knowledge of Colombian high school students to improve their reading comprehension of short scientific texts. Data collection instruments included students' work gathered during two workshops, field notes, and a questionnaire.…

Understanding Beliefs, Teachers' Beliefs and Their Impact on the Use of Computer Technology (Hacia la compresión de las creencias, convicciones del educador y su impacto en el uso de la tecnología)

ERIC Educational Resources Information Center

Galvis, Héctor Alejandro

2012-01-01

This theoretical review addresses the construct of beliefs in education and English as a foreign language, and their impact when integrating technology. A thorough definition and categorization of teachers' beliefs will be provided. In addition, studies conducted in various educational settings examining the effects of teachers' beliefs and the…

Impacts of Climate Change on Colombia’s National and Regional Security

DTIC Science & Technology

2009-10-01

Peru, and Chile have relatively diverse, industrialized economies and greater domestic resources and state capaci- ties for adaptation. Bolivia...Change on Colombia’s National and Regional Security References 1 Colombia, Sistema de Informacion sobre el Uso del Agua en la Agricultura y el Medio...Jul 2009. "El cambio climatico en Colombia." Unpublished report shared with authors. IDEAM. 26 "El agua para 40 millones de personas esta en riesgo

Comportamiento Sexual y Autoeficacia para la Negociación de Sexo Más Seguro en Personas Heterosexuales

PubMed Central

Pérez-Jiménez, David; Santiago-Rivas, Marimer; Serrano-García, Irma

2012-01-01

La autoeficacia se le ha identificado como uno de los factores que puede facilitar o dificultar llevar a cabo sexo más seguro. Estudios revelan que las personas que están el relaciones estables usan métodos de protección menos frecuente que quienes tienen parejas casuales. Realizamos un estudio con 447 personas heterosexuales activas sexualmente. Les administramos un cuestionario dirigido a medir el comportamiento sexual, el uso del condón masculino y la práctica de la masturbación mutua, y la autoeficacia para llevar a cabo estas conductas. Los resultados reflejan que los hombres están más activos sexualmente y que el uso del condón y la práctica de la masturbación mutua como alternativa de sexo más seguro es muy baja. En los casos donde se usa el condón esta práctica es realizada en su mayoría por las personas que se encuentran en una relación de pareja casual. No obstante, los/las participantes tienen altos niveles de autoeficacia hacia ambas prácticas. Aunque la autoeficacia es uno de los factores que incide en decidir llevar a cabo sexo más seguro, ésta no es suficiente para que esta meta se logre. PMID:22837585

Calidad de Imagen del Telescopio UNAM212

NASA Astrophysics Data System (ADS)

Cobos, F. J.; Teiada de Vargas, C.

1987-05-01

El telescopio UNAM2l2, del Observatorio Astronómico Nacional, situado en la Sierra de San Pedro Mártir (Baja California, México), cumplira en un futuro muy cercano siete años de uso para fines de investigación astronómica. Aunque en este tiempo no se ha efectuado un estudio sistemático acerca de su comportamiento óptico y de los factores que influyen en la calidad de las imágenes, se han realizado pruebas diversas, estudios parciales y reuniones especificas, cuyos resultados no siempre se han difundido ampliamente y generalmente no se han presentado por escrito. Es por ello que hemos creido necesario intentar una recopilación de la información existente para poder con ella establecer un diagnóstjco que, aunque no sea definitivo, sirva de base para futuros trabajos tendientes a optimizar el comportamiento óptico del telescopio. Es evidente que un buen número de las conclusiones que se presentan son resultado del trabajo de muchas personas ó de esfuerzos colectivos. Asimismo, hemos tratado de localizar información bibliográfica que pueda ser de utilidad. Nuestro objetivo primordial ha consistido en centrarnos en la óptica del telescopio y su calidad, pero también se han considerado otros aspectos que puedan afectar las imágenes obtenidas tales como: celda del primario, `seeing' local y externo, flexiones posibles en la estructura mecánica del telescopio, etc.

Desarrollo y validación de una nueva tecnología, basada en arginina al 1.5%, un compuesto de calcio insoluble y fluoruro, para el uso diario en la prevención y tratamiento de la caries dental.

PubMed

Cummins, D

2013-10-22

este artículo discute brevemente la prevalencia de caries, la naturaleza multifactorial de su etiología, el riesgo de caries y el papel y eficacia del fluoruro. Resalta también la investigación sobre el metabolismo bacteriano, que ha aportado conocimientos sobre la defensa natural oral contra la caries y la base para el desarrollo de una nueva tecnología para la prevención diaria y el tratamiento de la caries. Por último, se resume la evidencia que respalda que la tecnología complementa y mejora la eficacia anti-caries de la crema dental con fluoruro. los datos globales muestran que a pesar de la exitosa introducción del fluoruro, la caries dental es una enfermedad prevalente. La experiencia de caries depende del balance entre el consumo de azúcares, la higiene oral y el uso del fluoruro. Hay tres conceptos científicos que son fundamentales en las nuevas mediciones para detectar, tratar y monitorear la caries: (1) la caries dental es un proceso dinámico, (2) la caries dental es un proceso continuo de etapas que van desde reversible (pre-clínica) hasta irreversible (lesiones clínicamente detectables), y (3) el proceso de la caries es un balance de factores patológicos y protectores que pueden modularse para el manejo de la caries. El fluoruro funciona como factor protector al detener y revertir el proceso de la caries, pero el fluoruro no previene los factores patológicos que inician el proceso. Se ha identificado una tecnología novedosa, basada en arginina y un compuesto insoluble de calcio, que está dirigida a la placa dental para prevenir la iniciación del proceso de caries al reducir los factores patológicos. Como los mecanismos de acción de la arginina y el fluoruro son altamente complementarios, se ha desarrollado un nuevo dentífrico que combina la arginina y el fluoruro, y se ha probado clínicamente que brinda una prevención superior contra la caries. Copyright © 2013 Elsevier Ltd. All rights reserved.

Selective Use of the Mother Tongue to Enhance Students' English Learning Processes…Beyond the Same Assumptions (Uso selectivo de la lengua materna para mejorar el proceso de aprendizaje del inglés de los estudiantes…Más allá de las mismas suposiciones)

ERIC Educational Resources Information Center

Cuartas Alvarez, Luis Fernando

2014-01-01

This article reports the results of an action-research project that examines enhancing students' English learning processes through the selective use of their mother tongues with the aim of overcoming their reluctant attitudes toward learning English in the classroom. This study involves forty ninth-graders from an all-girls public school in…

New Educational Environments Aimed at Developing Intercultural Understanding while Reinforcing the Use of English in Experience-Based Learning (Nuevos entornos educativos destinados a desarrollar la comprensión intercultural y a reforzar el uso del inglés mediante el aprendizaje basado en experiencias)

ERIC Educational Resources Information Center

Bruguier, Leonard R.; Greathouse Amador, Louise M.

2012-01-01

New learning environments with communication and information tools are increasingly accessible with technology playing a crucial role in expanding and reconceptualizing student learning experiences. This paper reviews the outcome of an innovative course offered by four universities in three countries: Canada, the United States, and Mexico. Course…

Lo Gnomone Clementino Astronomia Meridiana in Basilica

NASA Astrophysics Data System (ADS)

Sigismondi, Costantino

2014-05-01

Costruito per chiara volontà del papa 70 anni dopo il caso Galileo, lo Gnomone Clementino è un grande telescopio solare che non fa uso di lenti a 92 anni dall’invenzione del cannocchiale. Queste due caratteristiche basterebbero da sole a giustificare l’interesse verso questo strumento. L’astronomia meridiana è alla base dell’astrometria e dell’astrofisica moderna. Lo Gnomone Clementino sta oggi all’astronomia, come il veliero “Amerigo Vespucci” sta alla Marina Italiana. E’ possibile svolgere ogni genere di osservazione e studio su questo strumento, e dal 2002 vi tengo lezioni teorico-pratiche del corso di Storia dell’Astronomia e La Terra nel Sistema Solare della Sapienza, Università di Roma, Facoltà di Lettere e Filosofia. Questo testo aggiunge alcuni tasselli alla ricerca storica sulla meridiana, appoggiandosi, com’è naturale, sulle spalle di giganti che mi hanno preceduto in questi studi. In particolare la misura dell’azimut della meridiana, ed il suo inquadramento tra gli strumenti simili ed alcuni studi di astrometria sui dati del 1701-1703 di Bianchini, che sono apparsi fin’ora soltanto su riviste specializzate ed in Inglese vengono qui proposti in Italiano e semplificati, per valorizzare sempre più questa straordinaria opera d’arte e di scienza.

Foco Nasmyth para el telescopio 2,15mts. de CASLEO

NASA Astrophysics Data System (ADS)

Casagrande, A. R.

En principio, este proyecto intenta lograr el mayor aprovechamiento posible del instrumental que se dispone, buscando la manera de optimizar y hacer más eficiente el servicio que brinda el CASLEO a la comunidad astronómica. El mismo consiste en utilizar dispositivos ya existentes en el telescopio, y darle una utilidad. Tal es el caso del camino óptico destinado al foco Coude. Si tenemos en cuenta que disponemos de un tercer espejo Coude, con todos sus mecanismos automatizados, (actualmente sin uso), una distancia apropiada del plano focal, el espacio y el lugar físico necesario para instalar un periférico, es posible la habilitación de un foco Nasmyth en el telescopio 2,15mts. El hecho de contar con este nuevo foco, redundará en importantes beneficios. En primer lugar, posibilitará la observación, casi simultánea, con dos instrumentos. Otro aspecto a tener en cuenta, es que disminuirá el frecuente cambio del instrumental periférico, motivo este que degrada su ideal puesta a punto. Por último, también de interés, es de destacar su escaso costo de ejecución.

PubMed

Damián-Bastidas, Narda; Chala-Florencio, Roni J; Chávez-Blanco, Ricardo; Mayta-Tristán, Percy

2016-11-29

Introducción: el etiquetado nutricional ayuda a los consumidores a realizar elecciones más saludables. Sin embargo, este es poco leído, mal interpretado o no usado.Objetivos: evaluar la frecuencia y los factores asociados a la lectura, el uso y la interpretación de etiquetas nutricionales en usuarios de gimnasios en la ciudad de Huancayo, Perú.Materiales y métodos: estudio de corte transversal en 385 usuarios de una cadena de gimnasios. Se midió la interpretación con un test a partir de dos etiquetas, lectura reportada (frecuentemente o no) y el uso reportado para elegir un producto (frecuentemente o no), así como variables demográficas, dietéticas y relacionadas con el gimnasio. Se evaluó la asociación calculando las razones de prevalencias ajustadas en base a las variables significativas del modelo bivariado.Resultados: los participantes tuvieron una edad media de 27,8 ± 9,3 años, 44,7% fueron varones, 49,4% contaron con educación universitaria. El 27,5% reporta leer frecuentemente y dentro de estos el 55,7% reporta usarlas frecuentemente, asimismo el 17,4% sabe interpretar. La lectura se asoció con factores dietéticos y de uso de gimnasio y la interpretación con capacitación previa de lectura de la etiqueta. El uso fue principalmente para seleccionar productos bajos en grasa total (65,1%), alto en proteínas (64,2%) y en menor proporción, productos bajos en sodio (47,2%).Conclusiones: la frecuencia de lectura, el uso y la interpretación de etiquetas nutricionales en usuarios de gimnasio de Huancayo es baja. La capacitación previa de lectura es un factor necesario para una elección saludable. Es necesario establecer estrategias educativas para enseñar a interpretar de forma adecuada las etiquetas nutricionales.

Seguridad del paciente en Radioterapia Intraoperatoria: Impacto de los elementos controlados por el Radiofisico

NASA Astrophysics Data System (ADS)

Tarjuelo, Juan Lopez

Introduccion: En la administracion de la radioterapia intervienen profesionales y equipos de tratamiento, por lo que existe el riesgo de error y se precisa que dicho equipamiento funcione conforme a lo esperado. A los radiofisicos les corresponde participar en las actividades de garantia o aseguramiento de la calidad, incluyendo el control de calidad de los equipos, y en la evaluacion de los riesgos asociados. La radioterapia intraoperatoria (RIO) es una tecnica radioterapica de intensificacion de dosis, altamente selectiva, dirigida a volumenes anatomicos restringidos durante el tratamiento quirurgico oncologico, basada en la administracion de una dosis absorbida alta por medio de un haz de electrones tras el examen visual directo del lecho tumoral. Como incorporar los ultimos avances en el refuerzo de la seguridad en radioterapia es una tarea ambiciosa y compleja, resulta mas concreta y de inmediata aplicacion su introduccion en la RIO. El objetivo es analizar los elementos que reducen los riesgos y aumentan la seguridad en la RIO y su dosimetria, y valorar la funcion del radiofisico en esta labor. Material y metodos: Se emplearon el planificador Radiance de GMV y el acelerador lineal de los tratamientos de RIO Elekta Precise, controlado con el verificador diario de haces Daily QA Check 1090 y medido con las camaras de ionizacion PPC 40, FC65-G y FC65-P de PTW-Freiburg, a su vez verificadas con fuentes radiactivas adecuadas de estroncio-90 modelos CDP y CDC de IBA Dosimetry. Se realizo un analisis de modos de fallo y efectos (failure mode and effect analysis, FMEA) con el fin de identificar los elementos que forman la RIO y aplicar las herramientas necesarias para la minimizacion de los riesgos y la mejora de la seguridad en la tecnica. Se estudiaron las verificaciones diarias de dicho acelerador Precise con el control estadistico de procesos (statistical process control, SPC) y se simularon intervenciones para devolverlo al estado llamado en control. El SPC tambien se uso para estudiar la estabilidad de las camaras de ionizacion mencionadas. Se realizo la dosimetria in vivo en 45 pacientes con MOSFET reforzados mobile TN-502RDM-H, pelicula radiocromica Gafchromic MD-55-2, y se elaboro un modelo teorico para explicar los datos. Por ultimo, al precisarse el uso en RIO de la simulacion virtual y del calculo de la dosis absorbida en el paciente virtual, se ha ilustrado este apartado con la aceptacion y el estado de referencia inicial del planificador de tratamientos modulados con calculo de Monte Carlo Elekta Monaco. Para ello se utilizaron la camara de ionizacion TW31016-0104 y la matriz seven29 de PTW-Freiburg, pelicula radiocromica Gafchromic EBT-2, y diferentes maniquies. Resultados: El FMEA identifico 57 modos de fallo y efectos potenciales. No se experimentaron sucesos relativos a una administracion inadecuada de la dosis absorbida. Se identificaron las revisiones dobles y por un par como claves para reducir los riesgos asociados al equipo de profesionales involucrado en la RIO. Se identificaron tambien oportunidades de mejora con el uso de la automatizacion y el enclavamiento. En cuanto al SPC, los indices de capacidad del proceso abarcaron de 1,6 a 9,3 para un nivel de especificaciones del +/-2%. Las intervenciones simuladas alcanzaron del 2% al 34% de las sesiones de medida. Las camaras de ionizacion Farmer derivaron en direcciones opuestas en un periodo de 6 anos; aunque ello no se aprecio en los informes de calibracion del laboratorio acreditado. No derivo la camara PPC-40. En la dosimetria in vivo, las medidas de los MOSFET no se desviaron significativamente de las medidas con pelicula. Los valores centrales de las dosis absorbidas quedaron entre la dosis absorbida prescrita y la maxima, con lo que indicaron un tratamiento correcto del lecho tumoral. Las anchuras de los intervalos de confianza de las dosis absorbidas esperadas segun el modelo teorico al nivel del 95% abarcaron del 8,6% al 14,7%. Las verificaciones de Monaco resultaron satisfactorias excepto en el caso de la transferencia de datos, que obligo a cambiar el flujo de trabajo. Conclusiones: El FMEA es crucial para priorizar las intervenciones reductoras del riesgo. Tipos diferentes de procesos fallidos se pueden eliminar o paliar con tipos diferentes de tales intervenciones. El SPC puede evaluar la variabilidad inherente del procedimiento monitorizador de haces de electrones, indica cuando intervenir para devolver un proceso al estado de control y si un proceso es capaz con respecto a unas especificaciones o requisitos establecidos. Es viable realizar dosimetria in vivo con un acelerador convencional fijo y obtener resultados satisfactorios en cada localizacion estudiada a pesar de su variabilidad. El modelo teorico desarrollado puede describir con exito resultados globales, aunque no puede explicar todos los datos experimentales. Se ha mostrado que un planificador puede funcionar correctamente en condiciones de laboratorio o trabajando solo; pero puede fallar cuando se conecta con otros equipos de radioterapia. Todos estos aspectos presentados y evaluados aqui constituyen competencias actuales o futuras, y deseables, de los radiofisicos, tanto en el campo de la RIO como en la extension a la radioterapia en su conjunto.

El uso de la neuromodulación para el tratamiento del temblor

PubMed Central

Bendersky, Damián; Ajler, Pablo; Yampolsky, Claudio

2014-01-01

Introducción: El temblor puede ser un desorden incapacitante y el tratamiento de primera línea para estos pacientes es farmacológico. Sin embargo, este tratamiento puede llevar a una reducción satisfactoria del temblor en sólo el 50% de los pacientes con temblor esencial. La talamotomía era el tratamiento de elección para el temblor refractario al tratamiento médico hasta que comenzó a utilizarse la estimulación cerebral profunda (ECP) del núcleo ventral intermedio (Vim) del tálamo. En la actualidad, raramente se realiza la talamotomía. Métodos: Este artículo es una revisión no sistemática de las indicaciones, resultados, parámetros de programación y técnica quirúrgica de la ECP del Vim para el tratamiento del temblor. Resultados: Aunque los resultados clínicos son similares usando la talamotomía o la ECP del Vim, la primera causa más efectos adversos que la última. Además, la ECP puede ser usada bilateralmente, mientras que la talamotomía tiene un alto riesgo de causar disartria cuando se realiza de ambos lados. La ECP del Vim logró una adecuada mejoría del temblor en varias series de pacientes con temblor causado por temblor esencial, enfermedad de Parkinson o esclerosis múltiple. Además del Vim, hay otros blancos que están siendo usados por varios autores, tales como la zona incerta y las radiaciones prelemniscales. Conclusión: La ECP del Vim es un tratamiento útil para el temblor incapacitante refractario al tratamiento médico. Es esencial realizar una precisa selección de pacientes, así como utilizar una técnica quirúrgica correcta. Aún se desconoce el mejor blanco estereotáctico para el temblor, aunque el Vim es el más usado. PMID:25165613

Computer and laboratory simulation in the teaching of neonatal nursing: innovation and impact on learning.

PubMed

Fonseca, Luciana Mara Monti; Aredes, Natália Del' Angelo; Fernandes, Ananda Maria; Batalha, Luís Manuel da Cunha; Apóstolo, Jorge Manuel Amado; Martins, José Carlos Amado; Rodrigues, Manuel Alves

2016-10-10

to evaluate the cognitive learning of nursing students in neonatal clinical evaluation from a blended course with the use of computer and laboratory simulation; to compare the cognitive learning of students in a control and experimental group testing the laboratory simulation; and to assess the extracurricular blended course offered on the clinical assessment of preterm infants, according to the students. a quasi-experimental study with 14 Portuguese students, containing pretest, midterm test and post-test. The technologies offered in the course were serious game e-Baby, instructional software of semiology and semiotechnique, and laboratory simulation. Data collection tools developed for this study were used for the course evaluation and characterization of the students. Nonparametric statistics were used: Mann-Whitney and Wilcoxon. the use of validated digital technologies and laboratory simulation demonstrated a statistically significant difference (p = 0.001) in the learning of the participants. The course was evaluated as very satisfactory for them. The laboratory simulation alone did not represent a significant difference in the learning. the cognitive learning of participants increased significantly. The use of technology can be partly responsible for the course success, showing it to be an important teaching tool for innovation and motivation of learning in healthcare. avaliar a aprendizagem cognitiva de estudantes de enfermagem na avaliação clínica neonatal a partir de um curso semipresencial com uso de simulação por computador e em laboratório; comparar a aprendizagem cognitiva dos estudantes em grupo controle e experimental ao testar a simulação em laboratório; e avaliar o curso semipresencial extracurricular oferecido sobre avaliação clínica do bebê pré-termo, segundo os estudantes. estudo quase-experimental com 14 estudantes portugueses contendo pré-teste, teste intermediário e pós-teste. As tecnologias oferecidas no curso foram serious game e-Baby, software instrucional de semiologia e semiotécnica e simulação em laboratório. Para a avaliação do curso e caracterização dos estudantes utilizou-se instrumentos de coleta de dados desenvolvidos para este estudo. Utilizou-se estatística não paramétrica: Mann-Whitney e Wilcoxon. O uso de tecnologias digitais validadas e de simulação em laboratório evidenciou diferença estatisticamente significativa (p=0,001) na aprendizagem dos participantes. O curso foi avaliado como muito satisfatório pelos mesmos. A simulação em laboratório isoladamente não representou diferença significativa no aprendizado. a aprendizagem cognitiva dos participantes aumentou significativamente. Considera-se que o uso de tecnologia foi responsável por parte do sucesso do curso, denotando ser uma importante ferramenta de inovação didática e motivação da aprendizagem na área da saúde. evaluar el aprendizaje cognitivo de estudiantes de enfermería en evaluación clínica neonatal, a partir de un curso semipresencial, utilizando simulación por computador y en laboratorio; comparar el aprendizaje cognitivo de los estudiantes, entre grupo control y experimental, comprobando la simulación en el laboratorio; y evaluar el curso semipresencial extracurricular ofrecido sobre evaluación clínica del bebé pretérmino, de acuerdo a los estudiantes. estudio casi experimental con 14 estudiantes portugueses, conteniendo preprueba, prueba intermedia y postprueba. Las tecnologías ofrecidas en el curso fueron serious game e-Baby, programa de instrucción en semiología y semiotecnia, y simulación en laboratorio. Para la evaluación del curso y caracterización de los estudiantes se utilizaron instrumentos de recolección de datos desarrollados para este estudio. Se utilizó la estadística no-paramétrica de Mann-Whitney y Wilcoxon. el uso de tecnologías digitales validadas y de simulación en laboratorio evidenció diferencia estadísticamente significativa (p=0,001) en el aprendizaje de los participantes. El curso fue evaluado como muy satisfactorio por los alumnos. La simulación en laboratorio, aisladamente, no presentó diferencia significativa en el aprendizaje. el aprendizaje cognitivo de los participantes aumentó significativamente. Se considera que el uso de la tecnología fue responsable por parte del éxito del curso, demostrando ser una importante herramienta de innovación didáctica y motivación del aprendizaje en el área de la salud.

Healing war wounds and perfuming exile: the use of vegetal, animal, and mineral products for perfumes, cosmetics, and skin healing among Sahrawi refugees of Western Sahara

PubMed Central

2012-01-01

Background Over the past decade, there has been growing interest within ethnobiology in the knowledge and practices of migrating people. Within this, scholars have given relatively less attention to displaced people and refugees: to the loss, maintenance, and adaptation of refugees’ ethnobiological knowledge, and to its significance for refugees’ wellbeing. This study focuses on cosmetics and remedies used to heal skin afflictions that are traditionally used by Sahrawi refugees displaced in South Western Algerian refugee camps. Methods The research methods included a structured survey carried out with 37 refugee households, semi-structured interviews with 77 refugees, 24 retrospective interviews with refugees and other knowledgeable informants, and a voucher specimen collection of the plants and products cited. Results We recorded the use of 55 plant species, nine animal species, and six mineral products used within the three main use categories discussed in this paper: 1) Remedies for health issues that are typical of the desert environment where the Sahrawi once lived as nomads and now live as refugees (e.g. eye afflictions); 2) Remedies for wounds that are influenced by the Sahrawi’s recent history of guerrilla warfare; and 3) Cosmetics and products used for body care, decoration and perfuming (e.g. hair care, teeth cleansing, henna use) and for aromatizing the air inside of tents and which are widely used in everyday life and social practices. Conclusions We discuss the changes that have occurred in the patterns of use and procurement of these products with exile and sedentarization in refugee camps, and conclude that refugees are not simply passive recipients of national and international aid, but rather struggle to maintain and recover their traditional ethnobiological practices in exile. Finally, we suggest further research into the ethnobiological practices and knowledge of displaced populations. Resumen Sanando las heridas de guerra y perfumando el exilio: el uso de productos vegetales, animales y minerales con fines de perfumería, cosmética y curativos de la piel entre los refugiados saharauis del Sáhara Occidental. Antecedentes Durante la última década ha habido un creciente interés en los estudios etnobiológicos de los conocimientos y prácticas de las personas que migran. Dentro de esta tendencia, los estudiosos han prestado relativamente menor atención a las personas desplazadas y a los refugiados: a la pérdida, el mantenimiento y la adaptación de sus conocimientos etnobiológicos, y su importancia para el bienestar de los refugiados. Este estudio se centra en los cosméticos y remedios para curar problemas de la piel tradicionalmente utilizados por los refugiados saharauis en los campamentos de desplazados al sudoeste de Argelia. Métodos Los métodos de investigación que se utilizaron son: una encuesta estructurada con 37 familias de refugiados, entrevistas semi-estructuradas con 77 refugiados, 24 entrevistas retrospectivas con refugiados e informantes conocedores, y una colección de muestra de las plantas y productos citados. Resultados Se registró el uso de 55 especies vegetales, nueve especies animales, y seis productos minerales utilizados en tres principales categorías de usos: 1) Recursos contra los problemas de salud característicos del entorno desértico donde una vez vivieron los saharauis como nómadas y donde ahora viven como refugiados (por ejemplo problemas en los ojos); 2) Remedios para heridas que reflejan la historia reciente de guerra de guerrilla de los nómadas saharauis; y 3) Cosméticos y productos utilizados para el cuidado del cuerpo, decoración y perfumes (por ejemplo, atención al cabello, limpieza de dientes, uso del henna) y como aromatizantes del aire al interior de las tiendas, que son ampliamente utilizados en la vida y las prácticas sociales cotidianas de los refugiados. Conclusiones En la discusión, se analizan los cambios que se han producido en los patrones de uso y en la adquisición de estos productos durante el exilio. Llegamos a la conclusión de que los refugiados no son recipientes pasivos de la ayuda nacional e internacional, sino más bien luchan para mantener y recuperar sus prácticas tradicionales etnobiológicas en el exilio. Finalmente, sugerimos nuevas direcciones para la investigación de las prácticas y los conocimientos etnobiológicos de las poblaciones desplazadas. PMID:23270531

Teaching Foreign Trade in English through the Modalities Based on Competences and Using Moodle (Enseñanza del régimen de comercio exterior a través de las modalidades centradas en el desarrollo de competencias y con el uso de Moodle)

ERIC Educational Resources Information Center

Correa Díaz, Ana María

2012-01-01

With the new approach to guide the learning process of students with a model based on the development of competences, and in comparison with the traditional lecture-based learning, it is necessary to start working with the teaching modalities that help to achieve this objective. With that in mind, the aim of the study reported in this article was…

CONTAMINACIÓN AMBIENTAL, VARIABILIDAD CLIMÁTICA Y CAMBIO CLIMÁTICO: UNA REVISIÓN DEL IMPACTO EN LA SALUD DE LA POBLACIÓN PERUANA

PubMed Central

Gonzales, Gustavo F.; Zevallos, Alisson; Gonzales-Castañeda, Cynthia; Nuñez, Denisse; Gastañaga, Carmen; Cabezas, César; Naeher, Luke; Levy, Karen; Steenland, Kyle

2015-01-01

RESUMEN El presente artículo es una revisión sobre la contaminación del agua, el aire y el efecto del cambio climático en la salud de la población peruana. Uno de los principales contaminantes del aire es el material particulado menor de 2,5 μ (PM 2,5), en la ciudad de Lima, anualmente 2300 muertes prematuras son atribuibles a este contaminante. Otro problema es la contaminación del aire domiciliario por el uso de cocinas con combustible de biomasa, donde la exposición excesiva a PM 2,5 dentro de las casas es responsable de aproximadamente 3000 muertes prematuras anuales entre adultos, con otro número desconocido de muertes entre niños debido a infecciones respiratorias. La contaminación del agua tiene como principales causas los desagües vertidos directamente a los ríos, minerales (arsénico) de varias fuentes, y fallas de las plantas de tratamiento. En el Perú, el cambio climático puede impactar en la frecuencia y severidad del fenómeno de El Niño oscilación del sur (ENSO) que se ha asociado con un incremento en los casos de enfermedades como cólera, malaria y dengue. El cambio climático incrementa la temperatura y puede extender las áreas afectadas por enfermedades transmitidas por vectores, además de tener efecto en la disponibilidad del agua y en la contaminación del aire. En conclusión, el Perú, pasa por una transición de factores de riesgo ambientales, donde coexisten riesgos tradicionales y modernos, y persisten los problemas infecciosos y crónicos, algunos de los cuales se asocian con problemas de contaminación de agua y de aire. PMID:25418656

Development of the TabacoQuest app for computerization of data collection on smoking in psychiatric nursing.

PubMed

Oliveira, Renata Marques de; Duarte, Alexandre Freitas; Alves, Domingos; Furegato, Antonia Regina Ferreira

2016-08-29

to develop a mobile app for research on the use of tobacco among psychiatric patients and the general population. applied research with the technological development of an app for data collection on an Android tablet. For its development, we considered three criteria: data security, benefits for participants and optimization of the time of researchers. We performed tests with twenty fictitious participants and a final test with six pilots. the app collects data, stores them in the database of the tablet and export then to an Excel spreadsheet. calculator, stopwatch, offline operation, branching logic, field validation and automatic tabulation. the app prevents human error, increases the quality of the data by validating them during the interview, allows the performing of automatic tabulation and makes the interviews less tiring. Its success may encourage the use of this and other computational resources by nurses as a research tool. desenvolver aplicativo mobile para pesquisa sobre o uso de tabaco entre pacientes psiquiátricos e a população geral. pesquisa aplicada com o desenvolvimento tecnológico de um aplicativo para coleta de dados em tablet Android. Para seu desenvolvimento, consideraram-se três critérios: segurança dos dados, benefícios para os participantes e otimização do tempo dos pesquisadores. Testes com 20 participantes fictícios e teste final com seis pilotos. o aplicativo coleta os dados, armazena-os no banco de dados do tablet e os exporta para planilha Excel. Recursos: calculadora; cronômetro; funcionamento off-line, lógica de ramificação, validação de campos e tabulação automática. o aplicativo previne erros humanos e aumenta a qualidade dos dados ao validá-los durante a entrevista, permite realizar tabulação automática e torna as entrevistas menos cansativas. Seu sucesso poderá incentivar o uso desse e outros recursos computacionais pelos enfermeiros, como ferramenta de pesquisa. desarrollar aplicativo móvil para hacer investigación sobre el uso de tabaco entre pacientes psiquiátricos y la población en general. investigación aplicada con el desarrollo tecnológico de un aplicativo para recolección de datos en tablet Android. Para su desarrollo, se consideraron tres criterios: seguridad de los datos, beneficios para los participantes y optimización del tiempo de los investigadores. Se realizaron pruebas con 20 participantes ficticios y un test piloto final. los datos del aplicativo almacenados en el banco de datos del tablet son exportados para planilla Excel. Recursos: calculadora, cronómetro, funcionamiento off-line, lógica de ramificación, validación de campos y tabulación automática. el aplicativo evita errores humanos y aumenta la calidad de los datos al validarlos durante la entrevista, también permite realizar una tabulación automática y torna las entrevistas menos agotadoras. Su éxito incentivará su uso y el de otros recursos computacionales por parte de los enfermeros, como herramienta de investigación.

PubMed

Litewka, Sergio; Goodman, Kenneth; Braunschweiger, Y Paul

2008-01-01

El Programa CITI (Collaborative Institutional Training Initiative) es un curso basado en Internet y desarrollado por voluntarios, que brinda material educacional sobre protección de sujetos humanos en investigaciones biomédicas y de conducta, buenas prácticas clínicas, conducta responsable de la investigación y trato humanitario a animales de laboratorio. Es un esfuerzo conjunto del Fred Hutchinson Cancer Research Center y la Universidad de Miami.Con la colaboración de expertos locales, gran parte del contenido se ha adaptado para América Latina, se ha traducido al español y portugués y se han establecido acuerdos de colaboración con instituciones especializadas en bioética en Chile, Brasil, Costa Rica y Perú. Los autores presentan una metodología accesible para la capacitación en ética de la investigación y una justificación de su uso y difusión en América Latina.

Mini-mastoidectomía para anastomosis hipogloso-facial con sección parcial del nervio hipogloso

PubMed Central

Campero, Álvaro; Ajler, Pablo; Socolovsky, Mariano; Martins, Carolina; Rhoton, Albert

2012-01-01

Introducción: La anastomosis hipogloso-facial es la técnica de elección para la reparación de la parálisis facial cuando no se dispone de un cabo proximal sano del nervio facial. La técnica de anastomosis mediante fresado mastoideo y sección parcial del hipogloso minimiza la atrofia lingual sin sacrificar resultados a nivel facial. Método: La porción mastoidea del nervio facial transcurre por la pared anterior de la AM, a un promedio de 18+/-3 mm de profundidad respecto de la pared lateral. Se debe reconocer la cresta supramastoidea, desde la cual se marca una línea vertical paralela al eje mayor de la AM, 1 cm por detrás de la pared posterior del CAE El fresado se comienza desde la línea medio mastoidea hasta la pared posterior del CAE. Una vez encontrado el nervio facial en el tercio medio del canal mastoideo, el mismo es seguido hacia proximal y distal. Resultados: El abordaje descripto permite acceder al nervio facial intratemporal en su porción mastoidea, y efectuar un fresado óseo sin poner en riesgo al nervio o a estructuras vasculares cercanas. Se trata de un procedimiento técnicamente más sencillo que los abordajes amplios habitualmente utilizados al hueso temporal; no obstante su uso debe ser restringido mayormente a la anastomosis hipogloso-facial. Conclusión: Esta es una técnica relativamente sencilla, que puede ser reproducida por cirujanos sin mayor experiencia en el tema, luego de su paso por el laboratorio de anatomía. PMID:23596555

Detección automática de NEOs en imágenes CCD utilizando la transformada de Hough

NASA Astrophysics Data System (ADS)

Ruétalo, M.; Tancredi, G.

El interés y la dedicación por los objetos que se acercan a la órbita de la Tierra (NEOs) ha aumentado considerablemente en los últimos años, tanto que se han iniciado varias campañas de búsqueda sistemática para aumentar la población identificada de éstos. El uso de placas fotográficas e identificación visual está siendo sustituído, progresivamente, por el uso de cámaras CCD y paquetes de detección automática de los objetos en las imágenes digitales. Una parte muy importante para la implementación exitosa de un programa automatizado de detección de este tipo es el desarrollo de algoritmos capaces de identificar objetos de baja relación señal-ruido y con requerimientos computacionales no elevados. En el presente trabajo proponemos la utilización de la transformada de Hough (utilizada en algunas áreas de visión artificial) para detectar automáticamente trazas, aproximadamente rectilíneas y de baja relación señal-ruido, en imágenes CCD. Desarrollamos una primera implementación de un algoritmo basado en ésta y lo probamos con una serie de imágenes reales conteniendo trazas con picos de señales de entre ~1 σ y ~3 σ por encima del nivel del ruido de fondo. El algoritmo detecta, sin inconvenientes, la mayoría de los casos y en tiempos razonablemente adecuados.

[Reconstrucción ósea de defectos craneales secundarios a traumatismo con implantes personalizados].

PubMed

Cienfuegos, Ricardo; Fernández, Gerardo; Cruz, Aída; Sierra, Eduardo

2018-01-01

Los defectos craneales secundarios a traumatismos son frecuentes. Por lo común se reparan de forma secundaria por sintomatología como el síndrome del paciente trepanado, por protección cerebral y por el aspecto cosmético. Históricamente se han utilizado diversos materiales para la reconstrucción. Se presentan cinco casos de pacientes reconstruidos con implantes personalizados de polieteretercetona (PEEK) o polimetilmetacrilato poroso (PMMA). Las localizaciones afectaron el frontal, el borde orbitario superior y el techo orbitario en cuatro casos, y la porción lateral del frontal, la zona temporoparietal y el borde del occipital en un caso. La reconstrucción en cuatro pacientes fue entre 6 y 12 meses después de la lesión, y en un caso después de 25 años. En dos casos se requirió expansión tisular antes de colocar el implante. Cuatro pacientes evolucionaron favorablemente, con mejoría de los síntomas neurológicos, forma y contorno adecuados, así como un proceso de cicatrización adecuada de los colgajos de piel cabelluda. Un paciente presentó infección por Staphylococcus aureus, atribuida a la presencia de un mucocele y una fístula de la vía aérea a la cavidad craneal, lo que hizo necesario retirar el implante. Los implantes personalizados son un recurso útil para defectos óseos craneales. Brindan resultados satisfactorios desde el punto de vista funcional y cosmético. Deben tomarse precauciones respecto al tratamiento de las lesiones que afecten el seno frontal, para evitar la comunicación entre la vía aérea y la cavidad craneal. Cranial defects due to trauma are frequent. They are usually repaired in a secondary fashion due to features such as syndrome of the trephined, for brain protection and for cosmetic purposes. Historically, various materials have been used for reconstruction. Five cases of patients reconstructed with customized polyetheretherketone (PEEK) o polymethyl methacrylate (PMMA) implants are presented. Defects involved the frontal bone, superior orbital rim and orbital roof in four cases, and the lateral area of the frontal bone, the temporoparietal area and the border of the occipital bone in one. In four patients, reconstruction took place between 6 and 12 months after the injury; in one patient, after 25 years. Two cases required tissue expansion before placing the implant. Four patients evolved favorably, with improvement in neurologic symptoms and adequate shape and contour, plus adequate healing of the scalp flaps. One patient had an infection due to Staphylococcus aureus, attributed to a mucocele and fistula between the airway and the cranial cavity, leading to removal of the implant. Customized implants are a useful resource for cranial defects. They offer satisfactory results, both functional and cosmetic. Precautions should be taken in treating injuries that involve the frontal sinus, to ensure there is no communication between the airway and the cranial cavity. Copyright: © 2018 SecretarÍa de Salud.

[Anaesthetic management in left ventricular assist device implantation as destination therapy: Our first experience].

PubMed

del Barrio Gómez, E; Rodríguez, J M; Martínez, S; García, E; Vargas, M C; Sastre, J A

2016-03-01

Left ventricular assist devices have emerged as one of the main therapies of advanced cardiac failure due the increase of this disease and lack of organ supply for cardiac transplantation. The anaesthetic management is described on a patient without cardiac transplantation criteria. The device was successfully implanted as a destination therapy. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

International Conference on Marine Corrosion and Fouling (5th), held 19-23 May 1980, Barcelona (Spain).

DTIC Science & Technology

1980-12-31

aguas de puertos i talianos." C.A. Viviani and L.H. Disalvo ( Chile ) :,"Biofouling in a north-central Chilean coastal bay." A.F.A. Ghobashy and A.K. Hassan...34Estudio del mechanismo de formaci6n de incrustationes en enfriadores por el uso de agua de mer." S.M. Coelho de Souza Medeiros Bastos and L.R...naval con cubierta de pinturas en agua de mar sintetica." T. Skoulikidis and P. Vassiliou (Greece): "Kinetic data on the leaching of 152?- antifouling

Los plaguicidas y la contaminacion del medio ambiente Venezolano

USGS Publications Warehouse

Stickel, L.F.; Stickel, W.H.

1972-01-01

RESUMEN DE RECOMENDACIONES Recomendaciones para el Programa de Investigacion: 1. Establecer un sistema de muestreo biologico para detectar los niveles tendencias de los productos quimicos toxicos en un peque?o numero de si tios representativos. 2. Mantener continua vigilancia de la contaminacion ambiental, mediante la seleccion acertadamente dirigida de las zonas afectadas y de las fuentes de contaminacion. 3. Realizar estudios acerca de las poblaciones de animales silvestres, y del exito de los procesos reproductivos de las especies o grupos clayes de animales que se consideran mas gravemente afectados. 4. Preparar recomendaciones para una accion gubernamental de proteccion al hombre, a la fauna silvestre y al medio ambiente. Recomendaciones para la Accion Administrativa: 1. Establecer limites a la tolerancia de los residuos de plaguicidas en los alimentos. Constituye una medida clave para disminuir la contaminacion ambiental. 2. Establecer normas de calidad del agua para las corrientes, represas, la gos y otros cuerpos. Es la segunda medida clave para reducir la contaminacion del ambiente 3. Exigir un tratamiento adecuado de los efluentes industriales, especialmente antes de que se construyan las nuevas plantas. 4. Exigir a los agricultores que en el uso de plaguicidas sigan los consejos tecnicos autorizados y negar a los vendedores el derecho a recomendar productos por su cuenta. 5. Tomar medidas para recoger y eliminar los recipientes y sobrantes de los plaguicidas.

Construction and validation of a tool to Assess the Use of Light Technologies at Intensive Care Units.

PubMed

Marinho, Pabliane Matias Lordelo; Campos, Maria Pontes de Aguiar; Rodrigues, Eliana Ofélia Llapa; Gois, Cristiane Franca Lisboa; Barreto, Ikaro Daniel de Carvalho

2016-12-19

to construct and validate a tool to assess the use of light technologies by the nursing team at Intensive Care Units. methodological study in which the tool was elaborated by means of the psychometric method for construction based on the categorization of health technologies by Merhy and Franco, from the National Humanization Policy, using the Nursing Intervention Classification taxonomy to categorize the domains of the tool. Agreement Percentages and Content Validity Indices were used for the purpose of validation. The result of the application of the Interrater Agreement Percentage exceeded the recommended level of 80%, highlighting the relevance for the proposed theme in the assessment, with an agreement rate of 99%. the tool was validated with four domains (Bond, Autonomy, Welcoming and Management) and nineteen items that assess the use of light technologies at Intensive Care Units. construir e validar um instrumento para avaliação do uso de tecnologias leves, pela equipe de enfermagem, em Unidades de Terapia Intensiva. estudo metodológico no qual o instrumento foi elaborado utilizando o método psicométrico para construção com base na categorização das tecnologias em saúde de Merhy e Franco, da Política Nacional de Humanização, utilizando-se a taxonomia Nursing Intervention Classification para categorizar os domínios do instrumento. Utilizou-se o Percentual de Concordância e o Índice de Validade de Conteúdo (IVC) para validação. o resultado da aplicação do Percentual de Concordância entre os juízes foi superior ao recomendado de 80%, havendo destaque na avaliação da pertinência ao tema proposto, apresentando um percentual de concordância de 99%. o instrumento foi validado com quatro domínios (Vínculo, Autonomia, Acolhimento e Gestão) e dezenove itens que avaliam o uso das tecnologias leves em Unidade de Terapia Intensiva. construir y validar un instrumento para evaluación del uso de tecnologías leves, por el equipo de enfermería, en Unidades de Terapia Intensiva. estudio metodológico en el cual el instrumento fue elaborado utilizando el método psicométrico para construcción con base en la categorización de las tecnologías en salud de Merhy y Franco, de la Política Nacional de Humanización, la que utilizó la taxonomía Nursing Intervention Classification para categorizar los dominios del instrumento. Para la validación se utilizó el Porcentaje de Concordancia y el Índice de Validez de Contenido (IVC). el resultado de la aplicación del Porcentaje de Concordancia entre los jueces fue superior al recomendado de 80%, destacándose la evaluación de la pertinencia al tema propuesto, presentando un porcentaje de concordancia de 99%. el instrumento fue validado en cuatro dominios (Vínculo, Autonomía, Acogimiento y Administración) y con diecinueve ítems que evalúan el uso de las tecnologías leves en Unidad de Terapia Intensiva.

Accounting for the Impact of Conservation on Human Well-Being

PubMed Central

Milner-Gulland, EJ; Mcgregor, JA; Agarwala, M; Atkinson, G; Bevan, P; Clements, T; Daw, T; Homewood, K; Kumpel, N; Lewis, J; Mourato, S; Palmer Fry, B; Redshaw, M; Rowcliffe, JM; Suon, S; Wallace, G; Washington, H; Wilkie, D

2014-01-01

Conservationists are increasingly engaging with the concept of human well-being to improve the design and evaluation of their interventions. Since the convening of the influential Sarkozy Commission in 2009, development researchers have been refining conceptualizations and frameworks to understand and measure human well-being and are starting to converge on a common understanding of how best to do this. In conservation, the term human well-being is in widespread use, but there is a need for guidance on operationalizing it to measure the impacts of conservation interventions on people. We present a framework for understanding human well-being, which could be particularly useful in conservation. The framework includes 3 conditions; meeting needs, pursuing goals, and experiencing a satisfactory quality of life. We outline some of the complexities involved in evaluating the well-being effects of conservation interventions, with the understanding that well-being varies between people and over time and with the priorities of the evaluator. Key challenges for research into the well-being impacts of conservation interventions include the need to build up a collection of case studies so as to draw out generalizable lessons; harness the potential of modern technology to support well-being research; and contextualize evaluations of conservation impacts on well-being spatially and temporally within the wider landscape of social change. Pathways through the smog of confusion around the term well-being exist, and existing frameworks such as the Well-being in Developing Countries approach can help conservationists negotiate the challenges of operationalizing the concept. Conservationists have the opportunity to benefit from the recent flurry of research in the development field so as to carry out more nuanced and locally relevant evaluations of the effects of their interventions on human well-being. Consideración del Impacto de la Conservación sobre el Bienestar Humano Resumen Los conservacionistas cada vez más se comprometen con el concepto del bienestar humano para mejorar el diseño y la evaluación de sus intervenciones. Desde la convención de la influyente Comisión Sarkozy en 2009, los investigadores del desarrollo han estado refinando las conceptualizaciones y los marcos de trabajo para entender y medir el bienestar humano y están comenzando a convergir con un entendimiento común de cuál es la mejor forma de hacer esto. En la conservación el término bienestar humano tiene un uso amplio, pero existe la necesidad de la orientación en su operación para medir los impactos de las intervenciones de la conservación sobre la gente. Presentamos un marco de trabajo para entender el bienestar humano que podría ser útil particularmente en la conservación. El marco de trabajo incluye tres condiciones: cumplir con las necesidades, perseguir objetivos y experimentar una calidad satisfactoria de vida. Resumimos algunas de las complejidades involucradas en la evaluación de los efectos del bienestar de las intervenciones de la conservación con el entendimiento de que el bienestar varía entre la gente, en el tiempo y con las prioridades del evaluador. Los retos clave para la investigación de los impactos del bienestar de las intervenciones de la conservación incluyen la necesidad de crear una colección de estudios de caso para trazar lecciones generalizables: hacer uso del potencial de la tecnología moderna para apoyar la investigación del bienestar; y contextualizar espacial y temporalmente las evaluaciones de los impactos de la conservación sobre el bienestar dentro del marco más amplio del cambio social. Existen caminos que atraviesan la confusión que rodea al término bienestar, y los marcos de trabajo existentes, como el del acercamiento de Bienestar en Países en Desarrollo, pueden ayudar a los conservacionistas a negociar los obstáculos de la operación del concepto. Los conservacionistas tienen la oportunidad de beneficiarse del frenesí reciente de investigación en el campo del desarrollo para así realizar evaluaciones más matizadas y relevantes localmente de los efectos de sus intervenciones sobre el bienestar humano. PMID:24641551

Las ideologias, las ciencias naturales y sus implicaciones en la educacion cientifica

NASA Astrophysics Data System (ADS)

Lozada Roldan, Sandra

Este estudio ausculto las concepciones epistemologicas de los docentes de ciencia del nivel secundario con relacion a las ideologias y las ciencias naturales. Tambien examino las posiciones de los docentes ante asuntos publicos relacionados a la ciencia. Para propositos de este estudio se diseno y se valido el cuestionario con el cual se obtuvieron los resultados. La investigacion es de tipo cuantitativa y se utilizo como diseno la encuesta. El cuestionario se administro en varias actividades de desarrollo profesional para maestros de ciencia. Un total de 78 maestros del nivel secundario respondieron el cuestionario. Para analizar los datos obtenidos se utilizaron estadisticas descriptivas como la distribucion de frecuencia y el porciento. Ademas se establecieron codigos y categorias para describir las posiciones de los maestros ante asuntos publicos relacionados a la ciencia. Los analisis demostraron que entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas adecuadas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) la filosofia materialista de las ciencias naturales, b) la naturaleza tentativa y constructivista del conocimiento cientifico, c) el uso de una metodologia que garantiza cierto grado de objetividad y con el que se justifican y validan los enunciados cientificos y d) la funcion instrumental del conocimiento cientifico. Sin embargo, entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas erroneas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) tendencia inductivista en el que las teorias cientificas comienzan con observaciones que establecen generalizaciones, b) secuencia jerarquica de la metodologia cientifica. Ademas, entre los docentes participantes de este estudio prevalecen concepciones epistemologicas adecuadas acerca de las ideologias, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) la funcion de las ideologias y b) la ausencia de validez ante el conocimiento cientifico. Sin embargo, en cuanto a considerar las ciencias naturales como una ideologia mas conocida como cientificismo, no hubo consistencia en las respuestas de los participantes por lo que no es posible afirmarlo o negarlo. Los hallazgos tambien revelaron que entre los docentes participantes hubo posiciones a favor y en contra para las dos situaciones sobre asuntos publicos relacionados a la ciencia que se presentaron. Estas posiciones fueron justificadas con argumentos cientificos y argumentos ideologicos, entre estos, los morales y los economicos. Con este dato se puede afirmar el uso de las ideologias en asuntos publicos relacionados a la ciencia.

Cystic fibrosis transmembrane regulator haplotypes in households of patients with cystic fibrosis.

PubMed

Furgeri, Daniela Tenório; Marson, Fernando Augusto Lima; Correia, Cyntia Arivabeni Araújo; Ribeiro, José Dirceu; Bertuzzo, Carmen Sílvia

2018-01-30

Nearly 2000 mutations in the cystic fibrosis transmembrane regulator (CFTR) gene have been reported. The F508del mutation occurs in approximately 50-65% of patients with cystic fibrosis (CF). However, molecular diagnosis is not always possible. Therefore, silent polymorphisms can be used to label the mutant allele in households of patients with CF. To verify the haplotypes of four polymorphisms at the CFTR locus in households of patients with CF for pre-fertilization, pre-implantation, and prenatal indirect mutation diagnosis to provide better genetic counseling for families and patients with CF and to associate the genotypes/haplotypes with the F508del mutation screening. GATT polymorphism analysis was performed using direct polymerase chain reaction amplification, and the MP6-D9, TUB09 and TUB18 polymorphism analyses were performed using restriction fragment length polymorphism. Nine haplotypes were found in 37 CFTR alleles, and of those, 24 were linked with the F508del mutation and 13 with other CFTR mutations. The 6 (GATT), C (MP6-D9), G (TUB09), and C (TUB18) haplotypes showed the highest prevalence (48%) of the mutant CFTR allele and were linked to the F508del mutation (64%). In 43% of households analyzed, at least one informative polymorphism can be used for the indirect diagnostic test. CFTR polymorphisms are genetic markers that are useful for identifying the mutant CFTR alleles in households of patients with CF when it is not possible to establish the complete CFTR genotype. Moreover, the polymorphisms can be used for indirect CFTR mutation identification in cases of pre-fertilization, pre-implantation and prenatal analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Perioperative management of patients with cardiac implantable electronic devices.

PubMed

Poveda-Jaramillo, R; Castro-Arias, H D; Vallejo-Zarate, C; Ramos-Hurtado, L F

2017-05-01

The use of implantable cardiac devices in people of all ages is increasing, especially in the elderly population: patients with pacemakers, cardioverter-defibrillators or cardiac resynchronization therapy devices regularly present for surgery for non-cardiac causes. This review was made in order to collect and analyze the latest evidence for the proper management of implantable cardiac devices in the perioperative period. Through a detailed exploration of PubMed, Academic Search Complete (EBSCO), ClinicalKey, Cochrane (Ovid), the search software UpToDate, textbooks and patents freely available to the public on Google, we selected 33 monographs, which matched the objectives of this publication. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

[Not Available].

PubMed

San Mauro Martin, Ismael; Mendive Dubourdieu, Paula; Paredes Barato, Víctor; Garicano Vilar, Elena

2016-07-19

Introducción: la tradición de la comida picante desempeña un papel muy importante en el gusto por este tipo de comida y su tolerancia. Las preferencias alimentarias muestran influencia genética y ambiental.Objetivos: estudiar la tolerancia y el gusto por el picante de tres poblaciones, y la influencia hereditaria y del ambiente.Métodos:se realizó una encuesta a 522 sujetos, de tres continentes (Asia, Europa y Latinoamérica) en tres idiomas (español, inglés y chino) a través de Internet. Se realizaron preguntas acerca de la tolerancia al picante, el gusto por los alimentos picantes, su uso, la edad de comienzo de consumo, el gusto del padre y de la madre y si ella lo consumía durante el embarazo y/o lactancia.Resultados: existe diferencia entre el gusto por el picante del hijo y el sexo (p < 0,001), la tolerancia (p < 0,001) y, solo en el sexo femenino, el gusto de la madre por el picante (p < 0,001), su consumo durante el embarazo (p < 0,001) y la lactancia (p = 0,005) y el gusto del padre por el picante (p = 0,003). Existe correlación entre el continente de residencia (p = 0,007) y de nacimiento (p = 0,012) y la tolerancia a los alimentos picantes.Conclusión: la influencia de los progenitores, el género y la composición corporal se relacionaron con gustos y tolerancias diferentes.

Diabetes mellitus and drug abuse during pregnancy and the risk for orofacial clefts and related abnormalities.

PubMed

Trindade-Suedam, Ivy Kiemle; Kostrisch, Lília Maria von; Pimenta, Luiz André Freire; Negrato, Carlos Antônio; Franzolin, Solange Braga; Trindade, Alceu Sergio

2016-08-08

to assessed the prevalence of diabetes mellitus (DM) and drug abuse in mothers of children with orofacial clefts (OFC). 325 women who had children (0-3y) with clefts were interviewed. Data regarding type of diabetes, use of legal/illegal drugs during pregnancy, waist girth and fasting blood sugar at the first prenatal consult were collected. twenty seven percent of the women had DM, out of these, 89% had gestational DM, 5,5% type 1 DM and 5,5% type 2 DM. The prevalence of DM in mothers of children with OFC was 27%, it is significantly higher than the average Brazilian population which is 7.6% (p<0.01) (OR=4.5, 95%CI=3.5-5.8). Regarding drug abuse during pregnancy, 32% of the mothers used drugs and a significant positive correlation was observed between drug abuse and the occurrence of clefts and other craniofacial anomalies (p=0.028) (OR=2.87; 95%CI=1.1-7.4). DM and drug abuse during pregnancy increases the risk for OFC and related anomalies and early diagnosis of DM and prevention of drug abuse, especially in pregnant women, should be emphasized. esta investigación estableció la prevalencia de diabetes mellitus (DM) y el abuso de drogas en madres de niños con malformaciones creaneofaciales (MCF). 325 mujeres que tuvieron hijos (0-3 años) con malformaciones fueron entrevistadas. Se obtuvieron datos referentes a: tipo de diabetes; uso de drogas lícitas o ilícitas durante el embarazo; circunferencia de la cintura; y, glucemia en ayunas en la primera consulta prenatal. el veintisiete por ciento de las mujeres tenían DM. Entre estas, el 89% tuvieron DM gestacional, el 5,5% DM tipo 1 y el 5,5% DM tipo 2. La prevalencia de DM en madres de hijos con MCF fue de 27%. Esto es significativamente más alto que el promedio de la población brasileña afectada por esa enfermedad, que es de 7,6% (p<0.01) (OR=4,5, 95%IC=3,5-5,8). Observando el abuso de drogas durante el embarazo, el 32% de las madres había utilizado drogas y una correlación positiva significativa fue observada entre el abuso de drogas y la ocurrencia de hendiduras y otras malformaciones craneofaciales (p=0,028) (OR=2,87; 95%IC=1,1-7,4). la DM y el abuso de drogas durante el embarazo aumentan el riesgo de MCF y de anomalías relacionadas; se enfatiza la importancia del diagnóstico precoz de DM y la prevención del abuso de drogas, especialmente entre las mujeres embarazadas. avaliar a prevalência de diabetes mellitus (DM) e o uso de drogas em mães de crianças com fissuras orofaciais (FOF). 325 mulheres que tiveram filhos (0-3 anos) com fissuras foram entrevistadas. Os dados referentes tipo de diabetes, uso de drogas lícitas / ilícitas durante a gravidez, circunferência abdominal e glicemia em jejum na primeira consulta pré-natal foram coletados. vinte e sete por cento das mulheres tinham DM. Destes, 89% tinham DM gestacional, 5,5% DM tipo 1 e 5,5% DM tipo 2. A prevalência de DM em mães de crianças com FOF foi de 27%, significativamente mais elevado que a média da população brasileira que é de 7,6% (p <0,01) (OR = 4,5, IC de 95% = 3,5-5,8). Com relação ao uso de drogas, 32% das mães eram usuárias drogas durante a gravidez e uma correlação positiva foi observada entre o uso de drogas e a ocorrência de FOF e anomalias relacionadas (p = 0,028) (OR = 2,87; IC95% = 1,1-7,4). DM e uso de drogas durante a gravidez aumentam o risco de FOF e anomalias relacionadas e o diagnóstico precoce de DM e a prevenção do uso de drogas, especialmente em mulheres grávidas, devem ser enfatizados.

Trayectoria de los tornillos pediculares lumbares y sacros: Comparación entre el abordaje por linea media versus el abordaje posterolateral tipo wiltse

PubMed Central

Gagliardi, Martín; Guiroy, Alfredo; Molina, Federico Fernández; Fasano, Francisco; Ciancio, Alejandro Morales; Mezzadri, Juan José; Jalón, Pablo

2017-01-01

Resumen Objetivos: El objetivo de este estudio fue comparar, en fusiones lumbosacras cortas, el ángulo de convergencia de los tornillos pediculares entre el abordaje posterolateral tipo Wiltse y el abordaje mediano convencional. Método: Se revisaron en forma retrospectiva los controles en tomografía axial computada (TAC) de 76 tornillos pediculares lumbares y sacros colocados por vía posterior, mediante un abordaje mediano convencional (n: 38) o por vía posterolateral transmuscular tipo Wiltse (n: 38). Se incluyeron fusiones lumbosacras cortas desde L3 a S1, en pacientes adultos, con patología degenerativa. Se excluyeron los tornillos con una brecha ósea >4 mm en cualquier dirección, los casos con instrumentaciones pediculares previas y aquellos con curvas en el plano coronal mayores de 20°. Resultados: Considerando la totalidad de los implantes, el ángulo de convergencia fue de 23,3° (+/- 15,82). La angulación promedio, en el grupo AW, fue de 29,3° (+/- 9,72). En el grupo AC, el grado de convergencia de los implantes fue de 17,2° (+/- 10,58). Esta diferencia fue estadísticamente significativa (P < 0,0001). Para el grupo AW, el grado de convergencia según nivel fue el siguiente: L3: 31,2° (+/- 1,9); L4: 31,4° (+/- 2,76); L5: 31,1° (+/- 5,62); S1: 24,2° (+/- 12,16). El promedio del ángulo del tornillo según nivel para el grupo AC fue: L3: 16° (+/- 7,16); L4: 20,3° (+/- 6,9) L5: 15,9° (+/- 13,38); S1: 15,2° (+/- 14,32). Los implantes del grupo AW tuvieron ángulos significativamente más convergentes que el grupo AC en todos los segmentos explorados. Conclusión: En las fusiones lumbosacras cortas, la utilización del abordaje tipo Wiltse permitió la colocación de tornillos pediculares con más convergencia que en el abordaje mediano convencional. La relevancia clínica de este hecho es desconocida y se requerirían trabajos prospectivos randomizados para determinar la misma. PMID:29142777

Quality of nursing documentation before and after the Hospital Accreditation in a university hospital.

PubMed

Nomura, Aline Tsuma Gaedke; Silva, Marcos Barragan da; Almeida, Miriam de Abreu

2016-11-21

to analyze the quality of nursing documentation by comparing the periods before and after the preparation for the hospital accreditation, using the Quality of Nursing Diagnoses, Interventions and Outcomes - Brazilian version (Q-DIO- Brazilian version). observational study of interventions conducted in a university hospital. Nursing documentation of 112 medical records for the period before and 112 for the period after the hospital accreditation were compared using the Q-DIO instrument - Brazilian version. Data were statistically analyzed. there was a significant improvement in the quality of nursing documentation. When the total score of the instrument was evaluated, a significant improvement was observed in 24 out of the 29 items (82.8%). there was commitment to the shift of culture by means of the interventions carried out, which resulted in the conquest of the quality seal ensured by the Joint Commission International. analisar a qualidade dos registros de enfermagem, comparando o período antes e depois do preparo para a acreditação hospitalar, fazendo uso do Quality of Nursing Diagnoses, Interventions and Outcomes - Versão brasileira (Q-DIO-Versão brasileira). estudo observacional de intervenções realizado em um hospital universitário. Comparados os registros de enfermagem em 112 prontuários referentes ao período anterior a acreditação hospitalar e 112 ao período posterior, por meio do instrumento Q-DIO - Versão brasileira. Os dados foram analisados estatisticamente. houve melhora significativa da qualidade dos registros de enfermagem. Quando avaliado o escore total do instrumento evidenciou melhora significativa em 24 dos 29 itens (82,8%). houve empenho à mudança de cultura por meio das intervenções realizadas, refletida na conquista do selo de qualidade da Joint Commission Internacional. analizar la calidad de los registros de enfermería, comparando los períodos antes y después de la preparación para la acreditación hospitalaria, haciendo uso del Quality of Nursing Diagnoses, Interventions and Outcomes - Versión brasileña (Q-DIO- Versión brasileña). estudio observacional de intervenciones realizado en un hospital universitario. Los registros de enfermería de 112 historias clínicas del período anterior y 112 historias clínicas del período posterior a la acreditación hospitalaria se compararon mediante el instrumento Q-DIO - Versión brasileña. Los datos fueron analizados estadísticamente. se observó una mejora significativa de la calidad de los registros de enfermería. Cuando se evaluó la puntuación total del instrumento, se observó una mejora significativa en 24 de los 29 ítenes (82,8%). hubo un compromiso con el cambio en la cultura por medio de las intervenciones realizadas, lo que resultó en la conquista del sello de calidad garantizado por la Joint Commission International.

EL PROGRAMA CITI: UNA ALTERNATIVA PARA LA CAPACITACIÓN EN ÉTICA DE LA INVESTIGACIÓN EN AMÉRICA LATINA

PubMed Central

Litewka, Sergio; Goodman, Kenneth; Braunschweiger, y Paul

2011-01-01

El Programa CITI (Collaborative Institutional Training Initiative) es un curso basado en Internet y desarrollado por voluntarios, que brinda material educacional sobre protección de sujetos humanos en investigaciones biomédicas y de conducta, buenas prácticas clínicas, conducta responsable de la investigación y trato humanitario a animales de laboratorio. Es un esfuerzo conjunto del Fred Hutchinson Cancer Research Center y la Universidad de Miami. Con la colaboración de expertos locales, gran parte del contenido se ha adaptado para América Latina, se ha traducido al español y portugués y se han establecido acuerdos de colaboración con instituciones especializadas en bioética en Chile, Brasil, Costa Rica y Perú. Los autores presentan una metodología accesible para la capacitación en ética de la investigación y una justificación de su uso y difusión en América Latina PMID:21687817

[Not Available].

PubMed

Curilem Gatica, Cristian; Almagià Flores, Atilio; Rodríguez Rodríguez, Fernando; Yuing Farias, Tuillang; Berral de la Rosa, Francisco; Martínez Salazar, Cristian; Jorquera Aguilera, Carlos; Bahamondes Ávila, Carlos; Soís Urra, Patricio; Cristi Montero, Carlos; Bruneau Chávez, José; Pinto Aguilante, Juan; Niedmann Brunet, Luis

2016-06-30

El índice de masa corporal (IMC) otorga uno de los índices más usados para determinar el estado nutricional de la población a nivel mundial, donde a pesar de existir recomendaciones claras y definidas para su interpretación como el sexo, edad, raza, entre otros, normalmente se estandariza su clasificación, independiente de las variables, aumentando el error en el resultado y en la clasificación del estado nutricional.El uso de la composición corporal a través de la antropometría entrega mayor información que el IMC, siendo la masa grasa y la masa muscular los principales resultados útiles.Este artículo presenta una revisión de las ecuaciones existentes y propone aquellas más simples y con menor error de estimación para ser usadas como una herramienta que reemplace o complemente al IMC, favoreciendo una mejor comprensión e interpretación del estado nutricional y nivelde actividad física en niños y adolescentes.

PubMed

Camporro, Fernando Astur; Gutierrez Magaldi, Ignacio; Bulacio, Exequiel

2017-09-08

Introducción: El tabaquismo es la primera causa evitable de muerte en el mundo. El cigarrillo electrónico (CE), es un dispositivo que simula a los cigarrillos convencionales y permite inhalar nicotina y otras sustancias de forma vaporizada, sin combustión de tabaco. Su conocimiento por parte de la población general, así como su comercialización y consumo viene en constante aumento. Es utilizado en todo el mundo con el objetivo de disminuir el consumo de tabaco, lograr su abandono o poder utilizarlo en lugares públicos donde el consumo de cigarrillos convencionales está prohibido. Efectos nocivos sobre la salud: Su utilización se ha asociado a neumonía lipoidea e irritación de la vía aérea superior y toxicidad por nicotina. Presenta sustancias cancerígenas como nitrosaminas, formaldeido y metales como el niquel, cromo y plomo. Aumenta la resistencia de la vía aérea, efecto que es similar al que se produce después de la inhalación del humo del tabaco. Eficacia para dejar de fumar: No hay hasta el momento trabajos que demuestren con poder estadístico y buena metodología que este producto sea eficaz para dejar de fumar.  Conclusiones: De acuerdo a la evidencia disponible, no podemos descartar que el uso del cigarrillo electrónico no tenga riesgos para la salud. La seguridad y eficacia de los cigarrillos electrónicos como ayuda para el abandono del hábito tabáquico no han sido demostradas.

Scale of attitudes toward alcohol - Spanish version: evidences of validity and reliability.

PubMed

Ramírez, Erika Gisseth León; Vargas, Divane de

2017-08-03

validate the Scale of attitudes toward alcohol, alcoholism and individuals with alcohol use disorders in its Spanish version. methodological study, involving 300 Colombian nurses. Adopting the classical theory, confirmatory factor analysis was applied without prior examination, based on the strong historical evidence of the factorial structure of the original scale to determine the construct validity of this Spanish version. To assess the reliability, Cronbach's Alpha and Mc Donalid's Omega coefficients were used. the confirmatory factor analysis indicated the good fit of the scale model in a four-factor distribution, with a cut-off point at 3.2, demonstrating 66.7% of sensitivity. the Scale of attitudes toward alcohol, alcoholism and individuals with alcohol use disorders in Spanish presented robust psychometric qualities, affirming that the instrument possesses a solid factorial structure and reliability and is capable of precisely measuring the nurses' atittudes towards the phenomenon proposed. validar a Escala de atitudes frente ao álcool, ao alcoolismo e a pessoas com transtornos relacionados ao uso do álcool, versão espanhola. estudo metodológico, realizado com 303 enfermeiros colombianos. Seguindo a teoria clássica, foi aplicada a análise fatorial confirmatória sem exploração preliminar, com base na forte evidência histórica da estrutura fatorial do instrumento original para a validação de construto desta versão em espanhol. Para a avaliação da confiabilidade foram utilizados os coeficientes de Alfa de Cronbach e Ômega de Mc Donald. a análise fatorial confirmatória indicou o bom ajuste do modelo da escala na distribuição de quatro fatores, compreendendo 48 itens em sua versão espanhola. Os índices de confiabilidade foram satisfatórios, com ponto de corte observado em 3,2, demonstrando sensibilidade de 66,7%. a Escala de atitudes frente ao álcool, ao alcoolismo e a pessoas com transtornos relacionados ao uso do álcool no idioma espanhol, apresentou qualidades psicométricas robustas, afirmando que se trata de um instrumento com estrutura fatorial e confiabilidade sólidas, capaz de medir com precisão as atitudes dos enfermeiros frente ao fenômeno proposto. validar la Escala de actitudes frente al alcohol, al alcoholismo y a la persona con trastornos relacionados al uso de alcohol en su versión española. estudio de tipo metodológico, realizado con 303 enfermeros colombianos. Siguiendo la teoría clásica, se utilizó análisis factorial confirmatoria sin exploración previa, con base en la fuerte evidencia histórica de la estructura factorial del instrumento original para determinar la validez de constructo de esta versión en español. La confiabilidad se evaluó por los coeficientes de Alfa de Cronbach y Omega de Mc Donald. el análisis factorial confirmatorio indicó buen ajuste del modelo de la escala en la distribución de cuatro factores, comportando 48 ítems en su versión en español. Los índices de confiabilidad fueron satisfactorios, con un punto de corte observado en 3,2, mostrando sensibilidad del 66,7%. la Escala de actitudes frente al alcohol, al alcoholismo y a la persona con trastornos relacionados al uso de alcohol en idioma español presentó cualidades psicométricas robustas, afirmando que se trata de un instrumento con estructura factorial y confiabilidad sólidas, capaz de medir con precisión las actitudes de los enfermeros frente al fenómeno propuesto.

A Reappraising of Cosmography: the Interface Between Astronomical and Geographic Studies. (Breton Title: Releitura do Conceito de Cosmografia: a Interface Entre os Estudos Astronômicos e Geográficos.) Una Relectura del Concepto de Cosmografía: la Interfase Entre los Estudios Astronómicos y Geográficos

NASA Astrophysics Data System (ADS)

Azevedo Sobreira, Paulo Henrique

2012-12-01

The concept of "Cosmography" is in disuse since the 80s of the last century, but the astronomical themes previously discussed in the school subjects of Geography and Cosmography remain in current textbooks. The use of term "Cosmography" was rescued in this research, and the study of its re-signification prompted the appearance of the term Geographic Cosmography. The Geographic Cosmography is a field of studies of the Geography, whose set of knowledge and skills is predominantly scholar. It studies the interface between terrestrial and celestial knowledge, and assigns a geographic significance to them. It examines human and natural relationships with Sidereal Space and its consequences for society and nature. O conceito de "Cosmografia" está em desuso desde os anos 80 do século XX, mas os temas astronômicos anteriormente abordados nas disciplinas escolares de Cosmografia e de Geografia permanecem nos atuais livros didáticos. O uso do termo "Cosmografia" foi resgatado nesta pesquisa e o estudo de sua ressignificação proporcionou o surgimento do termo Cosmografia Geográfica. A Cosmografia Geográfica é um campo de estudos da Geografia, cujo conjunto de conhecimentos e habilidades é predominantemente escolar. Estuda a interface entre os conhecimentos terrestres e os celestes e lhes atribui significância geográfica. Analisa as relações humanas e naturais com o Espaço Sideral e suas consequências para a sociedade e a natureza.

Aunque el concepto de "Cosmografía" no se usa desde la década de los '80 del siglo pasado, los temas astronómicos que se enseñaban anteriormente en las asignaturas escolares de Cosmografía y de Geografía permanecen en los actuales libros didácticos. El uso del término "Cosmografía" fue rescatado en esta investigación y el estudio de su resignificación proporcionó el surgimiento del término Cosmografía Geográfica. La Cosmografía Geográfica es un campo de estudio de la Geografía, donde el conjunto de conocimientos y habilidades es predominantemente escolar. Estudia la interfase entre los conocimientos terrestres y los celestes, dándoles un significado geográfico. Analiza las relaciones humanas y naturales con el Espacio Sideral y sus consecuencias para la sociedad y la naturaleza.

Cochlear Implantation in Siblings With Refsum's Disease.

PubMed

Stähr, Kerstin; Kuechler, Alma; Gencik, Martin; Arnolds, Judith; Dendy, Meaghan; Lang, Stephan; Arweiler-Harbeck, Diana

2017-08-01

Whether the origin of severe hearing loss in Refsum's syndrome is caused by cochlear impairment or retrocochlear degeneration remains unclear. This case report aims to investigate hearing performance before and after cochlear implantation to shed light on this question. Also, identification of new mutations causing Refsum's syndrome would be helpful in generating additional means of diagnosis. A family of 4 individuals was subjected to genetic testing. Two siblings (56 and 61 years old) suffered from severe hearing and vision loss and received bilateral cochlear implants. Genetic analysis, audiological outcome, and clinical examinations were performed. One new mutation in the PHYH gene (c.768del63bp) causing Refsum's disease was found. Preoperative distortion product otoacoustic emissions (DPAOEs) were absent. Postoperative speech perception in Freiburger speech test was 100% for bisyllabic words and 85% (patient No. 1) and 65% (patient No. 2), respectively, for monosyllabic words. Five years after implantation, speech perception remained stable for bisyllabic words but showed decreasing capabilities for monosyllabic words. A new mutation causing Refsum's disease is presented. Cochlear implantation in case of severe hearing loss leads to an improvement in speech perception and should be recommended for patients with Refsum's disease, especially when the hearing loss is combined with a severe loss of vision. Decrease of speech perception in the long-term follow-up could indicate an additional retrocochlear degeneration.

Revision curricular a partir de un analisis comparativo de las discrepancias en los curriculos de una escuela de optometria en Puerto Rico con las competencias requeridas para las agencias de revalida y acreditacion 2004

NASA Astrophysics Data System (ADS)

Rivera Pacheco, Andres

El proposito de esta investigacion, un estudio cualitativo de caso, fue comparar y contrastar el curriculo vigente de la Escuela de Optometria de la UIAPR con las competencias y estandares requeridos por las agencias de acreditacion y de revalida. Con este proposito, decidimos realizar una revision y un analisis de documentos: el prontuario de cada uno de los cursos de los curriculos implantados en el 1993 y en el 2001; las competencias y estandares establecidos por las agencias de revalida y de acreditacion; y las estadisticas en las que se analiza el porcentaje de estudiantes que aprueban cada una de las partes de los examenes de revalida entre el 1998 al 2003. Se realizaron entrevistas dirigidas para dar apoyo y complementar la revision y el analisis de estos documentos. Los participantes de las entrevistas fueron tres estudiantes de la clase de optometria del 2004 (ultima clase del curriculo del 1993); tres estudiantes de la clase de optometria del 2005 (primera clase graduanda del curriculo vigente) y tres profesores y/o directores de los Departamentos de Ciencias Basicas, Ciencias Clinicas y Cuidado al Paciente. Esta investigacion se enmarco en el modelo de evaluacion curricular de discrepancia de Malcolm Provus y en el modelo de desarrollo basado en competencias. Uno de los hallazgos mas importantes del estudio es que los cambios que se implantaron al curriculo del 2001 no han logrado que los estudiantes mejoren su ejecucion en los examenes de revalida. Por otro lado, se encontro que el curriculo vigente atiende completamente los estandares de la practica de Optometria, pero no las competencias. Esta informacion fue validada mediante el uso de una tabla de cotejo para el analisis de los cursos y de la informacion obtenida de las entrevistas. El estudio determina y concluye que existen discrepancias entre los prontuarios de los cursos del curriculo y las competencias requeridas por la agencia de revalida. Segundo, que el Departamento de Ciencias Basicas es el que presenta mas deficiencias en el desarrollo de las competencias. El investigador recomienda disenar e implantar un curriculo basado en competencias y proveer formacion en didactica y procesos de aprendizaje a los profesores.

Desarrollo de la Escala sobre el Estigma Relacionado con el VIH/SIDA para Profesionales de la Salud mediante el uso de métodos mixtos123

PubMed Central

Varas-Díaz, Nelson; Neilands, Torsten B.; Guilamo-Ramos, Vincent; Cintrón Bou, Francheska N.

2009-01-01

El estigma relacionado con el VIH/SIDA continúa siendo un obstáculo para la prevención primaria y secundaria del VIH. Las consecuencias para las personas que viven con la enfermedad han sido muy documentadas y continúan siendo una gran preocupación para las personas que proveen servicios de salud y para aquellas que investigan el tema. Estas consecuencias son preocupantes cuando el estigma emana de profesionales de la salud porque se puede limitar el acceso a los servicios. Uno de los principales obstáculos para la investigación del estigma relacionado con el VIH en Puerto Rico es la falta de instrumentos cuantitativos para evaluar las manifestaciones del estigma entre profesionales de la salud. El objetivo principal de este estudio fue desarrollar y probar las propiedades psicométricas de una escala sobre el estigma relacionado con el VIH/SIDA culturalmente apropiada para personas que proveen servicios de salud puertorriqueñas y desarrollar una versión corta de la escala que pudiera usarse en escenarios clínicos con tiempo limitado. El instrumento desarrollado estuvo basado en evidencia cualitativa recopilada entre profesionales y estudiantes de profesiones de la salud puertorriqueños/as (n=80) y administrado a una muestra de 421 profesionales de la salud en adiestramiento. La escala contenía 12 dimensiones del estigma relacionado con el VIH/SIDA. El análisis cuantitativo corroboró 11 de ellas, teniendo como resultado un instrumento con validez y confiabilidad satisfactoria. Estas dimensiones, a su vez, fueron subcomponentes de un factor de estigma general superior. PMID:20333258

Influencia atmosférica en la rotación terrestre

NASA Astrophysics Data System (ADS)

Fernández, L. I.; Arias, E. F.; Brunini, C. A.

Las observaciones de los parámetros de la orientación terrestre han alcanzado en estos últimos años una exactitud sin precedentes gracias al uso de modernas técnicas de geodesia espacial. Estudios previos han establecido que las variaciones en la rotación terrestre con períodos iguales o menores que dos años obedecen a cambios en la circulación atmosférica global. Para estos períodos puede comprobarse que existe un gran acuerdo entre las fluctuaciones de la longitud del día (LOD) y los cambios del momento angular atmosférico terrestre (AAM). Sin embargo, no existe un acuerdo general acerca de las causas que provocan las variaciones de largo período de la rotación de la Tierra, también conocidas como ``variaciones decenales''. En nuestro análisis examinamos las correlaciones entre las variaciones de los valores de LOD y las fluctuaciones en la componente polar del momento angular atmosférico terrestre. Con este propósito utilizamos los siguientes juegos de datos: las series de AAM, estimado siguiendo la definición de Barnes et al.(1983) para 2825 días provientes del National Meteorological Center (NMC) y del European Centre for Medium Range Weather Forecast (ECMWF); y las series de LOD que contienen valores alisados espaciados a intervalos de un día elaborados por el International Earth Rotation Service (IERS). Mostraremos que para los cambios anuales e interanuales en la rotación de la Tierra la influencia atmosférica es asombrosa, mientras que, tanto en las escalas temporales más grandes y como en las más pequeñas, ambas series, geodésica y atmosférica, parecen diverger aún cuando poseemos observaciones obtenidas con las técnicas más modernas al presente.

Estrategia de Aprendizaje Basado en Problemas (ABP) para explorar las concepciones alternativas relacionadas al tema estados de agregacion de la materia en estudiantes de nivel elemental =

NASA Astrophysics Data System (ADS)

Rosado Olivieri, Wilda Y.

Gran parte de la investigacion acerca de la ensenanza de las ciencias se dedica a estudiar la forma o manera en que los estudiantes visualizan los conceptos cientificos. Para Driver (1983) esas ideas o concepciones se conocen como concepciones alternativas; las cuales pueden ocasionar dificultad para comprender los conceptos de las diferentes areas del conocimiento. El proposito de este estudio fue: (a) indagar como las distintas etapas del ABP permiten explorar las concepciones alternativas que poseen los estudiantes de nivel elemental acerca de los estados de agregacion de la materia y, (b) explorar en que medida el ABP permite identificar e incorporar las concepciones alternativas que poseen los estudiantes de nivel elemental con relacion al concepto de estados de agregacion de la materia para facilitar su aprendizaje. Con el fin de explorar las concepciones alternativas en el tema de los estados agregados de la materia se implanto la estrategia de Aprendizaje Basado en Problemas (ABP) con estudiantes de quinto grado de nivel elemental. Se utilizo la metodologia mixta con varias estrategias de recopilacion de datos, como una pre y pos prueba para elucidar el conocimiento previo y al mismo tiempo las concepciones alternativas sobre el tema bajo estudio y luego verificar el aprendizaje en los estudiantes. Asimismo, el uso de mapas conceptuales para determinar la profundidad del tema estudiado y el entrelazamiento de los conceptos Una tercera estrategia fue el grupo focal para tomar en cuenta la impresion de los estudiantes acerca del proyecto ABP. El aspecto colaborativo y cooperativo fue un factor fundamental, ya que el aprendizaje ocurrio en ese contexto educativo. Para los hallazgos de esta investigacion fue tan importante el conocimiento previo como los procesos que se generaban para que la adquisicion del mismo fuera de forma significativa y funcional (Escribano & Del Valle, 2010). La estrategia de ABP constituyo en este estudio una forma para indagar las concepciones alternativas que poseian los estudiantes y a su vez, determinar como el estudiante manejaba dichas concepciones a situaciones que requeririan aplicar su conocimiento para luego modificar las estructuras conceptuales hacia el conocimiento cientifico.

Use of black vulture (Coragyps atratus) in complementary and alternative therapies for cancer in Colombia: A qualitative study

PubMed Central

2012-01-01

Background Although Coragyps atratus has been used as a traditional therapy for patients with cancer, the scientific literature does not contain enough information on how this therapy is used or the mechanisms that explain this therapeutic practice. Objectives To understand the methods of use and the reasons given by patients and caregivers for the use of Coragyps atratus in cancer treatment. Methods This study used a qualitative design based on twenty in-depth interviews of patients with cancer or caregivers of patients with the disease. The analysis of the text was based on an inductive thematic approach. Results Resistance to disease and immune enhancement are properties attributed to Coragyps atratus when used for cancer treatment. The most recommended method of use is fresh blood ingestion, and the associated mechanism of action is transfer of immune factors to the individual who consumes it. Conclusions Use of Coragyps atratus as a treatment for cancer is a popular alternative therapy in Colombia. More studies are needed to understand the clinical effects of this intervention in cancer patients. Spanish abstract Introducción Aunque Coragyps atratus se usa tradicionalmente como terapia para pacientes con cáncer, no existe suficiente información en la literatura científica sobre su forma de utilización ni sobre los mecanismos explicativos que subyacen a esta práctica terapéutica. Objetivos Conocer métodos de utilización y mecanismos explicativos dados por los pacientes y cuidadores de pacientes sobre el uso de Coragyps atratus en el tratamiento del cáncer. Materiales y métodos Diseño cualitativo basado en veinte entrevistas en profundidad de pacientes con cáncer o cuidadores de pacientes con esta enfermedad. Análisis de texto basado en enfoque temático inductivo. Resultados Al Coragyps atratus se le atribuyen propiedades de resistencia y fortalecimiento del sistema inmune de personas enfermas de cáncer. La forma de utilización mas común es la ingesta de la sangre fresca y el mecanismo de acción asociado es la transferencia de defensas a quien lo consume. Conclusiones La utilización del Coragyps atratus como tratamiento para el cáncer es una terapia alternativa usada popularmente en Colombia. El uso de este animal debe estudiarse más a fondo para conocer los efectos clínicos en los pacientes con cáncer. PMID:22651097

El rol de Ia colaboracion y el Modelo de Aprendizaje Basado en Proyectos (ABPr) mediante el lente de la Teoria de Actividad (CHAT): un estudio de caso con estudiantes de 9no grado

NASA Astrophysics Data System (ADS)

Delgado, Isabel C.

Los modelos de eensenanza y aprendizaje constructivistas conceptualizan el aprendizaje como un proceso activo. El modelo de Aprendizaje Basado en Proyectos (ABPr) se distingue por una serie de componentes, entre los cuales se destaca el aspecto colaborativo y cooperativo como un reto al momento de su implantacion. Son pocas las investigaciones que se concentran en este aspecto del modelo. En este estudio, se analizaron las diversas interacciones que surgen durante la implantacion de una unidad curricular sobre el tema de Geologia de Puerto Rico, la cual se diseno con el modelo ABPr cuyo enfoque es orientacion a proyectos. Particularmente, se examinaron las interacciones sociales que surgen entre los pares y entre pares y docente durante el proceso de planificacion y desarrollo de los productos finales, al igual que las interacciones entre los estudiantes y el material didactico en estas etapas del modelo. La investigacion es de tipo cualitativo e incorpora como diseno el estudio de caso. Las diversas interacciones constituyen la unidad de analisis. En el estudio participaron 19 estudiantes de 9no grado, a quienes se organizaron en 5 grupos colaborativos por temas de interes (Pangea, Placas tectonicas, Volcanes, Tsunamis y Terremotos). Las tecnicas que se utilizaron para recopilar los datos fueron: observaciones participativas, grupos focales y analisis de documentos (cuadernos reflexivos y respuestas de los estudiantes a la pregunta central del proyecto). Para el analisis de los datos se aplico la teoria de actividad (CHAT) que concentra la unidad de analisis en la actividad humana en un contexto particular. Los resultados del estudio senalan que las interacciones entre pares, entre pares y docente, asi como entre estudiantes y material didactico son fundamentales en el proceso de aprendizaje. Una mayor interaccion entre pares durante las etapas de planificar y desarrollar los productos finales de la unidad, promueve una mejor comprension de los conceptos de la unidad, segun evidencia los productos finales del ABPr. La interaccion con el docente es muy importante para mediar los conflictos y desacuerdos que surgen como parte de las interacciones entre pares. Por lo tanto, el uso de diversas estrategias de andamiaje por parte del docente durante las reuniones de los grupos colaborativos es esencial para el exito del modelo ABPr.

Defense.gov Special Report: Travels with Winnefeld: USO Tour

Science.gov Websites

: USO April 2012 Top Stories USO Tour Brings Ramstein Troops, Families Together Service members and USO celebrities paid a surprise visit to wounded warriors at an aeromedical staging facility on Ramstein Air Base in Germany. Story USO Spring Tour Entertains Troops in Afghanistan Nearly 400 excited

DUCHAS VAGINALES Y OTROS RIESGOS DE VAGINOSIS BACTERIANA

PubMed Central

Chávez, Natividad; Molina, Helfer; Sánchez, Jorge; Gelaye, Bizu; Sánchez, Sixto E.

2010-01-01

Vaginosis bacteriana (VB) es una infección caracterizada por el cambio en la microflora de la vagina, asociándose a resultados adversos del embarazo y a la adquisición de infecciones de transmisión sexual (ITS), incluyendo el VIH. En este estudio se buscó la asociación entre el uso de duchas vaginales y otros factores de riesgos con VB. Se usó un diseño observacional descriptivo transversal prospectivo, en 1,252 mujeres que asistieron al servicio de planificación familiar de tres hospitales nacionales (Dos de Mayo, Arzobispo Loayza, San Bartolomé) y el Instituto Materno Perinatal, durante el año 1997. Se utilizó un cuestionario estructurado donde se registraron variables socio demográficas y características del estilo de vida de las participantes. VB fue diagnosticada mediante el puntaje de Nugent. Se empleó análisis de regresión logística para calcular odds ratio (OR) e intervalos de confianza al 95%. La edad promedio de las participantes fue 25.1 ± 4,7 años, el 23.4% tenían más de 11 años de educación. La prevalencía de VB fue 20,1%. Las mujeres que practicaban duchas vaginales tuvieron 2.28 veces (OR = 2.28, IC 95% [1.0–5.0]) mayor probabilidad de tener VB comparado con aquellas que no lo practicaban. Tener dos o más parejas sexuales estuvo asociado con 2.0 veces (OR =2.0, IC 95% [1.2–3.5]) mayor probabilidad de adquirir VB comparado con aquellas que habían tenido solo una pareja sexual. Las participantes que iniciaron una relación sexual a una edad temprana tuvieron 1.4 veces (OR=1.4, IC 95% [1.0 –1.9]) mayor probabilidad de adquirir VB. El uso de duchas vaginales es un factor de riesgo de VB. Los programas destinados a la salud de la mujer deben abordar las repercusiones perjudiciales para la salud asociados con las duchas vaginales. PMID:21132048

[Anesthetic management and experience in the transcatheter implantation of the CoreValve(®) self-expanding aortic valve].

PubMed

Fernández Suárez, F E; del Valle Fernández, R; González Alvarez, A; Sánchez Lasheras, J; Fernández Sánchez, L; Argüelles Tamargo, L

2013-10-01

To analyze the experience and anesthetic management in the transcatheter implantation of the CoreValve(®) self-expanding aortic valve, in a university tertiary hospital. Observational analytical review of data incorporated into a prospectively maintained database of 142 patients diagnosed with severe aortic stenosis who underwent implantation of a CoreValve(®) aortic self-expanding aortic valve between December 2007 and December 2012. The mean age of patients was 82.5±6.1 years and the logistic EuroSCORE was 14.9±11.2. General anesthesia was used in 107 patients (75.3%), with local anesthesia with sedation in 35 (24.6%). Local anesthesia and sedation was associated with a lower requirement of vasoactive drugs (P=.003) during implantation. No statistically significant differences were found between the 2 anesthetic techniques in the duration of the procedure, hospital stay, or morbimortality. The success rate was 97.1%. The most common complication was conduction disorders that required implantation of a permanent pacemaker in 46 patients (32.3%). There was no intraoperative mortality, and all-cause mortality at 30 days was 6.3%, with a one-year survival estimated by the Kaplan-Meier of 83.1%. This study confirms that in patients with severe aortic stenosis and high surgical risk, transcatheter implantation of aortic valve is a safe and effective alternative. Both, general anesthesia and local anesthesia with sedation are valid options, depending on the experience of the team. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Errores fotométricos debido al uso del filtro anular de mediana en imágenes CCD

NASA Astrophysics Data System (ADS)

Gil-Hutton, R.; Cañada, M.; Noel, N.

El filtro anular de mediana tiene la importante propiedad de tener una escala claramente definida, lo que permite remover de una imagen CCD todos los objetos con tamaños menores a esta escala, independientemente de su morfología particular, y reemplazarlos por el correspondiente ``background" local. Este filtro es de gran utilidad para remover gradientes de fondo, ``fringing" y halos de objetos extendidos mediante el simple procedimiento de restar a la imagen original una imagen filtrada, repitiendo el proceso las veces que sea necesario. En este trabajo se presentan resultados sobre los errores que introduce este filtro en la fotometría de objetos con diferente relación S/N y su aplicación a imágenes con gradientes de fondo y ``fringing".

Medio ambiente y cáncer pediátrico en la Región de Murcia (España): integrando la historia clínica medioambiental en un sistema de información geográfica

PubMed Central

Ortega-García, J.A.; López-Hernández, F.A.; Sobrino-Najul, E.; Febo, I.; Fuster-Soler, J.L.

2016-01-01

Introducción Medio Ambiente y Cáncer Pediátrico (CP) en la Región de Murcia (RM) es un proyecto de investigación, cuya principal meta es el desarrollo de una cuidadosa historia ambiental pediátrica (HAP) y el uso de sistemas de información geográfica (SIG) para crear mapas de incidencia y analizar la distribución geográfica del CP en la RM. El objetivo es presentar la metodología, el estudio descriptivo y los primeros resultados sobre la incidencia espacial y temporal del CP en la RM (España). Material y métodos Estudio descriptivo y de georreferenciación de todos los casos de CP menores de 15 años, diagnosticados entre el 1 de enero de 1998 y el 31 de diciembre de 2009. Se han asociado a cada caso tres direcciones postales, durante el embarazo, en el período posnatal y en el momento del diagnóstico. También se han utilizado las siguientes variables: sexo, fechas de nacimiento y diagnóstico y el diagnóstico patológico. Resultados No se observa un incremento en la tendencia de la incidencia del CP. La tasa cruda de incidencia fue de 14,3 casos por 100.000 niños menores de 15 años. La razón de incidencia estandarizada es más elevada en el noroeste de la RM. El 30% tienen un domicilio previo al diagnóstico distinto al del embarazo. Conclusiones La integración de la información temporal y espacial de la HAP en un SIG permitirá la identificación y el estudio de conglomerados espacio-temporales a través de un sistema de vigilancia medioambiental que ayude a ponderar la importancia de los factores de riesgo asociados. PMID:21315667

Comportamiento del Helio en estrellas químicamente peculiares

NASA Astrophysics Data System (ADS)

Malaroda, S. M.; López García, Z.; Leone, F.; Catalano, F.

Las estrellas químicamente peculiares (CP) se caracterizan por tener deficiencias y sobreabundancias de algunos elementos químicos de hasta 106 veces la abundancia solar. Además presentan variaciones en las líneas espectrales. Se piensa que ello se debe a que los campos magnéticos presentes en este tipo de estrellas son principalmente dipolares, con un eje de simetría diferente del eje de rotación. La distribución de los elementos sobreabundantes y deficientes no es homogénea sobre la superficie estelar y las variaciones observadas serían una consecuencia directa de la rotación estelar. Entre los elementos con abundancia anómala se encuentra el Helio, cuyas líneas tienen intensidades que no son consistentes con una abundancia normal, que no puede ser determinada del modo usual, o sea, considerando una atmósfera con composición solar. Con el fin de determinar la abundancia de este elemento, se inició un estudio de estrellas anómalas de Helio, Hew y He strong. Además se determinarán las abundancias de otros elementos anómalos como ser el Si, Cr, Mg, Mn y Fe. Las mismas se determinan del modo tradicional, o sea: a) medida de los anchos equivalentes de las líneas de los distintos elementos analizados; b) adopción de la temperatura efectiva, gravedad y abundancia del Helio; c) cálculo del modelo de atmósfera d) comparación con las observaciones y reinicio de un proceso iterativo hasta lograr un acuerdo entre todos los parámetros analizados. Las observaciones se llevaron a cabo en el Complejo Astronómico El Leoncito. Se observaron setenta y ocho estrellas anómalas de Helio. En este momento se está procediendo a calcular las abundancias correspondientes a los distintos elementos químicos. Para ello se hace uso de los modelos de Kurucz, ATLAS9. Los cálculos NLTE de las líneas de Helio se llevan a cabo con el programa MULTI y se compararán con los realizados con el programa WIDTH9 de Kurucz (LTE), con el objeto de resaltar la importancia de los efectos NLTE.

Mapa Geologico de Venezuela a Escala 1:750,000

USGS Publications Warehouse

Hackley, Paul C.; Urbani, Franco; Karlsen, Alex W.; Garrity, Christopher P.

2006-01-01

Se presenta un mapa geologico digital de Venezuela sobre un fondo de relieve sombreado. Los datos geologicos e hidrologicos del norte del rio Orinoco proceden de la digitalizacion de mapas geologicos en papel a escala 1:500.000. Estos datos fueron integrados con el mapa geologico digital del Escudo de Guayana Venezolano, a su vez derivado de hojas en papel a escala 1:500.000. La informacion sobre los tipos de fallas mostrados en el mapa es igual que en las fuentes originales. Los poligonos geologicos fueron atribuidos por edad, litologia y nombre de la unidad siguiendo el Codigo geologico de Venezuela. Se incorporaron revisiones significativas de la geologia de la Cordillera de la Costa a partir de las nuevas hojas integradas a escala 1:25.000. Toda esta informacion geologico-estructural se sobrepuso a una imagen de relieve sombreado, producida por el procesamiento de los datos de radar interferometrico con 90 m (3 arcosegundos) de resolucion espacial obtenidos por la mision topografica de radar del transbordador espacial (SRTM). Las areas de la base de datos del SRTM carentes de informacion fueron llenadas por medio de la interpolacion de los datos de las celdas adyacentes. Para producir la imagen de relieve sombreado se uso una direccion de iluminacion de 315 deg con un angulo de 65 deg sobre el horizonte. La proyeccion usada en el mapa es conica equidistante, con latitudes de 4 y 9 deg norte como paralelos estandar y una longitud de 66 deg al oeste como meridiano central. Los datos en el mapa proceden primordialment de hojas a escala 1:500.000 y el producto esta preparado para una impresion optima en escala 1:750.000. Los usuarios pueden obtener ampliaciones mayores, sin embargo no se garantiza la precision del mapa a escalas mas detalladas. Especialmente en la region de Guayana, al sobreponer los mapas geologicos sobre la reciente imagen SRTM, se notan grandes discrepancias no sistematicas tanto en contactos como en fallas. Esto es debido a que los mapas geologicos de Guayana tienen como base topografica las imagenes de radar de vision lateral (SLAR), con muy control de campo de los a?os 1970's. La correccion de estos desfases esta planificada para el futuro.

International Conference on Surface Modification of Metals by Ion Beams Held in Riva Del Garda, Italy on 12-16 September 1988 (Final Program and Abstracts)

DTIC Science & Technology

1988-09-16

Precipitates in Carbon Steel by Low Dose alpha- particle bombard- mento, .M.M. Ramos. L. Amaral, M. Behar. A Vas- quez, G. Marest and F.C. Zawislak...planted martensitic low carbon steel (C - 0.2 wt%). The characteriza- tion of the precipitates is done via Conversion Electron Mbssbauer technique (CEMS... PHASE TRANSFORMATIONS OF A NITROGEN IMPLANTED AUSTENITIC STAINLESS STEEL (XO CrNITI 189) by R. Leutenecker Fraunhofer-Institut for

The flight performance of the Galileo orbiter USO

NASA Technical Reports Server (NTRS)

Morabito, D. D.; Krisher, T. P.; Asmar, S. W.

1993-01-01

Results are presented from an analysis of radio metric data received by the DSN stations from the Galileo spacecraft using an Ultrastable Oscillator (USO) as a signal source. These results allow the health and performance of the Galileo USO to be evaluated, and are used to calibrate this Radio Science instrument and the data acquired for Radio Science experiments such as the Red-shift Observation, Solar Conjunction, and Jovian occultations. Estimates for the USO-referenced spacecraft-transmitted frequency and frequency stability were made for 82 data acquisition passes conducted between launch (October 1989) and November 1991. Analyses of the spacecraft-transmitted frequencies show that the USO is behaving as expected. The USO was powered off and then back on in August 1991 with no adverse effect on its performance. The frequency stabilities measured by Allan deviation are consistent with expected values due to thermal wideband noise and the USO itself at the appropriate time intervals. The Galileo USO appears to be healthy and functioning normally in a reasonable manner.

The flight performance of the Galileo orbiter USO

NASA Technical Reports Server (NTRS)

Morabito, D. D.; Krisher, T. P.; Asmar, S. W.

1993-01-01

Results are presented in this article from an analysis of radio metric data received by the DSN stations from the Galileo spacecraft using an Ultrastable Oscillator (USO) as a signal source. These results allow the health and performance of the Galileo USO to be evaluated, and are used to calibrate this Radio Science instrument and the data acquired for Radio Science experiments such as the Redshift Observation, Solar Conjunction, and Jovian occultations. Estimates for the USO-referenced, spacecraft-transmitted frequency and frequency stability were made for 82 data acquisition passes conducted between launch (Oct. 1989) and Nov. 1991. Analyses of the spacecraft-transmitted frequencies show that the USO is behaving as expected. The USO was powered off and then back on in Aug. 1991 with no adverse effect on its performance. The frequency stabilities measured by Allan deviation are consistent with expected values due to thermal wideband noise and the USO itself at the appropriate time intervals. The Galileo USO appears to be healthy and functioning normally in a reasonable manner.

Education Through Aerospace Components. (Spanish Title: Educación Através de Elementos Aeroespaciales.) Educação Através de Elementos Aeroespaciais

NASA Astrophysics Data System (ADS)

Barbosa Loureda, Oswaldo; Sobral de Araújo, Jéssyca B.

2008-12-01

Education is a field that needs development. For such purposes, there are various methods and tools that suggest ideas in favor of the improvement of the Brazilian people in the pedagogical, psychological and cultural aspects. Teaching is an act that demands a lot of care and responsibility; the behavior and performance of an individual in the society is the result of way that people was educated. However, the area of hard sciences demands a special attention, because the acquired knowledge is essential for the personal development of the individual and the technological future of the country. As an alternative or complementary tool for education it is suggested the use of aerospace element, since they show a vast amount of subjects qualitatively dealing with abilities of great importance for the future professional life of the students. A new Race happens, however this time the goal is not the Moon, but knowledge. El área educacional es un campo que necesita desarrollo. Para esto se dispone de diversos métodos y medios que pueden implantar ideas en pro del avance del pueblo brasilero en los aspectos pedagógicos, psicológicos y culturales. Alfabetizar es un acto que exige mucho cuidado y responsabilidad; el comportamento y desempeño de un individuo en la sociedad es el resultado de la manera en que fue educado. En particular, el área de ciencias exactas exige especial atención, pues los conocimientos adquiridos son imprescindibles para el desarrollo personal del individuo y también para el futuro tecnológico del País. Como medio alternativo o complementar de enseñanza se sugiere el uso de elementos aeroespaciales, debido a que compreende una vasta cantidad de disciplinas cualitativamente involucradas en la adquisición de habilidades de gran importancia para su vida profesional futura. Una nueva Carrera está em marcha, sin embargo esta vez la meta no es la Luna, sino el conocimiento. A área educacional é um campo que necessita de desenvolvimento. Para tal, dispõe-se de diversos métodos e meios que vêm implantar idéias em prol do avanço do povo brasileiro nos aspectos pedagógicos, psicológicos e culturais. Alfabetizar é um ato que exige muito cuidado e responsabilidade; o comportamento e desempenho de um indivíduo na sociedade é resultado da maneira com que ele foi instruído. Contudo, a área de exatas exige especial atenção, pois os conhecimentos adquiridos são imprescindíveis para o desenvolvimento pessoal do individuo, assim como para o futuro tecnológico do País. Como meio alternativo ou complementar de ensino é sugerido o uso de elementos aeroespaciais, devido ao fato de comportar uma vasta quantidade e qualidade de disciplinas envolvidas respectivamente com competências de grande importância para sua vida profissional futura. Uma nova Corrida acontece, porém dessa vez a meta não é a Lua e sim o conhecimento.

Medicinal ethnobotany in Huacareta (Chuquisaca, Bolivia)

PubMed Central

2012-01-01

Background The aim of this study was to document the types of diseases treated by the use of medicinal plants, their main applications and also to have a report of the major diseases treated at the Hospital of San Pablo de Huacareta (Chuquisaca Bolivia). Methods We conducted semi-structured interviews on the use medicinal plants with 10 local informants, and categorized the kinds of diseases treated by traditional medicine. We obtained reports of cases treated at the Hospital of Huacareta in order to compare the use frequency of traditional medicine and allopathic medicine for the treatment of recurrent diseases in the area. Results Our survey identified 258 traditional medicine uses, spanning a total of 13 diseases categories and including 91 native and exotic plant species and one unidentified sample plant type. Gastrointestinal disorders (55%) were most frequently treated with medicinal plants, followed by afflictions of the musculoskeletal system (25%) and dermatological disorders (24%). Hospital information indicates that the most common diseases are acute respiratory infections (47%) and acute diarrheal diseases (37%). The herbal remedies were mostly used in the form of teas and decoctions. The informants used mainly native plant species, although exotic species has been introduced to the pharmacopoeia. Conclusions The treatment of gastrointestinal disorders is the primary objective of the medical ethnobotany of the inhabitants of Huacareta, while respiratory system diseases are mostly treated in the hospital. Looking at the data from the Hospital records we can infer that gastrointestinal disorders are among the most common diseases in the study area. For most respondents, traditional medicine is a reliable choice for the care of their illnesses. However, the preference of the population for either traditional medicine or allopathic medicine needs to be clarified in future comparative studies to obtain more convincing results. The results presented can be used as a base for subsequent work related to traditional medicine and its contribution to allopathic medicine in San Pablo de Huacareta. Resumen Introducción El objetivo del presente estudio fue documentar los tipos de enfermedades tratadas mediante el uso de plantas medicinales, sus aplicaciones principales y también tener un reporte de las enfermedades mayormente atendidas en el Hospital de San Pablo de Huacareta (Chuquisaca, Bolivia). Métodos Se realizaron encuestas semiestructuradas a 10 informantes locales anotando los usos atribuidos a sus plantas medicinales, se agruparon las plantas por categorías de enfermedades tratadas en la medicina tradicional. Se obtuvieron reportes de casos tratados en el Hospital de Huacareta para poder relacionar el tratamiento de enfermedades recurrentes en la zona entre la medicina tradicional y la medicina occidental. Resultados Se reportaron 91 especies nativas y exóticas, además de un espécimen indeterminado exótico que intervienen en un total de 258 aplicaciones medicinales, las cuales son empleadas en un total de 13 categorías de enfermedades. Los desórdenes gastrointestinales (55%) son mayormente tratados mediante plantas medicinales, seguidas de las afecciones al sistema esqueleto-muscular (25%) y enfermedades dermatológicas (24%). La información del Hospital indica que las enfermedades más frecuentes son Infecciones Respiratorias Agudas (47%) y Enfermedades Diarreicas Agudas (37%). Los remedios vegetales se emplean en forma de infusiones y cocciones principalmente. Se emplean mayormente plantas nativas, también se introdujo en la farmacopea médica el uso de plantas exóticas al lugar. Conclusiones El tratamiento de trastornos gastrointestinales constituye el objetivo primordial de la etnobotánica médica de los habitantes de Huacareta, las enfermedades del sistema respiratorio, son mayormente tratadas en el Hospital. Observando los datos del libro de consultas del Hospital, se puede inferir que los desórdenes gastrointestinales están entre las enfermedades más frecuentes en el área estudiada. Para la mayoría de los entrevistados, la medicina tradicional es una opción confiable para la atención de sus enfermedades. Sin embargo, la preferencia de los habitantes entre la medicina tradicional y la medicina alopática podría ser clarificada a partir de futuros estudios comparativos que permitan obtener resultados más convincentes. Los resultados expuestos pueden ser usados como una base de datos para posteriores trabajos relacionados a la medicina tradicional y su contribución con la medicina alopática en San Pablo de Huacareta. PMID:22856877

Evaluation of HLA-G 14-bp ins/del and +3142G>C polymorphisms with susceptibility to recurrent spontaneous abortion.

PubMed

Hashemi, Mohammad; Mokhtari, Mojgan; Khazaeian, Safura; Bahari, Gholamreza; Rezaei, Maryam; Nakhaee, Alireza; Taheri, Mohsen

2017-06-01

HLA-G is critically important for successful implantation during pregnancy. Increasing evidence supposed that HLA-G plays a key role in tolerance of the semi-allogeneic graft in pregnancy by inhibiting the cytotoxic functions of T and NK cells. The present study aimed to evaluate the impact of HLA-G rs1063320 (+3142G>C) and 14-bp insertion (ins)/deletion (del) polymorphisms on recurrent spontaneous abortion (RSA). Genomic DNA from 93 RSA patients and 93 normal fertile women was isolated using the salting out method. Genotyping of HLA-G +3142G>C and 14-bp ins/del variants was done by polymerase chain reaction restriction fragment length polymorphism (PCR-RFP) and PCR method, respectively. The HLA-G +3142G>C polymorphism increased the risk of RSA in codominant (OR = 2.39, 95%CI = 1.27-4.49, p = 0.010, GC vs GG; OR = 3.28, 95%CI = 1.16-9.72, p = 0.040, CC vs GG) and dominant (OR = 2.52, 95%CI = 1.37-4.64, p = 0.004, GC + CC vs GG) tested inheritance models. HLA-G rs1063320 C allele was associated with increased risk of RSA (OR = 1.84, 95%CI = 1.20-2.83, p = 0.007). The del/del genotype as well as del allele of 14-bp ins/del variant increased that risk of RSA (OR = 3.02, 95%CI = 1.23-7.41, p = 0.025 and OR = 1.65, 95%CI = 1.09-2.50, p = 0.022, respectively). In summary, our results showed that HLA-G gene polymorphisms significantly increased the risk of RSA in a sample of the Iranian population. Copyright © 2017. Published by Elsevier B.V.

Groundwater socio-ecology and governance: a review of institutions and policies in selected countries

NASA Astrophysics Data System (ADS)

Mukherji, Aditi; Shah, Tushaar

2005-03-01

Groundwater is crucial for the livelihoods and food security of millions of people, and yet, knowledge formation in the field of groundwater has remained asymmetrical. While, scientific knowledge in the discipline (hydrology and hydrogeology) has advanced remarkably, relatively little is known about the socio-economic impacts and institutions that govern groundwater use. This paper therefore has two objectives. The first is to provide a balanced view of the plus and the down side of groundwater use, especially in agriculture. In doing so, examples are drawn from countries such as India, Pakistan, Bangladesh, China, Spain and Mexico—all of which make very intensive use of groundwater. Second, institutions and policies that influence groundwater use are analyzed in order to understand how groundwater is governed in these countries and whether successful models of governance could be replicated elsewhere. Finally, the authors argue that there is a need for a paradigm shift in the way groundwater is presently perceived and managed—from management to governance mode. In this attempt, a number of instruments such as direct regulation, indirect policy levers, livelihood adaptation and people's participation will have to be deployed simultaneously in a quest for better governance. L'eau souterraine est cruciale pour la survie et la sécurité alimentaire de plusieurs millions de personnes mais cependant la foramtion en matière d'eaux souterraines reste asymmétrique. Alors que la connaissance scientifique dans la discipline (hydrologie et hydrogéologie) a avancée de manière remarquable, on connaît peu de choses sur les impacts socio-économiques et les institutions qui gouvernent l'utilisation des eaux souterraines. Cet article a par conséquent deux objectifs. Le premier est d'assurer un point de vue balancé entre le côté positif et le côté négatif de l'utilisation de l'eau souterraine, spécialement en agriculture. De cette manière, des exemples d'utilisation intensive des eaux souterraines sont présentés, provenant de pays tels que l'Inde, le Pakistan, le Bangladesh, la Chîne, l'Espagne et le Mexique. En second lieu, les institutions et les politiques qui influencent l' utilisation de l'eau souterraine sont analysées de telle manière à comprendre comment l'eau souterraine est gérée dans ces pays et comment les modèles de gestion présentant un certain succès pourraient être répliqués ailleurs. Finalement, les auteurs arguent qu'il existe un besoin pour un changement de paradigme dans le sens où l'eau souterraine est actuellement perçue et gérée du mode administratif au mode gouvernemental. Dans cette démarche un certain nombre d'instruments comme la régulation directe, les leviers politiques indirectes, l'adaptation vitale et la participation populaire devront être déployées simultanément dans la quête d'une meilleure gestion. El agua subterránea es crítica para la subsistencia y para la salubridad de la comida de millones de personas. Sin embargo, la formación de conocimientos en el campo de aguas subterráneas ha permanecido asimétrico. Mientras que el concocimiento científico en la disciplina (hidrología e hidrogeología) ha avanzado increíblemente, se conoce relativemente poco sobre los impactos socio-económicos y las instituciones que controlan el uso del agua subterránea. Este artículotiene dos objetivos. El primero es presenter una visión balanceada de los aspectos positivos y negativos concernientes al uso de agua subterránea, especialmente en la agricultura. Con este objetivo se presentan ejemplos de la India, Pakistán, Bangladesh, China, España y México ya que todos estos países hacen uso intensivo del agua subterránea. El segundo objetivo es el análisis de las instituciones y políticas que influyen en el uso del agua subterránea con el fin de entender cómo se gobierna el agua subterránea en estos países y si los modelos exitosos que pueden ser replicados en otros lugares. Finalmente los autores proponen que existe la necesidad de cambiar el paradigma en lo referente a la percepción y al manejo del agua subterránea desde su administración hasta su gobierno. En este intento, con el objeto de alcanzar un mejor gobierno, se debe implementar un número de instrumentos simultáneamente i.e la regulación directa, la política indirecta, la adaptación de las actividades de subsistencia y la participación de los usarios.

Sviluppi di Ricevitori E di Componentistica Per Banda 3 mm Ad INAF-OA Cagliari

NASA Astrophysics Data System (ADS)

Navarrini, Alessandro

2017-11-01

L'INAF-OA Cagliari (OACa) sta sviluppando un ricevitore criogenico a basso rumore basato su un mixer SSB (Single Side Band) a superconduttore SIS (Superconductor-Insulator-Superconductor) per la banda 3 mm. Il ricevitore, acquistato da IRAM, è stato fortemente modificato per essere adattato al fuoco Gregoriano di SRT (Sardinia Radio Telescope). Lo strumento è caratterizzato da una nuova criogenia a ciclo chiuso 4 K (per evitare l'uso di elio liquido in antenna), da un nuovo oscillatore locale (di tipo ALMA Banda 3) e da un nuovo sistema di controllo e di monitoraggio basato su schede Raspberry ed Arduino sviluppato ad OACa. Verranno presentati i recenti sviluppi sul ricevitore, inclusi i risultati preliminari della misura della temperatura di rumore, che raggiunge un valore pari a Trec=66 K alla frequenza di 86 GHz, nonostante la criogenia non sia ancora ottimizzata. L'INAF-OACa è coinvolto nel progetto AETHRA (Advanced European Technologies for Heterodyne Receivers for Astronomy) nel quadro del programma Radionet/Horizon2020 per il quale sta contribuendo al WP1 (Work Package 1). Lo scopo del WP1 è di sviluppare e costruire un dimostratore di un array di ricevitori a doppia polarizzazione per la banda 3 mm basato su amplificatori criogenici a basso rumore (LNA) in tecnologia a semiconduttore MMIC. Nell'ambito del WP1 l'OACa ha in carico il progetto di un OrthomodeTransducer (OMT) in guida d'onda o in tecnologia planare per la banda 72-116 GHz che sia integrabile con amplificatori MMICs ed adatto all'integrazione in un array da installare nel piano focale di un radiotelescopio. Verranno presentati i design preliminari degli OMT per AETHRA, che sono basati su prototipi sviluppati in passato da OACa.

Measurements of Ultra-Stable Oscillator (USO) Allan Deviations in Space

NASA Technical Reports Server (NTRS)

Enzer, Daphna G.; Klipstein, William M.; Wang, Rabi T.; Dunn, Charles E.

2013-01-01

Researchers have used data from the GRAIL mission to the Moon to make the first in-flight verification of ultra-stable oscillators (USOs) with Allan deviation below 10 13 for 1-to-100-second averaging times. USOs are flown in space to provide stable timing and/or navigation signals for a variety of different science and programmatic missions. The Gravity Recovery and Interior Laboratory (GRAIL) mission is flying twin spacecraft, each with its own USO and with a Ka-band crosslink used to measure range fluctuations. Data from this crosslink can be combined in such a way as to give the relative time offsets of the two spacecrafts USOs and to calculate the Allan deviation to describe the USOs combined performance while orbiting the Moon. Researchers find the first direct in-space Allan deviations below 10(exp -13) for 1-to-100-second averaging times comparable to pre-launch data, and better than measurements from ground tracking of an X-band carrier coherent with the USO. Fluctuations in Earth s atmosphere limit measurement performance in direct-to-Earth links. Inflight USO performance verification was also performed for GRAIL s parent mission, the Gravity Recovery and Climate Experiment (GRACE), using both Kband and Ka-band crosslinks.

Survey of Foreign Systems for Incineration and Energy Recovery.

DTIC Science & Technology

1983-04-01

grab * Carga del incinerador con cuchara de mandibulas A* Capacite 1 000 kg/h, implants. en ploins nature e Capacity 1 000 kg/h erected in the country...North Valley Road Xenia, Ohio N62583-82-MT- 150 L Approved for public release; distribution unlimited 88 04 29 042 1966 .I a .r I Air ~~ Y In~ 77- 7 77...selected for field visits DD ,’ 0,, 1473 LOIko oe uoecUnclass ifi ed SICuRITY CLAS~riCAtION OF Y .41S PAQL (*%.A Per& E01,e,.E . . ,.- -. CONTENTS

Estudio de la estructura logica utilizada en la ensenanza y el aprendizaje de los conceptos sobre el comportamiento de gases en el curso introductorio de quimica a nivel universitario

NASA Astrophysics Data System (ADS)

Costa Diaz, Agnes

El estudio que se presenta es de caracter cualitativo, un estudio multicasos donde se estudia la estructura logica utilizada por cuatro (4) profesores universitarios que ensenan el curso introductorio de quimica, en la planificacion, presentacion y evaluacion del tema sobre el comportamiento de los gases. Se utilizaron varias fuentes de informacion como: cuestionarios de profesores y estudiantes, entrevistas, grabaciones videomagnetofonicas, materiales didacticos y una prueba conceptual, entre otros. La informacion recopilada fue analizada de acuerdo al orden logico del contenido presentado, el estilo de ensenanza del profesor, las tecnicas y estrategias utilizadas para el desarrollo de destrezas de pensamiento, el ambiente fisico en el salon de clase y los instrumentos de evaluacion y avaluo. El estudio demuestra que lo que los profesores piensan y planifican para hacer sus presentaciones no necesariamente es lo que ocurre en el salon de clases. El desarrollo de destrezas de pensamiento, que constituye una prioridad de los profesores, no se elaboran efectivamente. El uso de las estrategias de resolucion de problemas numericos predomino. La participacion del estudiante en el salon de clases fue limitada y no se logro demostrar el desarrollo de las destrezas de pensamiento deseadas. Aunque los profesores tienen su propio estilo de ensenanza, el orden logico del contenido presentado en clase fue el mismo o siguio muy de cerca el orden establecido por el libro de texto. Los profesores utilizaron preferentemente la tiza y la pizarra para sus presentaciones y la dinamica en el salon de clases fue esencialmente tradicional. Los profesores hicieron su presentacion y los estudiantes copiaron pasivamente la informacion. Las evaluaciones de los estudiantes fueron esencialmente, pruebas escritas de seleccion multiple de acuerdo con el estilo en que se les enseno. El avaluo fue casi inexistente. La prueba conceptual administrada revela un aprendizaje pobre en los conceptos mas basicos sobre el comportamiento de los gases. El estudio senala que la ejecutoria del profesor en todos los aspectos de la ensenanza y el aprendizaje es un factor clave que debe darsele prioridad. Se recomienda que el profesor, en general, tenga un conocimiento basico de las teorias de aprendizaje, de los factores que afectan el aprendizaje y las tecnicas y estrategias mas efectivas en el desarrollo de destrezas de pensamiento entre sus estudiantes. La estructura de la disciplina debe incluir tanto lo experimental como lo teorico.

Analisis de Alteraciones EN la Imagen Debidas a Descolimacion de un Telescopio

NASA Astrophysics Data System (ADS)

Cobos, F. J.; Galan, M. J.

1987-05-01

Podemos considerar, en términos generales, que los espejos de un telescopio tienen una calidad óptica intrínseca, entendiendo por ésta la que se ha obtenido como resultado, fundamentalmente, de la destreza del personal del Taller Optico, que considerará terminadas las superficies ópticas cuando éstas satisfagan los requisitos de diseño y las pruebas de evaluación pertinentes. Debemos esperar que, una vez instalados los espejos en el telescopio, no se altere esta calidad de la óptica por un funcionamiento inadecuado de partes mecánicas del mismo. En los últimos años, en la medida que los problemas de infraestructuratura de nuestros Observatorios se han ido resolviendo, se ha hecho más patente la necesidad de llevar a la instrumentación existente al máximo de su potencial y parte esencial de ésta la conforman los mismos te lescopios. Mejorar la calidad óptica de las imágenes obtenidas con ellos ha hecho que sea prioritario el realizar una investigación más sistemática de sus características. Este trabajo ha tenido como objetivo primordial el usar un programa de diseño óptico, en el caso particular del telescopio UNAM212, con el fin de calcular y obtener gráficamente los diagramas de manchas de imagenes en foco y extrafocales, tanto con la óptica perfectamente alineada como descolimándola (mediante pequenos giros y descentramientos de los espejos). De esta manera, se hizo una evaluación de los efectos que estas alteraciones simuladas producirían en las imágenes focales y extra focales para así poder compararlas con las que realmente se han observado. Asimismo, se ha buscado información bibliográfica, en particular sobre los efectos de giros y descentramientos en las imágenes extrafocales, en lo que se ref iere a la falta de concentricidad de los círculos que forman la "dona" y a la distribución de intensidad luminosa en la misma. De ésta, l futuro un proceso que, haciendo uso de los detectores bidimensionales, nos permita Ilevar a cabo una alineación más rigurosa de la óptica del telescopio y evaluar con precisión Si variaciones en el posicionado del misesperamos desarrollar en emo producen efectos de descolimación.

Translation and cross-cultural adaptation of the Clinical Competence Questionnaire for use in Brazil.

PubMed

Kwiatkoski, Danielle Ritter; Mantovani, Maria de Fátima; Pereira, Evani Marques; Bortolato-Major, Carina; Mattei, Ângela Taís; Peres, Aida Maris

2017-06-05

translating and transculturally adapting the Clinical Competence Questionnaire to Brazilian senior undergraduate Nursing students, as well as measuring psychometric properties of the questionnaire. a methodological study carried out in six steps: translation of the Clinical Competence Questionnaire instrument, consensus of the translations, back-translation, analysis by an expert committee, pre-testing and then presentation of the cross-cultural adaptation process to the developers. Psychometric properties were measured using Cronbach's alpha, intraclass correlation coefficient and content validity index. the instrument was translated, transculturally adapted and its final version consisted of 48 items. Cronbach's alpha coefficient was 0.90, and the agreement index of the items was 99% for students and 98% for evaluators. the Clinical Competence Questionnaire was translated and adapted to Brazilian students, and the psychometric properties of the Portuguese version of the questionnaire presented satisfactory internal consistency regarding the studied sample. traduzir e adaptar transculturalmente o Clinical Competence Questionnaire aos estudantes brasileiros concluintes da graduação em enfermagem, bem como mensurar as propriedades psicométricas do questionário. estudo metodológico realizado em seis etapas: tradução do instrumento Clinical Competence Questionnaire, consenso das traduções, retrotradução, análise pelo comitê de especialistas, pré-teste e apresentação do processo de adaptação transcultural para os desenvolvedores. As propriedades psicométricas foram mensuradas utilizando-se o alfa de Cronbach, coeficiente de correlação intraclasse e índice de validade de conteúdo. o instrumento foi traduzido, adaptado transculturalmente e sua versão final foi constituída de 48 itens. O coeficiente alfa de Cronbach foi de 0,90, e o índice de concordância dos itens foi de 99% para os estudantes e de 98% para os avaliadores. o Clinical Competence Questionnaire foi traduzido e adaptado a estudantes brasileiros, e as propriedades psicométricas da versão em português do questionário apresentaram consistência interna satisfatória quanto à amostra estudada. traducir y adaptar transculturalmente el Clinical Competence Questionnaire para uso de los estudiantes brasileños que concluyen la graduación en enfermería, así como para medir las propiedades psicométricas del cuestionario. estudio metodológico realizado en seis etapas: traducción del instrumento Clinical Competence Questionnaire, obtención de consenso de las traducciones, retrotraducción, análisis por el comité de especialistas, pretest y presentación del proceso de adaptación transcultural para los desarrolladores. Las propiedades psicométricas fueron medidas utilizando el alfa de Cronbach, coeficiente de correlación intraclase e índice de validez de contenido. el instrumento fue traducido, adaptado transculturalmente y su versión final estuvo constituida por 48 ítems. El coeficiente alfa de Cronbach fue de 0,90; el índice de concordancia de los ítems fue de 99% para los estudiantes y de 98% para los evaluadores. el Clinical Competence Questionnaire fue traducido y adaptado para uso de estudiantes brasileños; las propiedades psicométricas, de la versión en portugués del cuestionario, presentaron consistencia interna satisfactoria encontrada en la muestra estudiada.

Effects of the application of therapeutic massage in children with cancer: a systematic review.

PubMed

Rodríguez-Mansilla, Juan; González-Sánchez, Blanca; Torres-Piles, Silvia; Martín, Jorge Guerrero; Jiménez-Palomares, María; Bellino, Macarena Núñez

2017-06-08

to learn about the effects of the use of therapeutic massage in children with cancer. systematic review of controlled clinical trials The search was conducted in November 2014 in the following databases: Pubmed, CSIC, Dialnet, Scopus, Cochrane and PEDro. Inclusion criteria were: clinical trials, published in English or Spanish, analyzing the effects of massage on the different stages and types of childhood cancer (between 1 and 18 years old). of 1007 articles found, 7 met the inclusion criteria. Their authors use different massage techniques (Swedish massage, effleurage, petrissage, frictions, pressures), obtaining benefits in the symptoms present during the illness (decrease of pain, nausea, stress, anxiety and increase of white blood cells and neutrophils). therapeutic massage improves the symptoms of children with cancer, but there is a need for more research that may support the effects attributed to it. conocer los efectos del uso del masaje terapéutico en niños con cáncer. revisión sistemática de ensayos clínicos controlados la búsqueda se llevó a cabo en noviembre de 2014 en las bases de datos científicas: Pubmed, CSIC, Dialnet, Scopus, Cochrane y PEDro. Los criterios de inclusión han sido: ensayos clínicos, publicados en inglés o español, en los que se analizaran los efectos del masaje en las diferentes etapas y tipos de cáncer infantil (entre 1 y 18 años). de 1007 artículos localizados, 7 cumplieron los criterios de inclusión. Sus autores utilizan diferentes técnicas de masaje (masaje sueco, effleurage, petrissage, fricciones, presiones), obteniendo beneficios en los síntomas presentes durante la enfermedad (disminución del dolor, náuseas, estrés, ansiedad y aumento de glóbulos blancos y neutrófilos). el masaje terapéutico mejora los síntomas de los niños con cáncer, que respalden los efectos que se le atribuyen. conhecer os efeitos do uso da massagem terapêutica em crianças com câncer. revisão sistemática de ensaios clínicos controlados. A pesquisa foi realizada em novembro de 2014 em bases de dados científicas: Pubmed, CSIC, Dialnet, Scopus, Cochrane and PEDro. Os critérios de inclusão foram: ensaios clínicos, publicados em inglês ou espanhol, analisando os efeitos da massagem nas diferentes fases e tipos de câncer infantil (entre 1 e 18 anos). de 1007 artigos encontrados, 7 preencheram os critérios de inclusão. Os autores utilizam diferentes técnicas de massagem (massagem sueca, effleurage, petrissage, fricções, pressões), obtendo benefícios nos sintomas presentes durante a doença (diminuição da dor, náusea, estresse, ansiedade e aumento de glóbulos brancos e neutrófilos). a massagem terapêutica melhora os sintomas das crianças com câncer, mas são necessárias mais pesquisas que apoiem os efeitos atribuídos a ela.

Shallow-water habitats as sources of fallback foods for hominins.

PubMed

Wrangham, Richard; Cheney, Dorothy; Seyfarth, Robert; Sarmiento, Esteban

2009-12-01

Underground storage organs (USOs) have been proposed as critical fallback foods for early hominins in savanna, but there has been little discussion as to which habitats would have been important sources of USOs. USOs consumed by hominins could have included both underwater and underground storage organs, i.e., from both aquatic and terrestrial habitats. Shallow aquatic habitats tend to offer high plant growth rates, high USO densities, and relatively continuous USO availability throughout the year. Baboons in the Okavango delta use aquatic USOs as a fallback food, and aquatic or semiaquatic USOs support high-density human populations in various parts of the world. As expected given fossilization requisites, the African early- to mid-Pleistocene shows an association of Homo and Paranthropus fossils with shallow-water and flooded habitats where high densities of plant-bearing USOs are likely to have occurred. Given that early hominins in the tropics lived in relatively dry habitats, while others occupied temperate latitudes, ripe, fleshy fruits of the type preferred by African apes would not normally have been available year round. We therefore suggest that water-associated USOs were likely to have been key fallback foods, and that dry-season access to aquatic habitats would have been an important predictor of hominin home range quality. This study differs from traditional savanna chimpanzee models of hominin origins by proposing that access to aquatic habitats was a necessary condition for adaptation to savanna habitats. It also raises the possibility that harvesting efficiency in shallow water promoted adaptations for habitual bipedality in early hominins.

[Migration of a stent implanted in the pulmonary artery of a patient with tetralogy of Fallot].

PubMed

Palomero Rodríguez, M A; Gabaldón Rivilla, M; Cabestrero Alonso, D; Gonzalez Cibrián, C; Abelleira Pardeiro, C; Centella Hernánez, T; Collado Gutierrez, R; Asuero de Lis, M S; Gómez González, R

2014-05-01

Tetralogy of Fallot is a congenital heart disease that accounts for 11-13% of the congenital cardiomyopathies. Stenosis and hyperplasia of the pulmonary arteries occur in a high proportion of them as this disease causes a native stenosis of the pulmonary branch, which can be surgically repaired with a stent. The use of balloon expandable intravascular stents is an alternative technique to further surgery in patients with congenital heart diseases. However, despite the gradual increase in their use, the limited number of procedures, combined with the wide anatomical variability and different characteristics of these patients, even in expert hands, stent implants are associated with a not inconsiderable incidence of complications. These are not always obvious and often require performing surgery in patients who have already had multiple interventions, thus increasing the complexity and the risk. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Negative pressure of the environmental air in the cleaning area of the materials and sterilization center: a systematic review.

PubMed

Ciofi-Silva, Caroline Lopes; Hansen, Lisbeth Lima; Almeida, Alda Graciele Claudio Dos Santos; Kawagoe, Julia Yaeko; Padoveze, Maria Clara; Graziano, Kazuko Uchikawa

2016-09-01

to analyze the scientific evidence on aerosols generated during cleaning activities of health products in the Central Service Department (CSD) and the impact of the negative pressure of the ambient air in the cleaning area to control the dispersion of aerosols to adjacent areas. for this literature systematic review the following searches were done: search guidelines, manuals or national and international technical standards given by experts; search in the portal and databases PubMed, Scopus, CINAHL and Web of Science; and a manual search of scientific articles. the five technical documents reviewed recommend that the CSD cleaning area should have a negative differential ambient air pressure, but scientific articles on the impact of this intervention were not found. The four articles included talked about aerosols formed after the use of a ultrasonic cleaner (an increased in the contamination especially during use) and pressurized water jet (formation of smaller aerosols 5μm). In a study, the aerosols formed from contaminated the hot tap water with Legionella pneumophila were evaluated. there is evidence of aerosol formation during cleanup activities in CSD. Studies on occupational diseases of respiratory origin of workers who work in CSD should be performed. analisar as evidências científicas sobre aerossóis gerados durante atividades de limpeza dos produtos para saúde no Centro de Material e Esterilização (CME) e o impacto da pressão negativa do ar ambiente na área de limpeza para controle da dispersão de aerossóis para áreas adjacentes. para essa revisão sistemática de literatura foram realizadas: busca de diretrizes, manuais ou normas técnicas nacionais e internacionais indicadas por especialistas; busca no portal e bases de dados PUBMED, SCOPUS, Cinahl e Web of Science; e busca manual de artigos científicos. Os cinco documentos técnicos analisados preconizam que na área de limpeza do CME haja diferencial negativo de pressão do ar ambiente, porém não foram encontrados artigos científicos sobre o impacto dessa intervenção. Os quatro artigos incluídos trataram dos aerossóis formados após uso de lavadora ultrassônica (aumento da contaminação principalmente durante o uso) e do jato de água pressurizado (formação de aerossóis menores que 5µm). Em um estudo foram avaliados aerossóis formados a partir de torneira de água quente contaminada com Legionella pneumophila. há evidências sobre formação de aerossóis durante atividades de limpeza em CME. Estudos sobre doenças ocupacionais de origem respiratória dos trabalhadores que atuam em CME devem ser realizados. examinar la evidencia científica sobre los aerosoles generados durante las actividades de limpieza de productos de salud en el Centro de Materiales y Esterilización (CME) y el impacto de la presión negativa del aire ambiente en la zona de limpieza para controlar la dispersión de aerosoles a las zonas adyacentes. para esta revisión sistemática de literatura se llevaron a cabo: búsqueda de directrices, manuales o normas técnicas nacionales e internacionales impartidas por expertos; búsqueda en las bases de datos PUBMED, SCOPUS, Cinahl y Web of Science; y búsqueda manual de artículos científicos. Los cinco documentos técnicos analizados recomiendan que el área de limpieza del CME tenga un diferencial negativo de presión en el aire ambiente, aunque no se han encontrado artículos científicos sobre el impacto de esta intervención. Los cuatro artículos incluidos fueron sobre los aerosoles formados después del uso de la lavadora ultrasónica (aumento de la contaminación, especialmente durante el uso) y chorro de agua a presión (formación de aerosoles menores a 5µm). De esta forma, en un solo estudio se evaluaron los aerosoles formados a partir de un grifo de agua caliente contaminada con Legionella pneumophila. hay evidencia de formación de aerosoles durante las actividades de limpieza en CME. Sin embargo, es necesario realizar estudios sobre las enfermedades profesionales de origen respiratorio de los trabajadores que trabajan en CME.

Quality of life of patients using intermittent urinary catheterization.

PubMed

Fumincelli, Laís; Mazzo, Alessandra; Martins, José Carlos Amado; Henriques, Fernando Manuel Dias; Orlandin, Leonardo

2017-07-10

measure and compare the quality of life of neurogenic bladder patients using intermittent urinary catheterization who were going through rehabilitation in Brazil and Portugal. multicenter, quantitative, cross-sectional, observational-analytic and correlational study executed in Brazil and Portugal. Two data collection tools were used, being one questionnaire with sociodemographic and clinical data and the World Health Organization Quality of Life-bref. Patients were included who were over 18 years of age, suffering from neurogenic urinary bladder and using intermittent urinary catheterization. in the sample of Brazilian (n = 170) and Portuguese (n = 52) patients, respectively, most patients were single (87-51.2%; 25-48.1%), had finished primary education (47-45.3%; 31-59.6%) and were retired (70-41.2%; 21-40.4%). Spinal cord injury was the main cause of using the urinary catheter in both countries. The Brazilian patients presented higher mean quality of life scores in the psychological domain (68.9) and lower scores in the physical domain (58.9). The Portuguese patients presented higher scores in the psychological domain (68.4) and lower scores in the environment domain (59.4). The execution of intermittent urinary self-catheterization was significant for both countries. in the two countries, these patients' quality of life can be determined by the improvement in the urinary symptoms, independence, self-confidence, social relationships and access to work activities. mensurar e comparar a qualidade de vida de pacientes com bexiga neurogênica em uso do cateterismo urinário intermitente em processo de reabilitação, no Brasil e em Portugal. estudo multicêntrico, Brasil e Portugal, quantitativo, transversal, observacional-analítico e correlacional. Foram utilizados dois instrumentos de coleta, um questionário de dados sociodemográficos e clínicos e World Health Organization Quality Life-bref. Foram inclusos pacientes maiores de 18 anos, com bexiga urinária neurogênica, e usuários do cateterismo urinário intermitente. na amostra de pacientes brasileiros (n = 170) e portugueses (n = 52), respectivamente, a maioria era solteira (87-51,2%; 25-48,1%), com ensino fundamental (47-45,3%; 31-59,6%), aposentada (70-41,2%; 21-40,4%). A lesão medular foi a principal causa do uso do cateter urinário nos dois países. Os pacientes brasileiros apresentaram média de escores mais elevados de qualidade de vida no domínio psicológico (68,9) e menos elevados no domínio físico (58,9). Os pacientes portugueses apresentaram escores mais elevados no domínio psicológico (68,4) e menos no domínio ambiente (59,4). A realização do autocateterismo urinário intermitente foi significativa para os dois países. nos dois países, a qualidade de vida desses pacientes pode ser determinada pela melhora dos sintomas urinários, da independência, autoconfiança, relações sociais e acesso a atividades laborais. mensurar y comparar la calidad de vida de pacientes con vejiga neurogénica en uso de cateterismo vesical intermitente durante el proceso de rehabilitación en Brasil y en Portugal. estudio multicéntrico, Brasil y Portugal, cuantitativo, trasversal, observacional-analítico y correlacional. Fueron utilizados dos instrumentos de recolecta, un cuestionario de datos sociodemográficos y clínicos y el World Health Organization Quality Life-bref. Fueron inclusos pacientes mayores de 18 años, con vejiga urinaria neurogénica, y usuarios de cateterismo vesical intermitente. en la muestra de pacientes brasileños (n = 170) y portugueses (n = 52), respectivamente, la mayoría era soltera (87-51,2%; 25-48,1%), con educación fundamental (47-45,3%; 31-59,6%), jubilada (70-41,2%; 21-40,4%). La lesión medular fue la principal causa del uso del catéter urinario en los dos países. En promedio, los pacientes brasileños presentaron scores de calidad de vida superiores en el dominio psicológico (68,9) e inferiores en el dominio físico (58,9). Los pacientes portugueses presentaron scores superiores en el dominio psicológico (68,4) y inferiores en el dominio ambiente (59,4). La ejecución del autocateterismo vesical intermitente fue significativa para los dos países. en los dos países, la calidad de vida de esos pacientes puede ser determinada por la mejora de los síntomas urinarios, de la independencia, autoconfianza, relaciones sociales y acceso a actividades laborales.

Advice given to women in Argentina about breast-feeding and the use of alcohol

PubMed Central

Pepino, M. Yanina; Mennella, Julie A.

2006-01-01

Objective To explore the types of advice that women in Argentina received from health professionals, family members, and friends about drinking alcoholic beverages and about alcohol usage during pregnancy and lactation. Methods In December 2001 and December 2002, structured interviews were conducted with a total of 167 women who were then breast-feeding or who had recently breast-fed their infant. Mothers were asked about the type of advice, if any, that they had received about the use of alcohol from health professionals and from family members and friends. Also included were questions related to the usage of the traditional Argentine beverage “mate” (an infusion widely consumed in South America that is prepared from the leaves of the Ilex paraguayensis plant) and the types of advice the women had received about breast-feeding and neonatal care in general. Results Of the 167 women studied, 96.4% of them reported that their physician had advised them to breast-feed their infant. In addition, 93.4% of the women said they had treated their infant’s umbilical cord stump with alcohol. Fewer than half of the women (46.7%) reported that their physician had advised them about drinking alcoholic beverages during pregnancy, and even fewer (25.7%) received such advice during lactation. Family and friends were about equally likely to give advice about the consumption of alcoholic beverages during pregnancy (42.6%) and during lactation (47.9%). However, the type of advice changed, with the family and friends being significantly more likely to encourage drinking when the women were lactating than when they were pregnant (P < 0.001). Family members and friends also encouraged the drinking of mate to increase milk production. Conclusions As in other cultures, in Argentina the belief exists that alcohol enhances lactation. However, the majority of women whom we interviewed had not been counseled by their health professional about the consumption of alcoholic beverages during pregnancy and lactation. There is a need for professional development strategies that will address women’s awareness of the risks of alcohol consumption and alcohol usage. RESUMEN Objetivo Explorar el tipo de consejos que los profesionales de la salud, parientes y amigos le dieron a una muestra de mujeres en Argentina acerca del consumo de bebidas alcohólicas y el uso de alcohol durante el embarazo y la lactancia. Métodos En diciembre de 2001 y diciembre de 2002 se llevaron a cabo entrevistas estructuradas con un total de 167 mujeres que estaban amamantando o que habían amamantado recientemente. A las madres se les preguntó qué tipo de consejos, en caso de haberlos, les dieron los profesionales de la salud y sus parientes y amistades acerca del consumo de alcohol. También se plantearon preguntas sobre la bebida tradicional argentina, el mate —infusión muy popular en América del Sur que se prepara con las hojas de la planta Ilex paraguayensis— y la clase de consejos que recibieron las mujeres acerca de la lactancia materna y los cuidados neonatales en general. Resultados De las 167 mujeres estudiadas, 96,4% indicaron que el médico les había aconsejado que amamantaran a su hijo. Además, 93,4% afirmaron que habían frotado con alcohol el muñón umbilical del niño. Menos de la mitad de las mujeres (46,7%) indicaron haber recibido del médico asesoramiento acerca del consumo de bebidas alcohólicas durante el embarazo, y un porcentaje aun menor (25,7%) indicó haber recibido este tipo de asesoramiento durante la lactancia. Los parientes y amigos mostraron aproximadamente la misma propensión a aconsejar acerca del consumo de bebidas alcohólicas durante el embarazo (42,6%) y la lactancia (47,9%). No obstante, el tipo de consejo fue distinto en uno y otro caso, en el sentido de que los parientes y amigos mostraron una proclividad mayor (en grado estadísticamente significativo) a alentar a la mujer a consumir bebidas alcohólicas durante la lactancia que durante el embarazo (P < 0,001). Los parientes y amigos también alentaron el consumo de mate para estimular la producción de leche. Conclusiones Como en otros contextos culturales, en Argentina existe la creencia de que el alcohol mejora la lactancia. Sin embargo, la mayoría de las mujeres entrevistadas no habían recibido asesoramiento profesional acerca del consumo de bebidas alcohólicas durante el embarazo y la lactancia. Se necesitan estrategias profesionales orientadas a lograr que las mujeres cobren mayor conciencia de los riesgos asociados con el consumo y uso del alcohol. PMID:15673483

Genes del receptor variable beta de células T en células circulantes de pacientes con lupus eritematoso generalizado y sus familiares sanos.

PubMed

Jakez-Ocampo, Juan; Paulín-Vera, Carmen María; Rivadeneyra-Espinoza, Liliana; Gómez-Martín, Diana; Carrillo-Maravilla, Eduardo; Lima, Guadalupe; Vargas-Rojas, María Inés; Pérez-Romano, Beatriz; Calva-Cevenini, Gabriella; García-Carrasco, Mario; Ruiz-Argüelles, Alejandro; Llorente, Luis

Se investigó la proporción de la expresión génica del receptor variable beta de células T (Vβ TCR) en linfocitos periféricos CD3+ en pacientes con lupus eritematoso generalizado (LEG) familiar y no familiar. El repertorio de Vβ TCR se estudió en 14 familias que presentaban más de un miembro con LEG. El uso de Vβ TCR en pacientes con LEG (n = 27) se comparó con el de los miembros sanos de estas familias (n = 47), con 37 pacientes con LEG esporádico y con 15 controles sanos. La expresión del repertorio de Vβ TCR se estudió por citometría de flujo multiparamétrica utilizando un arreglo de 24 diferentes anticuerpos monoclonales específicos de genes familiares para Vβ TCR. Se encontró el mismo perfil de expresión en las comparaciones entre los casos de LEG esporádico y familiar, así como en los consanguíneos sanos de las familias multicasos, que incluía una expresión incrementada de Vβ 5.2, Vβ 11 y Vβ 16, y una menor expresión de Vβ 3, Vβ4, Vβ 7.1 y Vβ 7. De manera interesante, solo Vβ 17 se expresó de modo diferente entre casos familiares y esporádicos de LEG. Igualmente, la expresión incrementada de Vβ 9 fue el distintivo entre los casos de LEG familiar (casos y consanguíneos sanos) y los controles sanos. Estos resultados refuerzan la noción de que el perfil final del repertorio Vβ TCR observado en LEG familiar y no familiar parece surgir de la interacción de factores genéticos, ambientales e inmunorreguladores, además de que pueden explicar las alteraciones inmunitarias que se observan en los consanguíneos sanos de pacientes con LEG. Copyright: © 2018 SecretarÍa de Salud

Analysis of South Atlantic Anomaly perturbations on Sentinel-3A Ultra Stable Oscillator. Impact on DORIS phase measurement and DORIS station positioning

NASA Astrophysics Data System (ADS)

Jalabert, Eva; Mercier, Flavien

2018-07-01

DORIS measurements rely on the precise knowledge of the embedded oscillator which is called the Ultra Stable Oscillator (DORIS USO). The important radiations in the South Atlantic Anomaly (SAA) perturb the USO behavior by causing rapid frequency variations when the satellite is flying through the SAA. These variations are not taken into account in standard DORIS processing, since the USO is modelled as a third degree polynomial over 7-10 days. Therefore, there are systematic measurements errors when the satellite passes through SAA. In standard GNSS processing, the clock is directly estimated at each epoch. On Sentinel-3A, the GPS receiver and the DORIS receiver use the same USO. It is thus possible to estimate the behavior of the USO using GPS measurements. This estimated USO behavior can be used in the DORIS processing, instead of the third degree polynomial, hence allowing an estimation of the orbit sensitivity to these USO anomalies. This study shows two main results. First, the SAA effect on the DORIS USO is observed well using GPS measurements. Second, the USO behavior observed with GPS can be used to mitigate the SAA effect. Indeed, when used in Sentinel-3A processing, the resulting DORIS orbit shows improved phase measurements and station positioning for stations inside the SAA (Arequipa and Cachoeira). The phase measurements residuals are improved by up to 10 cm, and station vertical positioning (i.e. on the estimated Up component in the North-East-Up station frame) is improved by up to a few centimeters. However, the orbit itself is not sensitive to the correction because only two stations (out of almost 60) are SAA-sensitive on Sentinel-3A.

Urbanization and the groundwater budget, metropolitan Seoul area, Korea

NASA Astrophysics Data System (ADS)

Kim, Yoon-Young; Lee, Kang-Kun; Sung, Ig Hwan

2001-07-01

The city of Seoul is home to more than 10 million people in an area of 605 km2. Groundwater is ed for public water supply and industrial use, and to drain underground facilities and construction sites. Though most tap water is supplied from the Han River, the quantity and quality of groundwater is of great concern to Seoul's citizens, because the use of groundwater for drinking water is continuously increasing. This study identifies the major factors affecting the urban water budget and quality of groundwater in the Seoul area and estimates the urban water budget. These factors include leakage from the municipal water-supply system and sewer systems, precipitation infiltration, water-level fluctuations of the Han River, the subway pumping system, and domestic pumping. The balance between groundwater recharge and discharge is near equilibrium. However, the quality of groundwater and ability to control contaminant fluxes are impeded by sewage infiltration, abandoned landfills, waste dumps, and abandoned wells. Résumé. La ville de Séoul possède une population de plus de 10 millions d'habitants, pour une superficie de 605 km2. Les eaux souterraines sont pompées pour l'eau potable et pour les usages industriels, ainsi que pour drainer les équipements souterrains et les sites en construction. Bien que l'essentiel de l'eau potable provienne de la rivière Han, la quantité et la qualité de l'eau souterraine présentent un grand intérêt pour les habitants de Séoul, parce qu'on utilise de plus en plus l'eau souterraine pour l'eau potable. Cette étude identifie les facteurs principaux qui affectent la qualité de l'eau souterraine dans la région de Séoul et fait l'estimation du bilan d'eau urbaine. Les principaux facteurs affectant le bilan d'eau urbaine et la qualité de l'eau souterraine sont les fuites du réseau d'adduction et du réseau d'égouts, l'infiltration des eaux de précipitation, les fluctuations du niveau de la rivière Han, le réseau de pompage du métro et les pompages privés. Le bilan entre la recharge de la nappe et sa décharge est proche de l'équilibre. Cependant, les infiltrations d'eaux usées, les décharges abandonnées, les décharges d'ordures et les puits abandonnés portent atteinte à la qualité de l'eau souterraine et à la capacité de contrôler les flux de contaminants. Resumen. La ciudad de Seúl tiene más de 10 millones de habitantes en un área de 605 km2. Se bombea aguas subterráneas para abastecimiento urbano y para usos industriales, así como para el drenaje de instalaciones subterráneas y de solares en construcción. Aunque la mayor parte del agua de boca procede del río Han, los ciudadanos de Seúl están muy concienciados por la cantidad y calidad de las aguas subterráneas, ya que su explotación para uso de boca está experimentando un continuo incremento. El presente estudio identifica los factores que más afectan a la calidad de las aguas subterráneas en el área de Seúl y hace una estimación del balance de agua en el territorio urbano. Entre los factores principales que afectan al balance y a la calidad de las aguas subterráneas, se incluye el lixiviado de la red municipal de suministro y de la red de alcantarillado, la infiltración de agua de lluvia, las fluctuaciones del nivel del río Han, el sistema de bombeo del metro y los bombeos domésticos. El balance entre la recarga y la descarga en el acuífero está próximo al equilibrio. Sin embargo, la calidad de las aguas subterráneas y la capacidad de controlar los flujos de contaminación están amenazadas por la infiltración de aguas residuales, vertederos abandonados, depósitos de residuos y pozos abanadonados.

Binge drinking: a pattern associated with a risk of problems of alcohol use among university students.

PubMed

Bedendo, André; Andrade, André Luiz Monezi; Opaleye, Emérita Sátiro; Noto, Ana Regina

2017-09-12

to evaluate problems associated with alcohol use among university students who reported binge drinking in comparison to students who consumed alcohol without binging. a cross-sectional study among university students (N=2,408) who accessed the website about alcohol use. Logistic and linear regression models were included in the statistical analyzes. alcohol use in the last three months was reported by 89.2% of university students; 51.6% reported binge drinking. Compared to students who did not binge drink, university students who presented this pattern were more likely to report all evaluated problems, among them: black out (aOR: 5.4); having academic problems (aOR: 3.4); acting impulsively and having regrets (aOR: 2.9); getting involved in fights (aOR: 2.6); drinking and driving (aOR: 2.6) and accepting a ride with someone who had drunk alcohol (aOR: 1.8). Students who binged also had higher scores on the Alcohol Use Disorders Identification Test (b=4.6; p<0.001), more negative consequences (b=1.0; p<0.001) and a reduced perception of the negativity of the consequences (b=-0.5; p<0.01). binge drinking was associated with an increase in the chances of manifesting problems related to alcohol use. The conclusions of this study cannot be generalized for all of the Brazilian population. avaliar problemas associados ao uso de álcool entre universitários que relataram binge drinking em comparação a estudantes que consumiram álcool sem binge drinking. estudo transversal entre universitários (N=2.408) que acessaram website sobre o uso de álcool. Nas análises estatísticas incluíram-se modelos de regressão logística e linear. o uso de álcool, nos últimos três meses, foi relatado por 89,2% dos universitários e 51,6% referiram uso binge. Comparados a estudantes que não praticaram binge, universitários que apresentaram esse padrão tiveram maior chance de relatar todos os problemas avaliados, entre eles: incapacidade de lembrar o que aconteceu (aOR:5,4); problemas acadêmicos (aOR:3,4); agir impulsivamente e se arrepender (aOR:2,9); envolver-se em brigas (aOR:2,6); dirigir após beber (aOR:2,6) e pegar carona com alguém que bebeu (aOR:1,8). Estudantes que consumiram álcool no padrão binge também apresentaram maior pontuação no Alcohol Use Disorders Identification Test (b=4,6; p<0,001), mais consequências negativas (b=1,0; p<0,001) e menos percepção da negatividade das consequências (b=-0,5; p<0,01). a prática de binge drinking esteve associada ao aumento das chances de manifestação de problemas relacionados ao uso de álcool. As conclusões deste estudo não podem ser reproduzidas para toda realidade brasileira. evaluar problemas asociados al uso de alcohol entre estudiantes universitarios que relataron binge drinking en comparación a estudiantes que consumieron alcohol sin binge drinking. estudio transversal entre estudiantes universitarios (N=2.408) que visitaron una página web sobre el uso de alcohol. En los análisis estadísticos, fueron incluidos modelos de regresión logística y linear. el uso de alcohol, en los últimos tres meses, fue relatado por 89,2% de los estudiantes universitarios, y entre ellos 51,6% relataron uso binge. En comparación a estudiantes universitarios que no practicaron binge, los estudiantes que presentaron ese estándar tuvieron una mayor oportunidad de relatar todos los problemas evaluados, entre ellos: incapacidad de recordar lo que sucedió (aOR:5,4); problemas académicos (aOR:3,4); actuar por impulso y arrepentirse (aOR:2,9); involucrarse en peleas (aOR:2,6); manejar después de beber (aOR:2,6) y compartieron viaje con alguien que bebió (aOR:1,8). Estudiantes que consumieron alcohol dentro del estándar binge también presentaron una mayor puntuación en el Alcohol Use Disorders Identification Test (b=4,6; p<0,001), más consecuencias negativas (b=1,0; p<0,001) y menor percepción de la negatividad de las consecuencias (b=-0,5; p<0,01). la práctica de binge drinking estuvo asociada al aumento de las oportunidades de manifestación de problemas relacionados al alcohol. Las conclusiones de este estudio no pueden ser adaptadas a toda la realidad brasileña.

[Linee guida italiane per il trattamento dell'alcolismo].

PubMed

Ceccanti, Mauro; Iannitelli, Angela; Fiore, Marco

2018-01-01

RIASSUNTO. L'Europa è la regione con il più forte consumo di alcol al mondo, con la più elevata percentuale di malattie totali e morti premature alcol-correlate. In Italia, questo fenomeno coinvolge circa il 13% della popolazione oltre i 18 anni e oltre il 25% dei pazienti ospedalizzati. Sfortunatamente, solo il 5% di questi pazienti vengono riconosciuti come persone affette da disturbo da uso di alcol (DUA). Una scarsa conoscenza della malattia, la mancanza di accesso alle cure e le poche risorse messe a disposizione nella gestione del problema sono tra le principali cause di ritardo nella diagnosi, alla fine con conseguenze cliniche molto più importanti e costose da gestire. Alla luce di ciò, abbiamo deciso di dedicare questo numero speciale della Rivista di psichiatria a una serie di articoli riguardanti le linee guida italiane per il trattamento della dipendenza da alcol. Realizzate in collaborazione con numerosi esperti e importanti società scientifiche italiane come il Centro di Riferimento Alcologico della Regione Lazio (CRARL), la Società Italiana Tossicodipendenze (SITD), la Società italiana per il Trattamento dell'Alcolismo e le sue Complicanze (SITAC), la Società Italiana Psichiatria delle Dipendenze (SIPDip), la Società Italiana Patologie da Dipendenza (SIPaD) e l'Istituto di Biologia Cellulare e Neurobiologia (IBCN-CNR), queste linee guida forniscono agli operatori una serie di raccomandazioni basate su prove di efficacia volte ad aumentare la conoscenza e un uso appropriato dei farmaci per le persone affette da DUA. Con la possibilità di un continuo aggiornamento, l'obiettivo principale di queste linee guida sarà quello di garantire l'omogeneità dei trattamenti e un incremento qualitativo nell'assistenza dei pazienti affetti da DUA, così da ridurre le conseguenze psicosociali e sulla salute pubblica di questa importante malattia psichiatrica.

Órbitas caóticas en satelites galácticos

NASA Astrophysics Data System (ADS)

Carpintero, D. D.; Muzzio, J. C.; Vergne, M. M.; Wachlin, F. C.

En trabajos anteriores investigamos las órbitas de estrellas que forman los satelites galácticos utilizando análisis de frecuencias. Su uso estaba plenamente justificado por su velocidad y la gran información que brinda, amén de haber dado resultados muy concordantes con los exponentes de Liapunov. Sin embargo, más recientemente, encontramos algunos problemas en la utilización del análisis de frecuencias en sistemas de referencia rotantes (como se utilizan para los satélites), por lo que en este trabajo rehicimos nuestras investigaciones previas utilizando exclusivamente exponentes de Liapunov. Algunas conclusiones anteriores se han confirmado, en tanto que otras deben modificarse. Además, los nuevos resultados muestran que las escalas de tiempo de los procesos caóticos en los satélites galácticos son comparables a, o más cortas que, las escalas de tiempo de otros procesos dinámicos característicos de estos objetos.

78 FR 31840 - Safety Zone; USO Patriotic Festival Air Show, Atlantic Ocean; Virginia Beach, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-28

...-AA00 Safety Zone; USO Patriotic Festival Air Show, Atlantic Ocean; Virginia Beach, VA AGENCY: Coast... provide for the safety of life on navigable waters during the USO Patriotic Festival Air Show. This action... Patriotic Festival Air Show, Atlantic Ocean; Virginia Beach, VA. (a) Regulated Area. The following area is a...

The legacy of care as reflexive learning.

PubMed

García, Marta Rodríguez; Moya, Jose Luis Medina

2016-06-14

to analyze whether the tutor's use of reflexive strategies encourages the students to reflect. The goal is to discover what type of strategies can help to achieve this and how tutors and students behave in the practical context. a qualitative and ethnographic focus was adopted. Twenty-seven students and 15 tutors from three health centers participated. The latter had received specific training on reflexive clinical tutoring. The analysis was developed through constant comparisons of the categories. the results demonstrate that the tutors' use of reflexive strategies such as didactic questioning, didactic empathy and pedagogical silence contributes to encourage the students' reflection and significant learning. reflexive practice is key to tutors' training and students' learning. analisar se o uso de estratégias reflexivas por parte da tutora de estágio clínico estimula a reflexão nos estudantes. A intenção é descobrir qual tipo de estratégias podem ajudar a fazê-lo e como as tutoras e os estudantes se comportam no contexto prático. foi adotado um enfoque qualitativo de cunho etnográfico em que participaram 27 estudantes e 15 tutores de três centros de saúde que haviam recebido formação específica sobre tutoria clínica reflexiva. A análise foi realizada por meio de comparações constantes das categorias. os resultados demonstram que o uso de estratégias reflexivas como a interrogação didática, a empatia didática e o silêncio pedagógico por parte das tutoras, contribui para fomentar a reflexão do estudante e sua aprendizagem significativa. a prática reflexiva é a chave para a formação dos tutores e para a aprendizagem dos estudantes. analizar si el uso de estrategias reflexivas por parte de la tutora de prácticas clínicas fomenta la reflexión en los estudiantes. Se trata de conocer qué tipo de estrategias pueden ayudar a hacerlo y cómo se comportan tutoras y estudiantes en el contexto práctico. se ha utilizado un enfoque cualitativo de corte etnográfico en el que participaron 27 estudiantes y 15 tutores de tres centros sanitarios que habían recibido formación específica sobre tutoría clínica reflexiva. El análisis se ha realizado mediante las comparaciones constantes de las categorías. los resultados demuestran que el uso de estrategias reflexivas como la interrogación didáctica, la empatía didáctica y el silencio pedagógico por parte de las tutoras contribuye a fomentar la reflexión del estudiante y su aprendizaje significativo. la práctica reflexiva es la clave para la formación de los tutores y para el aprendizaje de los estudiantes.

Clinical simulation with dramatization: gains perceived by students and health professionals.

PubMed

Negri, Elaine Cristina; Mazzo, Alessandra; Martins, José Carlos Amado; Pereira, Gerson Alves; Almeida, Rodrigo Guimarães Dos Santos; Pedersoli, César Eduardo

2017-08-03

to identify in the literature the gains health students and professionals perceive when using clinical simulation with dramatization resources. integrative literature review, using the method proposed by the Joanna Briggs Institute (JBI). A search was undertaken in the following databases: Latin American and Caribbean Health Sciences Literature, Web of Science, National Library of Medicine, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, Scopus, Scientific Electronic Library Online. 53 studies were analyzed, which complied with the established inclusion criteria. Among the different gains obtained, satisfaction, self-confidence, knowledge, empathy, realism, reduced level of anxiety, comfort, communication, motivation, capacity for reflection and critical thinking and teamwork stand out. the evidence demonstrates the great possibilities to use dramatization in the context of clinical simulation, with gains in the different health areas, as well as interprofessional gains. identificar na literatura quais os ganhos percebidos pelos estudantes e profissionais da área de saúde, utilizando-se da simulação clínica realizada com recursos da dramatização. revisão integrativa da literatura, com a metodologia proposta pelo Instituto Joanna Briggs (JBI), com busca nas bases de dados: Literatura Latino-Americana e do Caribe em Ciências da Saúde, Web of Science, National Library of Medicine, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, Scopus, Scientific Electronic Library Online. foram analisados 53 estudos, que atenderam os critérios de inclusão estabelecidos. Entre os diversos ganhos obtidos, destaca-se a satisfação, autoconfiança, conhecimento, empatia, realismo, diminuição do nível de ansiedade, conforto, comunicação, motivação, capacidade de reflexão e de pensamento crítico e trabalho em equipe. as evidências demonstram a ampla possibilidade de uso da dramatização no contexto de simulação clínica com ganhos nas diversas áreas de saúde e, também, interprofissionais. identificar en la literatura cuales los beneficios por los estudiantes y profesionales del área de salud, usándose la simulación clínica con recursos de dramatización. revisión integradora de la literatura, aplicándose la metodología propuesta por el Instituto Joanna Briggs (JBI), con búsqueda en las bases de datos: Literatura Latinoamericana y del Caribe en Ciencias de la Salud, Web of Science, National Library of Medicine, Cumulative Index to Nursing and Allied Health Literature, The Cochrane Library, Scopus, Scientific Electronic Library Online. fueron analizados 53 estudios, que cumplieron con los criterios de inclusión establecidos. Entre los diversos beneficios obtenidos, se destacan la satisfacción, autoconfianza, conocimiento, empatía, realismo, disminución del nivel de ansiedad, conforto, comunicación, motivación, capacidad de reflexión y de pensamiento crítico y trabajo en equipo. las evidencias demuestran la amplia posibilidad de uso de la dramatización en el contexto de simulación clínica con beneficios en las diversas áreas de salud, y también interprofesionales.

[Not Available].

PubMed

Germán Díaz, Marta; Moreno Villares, José Manuel; Gomis Muñoz, Pilar

2016-07-19

Introducción: la nutrición parenteral domiciliaria se ha convertido en un punto clave en el tratamiento de pacientes con fracaso intestinal crónico. A pesar de los importantes avances que se han producido en las últimas décadas, tanto en los accesos vasculares, como en las soluciones empleadas, las infecciones asociadas a catéter venoso central siguen constituyendo una de las complicaciones más importantes. Dentro de las estrategias para la prevención o el tratamiento de estas infecciones se encuentra el empleo de sellados con antisépticos, como el etanol o la taurolidina, o de antibióticos.Objetivo: el objetivo de este artículo es revisar la evidencia disponible sobre el empleo de sellados con antisépticos o antibióticos en el manejo de pacientes pediátricos con nutrición parenteral domiciliaria.Material y métodos: el uso de sellados con etanol o taurolidina para prevenir el desarrollo de infecciones asociadas a catéter central estaría indicado en pacientes con nutrición parenteral domiciliaria que hayan tenido más de una infección en el año anterior o que se consideren pacientes de riesgo. Los sellados con antibióticos están indicados en el tratamiento de bacteriemias asociadas a catéter central producidas por S. coagulasa-negativo o gramnegativos, asociados a un tratamiento sistémico, siempre que sea posible, con el fin de salvar el catéter. Se debería llevar a cabo la retirada del mismo cuando existan signos de infección del punto de entrada o del trayecto subcutáneo, o cuando el germen responsable de la infección sea S. aureus o Cándida.Conclusión: a pesar de que la fuerza de la evidencia sobre la eficacia del sellado en la prevención o el tratamiento de infecciones asociadas al catéter es limitada, tanto en el niño como en el adulto, cada vez existen más datos a usar esta alternativa en pacientes con nutrición parenteral domiciliaria en los que la atención y salvaguarda de los catéteres es primordial.

Costo- Efectividad Del Uso Profiláctico Del Factor Estimulante De Colonias De Granulocitos En Adultos Con Leucemia Linfoblástica Aguda en Colombia.

PubMed

Casadiego Rincón, Elkin Javier; Díaz Rojas, Jorge Augusto; Bermúdez, Carlos Daniel; Martínez, Víctor Prieto

2016-12-01

To assess the cost-effectiveness of prophylactic administration of Granulocyte Colony-Stimulating Factor (G-CSF) compared with no use of it, during the induction phase of chemotherapy in Adults with Acute Lymphoblastic Leukemia (ALL) in Colombia. A decision tree with a time horizon of 30 days was built under colombian health system perspective including only direct costs. The costs of procedures and medications were taken from official sources and an institution of national reference of oncology services. The safety and effectiveness data were taken from the literature and two Colombian cohorts with patients older than 15 years. The unit of outcome was the proportion of deaths avoided. Base-case results on a clinical trial indicate that using factor is a dominant strategy. The variable that most impacted the outcome was the incidence of febrile neutropenia. Considering a threshold of $22.228 USD in 80% of cases using factor was cost effective. However, the use of factor is not cost-effective for the country for incidences of febrile neutropenia > 48%. It was not possible to establish cost-effectiveness of pegfilgrastim because no information was found. As per Colombian data, the use of prophylactic factor under chemotherapeutic induction in adults with ALL, turns out to be not cost effective. The difference in the results suggests the need of a careful extrapolation of information from clinical trials (ideal world) for developing economic evaluations in Colombia. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Indicators to assess the quality of programs to prevent occupational risk for tuberculosis: are they feasible?

PubMed

Santos, Talita Raquel Dos; Padoveze, Maria Clara; Nichiata, Lúcia Yasuko Izumi; Takahashi, Renata Ferreira; Ciosak, Suely Itsuko; Gryschek, Anna Luiza de Fátima Pinho Lins

2016-06-07

to analyze the feasibility of quality indicators for evaluation of hospital programs for preventing occupational tuberculosis. a descriptive cross-sectional study. We tested indicators for evaluating occupational tuberculosis prevention programs in six hospitals. The criterion to define feasibility was the time spent to calculate the indicators. time spent to evaluate the indicators ranged from 2h 52min to 15h11min 24sec. The indicator for structure evaluation required less time; the longest time was spent on process indicators, including the observation of healthcare workers' practices in relation to the use of N95 masks. There was an hindrance to test one of the indicators for tuberculosis outcomes in five situations, due to the lack of use of tuberculin skin test in these facilities. The time requires to calculate indicators in regarding to the outcomes for occupational tuberculosis largely depends upon the level of organizational administrative structure for gathering data. indicators to evaluate the structure for occupational tuberculosis prevention are highly feasible. Nevertheless, the feasibility of indicators for process and outcome is limited due to relevant variations in administrative issues at healthcare facilities. analisar a viabilidade de indicadores de qualidade para avaliação de programas hospitalares de prevenção de tuberculose ocupacional. estudo descritivo transversal. Testaram-se indicadores de avaliação de programas de prevenção de tuberculose ocupacional em seis hospitais. O critério para definir a viabilidade foi o tempo necessário para aplicar os indicadores. o tempo necessário para avaliar os indicadores variou de 02'52'' até 15h11'24''. O indicador para a avaliação da estrutura demandou menor tempo; o maior tempo foi utilizado com os indicadores de processo, incluindo a observação das práticas dos trabalhadores de saúde em relação ao uso de máscaras N95. Um dos indicadores de resultados de tuberculose deixou de ser testado em cinco situações devido à falta de uso do teste tuberculínico nessas instituições. O tempo necessário para aplicar indicadores em relação aos resultados de tuberculose ocupacional depende em grande parte do nível da organização da estrutura administrativa para a coleta de dados. os indicadores de avaliação da estrutura de prevenção de tuberculose ocupacional são altamente viáveis. No entanto, a viabilidade de aplicação dos indicadores de processo e de resultado é limitada devido a variações relevantes em questões administrativas nas instituições de saúde. analizar la viabilidad de los indicadores de calidad de la evaluación de los programas hospitalarios para la prevención de la tuberculosis en el trabajo. estudio descriptivo transversal. Se probaron los indicadores dirigidos a evaluar los programas para la prevención de la tuberculosis laboral en seis hospitales. El criterio para definir la viabilidad fue el tiempo para aplicar los indicadores. el tiempo empleado para la evaluación de los los indicadores varió desde 02'52 '' hasta 15h11'24 ''. El indicador para la evaluación de la estructura requiere menos tiempo; se invirtió más tiempo en los indicadores de proceso, lo que incluye la observación de las prácticas de los empleados del cuidado de salud en relación con el uso de máscaras N95. No se pudo probar uno de los indicadores de resultados de tuberculosis en cinco situaciones debido a la falta de uso de la prueba de la tuberculina en estas centros. El tiempo necesario para aplicar los indicadores en relación con los resultados por tuberculosis laboral depende en gran medida del nivel de organización de la estructura administrativa para la recopilación de datos. los indicadores para evaluar la estructura para la prevención de la tuberculosis laboral son altamente factibles. Sin embargo, la viabilidad de aplicación de los indicadores de proceso y el resultado es limitada debido a las variaciones relevantes en cuestiones administrativas en los centros sanitarios.

Different Cultures in Astronomy Education and Their Meanings in the Classroom. (Spanish Title: Las Diferentes Culturas en la Educación en Astronomía y Sus Significados EN EL Aula. ) As Diferentes Culturas na Educação em Astronomia E Seus Significados em Sala de Aula

NASA Astrophysics Data System (ADS)

Pereira de Barros, Vicente; Bovolenta Ovigli, Daniel Fernando

2014-12-01

This paper is a reflection about the use of History of Science in the curriculum of formal education, through the discussion concerning cultural elements of several ethnic groups in Brazil, in actions related to astronomy education. The work was developed in the framework of an extension course and the analysis undertaken here refers to a meeting that discussed didactic sequences relating to that theme, based on the Brazilian law 11.645/2008, which states the obligation to present the subject "African-brazilian and indigenous History and Culture" in the official curriculum. The extension action was developed with teachers who teach Natural Sciences, in São Paulo state, discussing issues related to the use of History of Science and the relationship with cosmogonies from Iorubá and Tupi peoples, highlighting how they can enhance the work with Astronomy(ies) in the classroom. It was observed that the participants had not yet presented these themes in their classes and also did not participate in training courses that discussed these subjects. Este artículo presenta una reflexión sobre el uso de la historia de la ciencia en el currículo de la educación formal, a través de la discusión sobre el uso de los elementos culturales de los grupos étnicos en Brasil, en acciones relacionadas con la educación en astronomía. El trabajo se desarrolló en el marco de un curso de extensión y el análisis realizado aquí se refiere a un encuentro en el cual se abordaron secuencias didácticas relacionadas con ese tema, sobre la base de la ley brasilera 11.645/2008 que dispone la obligatoriedad del tema "Historia y Cultura africana e indígena en el Brasil" en el currículo oficial. La acción de extensión se desarrolló con los profesores de ciencias naturales en el interior del estado de São Paulo, discutiendo temas relacionados con el uso de la historia de la ciencia y la relación con las cosmogonías de los pueblos Iorubá y Tupi, que muestra cómo se puede mejorar el trabajo con Astronomía(s) en la clase. Se observó que los participantes todavía no habían presentado estos temas en sus clases y tampoco habían participado en cursos de formación que abordaran estos temas. O presente trabalho apresenta uma reflexão acerca da utilização da História da Ciência no currículo da educação formal, por meio da discussão relativa ao emprego de elementos culturais de grupos étnicos em ações voltadas à educação em Astronomia. O trabalho foi desenvolvido no âmbito de um curso de extensão e a análise aqui empreendida refere-se a um encontro que abordou sequências didáticas relativas àquele tema, com fundamento na lei 11.645/2008 e a obrigatoriedade de abordagem da temática "História e Cultura Afro-Brasileira e Indígena" no currículo oficial. A ação de extensão ocorreu junto a professores que ensinam Ciências da Natureza, no interior do estado de São Paulo, discutindo-se temas relativos ao uso de História da Ciência e o relacionamento com cosmogonias oriundas dos povos Iorubá e Tupi, evidenciando como podem enriquecer o trabalho com a(s) Astronomia(s) em sala de aula. Observou-se que os participantes ainda não haviam apresentado estes temas em suas aulas e, igualmente, não participaram de cursos de formação que contemplassem a referida temática.

Nursing care missed in patients at risk of or having pressure ulcers.

PubMed

Valles, Jonathan Hermayn Hernández; Monsiváis, María Guadalupe Moreno; Guzmán, Ma Guadalupe Interial; Arreola, Leticia Vázquez

2016-11-21

to determine the nursing care missed as perceived by the nursing staff and its relation with the nursing care missed identified in the assessment of patients at risk of or having pressur ulcers. descriptive correlation study. The participants were 161 nurses and 483 patients from a public hospital. The MISSCARE survey was used in combination with a Nursing Care Assessment Form for Patients at Risk of or having pressure ulcers. For the analysis, descriptive and inferential statistics were used. the nursing staff indicated greater omission in skin care (38.5%), position change (31.1%) and the registration of risk factors for the development of pressure ulcers (33.5%). The nursing care missed identified in the assessment related to the use of pressure relief on bony prominences and drainage tubes interfering in the patient's movements (both with 58.6%) and the use of pneumatic mattresses (57.6%). a high percentage of nursing care missed was found according to the staff's perception. Nevertheless, the assessment of the nursing care missed was much higher. No significant relation was found between both. Therefore, it is a priority to reflect on the importance of objective patient assessments. determinar o cuidado de enfermagem omitido percebido pela equipe de enfermagem e sua relação com o cuidado omitido identificado na avaliação de pacientes com risco ou com de úlceras por pressão. estudo descritivo correlacional. Participaram 161 enfermeiras e 483 pacientes de um hospital público. Foram utilizados o levantamento MISSCARE e um Formulário de Avaliação de Cuidados de Enfermagem em Pacientes com Risco ou com úlceras por pressão. Para a análise foi utilizada estatística descritiva e inferencial. a equipe de enfermagem assinalou que há maior omissão no cuidado da pele (38,5%), reposicionamento (31,1%) e no registro de fatores de risco para o aparecimento de úlceras por pressão (33,5%). Os cuidados de enfermagem omitidos identificados na avaliação foram o uso de redutor de pressão em proeminências ósseas e tubos de drenagem que interferem nos movimentos do paciente (ambos com 58,6%) e uso de colchões pneumáticos (57,6%). foi encontrada alta porcentagem de cuidado de enfermagem omitido na percepção da equipe. Porém, a avaliação do cuidado omitido foi muito superior. Não foi encontrada associação significativa entre ambos, priorizando reflexões sobre a importância de avaliações objetivas dos pacientes. determinar el cuidado de enfermería perdido percibido por el personal de enfermería y su relación con el cuidado perdido identificado en la valoración de pacientes con riesgo o con presencia de úlceras por presión. estudio descriptivo correlacional. Participaron 161 enfermeras y 483 pacientes de un hospital público. Se utilizó la encuesta MISSCARE y una Cédula de Valoración de Cuidados de Enfermería en Pacientes con Riesgo o con úlceras por presión. Para el análisis se utilizó estadística descriptiva e inferencial. el personal de enfermería señaló que existe mayor omisión en el cuidado de la piel (38.5%), cambio de posición (31.1%) y en el registro de factores de riesgo para la aparición de úlceras por presión (33.5%). Los cuidados de enfermería perdidos identificados en la valoración fueron uso de liberador de presión en prominencias óseas y tubos de drenaje que interfieren en movimientos del paciente (ambos con 58.6%) y uso de colchones neumáticos (57.6%). se encontró un alto porcentaje de cuidado de enfermería perdido de acuerdo a la percepción del personal, sin embargo, el cuidado perdido valorado fue mucho mayor. No se encontró relación significativa entre ambos por lo que es prioritario reflexionar acerca de la importancia de realizar valoraciones objetivas en los pacientes.

A Comparison of Ulnar Shortening Osteotomy Alone Versus Combined Arthroscopic Triangular Fibrocartilage Complex Debridement and Ulnar Shortening Osteotomy for Ulnar Impaction Syndrome

PubMed Central

Song, Hyun Seok

2011-01-01

Background This study compared the results of patients treated for ulnar impaction syndrome using an ulnar shortening osteotomy (USO) alone with those treated with combined arthroscopic debridement and USO. Methods The results of 27 wrists were reviewed retrospectively. They were divided into three groups: group A (USO alone, 10 cases), group B (combined arthroscopic debridement and USO, 9 cases), and group C (arthroscopic triangular fibrocartilage complex [TFCC] debridement alone, 8 cases). The wrist function was evaluated using the modified Mayo wrist score, disabilities of the arm, shoulder and hand (DASH) score and Chun and Palmer grading system. Results The modified Mayo wrist score in groups A, B, and C was 74.5 ± 8.9, 73.9 ± 11.6, and 61.3 ± 10.2, respectively (p < 0.05). The DASH score in groups A, B, and C was 15.6 ± 11.8, 19.3 ± 11.9, and 33.2 ± 8.5, respectively (p < 0.05). The average Chun and Palmer grading score in groups A and B was 85.7 ± 8.9 and 84.7 ± 6.7, respectively. The difference in the Mayo wrist score, DASH score and Chun and Palmer grading score between group A and B was not significant (p > 0.05). Conclusions Both USO alone and combined arthroscopic TFCC debridement with USO improved the wrist function and reduced the level of pain in the patients treated for ulnar impaction syndrome. USO alone may be the preferred method of treatment in patients if the torn flap of TFCC is not unstable. PMID:21909465

Enhancing the Art of Space Operations - Progress in JHU/APL Ultra-Stable Oscillator Capabilities

DTIC Science & Technology

2008-12-01

solution for robust extraterrestrial clocks with an operational life requirement greater than 10 years. Disciplined USO systems could be placed in very...USO) has been demonstrated in nearly 50 years of space applications to be a strategic asset to the space timekeeping and signal technologies of the...while also providing flight USO hardware to missions such as the NASA Gravity Recovery and Climate Experiment (GRACE) and JHU/APL’s New Horizons

Validation of Universal Scale in Oral Surgery (USOS) for Patient's Psycho-emotional Status Rating.

PubMed

Astramskaite, Inesa; Pinchasov, Ginnady; Gervickas, Albinas; Sakavicius, Dalius; Juodzbalys, Gintaras

2017-01-01

There aren't any objective methods that may help in standard evaluation of oral surgery patient's psycho-emotional status. Without any standardized evaluation, two main problems appear: heterogeneity between studies and ineffective patient's evaluation. Therefore, Universal Scale in Oral Surgery (USOS) for patient's psycho-emotional status rating has previously been proposed by authors. The aim of present study is to assess the clinical effectivity and validate the Universal Scale in Oral Surgery in case of outpatient tooth extraction for adult healthy patients. Clinical trial to validate the USOS for patient's psycho-emotional status rating was performed. In total 90 patients, that came for outpatient dental extraction to Lithuanian University of Health Sciences Oral and Maxillofacial Surgery Department ambulatory, were enrolled in clinical trial. Patients filled self-reported questionnaires before the procedure. Operating surgeon rated USOS for patient's psycho-emotional status rating doctor's part questionnaire after the procedure. 4 - 6 weeks later all patients were asked to fill USOS for patient's psycho-emotional status rating questionnaire retrospectively. According to the statistical analysis, the final composition of USOS for patient's psycho-emotional status rating that would fit to reliability coefficient should be composed from 6 patient part questions and 3 general doctor part questions. Universal Scale in Oral Surgery for patient's psycho-emotional status rating is a novel, doctor and patient rated scale which is suitable for clinical and scientific usage.

Oncologic and reproductive outcomes of cystectomy compared with oophorectomy as a treatment for borderline ovarian tumours.

PubMed

Song, Taejong; Hun Choi, Chel; Lee, Yoo-Young; Kim, Tae-Joong; Lee, Jeong-Won; Bae, Duk-Soo; Kim, Byoung-Gie

2011-08-01

The aim of this study was to compare the oncologic and reproductive outcomes of patients with borderline ovarian tumours (BOTs) who were treated with cystectomy or unilateral salpingo-oophorectomy (USO). The medical records of patients with BOTs who were treated between 1997 and 2009 were reviewed retrospectively. The recurrence rates were compared between the USO and cystectomy groups. The reproductive outcomes were assessed by telephone interviews. Patients with BOTs underwent a USO (n= 117) or cystectomy (n= 38). There were 12 patients who had recurrences: 1 patient had an invasive recurrence and 11 had borderline recurrences. The recurrence rate in the USO group (6.0%) was lower than in the cystectomy group (13.2%); however, this difference was not statistically significant (P= 0.110). All of the patients with recurrences were successfully treated with surgery and there was no clinical evidence of disease. Of the 116 patients contacted by telephone, 113 (97.4%) resumed menstruation following the surgery, and 45 of the 52 patients (86.5%) who attempted to conceive had successful pregnancies. USO (89.2%), like cystectomy (85.7%), resulted in excellent pregnancy rates for patients with BOTs. A USO is an appropriate treatment for women with BOTs who wish to preserve fertility. However, a cystectomy is a satisfactory fertility-sparing therapy when a cystectomy is the only surgical option.

Inversor Resonante de Tres Elementos L-LC con Caracteristica Cortocircuitable para Aplicaciones de Calentamiento por Induccion

NASA Astrophysics Data System (ADS)

Espi Huerta, Jose Miguel

Los generadores de calentamiento por induccion son puentes inversores con carga resonante, cuya mision es basicamente crear una corriente sinusoidal de gran amplitud sobre la "bobina de caldeo", que forma parte del tanque resonante. En el interior de esta bobina se introduce la pieza que se desea calentar. EI campo magnetico creado induce corrientes superficiales (corrientes de Foucault) sobre la pieza, que producen su calentamiento. Los tanques resonantes (tambien llamados osciladores) utilizados en la actualidad son el resonante serie y el resonante paralelo. Aunque ya desde hace algun tiempo se vienen construyendo generadores de alta potencia basados en estos dos osciladores, el exito nunca ha. sido completo en ninguno de los dos casos. Tal y como se explica en la introduccion de esta memoria, los puentes inversores utilizados deben operar sobre una carga inductiva (corriente retrasada) para evitar el fenomeno de la recuperacion inversa de sus diodos y la consiguiente ruptura de los transistores. De la restriccion topologica anterior se deduce que el generador paralelo debe conmutar a frecuencias inferiores a la resonancia, y el serie a frecuencias superiores. A esta restriccion topologica hay que unir otra que es exclusiva del calentamiento por induccion: La corriente por la bobina de caldeo debe ser sinusoidal. De no ser asi, resultaria imposible disponer toda la potencia de calentamiento sobre la pieza en el espesor requerido por la aplicacion. Como consecuencia, los inversores no pueden operar por debajo de la frecuencia de resonancia del oscilador, pues en ese caso se amplifican los armonicos de orden superior de la tension/corriente de entrada situados sobre la resonancia, con la consiguiente distorsion de la corriente de salida. La conjuncion de las dos restricciones anteriores obligan al inversor paralelo a funcionar a la frecuencia de resonancia del oscilador. Esto imposibilita un control por variacion de frecuencia, regulandose la potencia desde la seccion de entrada mediante un mayor o menor aporte de corriente al puente. Como consecuencia, la seccion de entrada del paralelo, ya de por si mas voluminosa que lao del serie por el uso de grandes componentes magneticos (bobinas de filtro o de "alisamiento"), result a tambien mas complicada y costosa debido a la necesidad de ser implementada mediante rectificador controlado. Ademas, la regulacion que ofrece el rectificador es pobre, dada su baja frecuencia de conmutacion. En cambio, el circuito serie puede funcionar por encima de la resonancia manteniendo una secuencia de conmutacion sin riesgos de recuperacion inversa y con una corriente de salida practicamente sinusoidal, lo que permite un control de la potencia por variacion de frecuencia. Puesto que la tarea de regulacion se realiza desde el puente inversor, la regulacion resulta mucho mas eficaz y la seccion de entrada se puede implementar mediante un simple rectificador no controlado y un condensador de filtro. (Abstract shortened by UMI.).

Trastornos mentales y consumo de drogas en la población víctima del conflicto armado en tres ciudades de Colombia.

PubMed

Castaño, Guillermo; Sierra, Gloria; Sánchez, Daniela; Torres, Yolanda; Salas, Carolina; Buitrago, Carolina

2018-05-01

Introducción. La violencia en sus diferentes modalidades incrementa el riesgo de trastornos mentales y de consumo de drogas.Objetivos. Estimar la prevalencia de los trastornos mentales, del uso y abuso de drogas, así como los factores asociados en víctimas de desplazamiento forzado en tres ciudades colombianas.Materiales y métodos. Se hizo un estudio de prevalencia en una muestra de 1.026 personas entre los 13 y los 65 años de edad, a quienes se entrevistó utilizando el instrumento Composite International Diagnostic Interview y el Alcohol Use Disorders Identification Test de la Organización Mundial de la Salud, así como un cuestionario sobre el consumo de drogas modificado a partir de la encuesta del Sistema Interamericano de Datos Uniformes sobre Drogas de la Comisión Interamericana para el Control del Abuso de Drogas de la Organización de Estados Americanos, y otro sobre aspectos relacionados con el desplazamiento forzado. El análisis se hizo mediante el programa estadístico SPSS™, versión 21.Resultados. La prevalencia de vida de los trastornos mentales fue la siguiente: fobia específica, 17,7 %; depresión mayor, 16,4 %; estrés postraumático, 9,9 %; trastorno oposicionista desafiante, 8,9 %; ansiedad por separación, 7,2 %; trastornos de conducta, 5,8 %, y déficit de atención, 5,6 %. La prevalencia de vida del consumo de alcohol fue de 68,7 %; de tabaco, 31,3 %, de marihuana, 11,2 %, de cocaína, 3,5 %, de basuco, 2,0 %, de inhalables, 2,3 %, y de medicamentos ansiolíticos sin receta, 2,5 %, en tanto que 0,7 % de los entrevistados se había inyectado drogas. El presentar cualquiera de los trastornos mentales se asoció con el sexo femenino (odds ratio, OR=1,61; IC95% 1,21-2,14), así como el haber sido sometido a más de un desplazamiento forzado (OR=1,47; IC95 1,05-2,05). El consumo de cualquiera de las drogas se asoció con ser hombre (OR=5,38; IC95% 2,35-12,34).Conclusiones. La alta prevalencia de trastornos mentales y de consumo de drogas en la población estudiada, comparada con la población general, constituye un problema de salud pública que justifica el diseño de planes y la implementación de programas orientados a la recuperación de su bienestar y salud mental.

Study on US/O3 mechanism in p-chlorophenol decomposition

PubMed Central

Xu, Xian-wen; Xu, Xin-hua; Shi, Hui-xiang; Wang, Da-hui

2005-01-01

Study on the effects of sonolysis, ozonolysis and US/O3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O3 system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.79% after a 16-min reaction while its CODcr (chemical oxygen demand) removal rate was 97.02%, 62.17%, 3.67% after a 120-min reaction. The decomposition reaction of p-chlorophenol follows pseudo-first-order kinetics. The enhancement factors of p-chlorophenol and its CODcr under US/O3 system reached 63% and 237% respectively. The main intermediates during the decomposition include catechol, hydroquinone, p-benzoquinone, phenol, fumaric acid, maleic acid, oxalic acid and formic acid. The decomposition mechanism of p-chlorophenol was also discussed. PMID:15909343

La salud en personas con discapacidad intelectual en España: estudio europeo POMONA-II

PubMed Central

Martínez-Leal, Rafael; Salvador-Carulla, Luis; Gutiérrez-Colosía, Mencía Ruiz; Nadal, Margarida; Novell-Alsina, Ramón; Martorell, Almudena; González-Gordón, Rodrigo G.; Mérida-Gutiérrez, M. Reyes; Ángel, Silvia; Milagrosa-Tejonero, Luisa; Rodríguez, Alicia; García-Gutiérrez, Juan C.; Pérez-Vicente, Amado; García-Ibáñez, José; Aguilera-Inés, Francisco

2011-01-01

Introducción Estudios internacionales demuestran que existe un patrón diferenciado de salud y una disparidad en la atención sanitaria entre personas con discapacidad intelectual (DI) y población general. Objetivo Obtener datos sobre el estado de salud de las personas con DI y compararlos con datos de población general. Pacientes y métodos Se utilizó el conjunto de indicadores de salud P15 en una muestra de 111 sujetos con DI. Los datos de salud encontrados se compararon según el tipo de residencia de los sujetos y se utilizó la Encuesta Nacional de Salud 2006 para comparar estos datos con los de la población general. Resultados La muestra con DI presentó 25 veces más casos de epilepsia y el doble de obesidad. Un 20% presentó dolor bucal, y existió una alta presencia de problemas sensoriales, de movilidad y psicosis. Sin embargo, encontramos una baja presencia de patologías como la diabetes, la hipertensión, la osteoartritis y la osteoporosis. También presentaron una menor participación en programas de prevención y promoción de la salud, un mayor número de ingresos hospitalarios y un uso menor de los servicios de urgencia. Conclusiones El patrón de salud de las personas con DI difiere del de la población general, y éstas realizan un uso distinto de los servicios sanitarios. Es importante el desarrollo de programas de promoción de salud y de formación profesional específicamente diseñados para la atención de personas con DI, así como la implementación de encuestas de salud que incluyan datos sobre esta población. PMID:21948011

Substance use, childhood sexual abuse, and sexual risk behavior among women in methadone treatment.

PubMed

Cohen, Lisa R; Tross, Susan; Pavlicova, Martina; Hu, Mei-Chen; Campbell, Aimee N; Nunes, Edward V

2009-01-01

Substance use and a history of childhood sexual abuse (CSA) are risk factors for unprotected sex among women, yet questions remain as to how their combined influence may differentially affect sexual risk. The current study investigated how complex relationships among drug use and CSA may contribute to unprotected sexual occasions (USO). A Generalized Linear Mixed Model was used to examine the interaction between current cocaine/stimulants and opioid use and CSA on number of USOs in a sample of 214 sexually active women in outpatient methadone maintenance treatment. For women with CSA, an increase in days of cocaine/stimulant use was associated with a significant increase in USOs. In contrast, an increase in days of opiate use was associated with a significant decrease in USOs. For the group of women who did not report CSA, there was a significant increase in USOs with increased opiate use. Findings indicate that CSA is related to unprotected sexual occasions depending on drug type and severity of use. Women with CSA using cocaine are at particularly high risk for having unprotected sex and should be specifically targeted for HIV prevention interventions.

The Moon Phases in a Paper Box. (Spanish Title: Las Fases de la Luna en Una Caja de Cartón.) As Fases da Lua Numa Caixa de Papelão

NASA Astrophysics Data System (ADS)

de Fátima O. Saraiva, Maria; Amador, Cláudio B.; Kemper, Érico; Goulart, Paulo; Muller, Angela

2007-12-01

We present a very simple concrete model to demonstrate the concept of phases of an illuminated body. The main objective of our model is to help the understanding of the Moon phases as viewed from the perspective of an observer on Earth. The material allows the visualization of two important effects: (1st) even though all the time half Moon is illuminated by the Sun, we see different fractions of the illuminated Moon surface, depending on our angle of sight; (2nd) the orientation of the convex part of the Moon in the crescent and waning phases on the sky also depends on our perspective from Earth. The use of a closed box allows one to see the contrast among the different phases with no need of a dark room. We also present a text on the Moon phases, emphasizing the dependence of the aspect of the bright part on the angle of sight. En este trabajo proponemos la construcción de material didáctico de bajo costo para demostración del concepto de fases de un cuerpo iluminado. El principal objetivo de nuestro material es facilitar la comprensión de las fases de la Luna desde la perspectiva de un observador en la Tierra. El material ayuda la visualización de dos efectos importantes: (1º) a pesar de tener siempre la mitad de la Luna (representada por una bolita de espuma plástica o de ping-pong), iluminada por el Sol ( representado por una fuente de luz natural o artificial), vemos diferentes fracciones de su superficie iluminada, dependiendo del ángulo por el cual la vemos; (2º) la orientación del borde convexo de la Luna en las fases Creciente y Menguante también depende de la perspectiva por la cual la miramos desde la Tierra. El uso de una caja cerrada permite observar el contraste entre las diferentes fases sin necesidad de estar en un recinto oscuro. Presentamos también un texto explicativo sobre las fases de la Luna, enfatizando la dependencia de la apariencia de la parte iluminada con el ángulo de visión. Neste trabalho propomos a construção de material didático de baixo custo para demonstração do conceito de fases de um corpo iluminado. O principal objetivo de nosso material é facilitar a compreensão das fases da Lua da perspectiva de um observador na Terra. O material ajuda na visualização de dois efeitos importantes: (1º) mesmo tendo sempre a metade da "Lua" (representada por uma bolinha de isopor ou de ping-pong) iluminada pelo "Sol" (representado por uma fonte de luz natural ou artificial), nós vemos diferentes frações de sua superfície iluminada, dependendo do ângulo pelo qual a olhamos; (2º) a orientação da borda convexa da Lua nas fases Crescente e Minguante também depende da perspectiva pela qual a olhamos da Terra. O uso de uma caixa fechada permite observar o contraste entre as diferentes fases sem necessidade de estar em uma sala escurecida. Apresentamos também um texto explicativo sobre fases da Lua, enfatizando a dependência da aparência da parte iluminada com o ângulo de visada.

Elaboration and Validation of the Medication Prescription Safety Checklist.

PubMed

Pires, Aline de Oliveira Meireles; Ferreira, Maria Beatriz Guimarães; Nascimento, Kleiton Gonçalves do; Felix, Márcia Marques Dos Santos; Pires, Patrícia da Silva; Barbosa, Maria Helena

2017-08-03

to elaborate and validate a checklist to identify compliance with the recommendations for the structure of medication prescriptions, based on the Protocol of the Ministry of Health and the Brazilian Health Surveillance Agency. methodological research, conducted through the validation and reliability analysis process, using a sample of 27 electronic prescriptions. the analyses confirmed the content validity and reliability of the tool. The content validity, obtained by expert assessment, was considered satisfactory as it covered items that represent the compliance with the recommendations regarding the structure of the medication prescriptions. The reliability, assessed through interrater agreement, was excellent (ICC=1.00) and showed perfect agreement (K=1.00). the Medication Prescription Safety Checklist showed to be a valid and reliable tool for the group studied. We hope that this study can contribute to the prevention of adverse events, as well as to the improvement of care quality and safety in medication use. elaborar e validar um instrumento tipo checklist para identificar a adesão às recomendações na estrutura das prescrições de medicamentos, a partir do Protocolo do Ministério da Saúde e Agência Nacional de Vigilância Sanitária. pesquisa metodológica, conduzida por meio do processo de validade e análise de confiabilidade, com amostra de 27 prescrições eletrônicas. análises realizadas confirmaram a validade de conteúdo e a confiabilidade da versão do instrumento. A validade de conteúdo, obtida por meio da avaliação de juízes, foi considerada satisfatória por contemplar itens que representam a adesão às recomendações na estrutura das prescrições de medicamentos. A confiabilidade, avaliada por interobservadores, apresentou-se excelente (ICC=1,00) e de concordância perfeita (K=1,00). o instrumento Lista de Verificação de Segurança na Prescrição de Medicamentos demonstrou-se válido e confiável para o grupo estudado. Espera-se que este estudo possa contribuir para a prevenção de eventos adversos, bem como para a melhoria da qualidade da assistência e segurança no uso de medicamentos. elaborar y validar un instrumento tipo checklist para identificar la adhesión a las recomendaciones en la estructura de las prescripciones de medicamentos, a partir del Protocolo del Ministerio de la Salud y Agencia Nacional de Vigilancia Sanitaria. investigación metodológica, conducida mediante el proceso de validez y análisis de confiabilidad, con muestra de 27 prescripciones electrónicas. los análisis llevados a cabo confirmaron la validez de contenido y la confiabilidad de la versión del instrumento. La validez de contenido, alcanzada mediante la evaluación de jueces, fue considerada satisfactoria por contemplar ítems que representan la adhesión a las recomendaciones en la estructura de las prescripciones de medicamentos. La confiabilidad, evaluada por interobservadores, se reveló excelente (ICC=1,00) y de concordancia perfecta (K=1,00). el instrumento Lista de Verificación de Seguridad en la Prescripción de Medicamentos se mostró válido y confiable para el grupo estudiado. Se espera que este estudio pueda contribuir hacia la prevención de eventos adversos, y también hacia la mejora de la calidad de la atención y seguridad en el uso de medicamentos.

Dicloruro de paraquat

EPA Pesticide Factsheets

El dicloruro de paraquat, comúnmente conocido como “paraquat,” es uno de los herbicidas registrados de mayor uso en los Estados Unidos. El paraquat también se conoce como Gramaxone (un producto popular de uso final

Arsenic contamination of groundwater: Mitigation strategies and policies

NASA Astrophysics Data System (ADS)

Alaerts, Guy J.; Khouri, Nadim

Contamination of groundwater by arsenic from natural geochemical sources is at present a most serious challenge in the planning of large-scale use of groundwater for drinking and other purposes. Recent improvements in detection limits of analytical instruments are allowing the correlation of health impacts such as cancer with large concentrations of arsenic in groundwater. However, there are at present no known large-scale technological solutions for the millions of people-mostly rural-who are potentially affected in developing countries. An overall framework of combating natural resource degradation is combined with case studies from Chile, Mexico, Bangladesh and elsewhere to arrive at a set of strategic recommendations for the global, national and local dimensions of the arsenic ``crisis''. The main recommendations include: the need for flexibility in the elaboration of any arsenic mitigation strategy, the improvement and large-scale use of low-cost and participatory groundwater quality testing techniques, the need to maintain consistent use of key lessons learned worldwide in water supply and sanitation and to integrate arsenic as just one other factor in providing a sustainable water supply, and the following of distinct but communicable tracks between arsenic-related developments and enhanced, long-term, sustainable water supplies. La contamination des eaux souterraines par l'arsenic provenant de sources naturelles est actuellement un sujet des plus graves dans l'organisation d'un recours à grande échelle des eaux souterraines pour la boisson et d'autres usages. De récentes améliorations dans les limites de détection des équipements analytiques permettent de corréler les effets sur la santé tels que le cancer à de fortes concentrations en arsenic dans les eaux souterraines. Toutefois, il n'existe pas actuellement de solutions technologiques à grande échelle connues pour des millions de personnes, surtout en zones rurales, qui sont potentiellement affectées dans les pays en développement. Un cadre d'ensemble pour lutter contre la dégradation naturelle des ressources est associé à des études de cas au Chili, au Mexique, au Bangladesh et ailleurs afin d'établir un ensemble de recommandations stratégiques pour les dimensions globale, nationale et locale de la «crise» de l'arsenic. Les principales recommandations sont les suivantes: le besoin d'une flexibilité pour élaborer une stratégie de diminution de l'arsenic, l'amélioration et l'utilisation à grande échelle de techniques peu coûteuses et associant les populations pour tester la qualité de l'eau souterraine, le besoin de maintenir un usage logique des leçons clés acquises de par le monde pour l'alimentation en eau et la santé publique, celui d'intégrer l'arsenic simplement comme un autre facteur pour assurer une alimentation durable en eau, et pour suivre des pistes distinctes mais communicables entre les développements liés à l'arsenic et les alimentations durables en eau mises en valeurs à long terme. La contaminación de las aguas subterráneas con arsénico procedente de fuentes geoquímicas naturales es actualmente uno de los retos principales de la planificación a gran escala de las aguas subterráneas para uso de boca y otros fines. Las recientes mejoras en los límites de detección del instrumental analítico permiten correlacionar impactos en la salud tales como el cáncer con concentraciones elevadas de arsénico en las aguas subterráneas. Sin embargo, a fecha de hoy no existen soluciones tecnológicas de gran escala para millones de personas-población principalmente rural-que están potencialmente afectadas en los países en vías de desarrollo. Se combina un enfoque general para combatir la degradación de los recursos naturales con estudios concretos de Chile, México, Bangladesh y cualquier otro lugar que permita obtener un conjunto de recomendaciones estratégicas para las dimensiones global, nacional y local de la ``crisis'' del arsénico. Las recomendaciones principales incluyen la necesidad de flexibilizar la elaboración de cualquier estrategia de mitigación del arsénico la mejora y uso a gran escala de técnicas de muestreo de las aguas subterráneas que sean económicas y participativas; la necesidad de mantener un uso coherente de las lecciones clave aprendidas a nivel mundial en el suministro y saneamiento del agua y de integrar el arsénico como otro factor más en la consecución de un suministro sustentable de agua; y el seguimiento de trazas distintas pero comunicables entre los desarrollos relacionados con el arsénico y los abastecimientos de agua sustentables a largo plazo.

Medición de los parámetros cosmológicos q0, ΩM, y ΩΛ, usando supernovas de Tipo Ia distantes

NASA Astrophysics Data System (ADS)

Clocchiatti, A.; High-Z Sne Search Team

Las supernovas de tipo Ia son una herramienta de gran precisión para la medición de distancias de interés cosmológico. Los métodos recientes de calibración de su luminosidad intrínseca, que hacen uso de la forma de las curvas de luz en varios colores y permiten diferenciar entre supernovas distantes, intrínsecamente débiles, u oscurecidas por extinción, reducen la dispersión del método que las asume de magnitud absoluta constante de 0.50 mag a 0.15 mag, e incrementa el valor de la constante de Hubble de ~55 km s-1 Mpc-1, a 65 km s-1 Mpc-1. A partir de la calibración de las supernovas cercanas, con redshifts menores que 0.1, se pueden obtener distancias precisas a supernovas que explotan a alto redshift. Hemos aplicado estos métodos a 16 supernovas con 0.16 < Z < 0.97, encontrando que sus distancias son, en promedio, entre 10% y 13% (dependiendo del método empleado) mayores que las que uno esperaría en un universo con poca masa (Ω = 0.2), sin una constante cosmológica. Todos los métodos de ajuste de curvas de luz, y selección de subgrupos de la muestra de supernovas observadas, favorecen consistentemente modelos del universo que se expanden eternamente y que tienen una constante cosmológica positiva (ΩΛ > 0), y una aceleración de la expansión al presente (q0 < 0). Hay distintas fuentes de posibles errores sistemáticos que merecen ser analizadas, entre ellas: evolución de la metalicidad y estrellas progenitoras, extinción, bias en la elección de la muestra, amplificación por gravitational lensing, y contaminación de la muestra. Ninguno de estos efectos alcanza para reconciliar los datos con ΩΛ = 0, o q0 > 0.

[Not Available].

PubMed

Vio, Fernando; Lera, Lydia; Salinas, Judith

2016-07-19

Objetivo: mediante la técnica de consenso Delphi, conocer la opinión de un grupo de expertos en nutrición, educación y gastronomía para buscar consenso sobre metodologías educativas en alimentación saludable, alumnos de tercero a quinto año básico, sus familias y profesores.Métodos: con los resultados de encuestas y grupos focales realizados previamente a niños, padres y profesores, se elaboró un cuestionario que fue enviado a 51 expertos en nutrición, educación y gastronomía en una primera ronda. Los resultados fueron analizados y reenviados en una segunda ronda con las preguntas no consensuadas, obteniendo 38 respuestas.Resultados: hubo consenso en que se pueden cambiar hábitos en escuelas mediante talleres de cocina con chefs o monitores, educación activo-participativa y huertos escolares. Padres y profesores deben tener habilidades culinarias saludables para educar a los niños. Estos deben hacer uso racional del dinero en la escuela. Para ello es necesario cambiar la oferta del kiosko hacia alimentos saludables, o suprimirlo si no es saludable. Los profesores deben capacitarse con talleres de autocuidado y vida sana para educar en alimentación saludable a los niños en horarios de clase con material educativo, talleres de cocina con recetas y aprovechar horarios de desayuno y almuerzo para actividades educativas. Los padres deben participar en talleres para escoger alimentos saludables en lugares de venta y preparar menús saludables. Los niños deben aprender habilidades culinarias simples, preparando y degustando alimentos saludables. Conclusiones: estos resultados son fundamentales para diseñar materiales educativos en alimentación saludable que cambien los malos hábitos alimentarios actuales.

Índice de vulnerabilidad de adultos mayores en Medellín, Barranquilla y Pasto.

PubMed

Cardona, Doris; Segura, Ángela; Segura, Alejandra; Muñoz, Diana; Jaramillo, Daniel; Lizcano, Douglas; Agudelo, Maite Catalina; Arango, Catalina; Morales, Santiago

2018-05-01

Introducción. La vulnerabilidad puede entenderse como la carencia de recursos materiales e inmateriales que impide el aprovechamiento de oportunidades en distintos aspectos de la vida. Estos recursos de bienestar evitan el deterioro de la calidad de vida.Objetivo. Construir un índice de vulnerabilidad con las características de los capitales físico, humano, social y funcional de los adultos mayores de tres ciudades de Colombia en el 2016, y determinar los factores asociados con esta condición.Materiales y métodos. Se hizo un estudio transversal con información primaria mediante 1.514 encuestas a personas de 60 años o más de Medellín, Barranquilla y Pasto. En la construcción del índice se usó el análisis factorial con los métodos de componentes principales y de rotación ortogonal varimax.Resultados. Las condiciones que generaban vulnerabilidad se relacionaron principalmente con el capital humano (calidad de vida, salud mental y hábitos); los demás capitales aportaron un solo componente, así: capital físico (ocupación), capital social (acompañamiento) y capital funcional (independencia funcional). La vulnerabilidad fue mayor en los residentes de Pasto. Los factores asociados con la vulnerabilidad fueron la ciudad de residencia, el sexo, el nivel educativo y el rol en el hogar.Conclusión. En el 58,55 % de las personas mayores, la vulnerabilidad se explicó por el uso del tiempo, la independencia funcional y el bienestar subjetivo. Estos hallazgos aportan elementos para el mejoramiento de la calidad de vida, principalmente en cuanto a la capacidad funcional para mantener la independencia, estar ocupados y fortalecer la salud mental.

Comparison of the frequency estimation of the DORIS/Jason2 oscillator thanks to the onboard DIODE and Time Transfer by Laser Link experiment

NASA Astrophysics Data System (ADS)

Jayles, C.; Exertier, P.; Martin, N.; Chauveau, J. P.; Samain, E.; Tourain, C.; Auriol, A.; Guillemot, P.

2016-12-01

The main applications for DORIS are precise orbit determination, and precise Geodesy. Onboard Jason-2 for instance, the DORIS tracking component is the French contribution to the precise orbit determination capability, a key capability for altimetry product scientific result accuracy. T2L2 is a time transfer technique based on the propagation of light pulses for synchronization between two clocks. Hosting T2L2 on-board Jason-2 was to allow for very fine DORIS USO (Ultra-Stable Oscillator) frequency monitoring, and for this purpose T2L2 was connected to the DORIS USO. Thanks to the continuous tracking of T2L2/Jason-2 by the Laser Ranging network it is possible to monitor the USO for several days, weeks, and even much longer, and thus to also compare with the DIODE (the DORIS on-board orbit determination software) frequency bias estimates. The DORIS USO frequency biases estimate comparison between two independent systems, T2L2 and DIODE, can be of benefit to both, allowing the accuracies of both systems to be better understood, and for improvements to be made to both systems. Such comparison is the central topic of the present paper. T2L2 monitors the DORIS on-board USO frequency with an accuracy of much better than 10-12 which is the specification for the Doppler instrumentation. The paper investigates the limits of the DORIS-DIODE frequency bias estimates using T2L2, showing that USO frequency compliance accuracy of 10-12 has been reached.

Defense.gov Special Report: Medal of Honor

Science.gov Websites

Recipients Joint Chiefs of Staff, USO Salute Medal of Honor Recipients At an awards dinner, members of the the USO-Metro's 33rd Annual Awards Dinner in Arlington, Va., March 24, 2015, where they shared their

Sociodemographic profile of medicines users in Brazil: results from the 2014 PNAUM survey.

PubMed

Bertoldi, Andréa Dâmaso; Pizzol, Tatiane da Silva Dal; Ramos, Luiz Roberto; Mengue, Sotero Serrate; Luiza, Vera Lucia; Tavares, Noemia Urruth Leão; Farias, Mareni Rocha; Oliveira, Maria Auxiliadora; Arrais, Paulo Sergio Dourado

2016-12-01

To analyze the prevalence of medicine use by the Brazilian population and its distribution according to sociodemographic factors. Study using data from the Pesquisa Nacional de Acesso, Utilização e Promoção do Uso Racional de Medicamentos (PNAUM - National Survey on Access, Use and Promotion of Rational Use of Medicines), a nationwide household survey of a representative sample of the Brazilian urban population. The data were collected between September 2013 and February 2014. The overall use of medicines, defined as the use of any medicine, use of medicines for treating chronic medical conditions and for acute health conditions, was evaluated. The independent variables included gender, age group, socioeconomic position, and region of Brazil. Analyzes included prevalence calculations, 95% confidence intervals (95%CI) and Pearson Chi-square tests to evaluate the differences between groups, considering a 5% level of significance. The prevalence of medicines use was 50.7% (95%CI 49.3-52.2), with 39.3% (95%CI 37.5-41.1) accounting for men and 61.0% (95%CI 59.3-62.6) for women. Medicines use was observed to increase with increasing age, except among children within the zero to four years age group. The lowest prevalence for medicines use was found among those with a low socioeconomic position and those who reside in the North region of Brazil. The prevalence of medicine use to treat chronic diseases was 24.3% (95%CI 23.3-25.4), whereas it was 33.7% (95%CI 32.1-35.4) for treating acute diseases. We found extensive variability in the prevalence of medicines use across regions of Brazil. The poorest regions (North, Northeast, and Midwest) have a lower prevalence of medicines use to treat chronic diseases, indicating the need to minimize inequalities in access to medicines within the country. Analisar a prevalência do uso de medicamentos pela população brasileira e sua distribuição segundo aspectos sociodemográficos. Estudo com dados da Pesquisa Nacional de Acesso, Utilização e Promoção do Uso Racional de Medicamentos (PNAUM), pesquisa nacional de base populacional, realizada entre setembro de 2013 e fevereiro de 2014 em residências de municípios urbanos. Avaliou-se o uso de todos os medicamentos (global), uso de medicamentos para doenças crônicas e uso de medicamentos para doenças agudas. As variáveis independentes utilizadas foram sexo, idade, classificação econômica e região do País. Foram calculados prevalências e intervalos de confiança de 95% (IC95%) e aplicado teste Qui-quadrado de Pearson para avaliação das diferenças entre os grupos, considerando o nível de significância de 5%. A prevalência global de uso de medicamentos foi de 50,7% (IC95% 49,3-52,2), sendo 39,3% (IC95% 37,5-41,1) no sexo masculino e 61,0% (IC95% 59,3-62,6) no sexo feminino. Observou-se aumento nas prevalências de uso com a idade (exceto de zero a quatro anos). As menores prevalências de uso ocorreram no grupo mais pobre e na região Norte do País. A prevalência de uso de medicamentos para doenças crônicas foi de 24,3% (IC95% 23,3-25,4) e para doenças agudas foi de 33,7% (IC95% 32,1-35,4). Existe grande variabilidade nas prevalências globais de uso de medicamentos por regiões brasileiras. As regiões consideradas mais pobres (Norte, Nordeste e Centro-Oeste) apresentam menores prevalências de uso de medicamentos para doenças crônicas, o que indica a necessidade de minimizar as desigualdades no acesso aos medicamentos dentro do País.

Defense.gov - Special Report: Travels with Mullen

Science.gov Websites

, 2010 Top Stories Mullen, USO Performers Thank Troops KUWAIT CITY, Kuwait, April 1, 2010 – U.S. Navy Sirico and Rose McGowan, and Brian Stinchcomb of the New Orleans Saints on a USO sponsored tour of

Substance Use, Depression and Sociodemographic Determinants of HIV Sexual Risk Behavior in Outpatient Substance Abuse Treatment Patients.

PubMed

Tross, Susan; Feaster, Daniel J; Thorens, Gabriel; Duan, Rui; Gomez, Zoilyn; Pavlicova, Martina; Hu, Mei Chen; Kyle, Tiffany; Erickson, Sarah; Spector, Anya; Haynes, Louise; Metsch, Lisa R

2015-01-01

The NIDA Clinical Trials Network trial of rapid HIV testing/counseling in 1281 patients was a unique opportunity to examine relationships among substance use, depressive symptoms, and sex risk behavior. Past 6-month substance use; substance use severity (Drug Abuse Screening Test - 10); depressive symptoms (Quick Inventory of Depressive Symptomatology); and three types of sex risk behavior (unprotected sex occasions [USOs] with primary partners; USOs with nonprimary partners; and USOs while high/drunk) were assessed. Zero-inflated negative binomial analyses provided: probability and rate of sex risk behavior (in risk behavior subsample). Levels of sexual risk behavior were high, while variable across the three types of sex risk behaviors. Among the patients, 50.4% had engaged in USOs with primary partners, 42% in sex while drunk or high, and 23.8% in USOs with nonprimary partners. Similar factors were significantly associated with all three types of sex risk behaviors. For all types, problem drinking, cocaine use, and substance use severity had an exacerbating effect. Older age was associated with lower risk behavior; other relationship categories (eg, married, separated/divorced, cohabitating) were associated with greater risk behavior than was single status. Depressive symptoms were associated with decreased likelihood of USOs with a primary partner. Sexual risk behavior is common among individuals in outpatient substance abuse treatment. Results highlight problem drinking (eg, up to three-fold) and cocaine (eg, up to twice) in increasing sex risk behavior. They demonstrate the utility of distinguishing between partner types and presence/absence of alcohol/drugs during sex. Findings argue for the need to integrate sex risk reduction into drug treatment.

Perfil das alterações vasculares periféricas em dependentes de crack acompanhados em Centro de Atenção Psicossocial para Álcool e Drogas (CAPS-AD)

PubMed Central

da Costa, Antônio Fagundes; Baldaçara, Leonardo Rodrigo; da Silva, Sílvio Alves; Tavares, Ana Célia de Freitas Ramos; Orsolin, Ederson de Freitas; Prehl, Vinícius Barros; Gondo, Fernando Hirohito Beltran; Santana, Hernani Lopes

2016-01-01

Resumo Contexto O consumo de crack é um dos grandes desafios em saúde pública, e o uso dessa droga tem efeitos diretos na saúde de seus usuários. Objetivos Avaliar o perfil das alterações vasculares em pacientes com dependência de crack em Centro de Atenção Psicossocial para Álcool e Drogas (CAPS-AD) e observar os possíveis efeitos vasculares periféricos. Métodos Trata-se de um estudo observacional, descritivo, de corte transversal. Os pacientes da amostra foram submetidos a um questionário objetivo para avaliar questões demográficas, padrão de uso da droga, coexistência de diabetes melito, hipertensão arterial ou tabagismo, exame físico e ecográfico. Os dados foram sumarizados e analisados estatisticamente com teste qui-quadrado ou teste exato de Fisher. Resultados A média de idade da amostra foi de 33,29 (±7,15) anos, e 74% eram do gênero masculino. A média de idade de início de uso da droga foi de 23,4 (±7,78) anos, com tempo médio de uso de 9,58 (±5,64) anos. O consumo médio diário de pedras de crack foi de 21,45 (±8,32) pedras. A alteração de pulsos em membros inferiores foi mais frequente em mulheres. A prevalência do espessamento da parede arterial nos membros inferiores foi de 94,8%. O tempo de uso da droga apresentou associação estatística (p = 0,0096) com alteração do padrão de curva espectral das artérias dos membros inferiores. Conclusões Há alterações vasculares periféricas em usuários de crack. O tempo de uso da droga exerceu um maior impacto nesse sistema, o que sugere associação entre o uso do crack e a diminuição de fluxo arterial.

76 FR 20392 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-12

..., SMH, SNDK, SPLS, SPXU, SPY, SSO, SYMC, TBT, T, TLT, TNA,TSM, TWM, TXN, TZA, UCO, USO, UWM, UYG, VALE..., S, SH, SLV, SPF, SPXU, SPY, SSO, TBT, TLT, TWM, TZA, UCO, USO, UWM, VXX, XLI, XLP. Transactions in...

A protocol for storage and long-distance shipment of Mediterranean fruit fly (Diptera: Tephritidae) eggs. 1. Effect of temperature, embryo age , and storage time on survival and quality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caceres, C.; Wornoayporn, V.; Islam, S.M.

The operational use of Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann), genetic sexing strains in Sterile Insect Technique applications can be maximized by developing methods for effective shipment of eggs. This would enable a central production facility to maintain the relevant mother stocks and large colonies to supply eggs to satellite centers that would mass produce only males for irradiation and release. In order to achieve this, the survival of medfly embryos of different ages was assessed after storage at 5, 10, 15, 20, and 25 deg. C in water for different periods of time. Survival was affected by allmore » 3 variables, i.e., embryo age, water temperature, and length of storage. Storage of embryos at any temperature for 120 h resulted in almost no survival. Controlling the age of the embryo at the time of the temperature treatment is crucial for the success of this procedure. Embryos collected between 0 to 12 h after oviposition and pre-incubated at 25 deg. C for 12 h provide a suitable 72 h window for shipment when maintained between 10 to 15 deg. C. Under these conditions, no significant reductions in survival during all the developmental stages were observed. (author) [Spanish] El uso operacional de cepas de la mosca del mediterraneo Ceratitis capitata (Wiedemann) en las cuales es posible separar los sexos a traves de mecanismos geneticos para su utilizacion en la Tecnica del Insecto Esteril (TIE), puede ser maximizado con el desarrollo de metodos efectivos para el envio y transporte de huevos. Esto permite que un laboratorio de produccion centralizada mantenga las respectivas colonias responsables por la produccion de huevos para este abastecer laboratorios satelites responsables por la produccion masiva de solamente machos para subsiguiente irradiacion y liberacion. Para ser posible esta alternativa fue evaluada la supervivencia de embriones de diferentes edades despues de su almacenamiento en agua a 5, 10, 15, 20 y 25 deg. C por diferentes periodos de tiempo. La supervivencia fue afectada por las 3 variables evaluadas, la edad del embrion, la temperatura del agua y el periodo de almacenamiento. El almacenamiento de los embriones a cualquier temperatura por 120 horas dio como resultado la casi no supervivencia. Una edad controlada de los embriones a tratar es crucial para el exito de este protocolo. Embriones colectados entre 0 a 12 horas despues de la oviposicion y su previa incubacion a 25 deg. C por 12 horas brinda un margen de hasta de 72 horas de duracion del almacenamiento y transporte, siempre y cuando estos se mantengan en una temperatura de entre 10 a 15{sup o}C. En estas condiciones, fue registrada una reduccion no significante de la supervivencia de los diferentes estados de desarrollo. (author)« less

Desarrollo de fotonovelas para concienciar sobre trastornos de la conducta alimentaria en latinos en los Estados Unidos

PubMed Central

Reyes-Rodríguez, Mae Lynn; García, Marissa; Silva, Yormeri; Sala, Margarita; Quaranta, Michela; Bulik, Cynthia M.

2016-01-01

Resumen El objetivo de este estudio fue desarrollar fotonovelas, un tipo de novela gráfica popular en la población latina, para crear conciencia y educar sobre los trastornos de la conducta alimentaria (TCA). Cuatro caricaturas ilustradas y guiones adaptados para adultos y adolescentes de ambos sexos fueron presentados en discusiones focales y en una entrevista de profundidad. Diecisiete latinos adultos (14 mujeres; 3 hombres) y 10 adolescentes (9 féminas; 1 varón) participaron en el estudio. Los participantes encontraron las fotonovelas interesantes y que captaban más la atención que los folletos tradicionales. El uso del espanglish y la clarificación de las diferencias entre los TCA fueron sugeridos por las adolescentes femeninas. Los adultos varones sugirieron cambiar el título, que se enfocara en las consecuencias en la salud de los TCA para que llame la atención en los hombres a leer la historia. Basado en la aceptación encontrada en este estudio, la fotonovela pudiera ser una avenida prometedora para crear conciencia y educar a la comunidad latina sobre los TCA en los Estados Unidos. PMID:27313838

The Dammam aquifer in Bahrain - Hydrochemical characterization and alternatives for management of groundwater quality

NASA Astrophysics Data System (ADS)

Zubari, Waleed K.

Over-ion of the Dammam aquifer, the principal aquifer in Bahrain, by the agricultural and domestic sectors, has led to its salinization by adjacent brackish and saline water bodies. A hydrochemical study identified the locations of the sources of aquifer salinization and delineated their areas of influence. The investigation indicates that the aquifer water quality is significantly modified as groundwater flows from the northwestern parts of Bahrain, where the aquifer receives its water by lateral underflow from eastern Saudi Arabia, to the southern and southeastern parts. Four types of salinization of the aquifer are identified: brackish-water up-flow from the underlying brackish-water zones in north-central, western, and eastern regions; seawater intrusion in the eastern region; intrusion of sabkha water in the southwestern region; and irrigation return flow in a local area in the western region. Four alternatives for the management of groundwater quality that are available to the water authorities in Bahrain are discussed and their priority areas are proposed, based on the type and extent of each salinization source, in addition to groundwater use in that area. The effectiveness of the proposed management options in controlling the degradation of water quality in the Dammam aquifer should be evaluated using simulation modeling. Résumé La surexploitation de l'aquifère de Damman, principal aquifère de Bahreïn, du fait des besoins agricoles et domestiques, a conduit à sa salinisation à partir d'eaux voisines saumâtres et salées. Une étude hydrochimique a identifié les origines de la salinisation de l'aquifère et a délimité leurs zones d'influence. Les recherches montrent que la qualité de l'eau souterraine est modifiée de façon significative pour les écoulements souterrains dirigés vers les secteurs sud et sud-est et provenant de la région nord-ouest de Bahreïn, là où l'aquifère est alimenté latéralement à partir de l'Arabie Saoudite orientale. Quatre types de salinisation de l'eau souterraine ont été identifiés : une drainance verticale en provenance d'eaux saumâtres sous-jacentes dans les régions nord-centrales, ouest et est, une intrusion marine dans la région est, une intrusion d'eau de sebkha dans la région sud-ouest, et le retour d'irrigation dans un secteur localisé de la région sud-ouest. Quatre démarches alternatives de gestion de la qualité des eaux souterraines, acceptables par les services chargés de l'eau à Bahreïn, sont discutées et des zones d'action prioritaire sont proposées, selon le type et l'étendue de chacune des sources de salinisation et en fonction des usages de les eaux souterraines dans chaque secteur. L'efficacité des options de gestion proposées pour le contrôle de la dégradation de la qualité de l'aquifère de Damman devrait être ensuite évaluée au moyen d'un modèle de simulation. Resumen El acuífero de Damman, el más importante de Bahrein, se explota para usos agrícolas y domésticos. La sobreexplotación del mismo ha provocado su salinización por cuerpos de agua salada y salobre cercanos. Un estudio hidroquímico identificó las fuentes de salinización y ayudó a dibujar sus áreas de influencia. La calidad del agua subterránea se modifica significativamente en la dirección del flujo, desde el noroeste del país, donde las entradas son laterales y procedentes de Arabia Saudí, hacia el sur y el sudeste. Se han identificado cuatro tipos de salinización: flujo ascendente de agua salobre en las regiones norte-central, este y oeste; intrusión de agua marina en la región este; intrusión de agua salobre al sudoeste y, finalmente, retorno de riego en un área local de la región oeste. Se discuten cuatro alternativas para la gestión del agua y se proponen áreas prioritarias basadas en el tipo y la extensión de cada fuente de salinización y en los usos de agua subterránea en cada zona. La efectividad de las opciones de gestión propuestas para controlar la degradación de la calidad del agua en el acuífero Damman deberá evaluarse mediante simulaciones realizadas con un modelo numérico

Risk factors for complications in peripheral intravenous catheters in adults: secondary analysis of a randomized controlled trial.

PubMed

Johann, Derdried Athanasio; Danski, Mitzy Tannia Reichembach; Vayego, Stela Adami; Barbosa, Dulce Aparecida; Lind, Jolline

2016-11-28

analyze the risk factors linked to complications in peripheral intravenous catheters. secondary data analysis of a randomized controlled trial with 169 medical and surgical patients placed in two groups, one with integrated safety catheter (n=90) and other using simple needle catheter (n=79), with three months follow-up time. the risk factors that raised the odds of developing complications were: hospitalization between 10-19 days (p=0.0483) and 20-29 days (p=0,0098), antimicrobial use (p=0.0288) and use of fluid solutions (p=0.0362). The 20 Gauge lowered the risks of complications (p=0.0153). Multiple analysis showed reduction of risk for the 20 Gauge (p=0.0350); heightened risk for solutions and fluids (p=0.0351) and use of corticosteroids (p=0.0214). risk factors linked to complications in peripheral intravenous catheters were: hospitalization periods between 10-29 days, antimicrobial infusion, solutions and fluids and corticosteroids. Regarding complications, 20 Gauge is a protecting factor compared with 22. Brazilian Clinical Trials Registry: RBR-46ZQR8. analisar os fatores de risco relacionados à ocorrência de complicações no cateterismo venoso periférico. análise secundária de dados de um ensaio clínico randomizado, no qual 169 pacientes clínicos e cirúrgicos foram alocados no grupo em uso de cateter de segurança completo (n = 90) e no grupo que utilizou cateter sobre agulha simples (n = 79), tempo de seguimento de três meses. os fatores de risco que aumentaram as chances de desenvolvimento de complicações foram: períodos de internação compreendidos entre 10 a 19 dias (p = 0,0483) e 20 a 29 dias (p = 0,0098), uso de antimicrobianos (p = 0,0288) e soluções e planos de soro (p = 0,0362). O calibre 20 Gauge diminuiu os riscos de ocorrência de complicações (p=0,0153). A análise múltipla apontou redução do risco para o calibre 20 (p = 0,0350); aumento do risco para a infusão de soluções e planos de soro (p = 0,0351) e administração de corticosteróides (p = 0,0214). os fatores de risco relacionados à ocorrência de complicações no cateterismo venoso periférico foram tempo de internação entre 10 e 29 dias, infusão de antimicrobianos, soluções e planos de soro e corticosteróides. Ressalta-se o calibre 20 como fator protetor ao desenvolvimento de complicações, quando comparado ao 22. Registro Brasileiro de Ensaios Clínicos: RBR-46ZQR8. analizar los factores de riesgo relacionados a la ocurrencia de complicaciones en el cateterismo venoso periférico. análisis secundario de datos de un ensayo clínico aleatorizado, en el cual 169 pacientes clínicos y quirúrgicos fueron asignados al grupo que usaba catéter de seguridad completo (n = 90) y al grupo que utilizó catéter plástico sobre aguja (tipo Abbocath) (n = 79); tiempo de seguimiento de tres meses. los factores de riesgo que aumentaron las probabilidades de desarrollar complicaciones fueron: períodos de internación comprendidos entre 10 y 19 días (p = 0,0483) y entre 20 y 29 días (p = 0,0098); uso de antimicrobianos (p = 0,0288); y uso soluciones y administración de suero (p = 0,0362). El calibre 20G de la aguja disminuyó los riesgos de ocurrencia de complicaciones (p = 0,0153). El análisis múltiple apuntó: reducción del riesgo para el calibre 20G (p = 0,0350); aumento del riesgo para la infusión de soluciones, administración de suero (p = 0,0351) y administración de corticosteroides (p = 0,0214). los factores de riesgo relacionados a la ocurrencia de complicaciones en el cateterismo venoso periférico fueron el tiempo de internación entre 10 y 29 días, la infusión de antimicrobianos, soluciones, administración de suero y corticosteroides. Se destaca el calibre 20G como factor protector para el desarrollo de complicaciones, cuando comparado al calibre 22G. Registro Brasileño de Ensayos Clínicos: RBR-46ZQR8.

Risk factors for unstable blood glucose level: integrative review of the risk factors related to the nursing diagnosis.

PubMed

Teixeira, Andressa Magalhães; Tsukamoto, Rosangela; Lopes, Camila Takáo; Silva, Rita de Cassia Gengo E

2017-06-05

to identify evidence in the literature on the possible risk factors for the risk of unstable blood glucose diagnosis in individuals with type 2 diabetes mellitus, and to compare them with the risk factors described by NANDA International. an integrative literature review guided by the question: what are the risk factors for unstable blood glucose level in people with type 2 diabetes mellitus? Primary studies were included whose outcomes were variations in glycemic levels, published in English, Portuguese or Spanish, in PubMed or CINAHL between 2010 and 2015. altered levels of glycated hemoglobin, body mass index>31 kg/m2, previous history of hypoglycemia, cognitive deficit/dementia, autonomic cardiovascular neuropathy, comorbidities and weight loss corresponded to risk factors described in NANDA International. Other risk factors identified were: advanced age, black skin color, longer length of diabetes diagnosis, daytime sleepiness, macroalbuminuria, genetic polymorphisms, insulin therapy, use of oral antidiabetics, and use of metoclopramide, inadequate physical activity and low fasting glycemia. risk factors for the diagnosis, risk for unstable blood glucose level, for persons with type 2 diabetes mellitus were identified, and 42% of them corresponded to those of NANDA International. These findings may contribute to the practice of clinical nurses in preventing the deleterious effects of glycemic variation. identificar evidências na literatura acerca de possíveis fatores de risco do diagnóstico risco de glicemia instável para pessoas com diabetes mellitus tipo 2 e compará-los com os fatores de risco descritos pela NANDA International . revisão integrativa norteada pela pergunta: quais são os fatores de risco de glicemia instável em pessoas com diabetes mellitus tipo 2? Incluíram-se estudos primários cujos desfechos eram variações nos níveis glicêmicos, publicados em inglês, português ou espanhol no PubMed ou CINAHL entre 2010 e 2015. observou-se que alteração nos níveis de hemoglobina glicada, índice de massa corpórea>31 Kg/m2, história prévia de hipoglicemia, déficit cognitivo/demência, neuropatia autonômica cardiovascular, comorbidades e perda de peso correspondiam a fatores de risco descritos pela NANDA International . Outros fatores de risco identificados foram: idade avançada, raça negra, maior tempo de diagnóstico de diabetes, sonolência diurna, macroalbuminúria, polimorfismos genéticos, insulinoterapia, uso de antidiabéticos orais, uso de metoclopramida, atividade física inadequada e glicemia de jejum baixa. identificaram-se fatores de risco do diagnóstico risco de glicemia instável para pessoas com diabetes mellitus tipo 2, dos quais 42% correspondiam àqueles da NANDA International . Esses achados podem contribuir para a prática de enfermeiros clínicos na prevenção dos efeitos deletérios da variação glicêmica. identificar evidencias en la literatura acerca de posibles factores de riesgo del diagnóstico "riesgo de nivel de glucemia inestable" para personas con diabetes mellitus tipo 2 y compararlos con los factores de riesgo descritos por la NANDA International . revisión integradora orientada por la pregunta: ¿Cuáles son los factores de riesgo de nivel de glucemia inestable en personas con diabetes mellitus tipo 2? Se incluyeron estudios primarios cuyos resultados eran variaciones en los niveles glucémicos, publicados en inglés, portugués o español en el PubMed o CINAHL entre 2010 y 2015. se observó que una alteración en los niveles de: hemoglobina glucosilada, índice de masa corporal >31 Kg/m2, historia previa de hipoglucemia, déficit cognitivo/demencia, neuropatía autonómica cardiovascular, comorbilidades y pérdida de peso, correspondían a factores de riesgo descritos por la NANDA International . Otros factores de riesgo identificados fueron: edad avanzada, raza negra, mayor tiempo de diagnóstico de diabetes, somnolencia diurna, macroalbuminuria, polimorfismos genéticos, insulinoterapia, uso de antidiabéticos orales, uso de metoclopramida, actividad física inadecuada y glucemia de ayuno baja. se identificaron factores de riesgo del diagnóstico riesgo de nivel de glucemia inestable para personas con diabetes mellitus tipo 2, de los cuales 42% correspondían a los de la NANDA International . Esos hallazgos pueden contribuir para la práctica de enfermeros clínicos en la prevención de los efectos deletéreos de la variación glucémica.

A Study of Distance Learning Technology in Utah: A Statewide Overview.

ERIC Educational Resources Information Center

Chow, Stanley H. L.; And Others

This report was commissioned by the Utah State Office of Education (USOE) to provide USOE with information about the potential applications of distance learning technology in schools. The study includes: (1) a statewide assessment of instructional, staff development, and administrative needs which may be met by distance learning technology; and…

Domestic violence on children: development and validation of an instrument to evaluate knowledge of health professionals.

PubMed

Oliveira, Lanuza Borges; Soares, Fernanda Amaral; Silveira, Marise Fagundes; Pinho, Lucinéia de; Caldeira, Antônio Prates; Leite, Maísa Tavares de Souza

2016-08-18

to develop and validate an instrument to evaluate the knowledge of health professionals about domestic violence on children. this was a study conducted with 194 physicians, nurses and dentists. A literature review was performed for preparation of the items and identification of the dimensions. Apparent and content validation was performed using analysis of three experts and 27 professors of the pediatric health discipline. For construct validation, Cronbach's alpha was used, and the Kappa test was applied to verify reproducibility. The criterion validation was conducted using the Student's t-test. the final instrument included 56 items; the Cronbach alpha was 0.734, the Kappa test showed a correlation greater than 0.6 for most items, and the Student t-test showed a statistically significant value to the level of 5% for the two selected variables: years of education and using the Family Health Strategy. the instrument is valid and can be used as a promising tool to develop or direct actions in public health and evaluate knowledge about domestic violence on children. elaborar e validar um instrumento para avaliação do conhecimento dos profissionais de saúde sobre a violência doméstica contra a criança. estudo realizado com 194 profissionais médicos, enfermeiros e cirurgiões dentistas. Para elaboração dos itens e identificação das dimensões, realizou-se a revisão da literatura. A validação aparente e de conteúdo foram realizadas por meio da análise de três especialistas e de 27 professores universitários da área de saúde da criança. Para a validação de construto, avaliou-se o coeficiente alfa de Cronbach, e o teste Kappa foi usado para verificar a reprodutibilidade. A validação de critério foi conduzida com uso do teste t-student. o instrumento final apresentou 56 itens, o alfa Cronbach foi de 0,734, o teste Kappa revelou concordância superior a 0,6 para a maioria dos itens, e o teste t-student apresentou valor estatisticamente significante até o nível de 5% para as duas variáveis selecionadas, tempo de formação e tempo na Estratégia Saúde da Família. o instrumento apresentou-se válido e, deste modo , pode ser usado como ferramenta promissora para desenvolver ou direcionar as ações em saúde pública e avaliação do conhecimento sobre a violência doméstica contra a criança. elaborar y validar un instrumento para evaluación del conocimiento de los profesionales de la salud sobre la violencia doméstica ejercida contra el niño. estudio realizado con 194 profesionales: médicos, enfermeros y cirujanos dentistas. Para elaboración de los ítems e identificación de las dimensiones, se realizó una revisión de la literatura. La validación aparente y de contenido fueron realizadas por medio del análisis de tres especialistas y de 27 profesores universitarios del área de la salud del niño. Para la validación de constructo, se evaluó el coeficiente alfa de Cronbach, y la prueba Kappa fue usada para verificar la reproductibilidad. La validación de criterio fue realizada con uso de la prueba t de Student. el instrumento final presentó 56 ítems, el alfa Cronbach fue de 0,734, la prueba Kappa reveló concordancia superior a 0,6 para la mayoría de los ítems, y la prueba t de Student presentó valor estadísticamente significativo hasta el nivel de 5% para las dos variables seleccionadas: tiempo de graduación y tiempo en el programa Estrategia Salud de la Familia. el instrumento se presentó válido y, de ese modo, puede ser usado como herramienta promisora para desarrollar o dirigir acciones de salud pública y evaluar el conocimiento sobre la violencia doméstica contra el niño.

[State Oversight in Postsecondary Education and the Office of Education's Eligibility Process. Collected Remarks.

ERIC Educational Resources Information Center

Jung, Steven M.; Proffitt, John

Perspectives on an American Institutes for Research (AIR) study of state oversight in postsecondary education, conducted for the U.S. Office of Education (USOE), are offered by researcher Steven M. Jung. In addition, a list of recommendations by the General Accounting Office concerning USOE's eligibility process and responses by John Proffitt, on…

Defense.gov Special Report: Travels with Winnefeld: USO Tour

Science.gov Websites

Kaneohe Bay - Hawaii Osan Air Base - South Korea CIA Factbook - Diego Garcia Bagram Air Base - Afghanistan Naval Support Activity - Bahrain Naval Support Activity Naples - Italy Ramstein Air Base - Germany Photo Attacked in Seoul Stars Bring Piece of Home to Bagram Airfield During USO Spring Troop Visit Forward Base

Annual Evaluation: Elementary and Secondary Act of 1965 - Title I, Maine, FY 1970.

ERIC Educational Resources Information Center

Maine State Dept. of Education, Augusta.

This evaluation attempts to measure the extent and effectiveness of ESEA Title I programs designed to meet the needs of disadvantaged children and apprizes the public and the legislature of program outcomes. In keeping with USOE requirements for evaluating Title I programs, this document is constructed of (1) responses to USOE probes by…

77 FR 6160 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Order Granting Approval of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-07

... SLV and USO strike price intervals. \\4\\ The Exchange also proposed certain non-substantive changes to... Strike Price Intervals for SLV and USO Options February 1, 2012. I. Introduction On December 7, 2011...-4 thereunder,\\2\\ a proposed rule change regarding strike price intervals for options on iShares[reg...

COBE navigation with one-way return-link Doppler in the post-helium-venting phase

NASA Technical Reports Server (NTRS)

Dunham, Joan; Nemesure, M.; Samii, M. V.; Maher, M.; Teles, Jerome; Jackson, J.

1991-01-01

The results of a navigation experiment with one way return link Doppler tracking measurements for operational orbit determination of the Cosmic Background Explorer (COBE) spacecraft are presented. The frequency of the tracking signal for the one way measurements was stabilized with an Ultrastable Oscillator (USO), and the signal was relayed by the Tracking and Data Relay Satellite System (TDRSS). The study achieved three objectives: space qualification of TDRSS noncoherent one way return link Doppler tracking; determination of flight performance of the USO coupled to the second generation TDRSS compatible user transponder; and verification of algorithms for navigation using actual one way tracking data. Orbit determination and the inflight USO performance evaluation results are presented.

Genetic Variation of Methylenetetrahydrofolate Reductase (MTHFR) and Thymidylate Synthase (TS) Genes Is Associated with Idiopathic Recurrent Implantation Failure.

PubMed

Choi, Youngsok; Kim, Jung Oh; Shim, Sung Han; Lee, Yubin; Kim, Ji Hyang; Jeon, Young Joo; Ko, Jung Jae; Lee, Woo Sik; Kim, Nam Keun

2016-01-01

The one-carbon metabolism pathway disorder was important role in successful pregnancy. The MTHFR and TS protein were crucial factor in one-carbon metabolism. To investigate the association between recurrent implantation failure (RIF) and enzymes in the one-carbon metabolism pathway. A total of 120 women diagnosed with RIF and 125 control subjects were genotyped for MTHFR 677C>T, 1298A>C, TSER 2R/3R and TS 1494del/ins by a polymerase chain reaction-restriction fragment length polymorphism assay. According to the gene-gene combination analysis, the MTHFR 677/MTHFR 1298 (TT/AA) and MTHFR 677/TS 1494 (TT/6bp6bp) genetic combinations were associated with relatively higher risks [adjusted odds ratio (AOR), 2.764; 95% CI, 1.065-7.174; P = 0.037 and AOR, 3.186; 95% CI, 1.241-8.178; P = 0.016] in RIF patients compared to the CC/AA (MTHFR 677/MTHFR 1298) and TT/6bp6bp (MTHFR 677/TS 1494) combinations, respectively. The results suggested that the combined MTHFR 677/MTHFR 1298 genotype might be associated with increased risk of RIF. To the best of our knowledge, this study is the first to elucidate the potential association of MTHFR, TS and TSER polymorphisms with RIF risk in Korean patients.

Uso de terreno urbano y rural en Puerto Rico

Treesearch

Sebastian Martinuzzi; William A. Gould; Olga M. Ramos Gonzalez; Maya Quinones; Michael E. Jimenez

2008-01-01

El Proyecto de Analisis de Gap de Puerto Rico (PRGAP) (Gould et al. 2008) desarrollo tres usos de terrenos para Puerto Rico: Urbano, Suburbano, y Rural (Martinuzzi et al. 2007). Estas regiones tambien pueden ser consideradas como urbano, densamente-poblado rural, y escasamente-poblado rural, o como urbano y area silvestre con una interfase de area silvestre-urbana. La...

Use of medicines and other products for therapeutic purposes among children in Brazil.

PubMed

Pizzol, Tatiane da Silva Dal; Tavares, Noemia Urruth Leão; Bertoldi, Andréa Dâmaso; Farias, Mareni Rocha; Arrais, Paulo Sergio Dourado; Ramos, Luiz Roberto; Oliveira, Maria Auxiliadora; Luiza, Vera Lucia; Mengue, Sotero Serrate

2016-12-01

To assess the prevalence of the use of medicines and other products for therapeutic purposes in the Brazilian pediatric population and test whether demographic, socioeconomic and health factors are associated with use. A cross-sectional population-based study (National Survey on Access, Use and Promotion of Rational Use of Medicines - PNAUM), including 7,528 children aged 12 or younger, living in urban areas in Brazil. Medicine use to treat chronic or acute diseases was reported by the primary caregiver present at the household interview. Associations between independent variables and medicine use were investigated by Poisson regression. The overall prevalence of medicine use was 30.7% (95%CI 28.3-33.1). The prevalence of medicine use for chronic diseases was 5.6% (95%CI 4.7-6.7) and for acute conditions, 27.1% (95%CI 24.8-29.4). The factors significantly associated with overall use were five years old or under, living in the Northeast region, having health insurance and using health services in the last 12 months (emergency visits and hospitalizations). The following were associated with drug use for chronic diseases: age ≥ 2 years, Southeast and South regions, and use of health services. For drug use in treating acute conditions, the following associated factors were identified: ≤ 5 years, North, Northeast or Midwest regions, health insurance, and one or more emergency visits. The most commonly used drugs among children under two years of age were paracetamol, ascorbic acid, and dipyrone; for children aged two years or over they were dipyrone, paracetamol, and amoxicillin. The use of medicine by children is considerable, especially in treating acute medical conditions. Children using drugs for chronic diseases have a different demographic profile from those using drugs for acute conditions in relation to gender, age, and geographic region. Estimar a prevalência de uso de medicamentos e outros produtos com finalidade terapêutica na população pediátrica brasileira e testar se fatores demográficos, socioeconômicos e médicos estão associados ao uso. Estudo transversal de base populacional (Pesquisa Nacional sobre Acesso, Utilização e Promoção do Uso Racional de Medicamentos - PNAUM), incluindo 7.528 crianças com 12 anos ou menos de idade, residentes na zona urbana do território brasileiro. O uso de medicamentos para tratar doenças crônicas ou agudas foi referido pelo principal cuidador da criança presente na entrevista domiciliar. Associações entre as variáveis independentes e o uso de medicamentos foram investigadas por meio de regressão de Poisson. A prevalência de uso global de medicamentos foi de 30,7% (IC95% 28,3-33,1). A prevalência de uso de medicamentos para doenças crônicas foi de 5,6% (IC95% 4,7-6,7) e para condições agudas, 27,1% (IC95% 24,8-29,4). Os fatores significativamente associados com o uso global foram ter no máximo cinco anos de idade, residir na região Nordeste, ter plano de saúde e utilizar serviços de saúde nos últimos 12 meses (consultas de emergência e internações). Associaram-se ao uso de medicamentos para doenças crônicas: idade ≥ 2 anos, regiões Sudeste e Sul e utilização de serviços de saúde. Para o uso de medicamentos em condições agudas, foram identificados os seguintes fatores associados: ≤ 5 anos, Norte, Nordeste ou Centro-Oeste, plano de saúde e uma ou mais consultas de emergência. Os medicamentos com maior prevalência de uso pelas crianças menores de dois anos foram paracetamol, ácido ascórbico e dipirona; nas crianças com 2 ou mais anos, foram dipirona, paracetamol e amoxicilina. O uso de medicamentos na população infantil é substancial, principalmente no tratamento de condições médicas agudas. As crianças usuárias de medicamentos para doenças crônicas apresentam perfil demográfico diferente das usuárias de medicamentos para condições agudas, em relação ao sexo, à idade e à região geográfica.

Comunicación de pareja y VIH en mujeres en desventaja social

PubMed Central

Rosina Cianelli, A.; Lilian Ferrer, L.; Margarita Bernales, S.; Natalia Villegas, R.

2009-01-01

Introducción La epidemia de VIH y SIDA se ha diseminado rápidamente a nivel mundial tendiendo a la feminización, pauperización y heterosexualización. La comunicación de pareja en torno el VIH es descrita como uno de los factores protectores en la adquisición de esta enfermedad, favoreciendo la adopción de conductas sexuales seguras tales como la negociación de pareja y la utilización de preservativo, consideróndose como un pilar fundamental en la incorporación de medidas de autocuidado en la sexualidad femenina. Objetivo Determinar el nivel de comunicación de pareja en torno al VIH en mujeres chilenas en desventaja social. Metodología Cuatrocientas noventa y seis mujeres contestaron la entrevista inicial de la investigación “Testing an HIV/AIDS Prevention Intervention for Chilean Women” (RO1 TW 006977 PI Cianelli). Se utilizó la escala “Health protective sexual communication scale (HPC)” (0–10 puntos). Se realizó un análisis descriptivo utilizando el programa SPSS 16.0. Resultados El promedio del nivel de comunicación de pareja fue de 3,26 ± 2,7 puntos con la pareja principal, de 2,52 ± 2,48 puntos con una segunda pareja y de 0 puntos con una tercera pareja. Los temas de menor comunicación entre las parejas fueron el uso de preservativo y la realización del test para VIH antes de tener relaciones sexuales. Conclusión Las mujeres de la muestra presentan bajos niveles de comunicación de pareja en relación a VIH con todas sus parejas sexuales. Son necesarias estrategias que potencien este tópico dentro de las intervenciones de prevención de VIH y SIDA de manera de fortalecer la adopción de conductas de autocuidado en torno al tema. PMID:19936328

PubMed

De Abajo Larriba, Ana Beatriz; Méndez Rodríguez, Enrique; González-Gallego, Javier; Capón Álvarez, Jessica; Díaz Rodríguez, Ángel; Peleteiro Cobo, Beatriz; Mahmoud Atoui, Omar; De Abajo Olea, Serafín; Martínez de Mandojana Hernández, Juan; Lumbreras González, Víctor

2016-11-29

Objetivos: estimar el porcentaje de pacientes con EPOC adiestrados en la consulta para el manejo de inhaladores en la provincia de León.Métodos: estudio epidemiológico, transversal, multicéntrico (30 centros de salud de la provincia de León). Incluyó pacientes mayores de 35 años diagnosticados y tratados de EPOC. Variables a estudio: edad, sexo, hábitat, datos antropométricos, estado nutricional, tabaquismo, espirometría postboroncodilatadora, disnea (mMRC), reagudizaciones, gravedad (Índice Bodex), hospitalizaciones, tratamiento, seguimiento y caracterización del fenotipo (GesEOPC 2014). Los resultados se expresan con sus IC al 95,5%.Resultados: se incluyeron 833 pacientes, el 85,8% varones, con edad media de 64,69 (53,66-75,61) años y 20,65 (4,47-36,8) años evolución de la EPOC. Empleaban 1,88 (1,64-2,16) dispositivos inhaladores de media, p = 0,006, (57% de forma correcta, 23% regular y el 20% incorrecta). El 20,9% no recibieron adiestramiento para usar inhaladores frente al 79,1% adiestrados, p < 0,001, (9,4% por neumólogos, 20,3% enfermeras y 43,5% médicos familia, p = 0,002). Los pacientes bien adiestrados realizan mejor el tratamiento, en el 60,60% (58,91-62,29), p = 0,002. No hubo diferencias significativas en el adiestramiento por tabaquismo, gravedad, ingresos hospitalarios, ni calidad de vida, obteniendo una reducción significativa del número de agudizaciones, siendo de 1,59 (1,12-2,15) reagudizaciones medias en el grupo adiestrado frente a 3,29 (2,50-4,11) en los no adiestrados, p = 0,002.Conclusiones: el nivel de adiestramiento en el uso de inhaladores en los pacientes con EPOC es insuficiente en nuestro medio. La mejor formación de los profesionales y la simplificación de los dispositivos contribuirán a que un mayor número de pacientes realicen el tratamiento de forma adecuada.

Groundwater for urban water supplies in northern China - An overview

NASA Astrophysics Data System (ADS)

Zaisheng, Han

Groundwater plays an important role for urban and industrial water supply in northern China. More than 1000 groundwater wellfields have been explored and installed. Groundwater provides about half the total quantity of the urban water supply. Complete regulations and methods for the exploration of groundwater have been established in the P.R. China. Substantial over-exploitation of groundwater has created environmental problems in some cities. Some safeguarding measures for groundwater-resource protection have been undertaken. Résumé Les eaux souterraines jouent un rôle important dans l'approvisionnement en eau des agglomérations et des industries du nord de la Chine. Les explorations ont conduit à mettre en place plus de 1000 champs de puits captant des eaux souterraines. Les eaux souterraines satisfont environ la moitié des besoins en eau des villes. Une réglementation complète et des méthodes d'exploration des eaux souterraines ont étéétablies en République Populaire de Chine. Une surexploitation très nette est à l'origine de problèmes environnementaux dans certaines villes. Des mesures ont été prises pour protéger la ressource en eau souterraine. Resumen El agua subterránea desempeña un papel importante en el suministro de agua para uso doméstico e industrial en la China septentrional. Se han explorado y puesto en marcha más de 1000 campos de explotación de aguas subterráneas, que proporcionan cerca de la mitad del total del suministro urbano. En la República Popular de China se han definido totalmente la legislación y la metodología para realizar estas explotaciones. La gran sobreexplotación en algunas ciudades ha creado algunos problemas medioambientales. Como consecuencia, se han llevado a cabo algunas medidas de protección de los recursos de aguas subterráneas.

Degradation of 2,4-dichlorophenol using combined approach based on ultrasound, ozone and catalyst.

PubMed

Barik, Arati J; Gogate, Parag R

2017-05-01

The present work investigates the application of ultrasound and ozone operated individually and in combination with catalyst (ZnO and CuO) for establishing the possible synergistic effects for the degradation of 2,4-dichlorophenol. The dependency of extent of degradation on the operating parameters like temperature (over the range of 30-36°C), initial pH (3-9), catalyst as ZnO (loading of 0.025-0.15g/L) and CuO (loading of 0.02-0.1g/L) and initial concentration of 2,4-DCP (20-50ppm) has been established to maximize the efficacy of ultrasound (US) induced degradation. Using only US, the maximum degradation of 2,4-DCP obtained was 28.85% under optimized conditions of initial concentration as 20ppm, pH of 5 and temperature of 34°C. Study of effect of ozone flow rate for approach of only ozone revealed that maximum degradation was obtained at 400mg/h ozone flow rate. The combined approaches such as US+O 3 , US+ZnO, US+CuO, O 3 +ZnO, O 3 +CuO, US+O 3 +ZnO and US+O 3 +CuO have been subsequently investigated under optimized conditions and observed to be more efficient as compared to individual approaches. The maximum extent of degradation for the combined operation of US+O 3 (400mg/h)+ZnO (0.1g/L) and US+O 3 (400mg/h)+CuO (0.08g/L) has been obtained as 95.66% and 97.03% respectively. The degradation products of 2,4-DCP have been identified using GC-MS analysis and the toxicity analysis has also been performed based on the anti-microbial activity test (agar-well diffusion method) for the different treatment strategies. The present work has conclusively established that the combined approach of US+O 3 +CuO was the most efficient treatment scheme resulting in near complete degradation of 2,4-DCP with production of less toxic intermediates. Copyright © 2016 Elsevier B.V. All rights reserved.

Collective strategy for facing occupational risks of a nursing team.

PubMed

Loro, Marli Maria; Zeitoune, Regina Célia Gollner

2017-03-09

To socialize an educational action through the process of group discussion and reflection, with the aim to increase the care of nursing workers in facing occupational risks. A qualitative descriptive study using the Convergent Care Research modality with nursing staff working in an emergency department of a hospital in the northwest region of the state of Rio Grande do Sul, Brazil. Data collection was carried out through educational workshops and information was processed using content analysis, resulting in two thematic categories: A look at the knowledge and practices about occupational risks in nursing; and adherence to protective measures by the nursing team against occupational risks. Twenty-four (24) workers participated in the study. When challenged to critically look at their actions, the subjects found that they relate the use of safety devices to situations in which they are aware of the patient's serological status. Subjects' interaction, involvement and co-responsibility in the health education process were determinant for their reflection on risky practices. They also had the potential to modify unsafe behaviors. Socializar uma ação educativa, por meio de um processo de discussão e reflexão em grupo, com vistas a ampliar o cuidado dos trabalhadores de enfermagem frente aos riscos ocupacionais. Estudo qualitativo, descritivo na modalidade Pesquisa Convergente Assistencial, com trabalhadores da equipe de enfermagem que atuavam no pronto atendimento de um hospital da região noroeste do estado do Rio Grande do Sul. A coleta de dados foi realizada por meio de oficinas educativas, e o tratamento das informações, por análise de conteúdo, resultando em duas categorias temáticas: Um olhar direcionado a saberes e práticas sobre riscos ocupacionais na enfermagem e Adesão às medidas de proteção pela equipe de enfermagem frente aos riscos ocupacionais. Integraram o estudo 24 trabalhadores. Ao serem desafiados a olhar criticamente sobre seu fazer, os sujeitos constataram que vinculam o uso dos dispositivos de segurança a situações em que conhecem o status sorológico do paciente. A interação, o envolvimento e a corresponsabilização dos sujeitos no processo de educação em saúde foram determinantes para a reflexão das práticas de risco, bem como tiveram potencial para modificar comportamentos inseguros. Socializar una acción educativa a través de un proceso de discusión y reflexión grupal, con el fin de ampliar el cuidado de los trabajadores de enfermería en relación a los riesgos ocupacionales. Estudio cualitativo, descriptivo en modalidad de Investigación Convergente Asistencial, con trabajadores del equipo de enfermería que actuaban en el servicio de urgencia de un hospital de la región noroeste del estado de Rio Grande del Sur. La recolección de datos se realizó a través de talleres educativos y el tratamiento de las informaciones por análisis de contenidos, lo que resultó en dos categorías temáticas: una mirada dirigida a los saberes y las prácticas relacionadas a riesgos ocupacionales y la adhesión a las medidas de protección por el equipo de enfermería para los riesgos ocupacionales. El estudio incluyó 24 trabajadores a los que cuando se presentó el desafío de observar su críticamente sus acciones, constataron que relacionan el uso de los dispositivos de seguridad a las situaciones en que el status serológico de los pacientes es ya conocido. La interacción, el involucramiento y la corresponsabilidad de los sujetos en el proceso de educación en salud son determinantes para la reflexión sobre las practicas riesgosas y tienen potencial para modificar comportamientos inseguros.

Measurement of the area of venous ulcers using two software programs.

PubMed

Eberhardt, Thaís Dresch; Lima, Suzinara Beatriz Soares de; Lopes, Luis Felipe Dias; Borges, Eline de Lima; Weiller, Teresinha Heck; Fonseca, Graziele Gorete Portella da

2016-12-19

to compare the measurement area of venous ulcers using AutoCAD(r) and Image Tool software. this was an assessment of reproducibility tests conducted in a angiology clinic of a university hospital. Data were collected from 21 patients with venous ulcers, in the period from March to July of 2015, using a collection form and photograph of wounds. Five nurses (evaluators) of the hospital skin wound study group participated. The wounds were measured using both software programs. Data were analyzed using intraclass correlation coefficient, concordance correlation coefficient and Bland-Altman analysis. The study met the ethical aspects in accordance with current legislation. the size of ulcers varied widely, however, without significant difference between the measurements; an excellent intraclass and concordance correlation was found between both software programs, which seem to be more accurate when measuring a wound area >10 cm². the use of both software programs is appropriate for measurement of venous ulcers, appearing to be more accurate when used to measure a wound area > 10 cm². comparar a mensuração de área de úlceras venosas por meio dos softwares AutoCAD(r) e Image Tool. trata-se de um estudo de avaliação de reprodutibilidade de testes, realizado em um ambulatório de angiologia de um hospital universitário. Os dados foram coletados de 21 pacientes com úlceras venosas, no período de março a julho de 2015, por meio de formulário de coleta e fotografia das feridas. Cinco enfermeiros (avaliadores) do Grupo de Estudos de Lesões de Pele do hospital participaram da pesquisa. As feridas foram mensuradas em ambos os softwares. Os dados foram analisados por meio do Coeficiente de correlação intraclasse, Coeficiente de correlação de concordância e procedimento de Bland e Altman. A pesquisa respeitou os aspectos éticos de acordo com a legislação vigente. os tamanhos das úlceras apresentaram grande amplitude, porém, sem diferença significativa entre as mensurações, existe excelente correlação intraclasse e de concordância entre os softwares, os quais parecem ser mais precisos na mensuração de feridas com área > 10 cm². o uso de ambos os softwares é indicado para a mensuração de úlceras venosas, parecendo ser mais precisos quando utilizados para mensurar feridas com área > 10 cm². comparar la medida del área de úlceras venosas por medio de los softwares AutoCAD(r) e Image Tool. se trata de un estudio de evaluación de reproducibilidad de pruebas, realizado en un ambulatorio de angiología de un hospital universitario. Los datos fueron recolectados de 21 pacientes con úlceras venosas, en el período de marzo a julio de 2015, por medio de formulario de recolección y fotografías de las heridas. Cinco enfermeros (evaluadores) del Grupo de Estudios de Lesiones de Piel del hospital participaron de la investigación. Las heridas fueron medidas en ambos softwares. Los datos fueron analizados por medio de: Coeficiente de correlación intraclase, Coeficiente de correlación de concordancia y Procedimiento de Bland y Altman. La investigación respetó los aspectos éticos de acuerdo con la legislación vigente. los tamaños de las úlceras presentaron gran amplitud, sin embargo, sin diferencia significativa entre las medidas; existe excelente correlación intraclase y de concordancia entre los softwares, los que parecen ser más precisos en medidas de heridas con área > 10 cm². el uso de ambos softwares es indicado para medir úlceras venosas, pareciendo ser más precisos cuando utilizados para medir heridas con área > 10 cm².

Complications of central venous catheter in patients transplanted with hematopoietic stem cells in a specialized service.

PubMed

Barretta, Lidiane Miotto; Beccaria, Lúcia Marinilza; Cesarino, Cláudia Bernardi; Pinto, Maria Helena

2016-06-07

to identify the model, average length of stay on site and complications of central venous catheter in patients undergoing transplant of hematopoietic stem cells and verify the corresponding relationship between the variables: age, gender, medical diagnosis, type of transplant, implanted catheter and insertion site. a retrospective and quantitative study with a sample of 188 patients transplanted records between 2007 and 2011. the majority of patients used Hickman catheter with an average length of stay on site of 47.6 days. The complication fever/bacteremia was significant in young males with non-Hodgkin's lymphoma undergoing autologous transplant, which remained with the device for a long period in the subclavian vein. nurses should plan with their team the minimum waiting time, recommended between the catheter insertion and start of the conditioning regimen, as well as not to extend the length of time that catheter should be on site and undertake their continuing education, focusing on the prevention of complications. identificar o modelo, tempo médio de permanência e complicações de cateter venoso central em pacientes submetidos ao transplante de células-tronco hematopoiéticas e verificar a relação de correspondência entre as variáveis: idade, sexo, diagnóstico médico, tipo de transplante, cateter implantado e local de inserção. retrospectivo, quantitativo, com amostra de prontuários de 188 pacientes transplantados, entre 2007 e 2011. a maioria dos pacientes utilizou o cateter de Hickman com permanência média de 47,6 dias. A complicação febre/bacteremia foi significante em jovens do sexo masculino, com linfoma não Hodgkin, submetidos ao transplante autólogo, que permaneceram com o dispositivo por longo período, em veia subclávia. os enfermeiros devem planejar com a equipe o aguardo do tempo mínimo preconizado entre o implante do cateter e início do regime de condicionamento, assim como não estender o período de permanência e realizar educação permanente, enfocando a prevenção das complicações. identificar el modelo, el tiempo medio de permanencia y las complicaciones del catéter venoso central en pacientes sometidos a trasplante de células madre hematopoyéticas y estimar la relación de correspondencia entre las variables: edad, sexo, diagnóstico médico, tipo de trasplante, catéter implantado y sitio de inserción. estudio retrospectivo y cuantitativo con una muestra de registros de 188 pacientes trasplantados entre 2007 y 2011. la mayoría de los pacientes utilizó el catéter Hickman con una permanencia media de 47,6 días. La complicación fiebre/bacteriemia fue significativa en los varones jóvenes con linfoma no Hodgkin sometidos a trasplante autólogo, que permanecieron con el dispositivo durante un largo período en la vena subclavia. los enfermeros deben planificar con el equipo, el tiempo de espera mínimo recomendado entre la inserción del catéter y el inicio del tratamiento de condicionamiento, así como no extender el período de permanencia del catéter y realizar su formación continua, centrándose en la prevención de complicaciones.

Applicability of common stomatal conductance models in maize under varying soil moisture conditions.

PubMed

Wang, Qiuling; He, Qijin; Zhou, Guangsheng

2018-07-01

In the context of climate warming, the varying soil moisture caused by precipitation pattern change will affect the applicability of stomatal conductance models, thereby affecting the simulation accuracy of carbon-nitrogen-water cycles in ecosystems. We studied the applicability of four common stomatal conductance models including Jarvis, Ball-Woodrow-Berry (BWB), Ball-Berry-Leuning (BBL) and unified stomatal optimization (USO) models based on summer maize leaf gas exchange data from a soil moisture consecutive decrease manipulation experiment. The results showed that the USO model performed best, followed by the BBL model, BWB model, and the Jarvis model performed worst under varying soil moisture conditions. The effects of soil moisture made a difference in the relative performance among the models. By introducing a water response function, the performance of the Jarvis, BWB, and USO models improved, which decreased the normalized root mean square error (NRMSE) by 15.7%, 16.6% and 3.9%, respectively; however, the performance of the BBL model was negative, which increased the NRMSE by 5.3%. It was observed that the models of Jarvis, BWB, BBL and USO were applicable within different ranges of soil relative water content (i.e., 55%-65%, 56%-67%, 37%-79% and 37%-95%, respectively) based on the 95% confidence limits. Moreover, introducing a water response function, the applicability of the Jarvis and BWB models improved. The USO model performed best with or without introducing the water response function and was applicable under varying soil moisture conditions. Our results provide a basis for selecting appropriate stomatal conductance models under drought conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Sociodemographic and Substance Use Disorder Determinants of HIV Sexual Risk Behavior in Men and Women in Outpatient Drug Treatment in the NIDA National Drug Abuse Treatment Clinical Trials Network.

PubMed

Kidd, Jeremy D; Tross, Susan; Pavlicova, Martina; Hu, Mei-Chen; Campbell, Aimee N C; Nunes, Edward V

2017-06-07

Sexual risk behavior is now the primary vector of HIV transmission among substance users in the United States with gender as a crucial moderator of risk behavior. The purpose of this study was to examine gender differences in factors (age, race/ethnicity, education) that predict main-partner unprotected sexual occasions (USO) using the unique platform of two parallel NIDA National Drug Abuse Treatment Clinical Trials Network gender-specific safer sex intervention trials. Baseline assessments of male (N = 430) and female (N = 377) participants included demographic characteristics; past 3-month sexual activity; and a diagnostic assessment for alcohol, cocaine/stimulant, and opioid use disorders. Using mixed effects generalized linear modeling of the main outcome USO, two-way interactions of gender with age, race/ethnicity, and education were evaluated and adjusted by alcohol, cocaine/stimulant, or opioid use disorder. When adjusted for alcohol use disorder, the interaction of education and gender was significant. For men, a high school or greater education was significantly associated with more USO compared to men with less than high school. For women, greater than high school education was significantly associated with less USO compared to women with a high school education. None of the other interactions were significant when adjusted for cocaine/stimulant or opioid use disorder. Conclusions/Importance: This study demonstrates gender differences in the relationship of education, alcohol use disorder, and main-partner USO in individuals in substance abuse treatment. This underscores the importance of considering demographic and substance use factors in HIV sexual risk behavior and in crafting prevention messages for this population.

[Trattamento della dipendenza da alcol. Alcol e persone senza fissa dimora: punto di vista sociale].

PubMed

Alessandrini, Giovanni; Ciccarelli, Rosaria; Battagliese, Gemma; Cereatti, Federica; Gencarelli, Simona; Messina, Marisa Patrizia; Vitali, Mario; De Rosa, Francesca; Ledda, Roberta; Mancini, Serena; Attilia, Maria Luisa

2018-01-01

RIASSUNTO. Il fenomeno delle persone senza fissa dimora sta assumendo in questi anni una rilevanza sociale devastante, con una prevalenza stimata in USA e in Europa compresa tra il 5,6% e il 13,9%. Queste persone hanno una scarsa qualità di vita, una limitata o assente vita sociale, sono spesso disoccupate o lavorano solo saltuariamente. Sono a rischio di problemi con la legge, sono spesso affette da dipendenza da droghe, da patologie psichiatriche e internistiche. L'alcol spesso non rappresenta la causa della loro condizione sociale, ma solo la conseguenza, contribuendo in questo modo al loro degrado bio-psico-sociale. Nel 2009 lo US Department of Housing and Urban Development's Homelessness Assistance Programs e nel 2010 la European Consensus Conference on Homelessness hanno segnato un grande passo avanti nella riabilitazione sociale di queste persone, utilizzando il concetto del "case management". In particolare lo Standard Case Management si è dimostrato in grado di migliorare la stabilità abitativa, di ridurre l'uso di droghe e di rimuovere le barriere lavorative. L'Assertive Community Treatment si è dimostrato, invece, in grado di migliorare la stabilità abitativa e ha un rapporto costo/beneficio migliore per i pazienti affetti da doppia diagnosi.

[Colorimetric card use for early detection visual biliary atresia].

PubMed

Reyes-Cerecedo, Alicia; Flores-Calderón, Judith; Villasis-Keever, Miguel Á; Chávez-Barrera, José A; Delgado-González, Elba E

2018-01-01

Bile duct atresia (BVA) is a condition that causes obstruction to biliary flow, not corrected surgically, causes cirrhosis and death before 2 years of age. In Mexico from 2013 the visual colorimetric card (VVC) was incorporated for the timely detection of BVA to the National Health Card (NHC). The aim of this study was to evaluate the impact of VCT for the detection of BVA before and after the use of NHC incorporation. Ambispective, analytical observational study. We included patients with AVB treated in two pediatric hospitals of third level care. We compared the age of reference, diagnosis and surgery before and after incorporation of the TCV. In addition, a questionnaire was made to the parents to know their perception about the TCV. In 59 children, there were no differences in age at diagnosis (75 vs 70 days) and age at surgery (84 vs 90 days) between the pre and post-implementation period of the VVC. The questionnaire showed that 10 (30%) of the parents received information about the use of the VVC and 13 (38%) identified the abnormal evacuations. This study did not show changes in time for the timely detection of BVA by using VVC. Therefore, it is necessary to reinforce the program in the three levels of care in our country. La atresia de vías biliares (AVB) es una condición que provoca obstrucción al flujo biliar, y de no corregirse quirúrgicamente, provoca cirrosis y la muerte antes de los 2 años de edad. En México, a partir del año 2013 se incorporó la tarjeta colorimétrica visual (TCV) para la detección oportuna de la AVB a la Cartilla Nacional de Salud (CNS). El objetivo de este estudio fue evaluar el impacto de la TCV para la detección de AVB antes y después de su incorporación a la CNS. Estudio ambispectivo, observacional y analítico. Se incluyeron pacientes con AVB atendidos en dos hospitales pediátricos de tercer nivel de atención. Se compararon la edad de referencia, el diagnóstico y la cirugía antes y después de la incorporación de la TCV. Además, se realizó un cuestionario a los padres para conocer su percepción sobre la TCV. En 59 niños no hubo diferencias en la edad al diagnóstico (75 vs 70 días) ni en la edad al momento de la cirugía (84 vs 90 días) entre antes y después de la implementación de la TCV. Solo el 30% de los padres recibieron información del uso de la TCV y solo el 38% identificaron las evacuaciones anormales. Este estudio no mostró cambios en el tiempo para la detección oportuna de AVB mediante el uso de la TCV. Por lo tanto, es necesario reforzar el programa en los tres niveles de atención en nuestro país. Copyright: © 2018 Permanyer.

Quality management systems for fruit fly (Diptera: Tephritidae) sterile insect technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caceres, C.; Robinson, A.; McInnis, D.

The papers presented in this issue are focused on developing and validating procedures to improve the overall quality of sterile fruit flies for use in area-wide integrated pest management (AW-IPM) programs with a sterile insect technique (SIT) component. The group was coordinated and partially funded by the Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria, under a five-year Coordinated Research Project (CRP) on 'Quality Assurance in Mass-Reared and Released Fruit Flies for Use in SIT Programmes'. Participants in the CRP from 16 countries came from both basic and applied fields of expertisemore » to ensure that appropriate and relevant procedures were developed. A variety of studies was undertaken to develop protocols to assess strain compatibility and to improve colonization procedures and strain management. Specific studies addressed issues related to insect nutrition, irradiation protocols, field dispersal and survival, field cage behavior assessments, and enhancement of mating competitiveness. The main objective was to increase the efficiency of operational fruit fly programs using sterile insects and to reduce their cost. Many of the protocols developed or improved during the CRP will be incorporated into the international quality control manual for sterile tephritid fruit flies, standardizing key components of the production, sterilization, shipment, handling, and release of sterile insects. (author) [Spanish] Los articulos presentados en este numero se enfocan en el desarrollo y la validacion de procedimientos para mejorar la calidad total de moscas de las frutas esteriles para su uso en programas de manejo integrado de plagas en donde la tecnica del insecto esteril (TIE) es uno de los componentes clave. El grupo fue coordinado y parcialmente financiado por la Division Conjunta de Tecnicas Nucleares para la Alimentacion y la Agricultura de la FAO/OIEA, Viena, Austria, por un periodo de cinco anos bajo el proyecto de Investigacion Coordinada (PIC) sobre 'el Aseguramiento de la Calidad de Moscas de las Frutas Criadas y Liberadas para su Uso en Programas de TIE'. Los participantes en el PIC representan 16 paises con experiencia en campos de investigacion basica y aplicada. Para asegurar que los procedimientos desarrollados fueran apropiados y pertinentes, se realizaron una variedad de estudios para el desarrollo de protocolos para evaluar la compatibilidad y para mejorar los procedimientos de colonizacion y manejo de cepas salvajes. Estudios especificos trataron asuntos relacionados con la nutricion de insectos, los protocolos de irradiacion, la dispersion y supervivencia en el campo, evaluacion del comportamiento en jaulas de campo, y el mejoramiento de la competitividad sexual. Los objetivos fundamentales fueron el aumentar la eficiencia y reducir los costos de los programas operacionales de control de moscas de las frutas donde TIE es utilizada. Muchos de los protocolos desarrollados o mejorados durante el PIC seran incorporados en el Manual Internacional de Control de Calidad para Moscas Estriles de la familia Tephritidae, para estandarizar componentes claves como la produccion, esterilizacion, envio, manejo y liberacion de insectos esteriles. (author)« less

Second-Generation central venous catheter in the prevention of bloodstream infection: a systematic review.

PubMed

Stocco, Janislei Gislei Dorociaki; Hoers, Hellen; Pott, Franciele Soares; Crozeta, Karla; Barbosa, Dulce Aparecida; Meier, Marineli Joaquim

2016-08-08

to evaluate the effectiveness and safety in the use of second-generation central venous catheters impregnated in clorhexidine and silver sulfadiazine when compared with other catheters, being them impregnated or not, in order to prevent the bloodstream infection prevention. systematic review with meta-analysis. Databases searched: MEDLINE, EMBASE, CINAHL, LILACS/SciELO, Cochrane CENTRAL; search in Congress Proceedings and records from Clinical Trials. 1.235 studies were identified, 97 were pre-selected and 4 were included. In catheter-related bloodstream infection, there was no statistical significance between second-generation impregnated catheter compared with the non-impregnated ones, absolute relative risk 1,5% confidence interval 95% (3%-1%), relative risk 0,68 (confidence interval 95%, 0,40-1,15) and number needed to treat 66. In the sensitivity analysis, there was less bloodstream infection in impregnated catheters (relative risk 0,50, confidence interval 95%, 0,26-0,96). Lower colonization, absolute relative risk 9,6% (confidence interval 95%, 10% to 4%), relative risk 0,51 (confidence interval 95% from 0,38-0,85) and number needed to treat 5. the use of second-generation catheters was effective in reducing the catheter colonization and infection when a sensitivity analysis is performed. Future clinical trials are suggested to evaluate sepsis rates, mortality and adverse effects. evaluar la efectividad y seguridad del uso de catéteres venosos centrales de segunda generación, impregnados en clorhexidina y sulfadiazina de plata, comparados con otros catéteres impregnados o no impregnados, para prevención de infección de la corriente sanguínea. revisión sistemática con metaanálisis. La búsqueda fue realizada en las bases: MEDLINE, EMBASE, CINAHL, LILACS/SciELO, Cochrane CENTRAL; fueron consultados anales de congresos y registros de ensayos clínicos. fueron identificados 1.235 estudios, 97 preseleccionados y cuatro incluidos. En la infección de la corriente sanguínea, relacionada al catéter, no hubo significación estadística entre catéter de segunda generación impregnado en comparación a los no impregnados, riesgo relativo absoluto 1,5%, intervalo de confianza 95% (3%-1%), riesgo relativo 0,68 (intervalo de confianza 95%, 0,40-1,15) y número necesario para tratar 66. En el análisis de sensibilidad, hubo disminución de la infección de la corriente sanguínea en los catéteres impregnados (riesgo relativo 0,50, intervalo de confianza 95%, 0,26-0,96). Reducción de la colonización, riesgo relativo absoluto de 9,6% (intervalo de confianza 95%, 10% a 4%), riesgo relativo 0,51 (intervalo de confianza 95% de 0,38-0,85) y número necesario para tratar 5. el uso de los catéteres de segunda generación fue efectivo en la reducción de la colonización del catéter y de infección cuando realizado análisis de sensibilidad. Se sugirieron ensayos clínicos futuros que evalúen tasas de sepsis, mortalidad y efectos adversos. avaliar a efetividade e segurança do uso de cateteres venosos centrais de segunda geração, impregnados em clorexidina e sulfadiazina de prata, comparados com outros cateteres impregnados ou não, na prevenção de infecção de corrente sanguínea. revisão sistemática com metanálise. Busca realizada nas bases: MEDLINE, EMBASE, CINAHL, LILACS/SciELO, Cochrane CENTRAL; consulta em anais de congresso e registro de ensaios clínicos. foram identificados 1.235 estudos, 97 pré-selecionados e quatro incluídos. Na infecção de corrente sanguínea, relacionada ao cateter, não houve significância estatística entre cateter de segunda geração impregnado em comparação aos não impregnados risco relativo absoluto 1,5%, intervalo de confiança 95% (3%-1%), risco relativo 0,68 (intervalo de confiança 95%, 0,40-1,15) e número necessário para tratar 66. Na análise de sensibilidade, houve diminuição da infecção de corrente sanguínea nos cateteres impregnados (risco relativo 0,50, intervalo de confiança 95%, 0,26-0,96). Redução da colonização, risco relativo absoluto de 9,6% (intervalo de confiança 95%, 10% a 4%), risco relativo 0,51 (intervalo de confiança 95% de 0,38-0,85) e número necessário para tratar 5. o uso dos cateteres de segunda geração foi efetivo na redução de colonização do cateter e de infecção quando realizada análise de sensibilidade. Sugerem-se ensaios clínicos futuros que avaliem taxas de sepse, mortalidade e efeitos adversos.

The Need to Disentangle Key Concepts from Ecosystem-Approach Jargon

PubMed Central

WAYLEN, K A; HASTINGS, E J; BANKS, E A; HOLSTEAD, K L; IRVINE, R J; BLACKSTOCK, K L

2014-01-01

The ecosystem approach—as endorsed by the Convention on Biological Diversity (CDB) in 2000—is a strategy for holistic, sustainable, and equitable natural resource management, to be implemented via the 12 Malawi Principles. These principles describe the need to manage nature in terms of dynamic ecosystems, while fully engaging with local peoples. It is an ambitious concept. Today, the term is common throughout the research and policy literature on environmental management. However, multiple meanings have been attached to the term, resulting in confusion. We reviewed references to the ecosystem approach from 1957 to 2012 and identified 3 primary uses: as an alternative to ecosystem management or ecosystem-based management; in reference to an integrated and equitable approach to resource management as per the CBD; and as a term signifying a focus on understanding and valuing ecosystem services. Although uses of this term and its variants may overlap in meaning, typically, they do not entirely reflect the ethos of the ecosystem approach as defined by the CBD. For example, there is presently an increasing emphasis on ecosystem services, but focusing on these alone does not promote decentralization of management or use of all forms of knowledge, both of which are integral to the CBD’s concept. We highlight that the Malawi Principles are at risk of being forgotten. To better understand these principles, more effort to implement them is required. Such efforts should be evaluated, ideally with comparative approaches, before allowing the CBD’s concept of holistic and socially engaged management to be abandoned or superseded. It is possible that attempts to implement all 12 principles together will face many challenges, but they may also offer a unique way to promote holistic and equitable governance of natural resources. Therefore, we believe that the CBD’s concept of the ecosystem approach demands more attention. La Necesidad de Desenredar Conceptos Clave del Argot Ambiente-Estrategia Resumen La estrategia ambiental – como es promocionada por la Convención Biológica sobre Diversidad en 2000 – es una estrategia para un manejo holístico, sustentable y equitativo de recursos naturales, que habrá de implementarse por vía de los 12 Principios de Malawi. Estos principios describen la necesidad de manejar la naturaleza en términos de ecosistemas dinámicos, mientras se compromete totalmente con las personas locales. Es un concepto ambicioso. Hoy en día, el término es común en la investigación y la literatura de políticas sobre el manejo ambiente. Sin embargo, se han relacionado múltiples significados con el término, lo que resulta en confusión. Revisamos referencias a la estrategia ambiental de 1957 a 2012 e identificamos tres usos principales: como una alternativa para manejo ambiental o basado en ecosistemas; en referencia a una estrategia integrada y equitativa para el manejo de recursos según la CBD; y como un término que indica un enfoque en el entendimiento y la valuación de los servicios ambientales. Aunque los usos de este término y sus variantes pueden traslaparse en su significado, típicamente no reflejan en su totalidad los valores de la estrategia ambiental como fue definida por la CBD. Por ejemplo, actualmente hay un énfasis creciente en los servicios ambientales, pero enfocarse solamente en estos no promueve la descentralización del manejo o el uso de todas las formas de conocimiento, siendo ambas integrales para el concepto de la CBD. Resaltamos que los Principios de Malawi están en riesgo de ser olvidados. Para entender mejor estos principios, se requiere de más esfuerzo para implementarlos. Dichos esfuerzos deben ser evaluados, idóneamente con estrategias comparativas, antes de permitir que el concepto de la CBD de manejo holístico y comprometido socialmente sea abandonado o reemplazado. Es posible que los intentos por implementar los 12 principios juntos enfrentarán muchos obstáculos, pero también pueden ofrecer una forma única de promover el gobierno holístico y equitativo de los recursos naturales. Así, creemos que el concepto de estrategia ambiental de la CBD exige mayor atención. PMID:25039668

Evaluation of the educational technology "Caring for dependent people" by family caregivers in changes and transfers of patients and tube feeding.

PubMed

Landeiro, Maria José Lumini; Peres, Heloísa Helena Ciqueto; Martins, Teresa Vieira

2016-08-18

to assess the contributions of interactive educational technology "Caring for Dependent People" in the development of knowledge to family caregivers of dependent people in a household context and their satisfaction in its use. quasi-experimental study, not randomized, of the before and after type, with a convenience sample of 65 family caregivers, from two Medicine services of a hospital in Porto, Portugal. The Control Group consisted of 33 family caregivers and the Experimental Group of 32, identified by consecutive sampling. The experimental group had access to educational technology at home. Data were collected by socio-demographic, satisfaction and evaluation of knowledge questionnaire, about how to feed by nasogastric tube, positioning and transferring the dependent person. The assessment in both groups had two moments: initial, during hospitalization and one month after discharge. the experimental group had a larger increase in knowledge related to the use of the educational technology. In the control group the knowledge did not differ in the two evaluation time points. these results confirm the improvement of interactive educational technologies and in the training of family caregivers to care for dependents. This technology successfully met the technical quality and learning needs of caregivers, and was considered easy and stimulating. avaliar os contributos da tecnologia educacional interativa "Cuidar de Pessoas Dependentes" no desenvolvimento de conhecimentos aos familiares cuidadores de pessoas dependentes, no contexto domiciliário e a satisfação no seu uso. estudo quasi-experimental, não randomizado, do tipo antes e depois, com amostra de conveniência constituída por 65 familiares cuidadores, de dois Serviços de Medicina de um hospital do Porto, Portugal. O Grupo Controle foi constituído por 33 familiares cuidadores e o Grupo Experimental por 32, identificados por amostragem consecutiva. O grupo experimental teve Acesso à tecnologia educacional no domicílio. Os dados foram colhidos por questionário sociodemográfico de satisfação e avaliação de conhecimentos sobre como alimentar por sonda nasogástrica, posicionar e transferir a pessoa dependente. A avaliação nos dois grupos teve dois momentos: inicial, no internamento e um mês após alta hospitalar. registou-se no grupo experimental um ganho maior de conhecimentos relacionado com a utilização da tecnologia educacional. No grupo controle os conhecimentos não variaram nos dois momentos de avaliação. esses resultados corroboraram na melhoria das tecnologias educacionais interativas e na capacitação dos familiares cuidadores para cuidar de pessoas dependentes. Essa tecnologia atendeu satisfatoriamente as necessidades de qualidade técnica e de aprendizagem dos cuidadores, sendo considerada fácil e estimulante. evaluar las contribuciones de la tecnología educativa interactiva "Cuidar de personas dependientes" en el desarrollo de conocimiento de los familiares cuidadores de personas dependientes en el contexto domiciliario y la satisfacción en su uso. estudio cuasi-experimental, no aleatorizado, de tipo antes-después, con una muestra de 65 familiares cuidadores, de dos servicios de Medicina de un hospital en Oporto, Portugal. El grupo control consistió en 33 familiares cuidadores y el grupo experimental en 32, identificados por muestreo consecutivo. El grupo experimental tuvo acceso a la tecnología de la educación en el hogar. Los datos fueron recolectados por cuestionario sociodemográfico de satisfacción y evaluación de los conocimientos sobre cómo alimentar por sonda nasogástrica, posicionar y transferir a la persona dependiente. La evaluación en ambos grupos tuvo dos etapas: inicial, durante la hospitalización y un mes después del alta. se registraron en el grupo experimental aumentos del conocimiento relacionado con el uso de la tecnología educativa. En el grupo control el conocimiento no difirió en los dos puntos en el tiempo. estos resultados confirmaron el beneficio de las tecnologías interactivas educativas y la formación de los familiares cuidadores para el cuidado de personas dependientes. Esta tecnología cumplió con éxito con las necesidades técnicas y de calidad de aprendizaje de los cuidadores, siendo considerada fácil y estimulante.

Tone based command system for reception of very weak signals

NASA Technical Reports Server (NTRS)

Bokulic, Robert Steven (Inventor); Jensen, James Robert (Inventor)

2006-01-01

This disclosure presents a communication receiver system for spacecraft that includes an open loop receiver adapted to receive a communication signal. An ultrastable oscillator (USO) and a tone detector are connected to the open loop receiver. The open loop receiver translates the communication signal to an intermediate frequency signal using a highly stable reference frequency from the USO. The tone detector extracts commands from the communication signal by evaluating the difference between tones of the communication signal.

Effectiveness of HIV/STD Sexual Risk Reduction Groups for Women in Substance Abuse Treatment Programs: Results of a NIDA Clinical Trials Network Trial

PubMed Central

Tross, Susan; Campbell, Aimee N. C.; Cohen, Lisa R.; Calsyn, Donald; Pavlicova, Martina; Miele, Gloria; Hu, Mei-Chen; Haynes, Louise; Nugent, Nancy; Gan, Weijin; Hatch-Maillette, Mary; Mandler, Raul; McLaughlin, Paul; El-Bassel, Nabila; Crits-Christoph, Paul; Nunes, Edward V.

2009-01-01

Context Since drug-involved women are among the fastest growing groups with AIDS, sexual risk reduction intervention for them is a public health imperative. Objective Test effectiveness of HIV/STD safer sex skills building (SSB) groups for women in community drug treatment. Design Randomized trial of SSB versus standard HIV/STD Education (HE); assessments at baseline, 3- and 6- months Participants Women recruited from 12 methadone or psychosocial treatment programs in NIDA’s Clinical Trials Network. 515 women with ≥ one unprotected vaginal or anal sex occasion (USO) with a male partner in the past 6 months were randomized. Interventions In SSB, five 90-minute groups used problem-solving and skills rehearsal to increase HIV/STD risk awareness, condom use and partner negotiation skills. In HE, one 60-minute group covered HIV/STD disease, testing, treatment, and prevention information. Main Outcome Number of USOs at follow up. Results A significant difference in mean USOs was obtained between SSB and HE over time (F=67.2, p<.0001). At 3 months, significant decrements were observed in both conditions. At 6 months SSB maintained the decrease, HE returned to baseline (p<.0377). Women in SSB had 29% fewer USOs than those in HE. Conclusions Skills building interventions can produce ongoing sexual risk reduction in women in community drug treatment. PMID:18645513

Effectiveness of HIV/STD sexual risk reduction groups for women in substance abuse treatment programs: results of NIDA Clinical Trials Network Trial.

PubMed

Tross, Susan; Campbell, Aimee N C; Cohen, Lisa R; Calsyn, Donald; Pavlicova, Martina; Miele, Gloria M; Hu, Mei-Chen; Haynes, Louise; Nugent, Nancy; Gan, Weijin; Hatch-Maillette, Mary; Mandler, Raul; McLaughlin, Paul; El-Bassel, Nabila; Crits-Christoph, Paul; Nunes, Edward V

2008-08-15

Because drug-involved women are among the fastest growing groups with AIDS, sexual risk reduction intervention for them is a public health imperative. To test effectiveness of HIV/STD safer sex skills building (SSB) groups for women in community drug treatment. Randomized trial of SSB versus standard HIV/STD Education (HE); assessments at baseline, 3 and 6 months. Women recruited from 12 methadone or psychosocial treatment programs in Clinical Trials Network of National Institute on Drug Abuse. Five hundred fifteen women with >or=1 unprotected vaginal or anal sex occasion (USO) with a male partner in the past 6 months were randomized. In SSB, five 90-minute groups used problem solving and skills rehearsal to increase HIV/STD risk awareness, condom use, and partner negotiation skills. In HE, one 60-minute group covered HIV/STD disease, testing, treatment, and prevention information. Number of USOs at follow-up. A significant difference in mean USOs was obtained between SSB and HE over time (F = 67.2, P < 0.0001). At 3 months, significant decrements were observed in both conditions. At 6 months, SSB maintained the decrease and HE returned to baseline (P < 0.0377). Women in SSB had 29% fewer USOs than those in HE. Skills building interventions can produce ongoing sexual risk reduction in women in community drug treatment.

Health Services Use and HIV Prevalence Among Migrant and National Female Sex Workers in Portugal: Are We Providing the Services Needed?

PubMed

Dias, Sónia; Gama, Ana; Pingarilho, Marta; Simões, Daniel; Mendão, Luís

2017-08-01

This cross-sectional bio-behavioral survey conducted with 853 female sex workers (FSW) aimed to examine differences in use of HIV health services, testing and prevalence among migrant and national FSW. A quarter of undocumented FSW had never used National Health Service (NHS) and 15 % never tested for HIV, significantly more than nationals (p < 0.001 and p = 0.024, respectively). HIV infection was self-reported by 11.9 % of nationals, 1.8 % of documented and 0.8 % of undocumented migrants (p < 0.001). The HIV rapid test was reactive in 13.6 % of undocumented, 8.0 % of nationals and 2.3 % of documented. A higher proportion of migrants were unaware of their positive serostatus compared to nationals. Ever had HIV testing was less likely among undocumented, who never used the NHS and who didn't know where to go if suspected being HIV-infected. Promoting early diagnosis with linkage to care among migrant FSW should be supported, while developing health services better tailored to their needs. Una encuesta transversal biocomportamental fue realizada con una muestra de 853 trabajadoras sexuales (TS) con el objetivo de examinar diferencias en el uso de servicios de salud del VIH, test y prevalencia entre TS migrantes y nacionales. Un cuarto de las TS indocumentadas nunca utilizaron el Servicio Nacional de Salud (SNS) y el 15 % nunca fueron testadas respecto al VIH, porcentajes significativamente superiores a las observadas para las nacionales (p < 0.001 y p = 0.024, respectivamente). La infección por VIH fue auto reportada por 11.9 % de las nacionales, 1.8 % de las migrantes documentadas y 0.8 % de las indocumentadas (p < 0.001). El test rápido del VIH fue reactivo para un 13.6 % de las indocumentadas, 8.0 % de las nacionales y 2.3 % de las documentadas. Una proporción mayor de migrantes desconocía su serostatus positivo en comparación con las nacionales. El test del VIH fue menos frecuente entre las indocumentadas, quien nunca utilizó el SNS y quien no sabía dónde recurrir si sospechaba estar infectada por el VIH. Promover un diagnóstico precoz en conexión con los cuidados en TS migrantes debe ser respaldado mientras se desarrollan servicios de salud mejor adaptados a sus necesidades.

Como Lo Hago Yo: Mielomeningocele En Bolivia

PubMed Central

Dabdoub, Carlos F.; Dabdoub, Carlos B.; Villavicencio, Ramiro; Quevedo, Germán

2014-01-01

Introducción: Las malformaciones del tubo neural (MTN) representan la segunda causa más frecuente de anomalías congénitas, luego de las cardiopatías. En este grupo se destaca el mielomeningocele (MMC) por su mayor incidencia, y por ser la más incapacitante y la más compleja entre todas las demás malformaciones del sistema nervioso c`entral (SNC). En Bolivia, como en muchos países de Sudamérica, los bajos niveles socio-culturales y la debilidad en el sistema sanitario, hacen que su incidencia y su morbilidad, sean mayores que en las naciones más desarrolladas. Material y Métodos: Se realizó un estudio retrospectivo y descriptivo de 70 casos de MMC, atendidos por un equipo multidisciplinario en el Hospital Universitario Japonés (HUJ) de Santa Cruz de la Sierra, entre 2008-2011. De ellos, 60 fueron intervenidos quirúrgicamente. Resultados: Se realizaron controles prenatales sólo en 27 mujeres (38.6%), diagnosticándose una disrafia espinal en apenas dos casos (7.4%). La edad de ingreso del MMC en su mayoría fue después de las 24 horas (65.6%), predominando su localización en la región lumbosacra (64.3%). De ellos, 67.2% eran abiertos, presentando un 32.9% un daño neurológico motor parcial mientras que 47.1% tenían paraplejia por debajo de la lesión. De los 70 casos, tres (4.3%) no fueron intervenidos, por presentar defectos congénitos severos o estado general grave. Las principales complicaciones posoperatorias inmediatas fueron: dehiscencia de sutura y/o infección de la herida (16.6%), fístula de líquido cefalorraquídeo (LCR) (10%) e infección del SNC (11.7%). La mortalidad general y postoperatoria fue de 7.1% y 3.3%, respectivamente. Al mes de vida presentaban hidrocefalia un 80% de los pacientes operados, colocándose una derivación ventriculoperitoneal (DVP) de presión media. De 9 pacientes que tuvieron un acompanamiento de dos o más años, seis presentaron una médula anclada, que fueron intervenidas quirúrgicamente. Conclusión: En esta serie, el diagnóstico prenatal del MMC fue ocasional y la derivación al HUJ de los recién nacidos con esta malformación fue generalmente tardía. No hubo predominio de género y la mayoría de los casos presentaron sus lesiones en la región lumbar y lumbosacra. La mortalidad general y postoperatoria fue similar a la reportada en la literatura. Pocos enfermos realizaron controles posteriores al alta hospitalaria. Igual que otros países de Sudamérica, las falencias en el sistema público de salud y el nivel sociocultural, son factores determinantes para un mal pronóstico en estos niños. Por sus múltiples complicaciones, el MMC requiere de una especial atención gubernamental, sobre todo de carácter preventivo mediante el uso de ácido fólico en mujeres fértiles, como también de un equipo profesional multidisciplinario, a fin de realizar un tratamiento adecuado y oportuno. Al mismo tiempo, trabajos multicéntricos en hospitales de América Latina, ayudarán al mejor manejo de estos pacientes. PMID:24791220

Capture-zone design in an aquifer influenced by cyclic fluctuations in hydraulic gradients

NASA Astrophysics Data System (ADS)

Zawadzki, Willy; Chorley, Don; Patrick, Guy

2002-10-01

Design of a groundwater pumping and treatment system for a wood-treatment facility adjacent to the tidally influenced Fraser River estuary required the development of methodologies to account for cyclic variations in hydraulic gradients. Design of such systems must consider the effects of these cyclic fluctuations on the capture of dissolved-phase contaminants. When the period of the cyclic fluctuation is much less than the travel time of the dissolved contaminant from the source to the discharge point, the hydraulic-gradient variations resulting from these cycles can be ignored. Capture zones are then designed based on the average hydraulic gradient determined using filter techniques on continuous groundwater-level measurements. When the period of cyclic fluctuation in hydraulic gradient is near to or greater than the contaminant travel time, the resulting hydraulic-gradient variations cannot be ignored. In these instances, procedures are developed to account for these fluctuations in the capture-zone design. These include proper characterization of the groundwater regime, assessment of the average travel time and period of the cyclic fluctuations, and numerical techniques which allow accounting for the cyclic fluctuations in the design of the capture zone. Résumé. L'étude d'un système de pompage et de traitement de l'eau souterraine d'une usine de traitement du bois proche de l'estuaire de la rivière Fraser, influencé par les marées, a nécessité la mise au point de méthodologies pour prendre en compte les variations cycliques de gradients hydrauliques. L'étude de tels systèmes doit considérer les effets de ces variations cycliques sur l'extraction des contaminants en phase dissoute. Lorsque la période des variations cycliques est très inférieure au temps de parcours du contaminant dissous entre la source et le point d'émergence, les variations du gradient hydraulique résultant de ces cycles peuvent être ignorées. Les zones d'extraction sont alors réalisées sur la base du gradient hydraulique moyen déterminé au moyen de techniques de filtrage sur des mesures continues de la piézométrie. Lorsque la période de la fluctuation cyclique dans le gradient hydraulique est proche de ou supérieure au temps de parcours du contaminant, les variations résultantes de gradient hydraulique ne peuvent plus être ignorées. Dans ces cas-là, des procédures ont été mises au point pour prendre en compte ces fluctuations dans la conception de la zone d'extraction. Celles-ci prennent en considération la caractérisation propre du régime de la nappe, l'évaluation du temps de parcours moyen et de la période des fluctuations cycliques, et des techniques numériques qui permettent de considérer les fluctuations cycliques dans la conception de la zone d'extraction. Resumen. El diseño de un sistema de bombeo y tratamiento de aguas subterráneas para una instalación de manufactura de madera que está próxima al estuario del río Fraser, sometido a la influencia de las mareas, ha requerido el desarrollo de metodologías para tener en cuenta las variaciones cíclicas de los gradientes hidráulicos. El diseño de tales sistemas debe considerar los efectos de las fluctuaciones cíclicas en la captura de contaminantes en fase disuelta. Cuando el período de la fluctuación cíclica es mucho menor que el tiempo de tránsito del contaminante disuelto entre el punto de entrada y el de descarga, se puede ignorar las variaciones del gradiente hidráulico provocadas por dichos ciclos. Las zonas de captura se diseñan entonces en función del gradiente hidráulico promedio, que se determina mediante técnicas de filtrado de medidas continuas del nivel piezométrico. Cuando el período de la fluctuación cíclica del gradiente hidráulico es comparable o mayor que el tiempo de tránsito del contaminante, no puede ignorarse las variaciones resultantes en el gradiente hidráulico. En ese caso, se tiene que desarrollar procedimientos para contar con las fluctuaciones en el diseño de las zonas de captura. Ello implica una adecuada caracterización del régimen de las aguas subterráneas, el establecimiento del tiempo de tránsito y del período de las fluctuaciones cíclicas, y el uso de técnicas numéricas que permitan incluirlas en el diseño de la zona de captura.

Cateteres venosos centrais de inserção periférica: alternativa ou primeira escolha em acesso vascular?

PubMed Central

Di Santo, Marcelo Kalil; Takemoto, Diogo; Nascimento, Robert Guimarães; Nascimento, Ariele Milano; Siqueira, Érika; Duarte, Caio Túlio; Jovino, Marco Antônio Caldas; Kalil, Jorge Agle

2017-01-01

Resumo Contexto Os cateteres venosos centrais de inserção periférica (PICC) são dispositivos intravenosos, introduzidos através de uma veia superficial ou profunda da extremidade superior ou inferior até o terço distal da veia cava superior ou proximal da veia cava inferior. Apresentam maior segurança para infusão de soluções vesicantes/irritantes e hiperosmolares, antibioticoterapia, nutrição parenteral prolongada (NPT) e uso de quimioterápicos; demonstram reduzido risco de infecção em comparação a outros cateteres vasculares e maior relação custo/benefício se comparados ao cateter venoso de inserção central (CVCIC). Objetivos Apresentar os resultados de implantes de PICCs ecoguiados e posicionados por fluoroscopia realizados no Hospital e Maternidade São Luiz (HMSL) Itaim, Rede D’or, Brasil. Métodos Estudo prospectivo, não randomizado, realizado entre fevereiro de 2015 e novembro de 2016. Utilizou-se protocolo pré-estabelecido pela instituição em casos de solicitação de acesso vascular. Foram analisadas indicações, doenças prevalentes, tipo do cateter implantado, sucesso técnico, complicações relacionadas ao cateter, e estabelecidos critérios de inclusão e exclusão. Resultados Solicitados 256 acessos vasculares, sendo implantados 236 PICCs (92,1%) e 20 CVCICs (7,9%). Principais indicações: antibioticoterapia prolongada (52,0%), NPT (19,3%) e acesso venoso difícil (16,0%). Houve sucesso técnico em 246 cateteres implantados (96,1%). A veia basílica direita foi a principal veia puncionada em 192 pacientes (75,0%), seguida da braquial direita em 28 pacientes (10,9%). Conclusões O implante dos PICCs ecoguiados e posicionados por fluoroscopia demonstrou baixa incidência de complicações, reduzidos índices de infecção e é seguro e eficaz em casos de acessos vasculares difíceis, sendo esses cateteres considerados dispositivos de escolha em acesso vascular central.

Disegno dello studio genomico, ambientale, microbiomico e metabolomico sulla celiachia: un approccio al futuro della prevenzione personalizzata della celiachia

PubMed Central

SERENA, GLORIA; LEONARD, MAUREEN M.; CAMHI, STEPHANIE; HUEDO-MEDINA, TANIA B.; FASANO, ALESSIO

2017-01-01

Riassunto Negli ultimi anni abbiamo assistito a un fiorire di novità cliniche e scientifiche sulla celiachia (CE), ma forse la novità più importante che influenzerà il futuro della ricerca e della clinica in questo campo riguarda la storia naturale della malattia. Per molti anni si è creduto che la predisposizione genetica e l’esposizione al glutine fossero necessarie e sufficienti allo sviluppo della CE. Studi recenti, però suggeriscono che la perdita di tolleranza al glutine possa apparire in qualsiasi momento della vita a seguito di altri elementi. Inoltre, diversi fattori ambientali conosciuti per il loro ruolo nell’influenzare la composizione della microflora intestinale sono anche stati considerati legati allo sviluppo della CE. Tra questi fattori sono inclusi la modalità di parto, la dieta dell’infante e l’uso di antibiotici. A tutt’oggi, nessuno studio longitudinale di ampia scala ha determinato se e come la composizione del microbioma e il suo profilo metabolomico possano influenzare la perdita di tolleranza al glutine e il successivo sviluppo della CE in soggetti geneticamente predisposti. In questo articolo descriviamo uno studio prospettico, multicentrico e longitudinale su infanti a rischio per la CE che utilizzerà diverse tecniche per approfondire il ruolo che il microbioma intestinale ha durante i primi passaggi dello sviluppo della malattia autoimmune. PMID:27362724

Using a Blog to Guide Beginner Students to Use Adjectives Appropriately When Writing Descriptions in English (El uso de una bitácora o "blog" para guiar a estudiantes principiantes en el uso apropiado de los adjetivos cuando escriben descripciones en inglés)

ERIC Educational Resources Information Center

Lizarazo Jara, Omar Yesid

2012-01-01

Beginner students often have difficulties using adjectives when they write descriptions in English. This article focuses on the procedures used to help my sixth grade students understand and use adjectives in the correct order by using a blog. To achieve the objective of the project I decided to implement an innovation in and out of class…

[Inhibitive effect of LAK cells induced by dendritic cells on implanted lung cancer in nude mice].

PubMed

Gao, Qiu; Li, Jintian; Wang, Siyu; Chen, Shiping; Liu, Wei; Wu, Yilong

2004-10-20

To study the inhibitive effect of LAK cells induced by dendritic cells (DCs) on implanted lung adenocarcinoma in nude mice. The lung adenocarcinoma model was constructed in nude mice using the resected samples of lung cancer patient. The lung cancer cell lysate was obtained by free-zing and thrawing cycles. Peripheral blood mononuclear cells (PBMNC) were obtained from venous blood of the same patient, in which the adherent PBMNC fraction was cultured with DCGF, and the non-adherent PBMNC fraction was cultured with rhIL-2. DCs were pulsed with lung cancer cell lysates. And then mature DCs were incubated with LAK cells and the mixed cells were named DC-LAK cells. DC-LAK cells were injected into lung cancer-bearing nude mice to observe the inhibitive effect. The lung adenocarcinoma mo-del was successfully constructed. The average tumor weights of DC-LAK, LAK, DC and saline control groups were 0.47, 1.05, 1.30 and 1.58 g respectively, and the inhibitive rates of DC-LAK, LAK and DC were 70.3%, 33.5% and 17.9% respectively. The antitumor activity of DC-LAK cells was significantly stronger than that of LAK cells (P < 0.05). The results of in vivo experiment show that the antitumor activity of DC-LAK cells is stronger than that of LAK cells, so DC-LAK cells treatment may be a more efficient approach of lung cancer biological therapy. This experiment may provide a foundation for clinical application of DC vaccine.

Care management: agreement between nursing prescriptions and patients' care needs.

PubMed

Faeda, Marília Silveira; Perroca, Márcia Galan

2016-08-08

analyze agreement between nursing prescriptions recorded in medical files and patients' care needs; investigate the correlation between the nurses' professional background and agreement of prescriptions. descriptive study with quantitative and documentary approach conducted in the medical clinic, surgical, and specialized units of a university hospital in the interior of São Paulo, Brazil. The new validated version of a Patient Classification Instrument was used and 380 nursing prescriptions written at the times of hospital admission and discharge were assessed. 75% of the nursing prescriptions items were compatible with the patients' care needs. Only low correlation between nursing prescription agreement and professional background was found. the nursing prescriptions did not fully meet the care needs of patients. The care context and work process should be analyzed to enable more effective prescriptions, while strategies to assess the care needs of patients are recommended. analisar a concordância entre prescrições de enfermagem, registradas nos prontuários, e as necessidades de cuidados dos pacientes; investigar a correlação entre o perfil profissional dos enfermeiros e a concordância das prescrições. estudo descritivo com abordagem quantitativa e documental, realizado em unidades de clínica médica, cirúrgica e especializada de um hospital de ensino, no interior do Estado de São Paulo. Foi aplicada a nova versão validada do Instrumento de Classificação de Pacientes e, posteriormente, investigadas 380 prescrições de enfermagem no momento da admissão e alta hospitalar. foi identificado que 75% dos itens das prescrições de enfermagem estavam compatíveis com as necessidades cuidativas dos pacientes. Encontrou-se baixa correlação entre a concordância da prescrição de enfermagem e o perfil profissional. as prescrições de enfermagem não estão sendo realizadas, em sua totalidade, em consonância com as necessidades dos pacientes. Para possibilitar prescrições mais efetivas, recomenda-se análise do contexto assistencial e processo de trabalho e o uso de estratégias avaliativas das necessida¬des de cuidados dos pacientes. analizar la concordancia entre prescripciones de enfermería, registradas en las fichas médicas, y las necesidades de cuidados de los pacientes; investigar la correlación entre el perfil profesional de los enfermeros y la concordancia de las prescripciones. estudio descriptivo con abordaje cuantitativo y documental, realizado en unidades de clínica médica, quirúrgica y especializada de un hospital de enseñanza, en el interior del Estado de Sao Paulo. Fue aplicada la nueva versión validada del Instrumento de Clasificación de Pacientes y, posteriormente, investigadas 380 prescripciones de enfermería en el momento de la admisión y alta hospitalaria. fue identificado que 75% de los ítems de las prescripciones de enfermería eran compatibles con las necesidades de cuidados de los pacientes. Se encontró baja correlación entre la concordancia de la prescripción de enfermería y el perfil profesional. las prescripciones de enfermería no están siendo realizadas, en su totalidad, en consonancia con las necesidades de los pacientes. Para posibilitar prescripciones más efectivas, se recomienda analizar el contexto asistencial y el proceso de trabajo y el uso de estrategias de evaluación de las necesidades de cuidados de los pacientes.

Social Representations of Gynecologic Cancer Screening Assessment a Qualitative research on Ecuadorian women.

PubMed

Godoy, Yolanda; Godoy, Clara; Reyes, Juan

2016-06-01

The purpose of this work was to explore: knowledge, attitudes, and beliefs regarding gynecologic cancer screening on Ecuadorian women users of primary care facilities, to identify the social representations that users of health services make about these programs and their influence on the decision to undergo a screening. An exploratory and qualitative research design was held using focus groups and in-depth interviews for data collection. A narrative content analysis of the results was conducted. Women's knowledge on gynecological cancer screening was confusing. Most frequent misconceptions related to the pap smear were: the belief that it could be useful for detecting pregnancy, ovarian cysts or infections. Most of the participants stated that the pap smear procedure is a traumatic and painful experience. Regarding to mammography women said it was used for sick woman and this procedure by itself may cause cancer. El propósito de esta investigación fue explorar los conocimientos, actitudes y creencias respecto a los programas de detección del cáncer ginecológico entre usuarias de centros de atención primaria de salud para identificar las representaciones sociales que las usuarias de los servicios de salud elaboran acerca de estos programas y de los diferentes procedimientos que comprenden. El diseño de la investigación fue exploratorio y cualitativo, mediante grupos focales y entrevistas a profundidad, con el respectivo análisis narrativo e interpretativo del contenido. Se encontró conocimiento confuso acerca de los programas de tamizaje de cáncer ginecológico y dificultades asociadas a la realización de los procedimientos. Los significados más frecuentes acerca de los programas fueron: el uso de la citología cérvico-vaginal para detectar embarazo, quistes ováricos o infecciones. La mayoría de los participantes asociaba este procedimiento con una experiencia dolorosa y traumática. Respecto al autoexamen de mamas, lo calificaron como un masaje preventivo-terapéutico y a la mamografía como peligrosa porque podría desarrollar cáncer.

Influence of biological soil crusts at different successional stages in the implantation of biogeochemical cycles in arid and semiarid zones

NASA Astrophysics Data System (ADS)

Gil-Sotres, F.; Miralles, I.; Canton-Castilla, Y.; Domingo, F.; Leiros, M. C.; Trasar-Cepeda, C.

2012-04-01

Influence of biological soil crusts at different successional stages in the implantation of biogeochemical cycles in arid and semiarid zones I. Miralles1, F. Gil-Sotres2, Y. Cantón-Castilla3, F. Domingo1, M.C. Leirós2, C. Trasar-Cepeda4 1 Experimental Estation of Arid Zones (CSIC), E-04230 La Cañada de San Urbano, Almería, Spain. 2 Departamento Edafología y Química Agrícola, Grupo de Evaluación de la Calidad del Suelo, Unidad Asociada CSIC, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain. 3 University of Almería, Departamento de Edafología y Química Agrícola, E-04230-La Cañada de San Urbano, Almería, Spain. 4 Departamento Bioquímica del Suelo, IIAG-CSIC, Apartado 122, E-15708 Santiago de Compostela, Spain. Crusts (BSCs) are formed by a close association between soil particles and cyanobacteria, algae, lichens, bryophytes and microfungi in varying proportions. Their habitat is within or immediately on top of the uppermost millimetres of the soil and are the predominant surface cover in arid and semiarid zones. Among the diverse functions developed by BSCs in the ecosystem (hydrology, erosion, soil properties, etc.), one of the most important is its role in nutrient cycling. Within arid and semiarid environments, BSCs have been termed 'mantles of fertility' being considered hotspots of biogeochemical inputs, fixing C, N and P above- and below-ground. However, there are differences in N and C fixation rates between BSCs types. Early successional BSCs, dominated by cyanobacterial species, fix lower quantities of C and N than mature BSCs dominated by lichens. Although the positive effects of BSCs on biogeochemical soil cycles are widely accepted, no previous studies have evaluated the activities of the enzymes involved in C, N and P cycles of BSCs and how they are affected by the successional stage of the BSC. In this work, performed in the Tabernas desert (SE Spain), we studied the hydrolase enzymes involved in C (invertase, CM-cellulase, β-glucosidase), N (urease, BAA-protease, casein-protease) and P (phosphomonoesterase) cycles in BSCs at different successional stages (cyanobacteria represents the first successional stage, lichen Diploschistes diacapsis in an intermediate state and lichen Lepraria crassissima, with the greatest successional state). Our results show that BSCs at lower successional stage enriched the surface geological substrate in hydrolase enzymes to a lesser extent than mature BSCs (Lepraria crassissima), which show the highest values in all enzymatic activities. In contrast, the specific enzyme activities (activity values expressed per unit of carbon) were higher in the BSCs at lower successional stage, decreasing in the direction: cyanobacteria > Diploschistes diacapsis-lichen > Lepraria crassissima-lichen. These results suggest a different role of BSCs depending on their successional stage with regard to the implantation of biogeochemical cycles during the surface substrate colonization. Our conclusions are highly relevant to improve the knowledge of biogeochemical cycles in arid and semiarid areas. Keywords: Biological Soil Crusts, arid ecosystems, hydrolytic enzymes, biochemical activity

Stress among healthcare students--a cross disciplinary perspective.

PubMed

Jacob, Tamar; Itzchak, Esther Ben; Raz, Olga

2013-07-01

Perceived stress (PS) among healthcare students worldwide is a recognized problem. To address the paucity of data about the actual degree of PS, this study aimed to: 1) evaluate and compare PS across three healthcare programs (Physical Therapy [PT], Communication Disorders [CD], and Nutrition Sciences [NS]) in one university; 2) evaluate changes in PS across study years; 3) identify the contribution of academic- and socio-demographic-related variables to PS; and 4) determine whether the Israeli students' PS levels differ from those of their peers in other countries. A cross-sectional survey was performed among all undergraduate PT, CD, and NS students from one university. Data were collected using anonymous questionnaires. Instruments included the Perceived Stress Scale 10 (PSS) and the Undergraduate Sources of Stress (USOS). ANOVA was used to evaluate the differences between the three programs, and regression analysis to evaluate the contribution of socio-demographic factors to PS and USOS. A total of 312 students (PT--154; CD--92; NS--66) participated in the study. Mean PSS (range: 13.5-13.6) was similar in the three programs. The USOS academic factor was the most reported source of stress in all programs. Most socio-demographic variables were not related to either PS or USOS. Students from PT, CD, and NS programs perceived similar levels of stress. The academic factor was perceived as the most important source of stress by students from the three departments, despite differences in the academic educational programs. Further studies are needed to generalize these results and enable a comparison between healthcare students and other students' stress perceptions.

Subgingival microbiome in patients with healthy and ailing dental implants

PubMed Central

Zheng, Hui; Xu, Lixin; Wang, Zicheng; Li, Lianshuo; Zhang, Jieni; Zhang, Qian; Chen, Ting; Lin, Jiuxiang; Chen, Feng

2015-01-01

Dental implants are commonly used to replace missing teeth. However, the dysbiotic polymicrobial communities of peri-implant sites are responsible for peri-implant diseases, such as peri-implant mucositis and peri-implantitis. In this study, we analyzed the microbial characteristics of oral plaque from peri-implant pockets or sulci of healthy implants (n = 10), peri-implant mucositis (n = 8) and peri-implantitis (n = 6) sites using pyrosequencing of the 16S rRNA gene. An increase in microbial diversity was observed in subgingival sites of ailing implants, compared with healthy implants. Microbial co-occurrence analysis revealed that periodontal pathogens, such as Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia, were clustered into modules in the peri-implant mucositis network. Putative pathogens associated with peri-implantitis were present at a moderate relative abundance in peri-implant mucositis, suggesting that peri-implant mucositis an important early transitional phase during the development of peri-implantitis. Furthermore, the relative abundance of Eubacterium was increased at peri-implantitis locations, and co-occurrence analysis revealed that Eubacterium minutum was correlated with Prevotella intermedia in peri-implantitis sites, which suggests the association of Eubacterium with peri-implantitis. This study indicates that periodontal pathogens may play important roles in the shifting of healthy implant status to peri-implant disease. PMID:26077225

International Space Station USOS Waste and Hygiene Compartment Development

NASA Technical Reports Server (NTRS)

Link, Dwight E., Jr.; Broyan, James Lee, Jr.; Gelmis, Karen; Philistine, Cynthia; Balistreri, Steven

2007-01-01

The International Space Station (ISS) currently provides human waste collection and hygiene facilities in the Russian Segment Service Module (SM) which supports a three person crew. Additional hardware is planned for the United States Operational Segment (USOS) to support expansion of the crew to six person capability. The additional hardware will be integrated in an ISS standard equipment rack structure that was planned to be installed in the Node 3 element; however, the ISS Program Office recently directed implementation of the rack, or Waste and Hygiene Compartment (WHC), into the U.S. Laboratory element to provide early operational capability. In this configuration, preserved urine from the WHC waste collection system can be processed by the Urine Processor Assembly (UPA) in either the U.S. Lab or Node 3 to recover water for crew consumption or oxygen production. The human waste collection hardware is derived from the Service Module system and is provided by RSC-Energia. This paper describes the concepts, design, and integration of the WHC waste collection hardware into the USOS including integration with U.S. Lab and Node 3 systems.

International Space Station USOS Crew Quarters Development

NASA Technical Reports Server (NTRS)

Broyan, James Lee, Jr.; Borrego, Melissa Ann; Bahr, Juergen F.

2008-01-01

The International Space Station (ISS) United States Operational Segment (USOS) currently provides a Temporary Sleep Station (TeSS) as crew quarters for one crewmember in the Laboratory Module. The Russian Segment provides permanent crew quarters (Kayutas) for two crewmembers in the Service Module. The TeSS provides limited electrical, communication, and ventilation functionality. A new permanent rack sized USOS ISS Crew Quarters (CQ) is being developed. Up to four CQs can be installed into the Node 2 element to increase the ISS crewmember size to six. The new CQs will provide private crewmember space with enhanced acoustic noise mitigation, integrated radiation reduction material, controllable airflow, communication equipment, redundant electrical systems, and redundant caution and warning systems. The rack sized CQ is a system with multiple crewmember restraints, adjustable lighting, controllable ventilation, and interfaces that allow each crewmember to personalize their CQ workspace. Providing an acoustically quiet and visually isolated environment, while ensuring crewmember safety, is critical for obtaining crewmember rest and comfort to enable long term crewmember performance. The numerous human factor, engineering, and program considerations during the concept, design, and prototyping are outlined in the paper.

Conversations with Marcgrave: the Origin of Modern Astronomy in the Southern Hemisphere (Spanish Title: Conversando con Marcgrave: El Origen de la Astronomía Moderna en el Hemisferio Sur) Conversando Com Marcgrave: a Origem da Moderna Astronomia no Hemisfério Sul

NASA Astrophysics Data System (ADS)

Medeiros, Alexandre; Araújo, Fábio

2005-12-01

The year 2004 signals the 400th anniversary of the birth of count Mauricio of Nassau, an important character in the history of Brazil. The present text is related to the period of Dutch domination in Pernambuco. The article attempts to rescue the beginnings of Astronomy study in the South hemisphere. Therefore, we idealized a dramatization of a fictitious interview with German astronomer Georg Marcgrave, who was the constructor of the first astronomical observatory in this hemisphere and the author of the first systematic astronomical observations using telescopes in this side of the world. Our "conversation" with Marcgrave is idealized in the old Recife scenario, a place where he lived in Mauricio of Nassau's period and gathers some fellow teachers who love the teaching of Astronomy. The story, this way, is reported in a possibly light and funny atmosphere. Nevertheless, the conceptual and historical framework presented is based on reliable bibliographical sources pointed out at the end of the text. The sources range from the original book of that scientist, in which a solar eclipse is reported, passing through some other classical texts, such as that of Professor Juliano Moreira, up to more recent sources such as the very influential work of professor John North. Other influential texts about the Dutch period in Brazil, such as the classical works of Charles Boxer, Bouman and Boogaart, among others, are also used in the construction of this pedagogical dramatization, which involves an interesting chapter of the history of Astronomy. El año 2004 marca los 400 años del nacimineto del conde Mauricio de Nassau, un importante personaje de la historia del Brasil. El presente texto está relacionado con el período del dominio holandés en Pernambuco. El artículo intenta rescatar los comienzos del estudio de la Astronomía en el hemisferio Sur. Para esto, ideamos una dramatización de una entrevista ficticia con el astrónomo alemán Georg Marcgrave, constructor del primer observatorio astronómico del hemisferio y autor de las primeras observaciones astronómicas sistemáticas utilizando telescopios de este lado del mundo. Nuestra "conversación" con Marcgrave es imaginada en el marco del Recife antiguo, lugar donde él vivió durante el período de Mauricio de Nassau, y reune algunos colegas profesores apasionados por la enseñanza de la Astronomía. La historia es contada, de esta forma, dentro de un clima ameno y hasta un poco divertido, si bien las informaciones históricas y conceptuales contenidas en ella están basadas en fuentes bibliográficas confiables, debidamente referenciadas al final del texto. Estas fuentes van desde la obra original de este científico, en la cual aparece su relato sobre la observación de un eclipse solar en Recife, pasando por obras clásicas respecto de él mismo, como la del profesor Juliano Moreira, hasta fuentes mucho más recientes como el influyente trabajo del profesor John North. Otros textos importantes referidos al período de la colonización holandesa en el Brasil, tales como las obras clásicas de Charles Boxer, Bouman y Boogaart entre otros, son también utilizados en la construcción de esta dramatización pedagógica que se refiere a un interesante capítulo de la Historia de la Astronomía. O ano de 2004 assinala os 400 anos do nascimento do conde Maurício de Nassau, um importante personagem da história do Brasil. O presente texto está relacionado com o período do domínio holandês em Pernambuco. O artigo tenta resgatar o começo do estudo da Astronomia no hemisfério Sul. Para tal, idealizamos uma dramatização de uma entrevista fictícia com o astrônomo alemão Georg Marcgrave, construtor do primeiro observatório astronômico deste hemisfério e autor das primeiras observações astronômicas sistemáticas com o uso de telescópios neste lado do mundo. Nossa "conversa" com Marcgrave é idealizada no cenário do Recife antigo, local em que ele viveu no período de Maurício de Nassau e reúne alguns colegas professores apaixonados pelo ensino da Astronomia. A história é contada, deste modo, em um clima ameno e pretensamente divertido, mas as informações históricas e conceituais nele contidas estão apoiadas em fontes bibliográficas confiáveis devidamente apontadas ao final do texto. Elas vão desde a obra original desse cientista, na qual aparece o seu relato sobre a observação de um eclipse solar no Recife, passando por obras clássicas a seu respeito, como a do professor Juliano Moreira, até fontes bem mais recentes, como o trabalho muito influente do Professor John North. Outros textos de porte sobre o período da colonização holandesa no Brasil, como as obras já clássicas de Charles Boxer, Bouman e Boogaart, dentre outras, são também utilizados na construção desta dramatização pedagógica envolvendo um interessante capítulo da História da Astronomia.

Regional characterisation of hydraulic properties of rock using air-lift data

NASA Astrophysics Data System (ADS)

Wladis, David; Gustafson, Gunnar

Hydrogeologic studies are commonly data-intense. In particular, estimations of hydraulic properties of hard rock often require large amounts of data. In many countries, large quantities of hydrogeologic data have been collected and archived over the years. Therefore, the use of existing data may provide a cost-efficient alternative to collecting new data in early stages of hydrogeologic studies, although the available data may be considered imprecise. Initially, however, the potential usefulness, i.e., the expected accuracy, of the available data in each specific case must be carefully examined. This study investigates the possibilities of obtaining estimates of transmissivity from hard-rock air-lift data in Sweden within an order of magnitude of results obtained from high-quality injection-test data. The expected accuracy of the results was examined analytically and by means of statistical methods. The results were also evaluated by comparison with injection-test data. The results indicate that air-lift data produce estimates of transmissivity within an order of magnitude compared to injection-test data in the studied examples. The study also shows that partial penetration and hydrofracturing may only affect the estimations approximately half an order of magnitude. Thus, existing data may provide a cost-efficient alternative to collection of new data in early stages of hydrogeologic studies. Résumé Les études hydrogéologiques reposent en général sur un nombre important de données. En particulier, l'estimation des propriétés hydrauliques des roches indurées exige souvent un grand nombre de données. Dans de nombreuses régions, des données hydrogéologiques très nombreuses ont été recueillies et archivées depuis longtemps. C'est pourquoi le recours à des données existantes peut être une alternative intéressante en termes de coût par rapport à l'obtention de nouvelles données dans les premières étapes des études hydrogéologiques, même si les données disponibles présentent une certaine imprécision. Au départ, il faut cependant examiner l'utilité potentielle, c'est-à-dire la précision attendue, de données imprécises dans chaque cas spécifique. Cette étude analyse les possibilités d'obtenir des estimations de transmissivitéà partir de données d'air-lift dans des roches de socle en Suède, au mieux à un facteur 10 près par rapport aux données d'excellente qualité fournies par des essais d'injection. La précision attendue des résultats a été examinée analytiquement et grâce à des méthodes statistiques. Les résultats ont aussi été comparés aux données d'essais d'injection. Les résultats indiquent que les données obtenues par air-lift fournissent des estimations de transmissivitéà un facteur 10 près par comparaison avec celles des essais d'injection des exemples étudiés. L'étude montre aussi que la pénétration partielle et la fracturation hydraulique peuvent affecter les estimations seulement d'environ un facteur 5. Ainsi, le recours à des données existantes peut être économiquement plus intéressant que le recueil de nouvelles données dans les premières étapes des études hydrogéologiques. Resumen Los estudios hidrogeológicos, en general, y las estimaciones de propiedades hidráulicas en rocas, en particular, requieren gran cantidad de datos. En muchos países se han creado grandes bases de datos hidrogeológicos, recogidos y almacenados a lo largo de los años. Por tanto, el uso de los datos ya existentes, aunque imprecisos, puede suponer una alternativa barata a la recopilación de nuevos datos, particularmente en las primeras fases de un estudio hidrogeológico. Sin embargo la precisión y utilidad del método deben analizarse para cada caso específico. En este estudio se contempla la posibilidad de, a partir de datos de ensayos de inyección de aire realizados en Suecia, obtener valores estimativos de transmisividad dentro del orden de magnitud de los resultados obtenidos de ensayos de inyección de alta calidad. La precisión del método se examinó de manera analítica y mediante métodos estadísticos, así como mediante la comparación con los datos de ensayos de inyección tradicionales. Del trabajo se observa que los datos procedentes de ensayos de inyección de aire dan lugar a unas estimaciones de transmisividad dentro del mismo orden de magnitud que los datos obtenidos en ensayos de inyección para los ejemplos que se han estudiado. También se concluye que la penetración parcial y la hidrofractura afectan las estimaciones de transmisividad en medio orden de magnitud, como mucho. Por tanto, el uso de los datos ya existentes es una alternativa eficiente y barata a la recopilación de nuevos datos en una primera fase de un estudio hidrogeológico.

Survival of Implants in Immediate Extraction Sockets of Anterior Teeth: Early Clinical Results.

PubMed

Sabir, Mohammad; Alam, Mohammad Nazish

2015-06-01

The aims and objectives of this study were placement of implants in freshly extracted sockets of anterior teeth and to evaluate the implant stability, peri-implant radiolucency and gingival inflammation around implant over a short period of 30 months. A total of 12 patients (8 male and 4 female), ranging in the age from 20 to 50 years, from March 2007 to June 2007, were evaluated for immediate implant placement into 22 fresh extraction sockets. Only maxillary and mandibular anterior teeth/roots (central incisors, lateral incisors and canines) were considered for replacement with implants. One piece implant with integrated abutment and integrated surface, non-submerged, threaded and tapered at apical 5 mm, sand-blasted and acid etched surfaced implants (HI-TEC TRX-OP Implants of Life Care Company) were used. The mobility was not present in any of the implants at all the follow up visits. There were 2 implants at 6 month, 1 implant at 12 month, 1 implant at 18 month visits, showing peri-implant radiolucency at some sites at bone to implant contact site. Severe gingival inflammation was not observed in any of the implant site. At every follow-up visit, every implant met the criteria of success and none was found to be failed over a 30 months duration i.e. 100% success rate was achieved by implants in immediate extraction socket. The success rate of implant survival in this study was found 100%. These implants have fulfilled all the criteria of implant success and based on the defined criteria, the success rate of implants placed in immediate extraction sockets of anterior teeth compared favorably with the conventional implants. The early results of the present study showed that high survival rates with the implants in immediate extraction sockets can be achieved.

Temperature, radiation and aging analysis of the DORIS Ultra Stable Oscillator by means of the Time Transfer by Laser Link experiment on Jason-2

NASA Astrophysics Data System (ADS)

Belli, Alexandre; Exertier, P.; Samain, E.; Courde, C.; Vernotte, F.; Jayles, C.; Auriol, A.

2016-12-01

The Time Transfer by Laser Link (T2L2) experiment on-board the Jason-2 satellite was launched in June 2008 at 1335 km altitude. It has been designed to use the Satellite Laser Ranging (SLR) space technique as an optical link between ground and space clocks. T2L2, as all the instruments aboard Jason-2, is referenced to the Ultra Stable Oscillator (USO) provided by the Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS) system. A complex data processing has been developed in order to extract time & frequency products as the relative frequency bias of the USO from ground-to-space time transfer passages. The precision of these products was estimated of a few parts in 10-13 given the very good in-flight performance of T2L2 with a ground-to-space time stability of a few picoseconds (ps) over 100 s. Frequency bias from T2L2 were compared with results from operational orbit computation, notably with the DIODE (Détermination Immédiate d'Orbite par Doris Embarqué) outputs (see Jayles et al. (2016) same issue) at the level of 1 · 10-12. The present paper is focusing on the main physical effects which drive the frequency variations of the Jason-2 USO during its flight, notably over the South Atlantic Anomaly (SAA) area. In addition to the effects of radiation we studied the effect of the residual temperature variations, in the range 8-11 °C (measured on-board). A model was established to represent these effects on the short term with empirical coefficients (sensitivities of the USO) to be adjusted. The results of fitting the model over ∼200 10-day periods, from 2008 to 2014, show the sensitivities of the Jason-2 USO to temperature and radiation. The analysis of the 6-year output series of empirical coefficients allows us to conclude that: (i) the temperature to frequency dependence is very stable along time at the level of around -1.2 · 10-12 per °C, (ii) the radiation effects are much lower than those previously detected on the Jason-1 USO with a factor > 10. The swept material used by manufacturers for the Jason-2 quartz oscillator has such properties to avoid non-linear effects >1-2 · 10-12, (iii) the model is available at 1 min or less over the Jason-2 mission, with a level of consistency of 5 · 10-13, which is the average RMS of the post-fit residuals.

A new system of implant abutment connection: how to improve a two piece implant system sealing.

PubMed

Grecchi, F; DI Girolamo, M; Cura, F; Candotto, V; Carinci, F

2017-01-01

Implant dentistry has become one of the most successful dentistry techniques for replacing missing teeth. The success rate of implant dentistry is above 80%. However, peri-implantitis is a later complication of implant dentistry that if untreated, can lead to implant loss. One of the hypotized causes of peri-implantis is the bacterial leakage at the level of implant-abutment connection. Bacterial leakage is favored to the presence of a micro gap at the implant-abutment interface, allowing microorganisms to penetrate and colonize the inner part of the implant leading to biofilm accumulation and consequently to peri-implantitis development. To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Implants were immerged in a bacterial culture for twenty-four hours and then bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 9%. The reported results are better to those of previous studies carried out on different implant systems. Until now, none implant-abutment system has been proven to seal the gap between implant and abutment.

Incidence of Peri-implant Diseases on Implants With and Without Laser-Microgrooved Collar: A 5-Year Retrospective Study Carried Out in Private Practice Patients.

PubMed

Guarnieri, Renzo; Grande, Maurizio; Zuffetti, Francesco; Testori, Tiziano

To retrospectively evaluate the incidence of peri-implant mucositis and peri-implantitis around dental implants with the same body design and surface but different collar surface (laser-microgrooved vs not laser-microgrooved) after 5 years of loading in private practice patients. The study was carried out on patients at a private dental clinic enrolled in a periodontal maintenance program, who received at least one implant with a laser-microgrooved collar surface and one implant without a laser-microgrooved collar surface. Clinical variables such as plaque, pocket depth, bleeding on probing, suppuration, and radiographic marginal bone loss at > 5 years around implants were investigated. The correlation between the prevalence of peri-implant mucositis/peri-implantitis and biotype, keratinized tissue width, prosthetic connection type, and prosthetic design type was also analyzed. A total of 166 implants in 74 patients were investigated. At the end of the 5-year follow-up period, 38 implants presented peri-implant mucositis, accounting for 22.8% of the total, affecting a total of 24 patients (32.4%), while 13 implants (7.8%) in 10 patients (13.5%) were diagnosed with peri-implantitis. Sixteen of 82 laser-microgrooved implants (19.5%) and 24 of 84 implants (28.5%) without a laser-microgrooved collar presented peri-implant mucositis, while 3 of 82 (3.6%) of laser-microgrooved implants and 10 of 84 (11.9%) implants without a laser-microgrooved collar demonstrated peri-implantitis. Differences in implant-based incidence of peri-implant diseases between implants with and without a laser-microgrooved collar were statistically significant (P < .05). In private practice patients enrolled in a professional, controlled oral hygiene regimen, implants with a laser-microgrooved collar, compared with implants without a laser-microgrooved collar, presented a statistically significantly lower incidence of peri-implant diseases.

Influence of Palatal Coverage and Implant Distribution on Implant Strain in Maxillary Implant Overdentures.

PubMed

Takahashi, Toshihito; Gonda, Tomoya; Mizuno, Yoko; Fujinami, Yozo; Maeda, Yoshinobu

2016-01-01

Maxillary implant overdentures are often used in clinical practice. However, there is no agreement or established guidelines regarding prosthetic design or optimal implant placement configuration. The purpose of this study was to examine the influence of palatal coverage and implant number and distribution in relation to impact strain under maxillary implant overdentures. A maxillary edentulous model with implants and experimental overdentures with and without palatal coverage was fabricated. Four strain gauges were attached to each implant, and they were positioned in the anterior, premolar, and molar areas. A vertical occlusal load of 98 N was applied through a mandibular complete denture, and the implant strains were compared using one-way analysis of variance (P = .05). The palatolabial strain was much higher on anterior implants than on other implants in both denture types. Although there was no significant difference between the strain under dentures with and without palatal coverage, palateless dentures tended to result in higher implant strain than dentures with palatal coverage. Dentures supported by only two implants registered higher strain than those supported by four or six implants. Implants under palateless dentures registered higher strain than those under dentures with palatal coverage. Anterior implants exhibited higher palatolabial strain than other implants regardless of palatal coverage and implant configuration; it is therefore recommended that maxillary implant overdentures should be supported by six implants with support extending to the distal end of the arch.

Dental Implant Macro-Design Features Can Impact the Dynamics of Osseointegration.

PubMed

Vivan Cardoso, Marcio; Vandamme, Katleen; Chaudhari, Amol; De Rycker, Judith; Van Meerbeek, Bart; Naert, Ignace; Duyck, Joke

2015-08-01

The purpose of this study was to compare the clinical performance of two dental implant types possessing a different macro-design in the in vivo pig model. Titanium Aadva(TM) implants (GC, Tokyo, Japan) were compared with OsseoSpeed(TM) implants (Astra, Mölndal, Sweden), with the Aadva implant displaying significant larger inter-thread dimensions than the OsseoSpeed implant. Implants were installed in the parietal bone of 12 domestic pigs and left for healing for either 1 or 3 months. Implant osseointegration was evaluated by quantitative histology (bone volume relative to the tissue volume [BV/TV]; bone-to-implant contact [BIC]) for distinct implant regions (collar, body, total implant length) with specific implant thread features. The Wilcoxon-Mann-Whitney nonparametric test with α = 0.05 was performed. An inferior amount of bone enveloping the Aadva implant compared with the OsseoSpeed implant was observed, in particular at the implant body part with its considerable inter-thread gaps (p < .05). Concomitantly, the Aadva macro-design negatively affected the amount of bone in direct contact with the implant for this specific implant part (p < .05), and resulted in an overall impaired implant osseointegration at the initial healing stage (total implant length; 1-month healing; p < .05). Although the Aadva implant displayed a clinically acceptable level of osseointegration, the findings demonstrate that implant macro-design features can impact the dynamics of implant osseointegration. Consideration of specific implant macro-design features should be made relative to the biological and mechanical microenvironment. © 2013 Wiley Periodicals, Inc.

Imaging of common breast implants and implant-related complications: A pictorial essay

PubMed Central

Shah, Amisha T; Jankharia, Bijal B

2016-01-01

The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer. PMID:27413269

Imaging of common breast implants and implant-related complications: A pictorial essay.

PubMed

Shah, Amisha T; Jankharia, Bijal B

2016-01-01

The number of women undergoing breast implant procedures is increasing exponentially. It is, therefore, imperative for a radiologist to be familiar with the normal and abnormal imaging appearances of common breast implants. Diagnostic imaging studies such as mammography, ultrasonography, and magnetic resonance imaging are used to evaluate implant integrity, detect abnormalities of the implant and its surrounding capsule, and detect breast conditions unrelated to implants. Magnetic resonance imaging of silicone breast implants, with its high sensitivity and specificity for detecting implant rupture, is the most reliable modality to asses implant integrity. Whichever imaging modality is used, the overall aim of imaging breast implants is to provide the pertinent information about implant integrity, detect implant failures, and to detect breast conditions unrelated to the implants, such as cancer.

Infection rates of rifampin/gentamicin-coated Titan Coloplast penile implants. Comparison with Inhibizone-impregnated AMS penile implants.

PubMed

Dhabuwala, Chirpriya; Sheth, Sheila; Zamzow, Brent

2011-01-01

It is a common practice to soak Titan(®) Coloplast penile implants in antibiotic solution prior to implantation. Experience with Inhibizone impregnation suggests that rifampin coating significantly reduces infection rates of penile implant surgery. In this article we describe the results of coating Titan Coloplast penile implants with rifampin/gentamicin solution. To compare infection rates of Titan(®) Coloplast penile implants coated with vancomycin/gentamycin, rifampin/gentamicin, and Inhibizone-impregnated American Medical Systems (AMS) penile implants. Chart review was done for all Mentor/Coloplast and AMS implant surgeries performed at our center between the dates January 1, 2002 and February 8, 2010. Infection rates for Titan(®) Coloplast penile implants coated with vancomycin/gentamycin, rifampin/gentamicin, and Inhibizone-impregnated (AMS) penile implants were compared. Infection rates for penile implants coated with different antibiotics. Infection rates for Titan(®) Coloplast penile implants coated with vancomycin/gentamycin and Inhibizone-impregnated (AMS) penile implants was 4.4% and 1.3%, respectively (P = 0.05). None of the rifampin/gentamicin-coated Titan(®) Coloplast penile implants have developed infection. Rifampin is the common antibiotic both in rifampin/gentamicin-coated Coloplast implants and Inhibizone(®) . The infection rate in this combined rifampin/gentamicin-coated Titan Coloplast implants and Inhibizone-coated AMS implants group was 0.63% (P = 0.03). Both rifampin/gentamicin-coated Titan(®) Coloplast penile implants and Inhibizone-impregnated (AMS) penile implants appear to have lower infection rates compared with vancomycin/gentamycin-coated Titan(®) Coloplast penile implants The present study does not suggest superiority of rifampin/gentamicin-coated Titan(®) Coloplast penile implants or Inhibizone-impregnated (AMS) penile implants but we strongly suggest that all Titan(®) Coloplast penile implants should be coated with rifampin/gentamicin solution. © 2010 International Society for Sexual Medicine.

Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study.

PubMed

Aunmeungtong, W; Khongkhunthian, P; Rungsiyakull, P

2016-01-01

Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant should exhibit the same behavior to chewing force.

Occlusal considerations in implant therapy: clinical guidelines with biomechanical rationale.

PubMed

Kim, Yongsik; Oh, Tae-Ju; Misch, Carl E; Wang, Hom-Lay

2005-02-01

Due to lack of the periodontal ligament, osseointegrated implants, unlike natural teeth, react biomechanically in a different fashion to occlusal force. It is therefore believed that dental implants may be more prone to occlusal overloading, which is often regarded as one of the potential causes for peri-implant bone loss and failure of the implant/implant prosthesis. Overloading factors that may negatively influence on implant longevity include large cantilevers, parafunctions, improper occlusal designs, and premature contacts. Hence, it is important to control implant occlusion within physiologic limit and thus provide optimal implant load to ensure a long-term implant success. The purposes of this paper are to discuss the importance of implant occlusion for implant longevity and to provide clinical guidelines of optimal implant occlusion and possible solutions managing complications related to implant occlusion. It must be emphasized that currently there is no evidence-based, implant-specific concept of occlusion. Future studies in this area are needed to clarify the relationship between occlusion and implant success.

Peri-implant bone formation and surface characteristics of rough surface zirconia implants manufactured by powder injection molding technique in rabbit tibiae.

PubMed

Park, Young-Seok; Chung, Shin-Hye; Shon, Won-Jun

2013-05-01

To evaluate osseointegration in rabbit tibiae and to investigate surface characteristics of novel zirconia implants made by powder injection molding (PIM) technique, using molds with and without roughened inner surfaces. A total of 20 rabbits received three types of external hex implants with identical geometry on the tibiae: machined titanium implants, PIM zirconia implants without mold etching, and PIM zirconia implants with mold etching. Surface characteristics of the three types of implant were evaluated. Removal torque tests and histomorphometric analyses were performed. The roughness of PIM zirconia implants was higher than that of machined titanium implants. The PIM zirconia implants exhibited significantly higher bone-implant contact and removal torque values than the machined titanium implants (P < 0.001). The PIM zirconia implants using roughened mold showed significantly higher removal torque values than PIM zirconia implants without using roughened mold (P < 0.001). It is concluded that the osseointegration of PIM zirconia implant is promising and PIM using roughened mold etching technique can produce substantially rough surfaces on zirconia implants. © 2012 John Wiley & Sons A/S.

Short Implants Versus Standard Implants: Midterm Outcomes of a Clinical Study.

PubMed

Benlidayi, M Emre; Ucar, Yurdanur; Tatli, Ufuk; Ekren, Orhun; Evlice, Burcu; Kisa, Halil Ibrahim; Baksi, Uygar

2018-02-01

The aim of this study was to evaluate the midterm survival rate, marginal bone resorption (MBR), and stability of short implants and to compare the results with standard length implants. A total of 38 patients were included. In total, 147 implants (Nucleoss Implants, Izmir, Turkey) were placed (86 short implants and 61 standard implants). Cement-retained metal-ceramic prostheses were fabricated. MBR was evaluated on periapical radiographs taken at implant placement, at the time of crown insertion and annually thereafter. The stability of the implants was evaluated by resonance frequency analysis. The 3- and 5-year cumulative survival rates for standard implants was 98.4% and for short implants was 96.5% (P = 0.644). The MBR of the short implants was significantly lower than that of the standard implants after 1, 2, and 3 years of loading (P < 0.05). No significant differences were found between 2 groups after 6 and 12 months of loading in terms of implant stability (implant stability quotient values) (P > 0.05). Within the limits of this study, it is concluded that short implants achieved similar results as standard implants after 3 to 5 years of loading.

Effect of implant position, angulation, and attachment height on peri-implant bone stress associated with mandibular two-implant overdentures: a finite element analysis.

PubMed

Hong, Hae Ryong; Pae, Ahran; Kim, Yooseok; Paek, Janghyun; Kim, Hyeong-Seob; Kwon, Kung-Rock

2012-01-01

The aim of this study was to analyze and compare the level and distribution of peri-implant bone stresses associated with mandibular two-implant overdentures with different implant positions. Mathematical models of mandibles and overdentures were designed using finite element analysis software. Two intraosseous implants and ball attachment systems were placed in the interforaminal region. The overdenture, which was supported by the two implants, was designed to withstand bilateral and unilateral vertical masticatory loads (total 100 N). In all, eight types of models, which differed according to assigned implant positions, height of attachments, and angulation, were tested: MI (model with implants positioned in the lateral incisor sites), MC (implants in canine sites), MP (implants in premolar sites), MI-Hi (greater height of attachments), MC-M (canine implants placed with mesial inclination), MC-D (canine implants placed with distal inclination), MC-B (canine implants placed with buccal inclination), and MC-L (canine implants placed with lingual inclination). Peri-implant bone stress levels associated with overdentures retained by lateral incisor implants resulted in the lowest stress levels and the highest efficiency in distributing peri-implant stress. MI-Hi showed increased stress levels and decreased efficiency in stress distribution. As the implants were inclined, stress levels increased and the efficiency of stress distribution decreased. Among the inclined models, MC-B showed the lowest stress level and best efficiency in stress distribution. The lowest stress and the best stability of implants in mandibular two-implant overdentures were obtained when implants were inserted in lateral incisor areas with shorter attachments and were placed parallel to the long axes of the teeth.

Survival of Implants in Immediate Extraction Sockets of Anterior Teeth: Early Clinical Results

PubMed Central

Sabir, Mohammad

2015-01-01

Background The aims and objectives of this study were placement of implants in freshly extracted sockets of anterior teeth and to evaluate the implant stability, peri-implant radiolucency and gingival inflammation around implant over a short period of 30 months. Materials and Methods A total of 12 patients (8 male and 4 female), ranging in the age from 20 to 50 years, from March 2007 to June 2007, were evaluated for immediate implant placement into 22 fresh extraction sockets. Only maxillary and mandibular anterior teeth/roots (central incisors, lateral incisors and canines) were considered for replacement with implants. One piece implant with integrated abutment and integrated surface, non-submerged, threaded and tapered at apical 5 mm, sand-blasted and acid etched surfaced implants (HI-TEC TRX-OP Implants of Life Care Company) were used. Results The mobility was not present in any of the implants at all the follow up visits. There were 2 implants at 6 month, 1 implant at 12 month, 1 implant at 18 month visits, showing peri-implant radiolucency at some sites at bone to implant contact site. Severe gingival inflammation was not observed in any of the implant site. At every follow-up visit, every implant met the criteria of success and none was found to be failed over a 30 months duration i.e. 100% success rate was achieved by implants in immediate extraction socket. Conclusion The success rate of implant survival in this study was found 100%. These implants have fulfilled all the criteria of implant success and based on the defined criteria, the success rate of implants placed in immediate extraction sockets of anterior teeth compared favorably with the conventional implants. The early results of the present study showed that high survival rates with the implants in immediate extraction sockets can be achieved. PMID:26266220

[Effect of the number and inclination of implant on stress distribution for mandibular full-arch fixed prosthesis].

PubMed

Zheng, Xiaoying; Li, Xiaomei; Tang, Zhen; Gong, Lulu; Wang, Dalin

2014-06-01

To study the effect of implant number and inclination on stress distribution in implant and its surrounding bone with three-dimensional finite element analysis. A special denture was made for an edentulous mandible cast to collect three-dimensional finite element data. Three three-dimensional finite element models were established as follows. Model 1: 6 paralleled implants; model 2: 4 paralleled implants; model 3: 4 implants, the two anterior implants were parallel, the two distal implants were tilted 30° distally. Among the three models, the maximum stress values found in anterior implants, posterior implants, and peri-implant bone were modle 3

A business strategy formulation for commercializing university-created technology: A university spin-offs

NASA Astrophysics Data System (ADS)

Saputra, Iqbal Wahyu; Sutopo, Wahyudi; Zakaria, Roni

2018-02-01

There are some mechanism to commercialize the innovations that have been developed by academic scientists in universities, i.e. patenting, licensing, start-up creation, and university-industry partnerships. The start-up creations or university spin-offs (USOs) company is a very special start-up company that is founded by an academic inventor and the university with the aim to commercialize the technological innovation that created by the university. However, it is not always as smooth as expected. The market competitiveness of the USOs obviously has many challenges to be able to compete with the existing companies, analysis need to be done to get the right business step so the business strategy will be efficient. In this article, we discuss a real case study of a university spin-off that owned by Sebelas Maret University for Commercializing Battery Lithium. The aim of our research is twofold: first, to identify the gap in the literature of business strategy formulation between a conventional and USOs. Second, to propose a business strategy formulation for commercializing university-created technology, i.e. battery lithium as core business of a university spin-off as a case study. We conduct surveys, observation and FGD in order to collect the data and information to build the company objective and goals. The analytical tools to generate the solution of business strategy are SWOT analysis, IFE-EFE matrix, and QSPM model so the result will be the most attractive and suitable for the company. The result shows that the case study of USO company is classified on conservative continuous improvement phase so the suitable strategy for this company are product development and business strategy integration.

Current use of wild plants with edible underground storage organs in a rural population of Patagonia: between tradition and change.

PubMed

Ochoa, Juan José; Ladio, Ana Haydee

2015-09-25

Edible plants with underground storage organs (USOs) are neglected resources. We studied the local ecological knowledge edible plants with (USOs) in rural populations of North-Patagonia in order to establish how people are utilizing these plants. Some aspect of corpus-praxis-cosmos complex associated to the local ecological knowledge was documented and discussed. In addition, variation in this ecological knowledge due to age, gender, family structure, ethnic self-determination was also evaluated. Semi-structured interviews were conducted with 51 inhabitants in order to study the relationship between the current use of plants with USOs and the age, sex, family group composition and ethnic self-identification of interviewees. In addition, the Cultural Importance Index for each species was calculated. The current richness of known species in these populations is a total of 9 plants. Plants with USOs tend to be used more frequently as the age of the interviewee increases. Women and men showed no differences in the average richness of species cited. The interviewees who share their homes with other generations use these plants more frequently than those who live alone. Our results indicate that the interviewees who identified themselves as belonging to the Mapuche people use these plants more frequently. For the Mapuche people, wild plants have constituted material and symbolic resources of great importance in their historical subsistence. In addition, they are currently being redefined as elements which present a connection with ancestral practices, produce a strong relationship with the 'land', and become markers which identify the 'natural' (historical) ways of their people; these are key elements in the current political processes of identity revaluation. This research is valuable to stimulate cultural revival and health promotion programs in the communities with their own local, cultural food.

Why are mini-implants lost: the value of the implantation technique!

PubMed

Romano, Fabio Lourenço; Consolaro, Alberto

2015-01-01

The use of mini-implants have made a major contribution to orthodontic treatment. Demand has aroused scientific curiosity about implant placement procedures and techniques. However, the reasons for instability have not yet been made totally clear. The aim of this article is to establish a relationship between implant placement technique and mini-implant success rates by means of examining the following hypotheses: 1) Sites of poor alveolar bone and little space between roots lead to inadequate implant placement; 2) Different sites require mini-implants of different sizes! Implant size should respect alveolar bone diameter; 3) Properly determining mini-implant placement site provides ease for implant placement and contributes to stability; 4) The more precise the lancing procedures, the better the implant placement technique; 5) Self-drilling does not mean higher pressures; 6) Knowing where implant placement should end decreases the risk of complications and mini-implant loss.

Comparison of peri-implant bone formation around injection-molded and machined surface zirconia implants in rabbit tibiae

PubMed Central

Kim, Hong-Kyun; Woo, Kyung mi; Shon, Won-Jun; Ahn, Jin-Soo; Cha, Seunghee; Park, Young-Seok

2017-01-01

The aim of this study was to compare osseointegration and surface characteristics of zirconia implants made by the powder injection molding (PIM) technique and made by the conventional milling procedure in rabbit tibiae. Surface characteristics of 2 types of implant were evaluated. Sixteeen rabbits received 2 types of external hex implants with similar geometry, machined zirconia implants and PIM zirconia implants, in the tibiae. Removal torque tests and histomorphometric analyses were performed. The roughness of PIM zirconia implants was higher than that of machined zirconia implants. The PIM zirconia implants exhibited significantly higher bone-implant contact and removal torque values than the machined zirconia implants (P < 0.001). The osseointegration of the PIM zirconia implant is promising, and PIM, using the roughened mold etching technique, can produce substantially rough surfaces on zirconia implants. PMID:26235717

Evaluation of possible prognostic factors for the success, survival, and failure of dental implants.

PubMed

Geckili, Onur; Bilhan, Hakan; Geckili, Esma; Cilingir, Altug; Mumcu, Emre; Bural, Canan

2014-02-01

To analyze the prognostic factors that are associated with the success, survival, and failure rates of dental implants. Data including implant sizes, insertion time, implant location, and prosthetic treatment of 1656 implants have been collected, and the association of these factors with success, survival, and failure of implants was analyzed. The success rate was lower for short and maxillary implants. The failure rate of maxillary implants exceeded that of mandibular implants, and the failure rate of implants that were placed in the maxillary anterior region was significantly higher than other regions. The failure rates of implants that were placed 5 years ago or more were higher than those that were placed later. Anterior maxilla is more critical for implant loss than other sites. Implants in the anterior mandible show better success compared with other locations, and longer implants show better success rates. The learning curve of the clinician influences survival and success rates of dental implants.

[Comparative evaluation of two kinds of micro-implant system with different size].

PubMed

Wang, Zhen-Dong; Li, Qing-Yi; Wang, Lin; Gu, Yong-Jia

2009-04-01

To offer some reference for micro-implant's development and population by analyzing clinical application of two kinds of micro-implant systems. 38 patients treated with MIA (micro-implant anchorage) and 28 patients treated with SDIA (self-driven titanium implant for orthodontic anchorage) were included. Analyzing the rate of lost implants, the gum's reactivity and the efficiency of moving teeth summarized the excellences and shortcomings of two systems. 1) Six of MIA implants fell off after being inserted. Seven of SDIA implants lost when they had been implanted for a month. But they were stable after being inserted again. 2) The gum around 12 SDIA implants got inflammation symptom, but the gum around MIA implants was normal. 3) Both MIA implants and SDIA implants could move teeth effectively and persistently when they were stable. When we apply micro-implant in clinic, we should prevent it from closing roots of teeth and choose the small tip micro-implant. The embedded position should be in area of attachment gum. At the same time, the areas around the tip of micro-implant should be keeping clean.

Comparison of surface modified zirconia implants with commercially available zirconium and titanium implants: a histological study in pigs.

PubMed

Gredes, Tomasz; Kubasiewicz-Ross, Pawel; Gedrange, Tomasz; Dominiak, Marzena; Kunert-Keil, Christiane

2014-08-01

New biomaterials and their various surface modifications should undergo in vitro and in vivo evaluation before clinical trials. The objective of our in vivo study was to evaluate the biocompatibility of newly created zirconium implant surfaces after implantation in the lower jaw of pigs and compare the osseointegration of these dental implants with commercially available zirconium and titanium implants. After a healing period of 12 weeks, a histological analysis of the soft and hard tissues and a histomorphometric analysis of the bone-implant contact (BIC) were performed. The implant surfaces showed an intimate connection to the adjacent bone for all tested implants. The 3 newly created zirconium implant surfaces achieved a BIC of 45% on average in comparison with a BIC of 56% from the reference zirconium implants and 35% from titanium implants. Furthermore, the new zirconium implants had a better attachment to gingival and bone tissues in the range of implant necks as compared with the reference implants. The results suggest that the new implants comparably osseointegrate within the healing period, and they have a good in vivo biocompatibility.

Acid Etching and Plasma Sterilization Fail to Improve Osseointegration of Grit Blasted Titanium Implants

PubMed Central

Saksø, Mikkel; Jakobsen, Stig S; Saksø, Henrik; Baas, Jørgen; Jakobsen, Thomas; Søballe, Kjeld

2012-01-01

Interaction between implant surface and surrounding bone influences implant fixation. We attempted to improve the bone-implant interaction by 1) adding surface micro scale topography by acid etching, and 2) removing surface-adherent pro-inflammatory agents by plasma cleaning. Implant fixation was evaluated by implant osseointegration and biomechanical fixation. The study consisted of two paired animal sub-studies where 10 skeletally mature Labrador dogs were used. Grit blasted titanium alloy implants were inserted press fit in each proximal tibia. In the first study grit blasted implants were compared with acid etched grit blasted implants. In the second study grit blasted implants were compared with acid etched grit blasted implants that were further treated with plasma sterilization. Implant performance was evaluated by histomorphometrical investigation (tissue-to-implant contact, peri-implant tissue density) and mechanical push-out testing after four weeks observation time. Neither acid etching nor plasma sterilization of the grit blasted implants enhanced osseointegration or mechanical fixation in this press-fit canine implant model in a statistically significant manner. PMID:22962567

A Retrospective Analysis of Ruptured Breast Implants

PubMed Central

Baek, Woo Yeol; Lew, Dae Hyun

2014-01-01

Background Rupture is an important complication of breast implants. Before cohesive gel silicone implants, rupture rates of both saline and silicone breast implants were over 10%. Through an analysis of ruptured implants, we can determine the various factors related to ruptured implants. Methods We performed a retrospective review of 72 implants that were removed for implant rupture between 2005 and 2014 at a single institution. The following data were collected: type of implants (saline or silicone), duration of implantation, type of implant shell, degree of capsular contracture, associated symptoms, cause of rupture, diagnostic tools, and management. Results Forty-five Saline implants and 27 silicone implants were used. Rupture was diagnosed at a mean of 5.6 and 12 years after insertion of saline and silicone implants, respectively. There was no association between shell type and risk of rupture. Spontaneous was the most common reason for the rupture. Rupture management was implant change (39 case), microfat graft (2 case), removal only (14 case), and follow-up loss (17 case). Conclusions Saline implants have a shorter average duration of rupture, but diagnosis is easier and safer, leading to fewer complications. Previous-generation silicone implants required frequent follow-up observation, and it is recommended that they be changed to a cohesive gel implant before hidden rupture occurs. PMID:25396188

Effect of Attachment Type on Implant Strain in Maxillary Implant Overdentures: Comparison of Ball, Locator, and Magnet Attachments. Part 1. Overdenture with Palate.

PubMed

Takahashi, Toshihito; Gonda, Tomoya; Maeda, Yoshinobu

Implant overdentures with attachments have been used in clinical practice and the effect of attachments on implant strain has been frequently reported. However, most studies have focused on mandibular overdentures; there are few reports on maxillary overdentures. The purpose of this study was to examine the influence of attachment type on implant strain in maxillary overdentures under various implant configurations. A maxillary edentulous model with implants and experimental overdentures were fabricated. Four strain gauges were attached to each implant, positioned in anterior, premolar, and molar areas. Three types of unsplinted attachments-ball, locator, and magnet-were set on the implants under various implant configurations. A vertical occlusal load of 98 N was applied through the mandibular complete denture, and implant strain was compared using the Kruskal-Wallis test. Ball attachments caused the greatest amount of strain, while magnet attachments caused the least amount under all conditions. For all attachments, two anterior implants caused significantly more strain than four implants (P < .05). No significant difference was observed between subtypes in four-implant configurations except when using locator attachments. When using unsplinted attachments for maxillary implant overdentures, magnet attachments are recommended to reduce implant stress. Using only two implants, especially two anterior implants, is not recommended regardless of attachment type.

Effect of implant design and bioactive glass coating on biomechanical properties of fiber-reinforced composite implants.

PubMed

Ballo, Ahmed M; Akca, Eralp; Ozen, Tuncer; Moritz, Niko; Lassila, Lippo; Vallittu, Pekka; Närhi, Timo

2014-08-01

This study aimed to evaluate the influence of implant design and bioactive glass (BAG) coating on the response of bone to fiber-reinforced composite (FRC) implants. Three different FRC implant types were manufactured for the study: non-threaded implants with a BAG coating; threaded implants with a BAG coating; and threaded implants with a grit-blasted surface. Thirty-six implants (six implants for each group per time point) were installed in the tibiae of six pigs. After an implantation period of 4 and 12 wk, the implants were retrieved and prepared for micro-computed tomography (micro-CT), push-out testing, and scanning electron microscopy analysis. Micro-CT demonstrated that the screw-threads and implant structure remained undamaged during the installation. The threaded FRC/BAG implants had the highest bone volume after 12 wk of implantation. The push-out strengths of the threaded FRC/BAG implants after 4 and 12 wk (463°N and 676°N, respectively) were significantly higher than those of the threaded FRC implants (416°N and 549°N, respectively) and the nonthreaded FRC/BAG implants (219°N and 430°N, respectively). Statistically significant correlation was found between bone volume and push-out strength values. This study showed that osseointegrated FRC implants can withstand the static loading up to failure without fracture, and that the addition of BAG significantly improves the push-out strength of FRC implants. © 2014 Eur J Oral Sci.

Finite element analysis of different loading conditions for implant-supported overdentures supported by conventional or mini implants.

PubMed

Solberg, K; Heinemann, F; Pellikaan, P; Keilig, L; Stark, H; Bourauel, C; Hasan, I

2017-05-01

The effect of implants' number on overdenture stability and stress distribution in edentulous mandible, implants and overdenture was numerically investigated for implant-supported overdentures. Three models were constructed. Overdentures were connected to implants by means of ball head abutments and rubber ring. In model 1, the overdenture was retained by two conventional implants; in model 2, by four conventional implants; and in model 3, by five mini implants. The overdenture was subjected to a symmetrical load at an angle of 20 degrees to the overdenture at the canine regions and vertically at the first molars. Four different loading conditions with two total forces (120, 300 N) were considered for the numerical analysis. The overdenture displacement was about 2.2 times higher when five mini implants were used rather than four conventional implants. The lowest stress in bone bed was observed with four conventional implants. Stresses in bone were reduced by 61% in model 2 and by 6% in model 3 in comparison to model 1. The highest stress was observed with five mini implants. Stresses in implants were reduced by 76% in model 2 and 89% increased in model 3 compared to model 1. The highest implant displacement was observed with five mini implants. Implant displacements were reduced by 29% in model 2, and increased by 273% in model 3 compared to model 1. Conventional implants proved better stability for overdenture than mini implants. Regardless the type and number of implants, the stress within the bone and implants are below the critical limits.

"Not all breast implants are equal: a 13-year review of implant longevity and reasons for explantation".

PubMed

Van Slyke, Aaron C; Carr, Michael; Carr, Nicholas J

2018-06-04

Augmentation mammoplasty is the most common aesthetic procedure. Textured implants control implant position and have improved capsular contracture rates; however, the impact of texturing on longevity and clinical findings at explantation is unclear. All cases of explantation between January 2005 - April 2017 from an aesthetic practice were reviewed retrospectively. Patient demographics, implant characteristics, time-to-explantation, and clinical presentation and intraoperative findings at explantation were analyzed. 539 breast implants were explanted during the study period: 249 saline, 147 smooth gel, 123 Biocell, and 20 other nonaggressively textured breast implants. Average time from placement to explantation was 7.5 years, 5.6 years, 4.9 years, and 4.0 years for saline, other textured, smooth gel, and Biocell implants, respectively (p-value = 3.25e-08). The percentage of implants removed associated with implant performance failure was 50.3%, 57.5%, 75.0%, and 85.4% for smooth gel, saline, other textured, and Biocell implants, respectively (p-value = 7.25e-09). 21.1% of Biocell implants versus 1.5% of all other implants presented with pain (p-value = 2.71e-15). 45 Biocell implants had double capsules; this phenomenon was not observed with any other implant type (p-value = 5.85e-37). Seven Biocell implants had late seromas, compared to three late seromas with any other implant type (p-value = 0.0013). Here, we provide evidence that Biocell implants have the shortest time-to-explantation and the highest proportion of implants associated with implant performance failure. This information should complement the informed consent process when selecting an appropriate implant.

Breast Implant-Associated Anaplastic Large Cell Lymphoma in Australia and New Zealand: High-Surface-Area Textured Implants Are Associated with Increased Risk.

PubMed

Loch-Wilkinson, Anna; Beath, Kenneth J; Knight, Robert John William; Wessels, William Louis Fick; Magnusson, Mark; Papadopoulos, Tim; Connell, Tony; Lofts, Julian; Locke, Michelle; Hopper, Ingrid; Cooter, Rodney; Vickery, Karen; Joshi, Preeti Avinash; Prince, H Miles; Deva, Anand K

2017-10-01

The association between breast implants and breast implant-associated anaplastic large cell lymphoma (ALCL) has been confirmed. Implant-related risk has been difficult to estimate to date due to incomplete datasets. All cases in Australia and New Zealand were identified and analyzed. Textured implants reported in this group were subjected to surface area analysis. Sales data from three leading breast implant manufacturers (i.e., Mentor, Allergan, and Silimed) dating back to 1999 were secured to estimate implant-specific risk. Fifty-five cases of breast implant-associated ALCL were diagnosed in Australia and New Zealand between 2007 and 2016. The mean age of patients was 47.1 years and the mean time of implant exposure was 7.46 years. There were four deaths in the series related to mass and/or metastatic presentation. All patients were exposed to textured implants. Surface area analysis confirmed that higher surface area was associated with 64 of the 75 implants used (85.3 percent). Biocell salt loss textured (Allergan, Inamed, and McGhan) implants accounted for 58.7 percent of the implants used in this series. Comparative analysis showed the risk of developing breast implant-associated ALCL to be 14.11 times higher with Biocell textured implants and 10.84 higher with polyurethane (Silimed) textured implants compared with Siltex textured implants. This study has calculated implant-specific risk of breast implant-associated ALCL. Higher-surface-area textured implants have been shown to significantly increase the risk of breast implant-associated ALCL in Australia and New Zealand. The authors present a unifying hypothesis to explain these observations.

Fortifying the Bone-Implant Interface Part 2: An In Vivo Evaluation of 3D-Printed and TPS-Coated Triangular Implants.

PubMed

MacBarb, Regina F; Lindsey, Derek P; Woods, Shane A; Lalor, Peggy A; Gundanna, Mukund I; Yerby, Scott A

2017-01-01

Minimally invasive surgical fusion of the sacroiliac (SI) joint using machined solid triangular titanium plasma spray (TPS) coated implants has demonstrated positive clinical outcomes in SI joint pain patients. Additive manufactured (AM), i.e. 3D-printed, fenestrated triangular titanium implants with porous surfaces and bioactive agents, such as nanocrystalline hydroxyapatite (HA) or autograft, may further optimize bony fixation and subsequent biomechanical stability. A bilateral ovine distal femoral defect model was used to evaluate the cancellous bone-implant interfaces of TPS-coated and AM implants. Four implant groups (n=6/group/time-point) were included: 1)TPS-coated, 2)AM, 3)AM+HA, and 4)AM+Autograft. The bone-implant interfaces of 6- and 12-week specimens were investigated via radiographic, biomechanical, and histomorphometric methods. Imaging showed peri-implant bone formation around all implants. Push-out testing demonstrated forces greater than 2500 N, with no significant differences among groups. While TPS implants failed primarily at the bone-implant interface, AM groups failed within bone ~2-3mm away from implant surfaces. All implants exhibited bone ongrowth, with no significant differences among groups. AM implants had significantly more bone ingrowth into their porous surfaces than TPS-coated implants ( p <0.0001). Of the three AM groups, AM+Auto implants had the greatest bone ingrowth into the porous surface and through their core ( p <0.002). Both TPS and AM implants exhibited substantial bone ongrowth and ingrowth, with additional bone through growth into the AM implants' core. Overall, AM implants experienced significantly more bone infiltration compared to TPS implants. While HA-coating did not further enhance results, the addition of autograft fostered greater osteointegration for AM implants. Additive manufactured implants with a porous surface provide a highly interconnected porous surface that has comparatively greater surface area for bony integration. Results suggest this may prove advantageous toward promoting enhanced biomechanical stability compared to TPS-coated implants for SI joint fusion procedures.

Peri-implantitis.

PubMed

Schwarz, Frank; Derks, Jan; Monje, Alberto; Wang, Hom-Lay

2018-06-01

This narrative review provides an evidence-based overview on peri-implantitis for the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. A literature review was conducted addressing the following topics: 1) definition of peri-implantitis; 2) conversion from peri-implant mucositis to peri-implantitis, 3) onset and pattern of disease progression, 4) characteristics of peri-implantitis, 5) risk factors/indicators for peri-implantitis, and 6) progressive crestal bone loss in the absence of soft tissue inflammation. 1)Peri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. 2)The histopathologic and clinical conditions leading to the conversion from peri-implant mucositis to peri-implantitis are not completely understood. 3)The onset of peri-implantitis may occur early during follow-up and the disease progresses in a non-linear and accelerating pattern. 4a)Peri-implantitis sites exhibit clinical signs of inflammation and increased probing depths compared to baseline measurements. 4b)At the histologic level, compared to periodontitis sites, peri-implantitis sites often have larger inflammatory lesions. 4c)Surgical entry at peri-implantitis sites often reveals a circumferential pattern of bone loss. 5a)There is strong evidence that there is an increased risk of developing peri-implantitis in patients who have a history of chronic periodontitis, poor plaque control skills, and no regular maintenance care after implant therapy. Data identifying "smoking" and "diabetes" as potential risk factors/indicators for peri-implantitis are inconclusive. 5b)There is some limited evidence linking peri-implantitis to other factors such as: post-restorative presence of submucosal cement, lack of peri-implant keratinized mucosa and positioning of implants that make it difficult to perform oral hygiene and maintenance. 6)Evidence suggests that progressive crestal bone loss around implants in the absence of clinical signs of soft tissue inflammation is a rare event. © 2018 American Academy of Periodontology and European Federation of Periodontology.

Stress and strain distribution in three different mini dental implant designs using in implant retained overdenture: a finite element analysis study

PubMed Central

AUNMEUNGTONG, W.; KHONGKHUNTHIAN, P.; RUNGSIYAKULL, P.

2016-01-01

SUMMARY Finite Element Analysis (FEA) has been used for prediction of stress and strain between dental implant components and bone in the implant design process. Purpose Purpose of this study was to characterize and analyze stress and strain distribution occurring in bone and implants and to compare stress and strain of three different implant designs. Materials and methods Three different mini dental implant designs were included in this study: 1. a mini dental implant with an internal implant-abutment connection (MDIi); 2. a mini dental implant with an external implant-abutment connection (MDIe); 3. a single piece mini dental implant (MDIs). All implant designs were scanned using micro-CT scans. The imaging details of the implants were used to simulate models for FEA. An artificial bone volume of 9×9 mm in size was constructed and each implant was placed separately at the center of each bone model. All bone-implant models were simulatively loaded under an axial compressive force of 100 N and a 45-degree force of 100 N loading at the top of the implants using computer software to evaluate stress and strain distribution. Results There was no difference in stress or strain between the three implant designs. The stress and strain occurring in all three mini dental implant designs were mainly localized at the cortical bone around the bone-implant interface. Oblique 45° loading caused increased deformation, magnitude and distribution of stress and strain in all implant models. Conclusions Within the limits of this study, the average stress and strain in bone and implant models with MDIi were similar to those with MDIe and MDIs. The oblique 45° load played an important role in dramatically increased average stress and strain in all bone-implant models. Clinical implications Mini dental implants with external or internal connections have similar stress distribution to single piece mini dental implants. In clinical situations, the three types of mini dental implant should exhibit the same behavior to chewing force. PMID:28042449

Biomechanical behavior of 2-implant-and single-implant-retained mandibular overdentures with conventional or mini implants.

PubMed

Pisani, Marina Xavier; Presotto, Anna Gabriella Camacho; Mesquita, Marcelo Ferraz; Barão, Valentim Adelino Ricardo; Kemmoku, Daniel Takanori; Del Bel Cury, Altair Antoninha

2018-04-24

The use of single or mini dental implants to retain mandibular overdentures is still questionable. The purpose of this finite element analysis (FEA) study was to investigate the biomechanical behavior of 2- and single-implant-retained mandibular overdentures with conventional or mini implants. Four 3-dimensional (3D) finite element models were constructed with the following designs of mandibular overdentures: 2 (group 2-C) and single (group 1-C) conventional external hexagon implants with ball or O-ring attachment and 2 (group 2-M) and single (group 1-M) 1-piece mini implants. A 150-N axial load was applied bilaterally and simultaneously on the first molar. Overdenture displacement, von Mises equivalent stress (implants and/or prosthetic components), and maximum principal stresses (peri-implant bone) were recorded numerically and then color-coded and compared among the groups. The overdenture displacement (in mm) was higher for the 1-M (0.16) and 2-M (0.17) groups when compared with 1-C (0.09) and 2-C (0.08). Irrespective of the type of implant, the single-implant groups presented higher values of stress (in MPa) on the implants than did the 2-implant groups (1-C=52.53; 1-M=2.95; 2-C=34.66; 2-M=2.37), ball attachment (1-C=201.33; 2-C=159.06), housing or O-ring (1-C=125.01; 1-M=1.96; 2-C=88.84; 2-M=1.27), and peri-implant cortical bone (1-C=19.37; 1-M=1.47; 2-C=15.70; 2-M=1.06). The mini implant overdentures presented lower stress values on the implants, housing or O-ring, and peri-implant bone than did the conventional implant overdentures, regardless of the number of implants. The 2-implant-retained overdentures exhibited lower stresses than the single- implant-retained overdentures, irrespective of the type of implant. The mini implants demonstrated higher overdenture displacement and lower stresses than did conventional implant overdentures for single- and 2-implant-retained overdentures. Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Metallic orthopaedic implants and airport metal detectors.

PubMed

Kamineni, S; Legge, S; Ware, H

2002-01-01

Airport security can detect in vivo metallic implants. We hypothesized that a soft tissue shield and fast transit through archway detectors would decrease implant detectability, whereas greater implant mass would increase detectability. Twelve patients with 8 orthopaedic implants in vivo and 60 trauma and arthroplasty implants in vitro were subjected to standard airport security measures at Stanstead Airport (British Airports Authority), including arch and standard and nonstandard hand-held detectors. Archway detectors failed to detect some implants; hand-held detectors detected almost all implants except an ankle arthroplasty. Positive archway detection was related to implant transit speed through the detection field. The implant mass consistently affected detection in stainless steel and titanium implants, and a 1-inch wax shield had no effect. Patients with metallic implants should prepare routinely with documentation of their implant before traveling through security ports.

Bone morphology changes around two types of bone-level implants installed in fresh extraction sockets--a histomorphometric study in Beagle dogs.

PubMed

Alharbi, Hend M; Babay, Nadir; Alzoman, Hamad; Basudan, Sumaya; Anil, Sukumaran; Jansen, John A

2015-09-01

Minimizing crestal bone loss following immediate implant placement is considered the most challenging aspect in implant therapy. Implant surface topography and chemical modifications have been shown to influence the success of Osseointegration. The Straumann Bone Level implant, featuring SLActive surface, has been introduced with the aim of enhancing bone apposition. Similarly, the OsseoSpeed implants from Astra Tech claim to have an enhanced osseointegration. Because of the specific features in the implant design, both companies claim that crestal resorption is minimal with these implants. To evaluate the osseointegration and crestal bone level following immediate placement of Straumann Bone Level implant and OsseoSpeed implants in fresh extraction sockets in Beagle dogs. The distal roots of the second, third and fourth premolars were extracted in both sides of the mandible. The distal roots were removed using a dental elevator. A total of 60 fixtures were installed in 10 Beagle dogs. Two types of implants were used: Straumann Bone-Level implants, which were 8 × 3.3 mm in size, and Astra Tech OsseoSpeed 3.5 S MicroThread implants, which were 8 × 3.5 mm in size. The histomorphometrical evaluation was performed at the end of 4- and 12-week healing. The implant-bone contact and bone volume percentage were assessed. The bone-to-implant contact (BIC) and the bone volume did not show any significant changes for both types of implants. The OsseoSpeed™ implants showed 67.4% and 65.3% BIC, respectively, at 4 and 12 weeks compared with 71.7 and 73.1 for the Straumann Bone-Level implants. The bone volume around both types of implants did not differ significantly at both time periods. The crestal bone resorption was observed for both types of implants. The first BIC at buccal side and lingual side of the implants also did not differ significantly for both implant systems. This study showed that Straumann Bone Level and OsseoSpeed implants induced similar bone response after immediate implantation at 4 and 12 weeks. The immediate implant placement resulted in peri-implant crestal bone-level changes for both types of implants. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of implant macro-design on primary stability: A prospective clinical study.

PubMed

Lozano-Carrascal, Naroa; Salomó-Coll, Oscar; Gilabert-Cerdà, Marta; Farré-Pagés, Nuria; Gargallo-Albiol, Jordi; Hernández-Alfaro, Federico

2016-03-01

Implant restorations have become a high predictable treatment option. Several caracteristics such as surgical technique and implant design can influence the treatment outcomes. The aim of the present study was to evaluate the influence of implant macro-design on primary stability measured with resonance frequency analysis (RFA) and insertion torque (IT). Material and Mehods: A total of 47 implants divided in two groups: Test group (TI): 22 Tapered MIS® Seven implants; Control group (CI): 25 cylindrical Astra® Osseospeed implants. All implants were inserted following the manufacturers' standard protocols. Implant primary stability was measured at the moment of implant placement by registering insertion torque values (ITv) and ISQ values by means of Osstell™ Mentor (ISQv) (Integration Diagnostic Ltd., Goteborg, Sweden). In the mandible, mean ISQv for tapered implants (TI) was 71.67±5.16 and for cylindrical implants (CI) 57.15±4.83 (p=0.01). Mean insertion torque was 46.67±6.85 Ncm for TI and 35.77±6.72 Ncm for CI (p=0.01). In the maxilla, mean ISQ was 67.2±4.42 for tapered implants and 49.17±15.30 for cylindrical implants (p=0.01). Mean insertion torque for TI was 41.5±6.26 Ncm and for CI 39.17±6.34 Ncm (p>0.05). For tapered implants, no correlation could be found between implant diameter and primary stability. But for cylindrical implants there was a statistically significant correlation between implant diameter and primary stability: ITv (p=0.03); ISQv (p=0.04). Within the limits of the present study, tapered shaped implants achieve higher primary stability measured through ISQ and insertion torque values. Moreover, for cylindrical implants positive correlation has been established between implant diameter and primary stability.

Restoration of reproductive potential after expiration or removal of melengestrol acetate contraceptive implants in Tigers (Panthera tigris).

PubMed

Chuei, Jason Y; Asa, Cheryl S; Hall-Woods, Monica; Ballou, Jonathon; Traylor-Holzer, Kathy

2007-07-01

The need for contraception in the successful management of captive wild animals is becoming increasingly apparent. Because concerns exist regarding the reversibility of the contraceptive implant melengestrol acetate (MGA), reproductive data for 94 female Amur (Panthera tigris altaica) and Sumatran tigers (Panthera tigris sumatrae) were analyzed using survival analyses to evaluate return to reproductive status after implant removal or assumed expiration. Females placed in potential breeding situations after MGA implants were surgically removed showed a 62% return to reproduction by 5.25 years, whereas females with implants that were assumed to have expired showed only a 30% return to reproduction by 6 years. Implanted females did not reproduce as successfully as non-implanted control females, which showed an 85% probability of reproducing after placement in a new breeding situation by 2.66 years. Parturition increased the probability of reproducing in non-implanted females, but not in implanted females. Litter size, stillbirths, and offspring survival were not significantly different between non-implanted, implant-removed and implant-expired female tigers. Ten female tigers reproduced both before and after implant placement, and the differences in litter size, stillbirths, and offspring survival were not significant, nor were they significantly different from non-implanted females. Prior parturition, age when implant was removed, and duration of implantation did not affect the probability of reproducing for females after implant removal. These results show substantial reversibility of MGA implants, leading to 62% successful reproduction after implant removal. The reasons for lower successful reproduction in animals previously treated with the contraceptive compared to non-implanted females are not known, but a greater delay in reversibility was seen when implants were left in place and only presumed expired. Zoo Biol 26:275-288, 2007. (c) 2007 Wiley-Liss, Inc.

Poly Implants Prosthèse Breast Implants: A Case Series and Review of the Literature.

PubMed

Klein, Doron; Hadad, Eran; Wiser, Itay; Wolf, Omer; Itzhaki Shapira, Ortal; Fucks, Shir; Heller, Lior

2018-01-01

Silicone breast implants from the French manufacturer Poly Implants Prosthèse (PIP) were recalled from the European market after the French regulator has revealed the implants contain non-medical-grade silicone filler. In December 2011, following a large increase in reported rupture rate and a possible cancer risk, the French Ministry of Health recommended consideration of the PIP explantation, regardless of their condition. In 2012, the Israel Ministry of Health recommended to replace the implants only upon suspected implant rupture. The aims of this study were to characterize breast-augmented Israeli patients with PIP implants, compare their outcomes with those of breast-augmented patients with different implant types, and review the current PIP literature. Breast-augmented patients who underwent an elective breast implant exchange in Israel between January 2011 and January 2017 were included in the study. Data were collected from electronic and physical medical files. There were 73 breast-augmented female patients with 146 PIP breast implants included in this study. Average implant age was 6.7 ± 2.79 years. Mean implant size was 342.8 ± 52.9 mL. Fourteen women (19 implants [16%]) had a high-grade capsular contracture (Baker grade 3-4). During exchange, 28 implants were found to be ruptured (19.2%). Less than 10 years following breast augmentation, PIP implants demonstrated higher rupture rate compared with other implants. Our data are comparable to overall available rupture rate. Among patients with definitive rupture diagnosis, an elective implant removal should be recommended. In cases of undamaged implants, plastic surgeons should also seriously consider PIP implant explantation. When the patient does not desire to remove the implant, an annual physical examination and breast ultrasound are recommended, beginning a year after augmentation.

Macro design effects on stress distribution around implants: a photoelastic stress analysis.

PubMed

Ozkir, Serhat Emre; Terzioglu, Hakan

2012-01-01

Biomechanics is one of the main factors for achieving long-term success of implant supported prostheses. Long-term failures mostly depend on biomechanical complications. It is important to distinguish the effects of macro design of the implants. In this study, the photoelastic response of four different types of implants that were inserted with different angulations were comparatively analyzed. The implant types investigated were screw cylinder (ITI, Straumann AG, Basel, Switzerland), stepped cylinder (Frialit2, Friadent GmbH, Manheim, Germany), root form (Camlog Rootline, Alatatec, Wilshelm, Germany), and cylindrical implant, with micro-threads on the implant neck (Astra, AstraTech, Mölndal, Sweden). In the test models, one of the implants was inserted straight, while the other one was aligned mesially with 15° angles. The superstructures were prepared as single crowns. A 150N loading was applied to the restorations throughout the test. A comparison of the implant designs showed that there were no significant differences between the straight implants; however, between the inclined implants, the most favorable stress distribution was seen with the stepped cylinder implants. The least favorable stress concentration was observed around the root formed implants. Microthreads around the implant neck appeared to be effective in a homogenous stress distribution. Observations showed that misaligned implants caused less stress than straight implants, but the stress concentrations were not homogenous. As there were observable differences between the implant types, straight placed cylindrical implants showed better stress distribution characteristics, while inclined tapering implants had better stress distribution characteristics.

Number of implants for mandibular implant overdentures: a systematic review

PubMed Central

Lee, Jeong-Yol; Kim, Ha-Young; Bryant, S. Ross

2012-01-01

PURPOSE The aim of this systematic review is to address treatment outcomes of Mandibular implant overdentures relative to implant survival rate, maintenance and complications, and patient satisfaction. MATERIALS AND METHODS A systematic literature search was conducted by a PubMed search strategy and hand-searching of relevant journals from included studies. Randomized Clinical Trials (RCT) and comparative clinical trial studies on mandibular implant overdentures until August, 2010 were selected. Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants. RESULTS Six studies presented the data of the implant survival rate which ranged from 95% to 100% for 2 and 4 implant group and from 81.8% to 96.1% for 1 and 2 implant group. One study, which statistically compared implant survival rate showed no significant differences relative to the number of implants. The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group, and denture repair due to the fracture around an implant for 1 and 2 implant groups. Most studies showed no significant differences in the rate of prosthetic maintenance and complication, and patient satisfaction regardless the number of implants. CONCLUSION The implant survival rate of mandibular overdentures is high regardless of the number of implants. Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants. PMID:23236572

Stability of tapered and parallel-walled dental implants: A systematic review and meta-analysis.

PubMed

Atieh, Momen A; Alsabeeha, Nabeel; Duncan, Warwick J

2018-05-15

Clinical trials have suggested that dental implants with a tapered configuration have improved stability at placement, allowing immediate placement and/or loading. The aim of this systematic review and meta-analysis was to evaluate the implant stability of tapered dental implants compared to standard parallel-walled dental implants. Applying the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement, randomized controlled trials (RCTs) were searched for in electronic databases and complemented by hand searching. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool and data were analyzed using statistical software. A total of 1199 studies were identified, of which, five trials were included with 336 dental implants in 303 participants. Overall meta-analysis showed that tapered dental implants had higher implant stability values than parallel-walled dental implants at insertion and 8 weeks but the difference was not statistically significant. Tapered dental implants had significantly less marginal bone loss compared to parallel-walled dental implants. No significant differences in implant failure rate were found between tapered and parallel-walled dental implants. There is limited evidence to demonstrate the effectiveness of tapered dental implants in achieving greater implant stability compared to parallel-walled dental implants. Superior short-term results in maintaining peri-implant marginal bone with tapered dental implants are possible. Further properly designed RCTs are required to endorse the supposed advantages of tapered dental implants in immediate loading protocol and other complex clinical scenarios. © 2018 Wiley Periodicals, Inc.

Indications of Free Grafts in Mandibular Reconstruction, after Removing Benign Tumors: Treatment Algorithm

PubMed Central

Alister, Juan Pablo; Uribe, Francisca; Olate, Sergio; Arriagada, Alvaro

2016-01-01

Background: Mandibular reconstruction has been the subject of much debate and research in the fields of maxillofacial surgery and head and neck surgery. Materials and Methods: A retrospective observational study was undertaken with 14 patients diagnosed with benign tumorous pathologies and who underwent immediate mandibular resection and reconstruction at the Hospital del Salvador Maxillofacial Surgery Unit and Dr. Rodrigo Fariña’s private clinic between the years 2002 and 2012. We propose a treatment algorithm, which is previous teeth extractions in area that will be removed. Results: Fourteen patients underwent surgery, and a total of 40 dental implants were installed in 6 men and 8 women, the mean age of 33.5 (age range, 14–58 y). Reconstruction with iliac crest bone graft, and rehabilitation following this protocol (average of reconstruction was 8.7 cm), was successful with no complications at all in 12 patients. One patient had a minor complication, and the graft was partially reabsorbed because of communication of the graft with the oral cavity. This complication did not impede rehabilitation with dental implants. Another patient suffered the total loss of the graft due to infection because of dehiscence of oral mucosa and great communication with the mouth. Another iliac crest free graft reconstruction was undertaken 6 months later. Conclusions: The scientific evidence suggests that mandibular reconstruction using free grafts following the removal of benign tumors is a biologically sustainable alternative. The critical factor to improve the prognosis of free grafts reconstruction in benign tumors is to have good quality soft tissue and avoid communication with the oral cavity. For this, it is vital to do dental extractions before removing the tumor. PMID:27622113

The effect of microgeometry, implant thickness and polyurethane chemistry on the foreign body response to subcutaneous implants.

PubMed

Ward, W Kenneth; Slobodzian, Emily P; Tiekotter, Kenneth L; Wood, Michael D

2002-11-01

We addressed the effect of implant thickness, implant porosity, and polyurethane (PU) chemistry on angiogenesis and on the foreign body response in rats. The following materials were implanted subcutaneously for 7 weeks then excised for histologic analysis: a solid PU; a solid polyurethane with silicone and polyethylene oxide (PU-S-PEO); porous expanded polytetrafluoroethylene (ePTFE); and porous polyvinyl alcohol sponge (PVA). Two thicknesses of PU-S-PEO were compared: 300 microns (thin) and 2000 microns (thick). Foreign body capsule (FBC) thickness was much less in PU-S-PEO implants than in PU implants. In addition, FBC were thinner in thin implants than in thick implants. FBC was much more dense in solid implants than in porous implants. As compared with solid implants, porous implants (PVA and ePTFE) led to a marked increase in the number of microvessels that developed adjacent to the implant, as observed both with hematoxylin/eosin staining and with an immunohistochemical anti-endothelial stain. We conclude that the polyethylene oxide and silicone moieties in PU reduce the thickness of the subsequent FBC. In addition, thin implants lead to a thin FBC. Porous implants (PVA and ePTFE) cause more angiogenesis than solid implants. These results may have implications for the measurement of blood-derived analytes by biosensors.

Comparative silicone breast implant evaluation using mammography, sonography, and magnetic resonance imaging: experience with 59 implants.

PubMed

Ahn, C Y; DeBruhl, N D; Gorczyca, D P; Shaw, W W; Bassett, L W

1994-10-01

With the current controversy regarding the safety of silicone implants, the detection and evaluation of implant rupture are causing concern for both plastic surgeons and patients. Our study obtained comparative value analysis of mammography, sonography, and magnetic resonance imaging (MRI) in the detection of silicone implant rupture. Twenty-nine symptomatic patients (total of 59 silicone implants) were entered into the study. Intraoperative findings revealed 21 ruptured implants (36 percent). During physical examination, a positive "squeeze test" was highly suggestive of implant rupture. Mammograms were obtained of 51 implants (sensitivity 11 percent, specificity 89 percent). Sonography was performed on 57 implants (sensitivity 70 percent, specificity 92 percent). MRI was performed on 55 implants (sensitivity 81 percent, specificity 92 percent). Sonographically, implant rupture is demonstrated by the "stepladder sign." Double-lumen implants may appear as false-positive results for rupture on sonography. On MRI, the "linguine sign" represents disrupted fragments of a ruptured implant. The most reliable imaging modality for implant rupture detection is MRI, followed by sonogram. Mammogram is the least reliable. Our study supports the clinical indication and diagnostic value of sonogram and MRI in the evaluation of symptomatic breast implant patients.

Influence of immediate loading on provisional restoration in dental implant stability

NASA Astrophysics Data System (ADS)

Ikbal, M.; Odang, R. W.; Indrasari, M.; Dewi, R. S.

2017-08-01

The success of dental implant treatment is determined by the primary stability at placement. One factor that could influence this stability is occlusal loading through provisional restoration. Two types of loading protocols are usually used: immediate and delayed loading. However, some controversies remain about the influence of occlusal loading on implant stability. Therefore, the influence of immediate loading on implant stability must be studied. An animal study was conducted by placing nine dental implants in the mandibular jaw of three Macaca fascicularis. Provisional restorations with various occlusal contacts (no, light, and normal contact) were placed on the implant. The implant stability was measured using the Ostell ISQ three times: immediately (baseline) and at the first and second months after implant placement. The implant stability between implants with no and normal occlusal contact as well as light and normal occlusal contact showed significant differences (p < 0.05) at the first and second months after implant placement. However, no significant increase (p > 0.05) in implant stability was seen at the baseline and the first and second months after implant placement for all occlusal contact groups. Immediate loading influenced the implant stability, and provisional restoration of implant without occlusal contact showed the highest implant stability.

Clinical Management of Implant Prostheses in Patients with Bruxism

PubMed Central

Komiyama, Osamu; Lobbezoo, Frank; De Laat, Antoon; Iida, Takashi; Kitagawa, Tsuyoshi; Murakami, Hiroshi; Kato, Takao; Kawara, Misao

2012-01-01

There is general agreement that excessive stress to the bone-implant interface may result in implant overload and failure. Early failure of the implant due to excessive loading occurs shortly after uncovering the implant. Excess load on a final restoration after successful implant integration can result in physical failure of the implant structure. Many clinicians believe that overload of dental implants is a risk factor for vertical peri-implant bone loss and/or may be detrimental for the suprastructure in implant prostheses. It has been documented that occlusal parafunction, such as, bruxism (tooth grinding and clenching) affects the outcome of implant prostheses, but there is no evidence for a causal relation between the failures and overload of dental implants. In spite of this lack of evidence, often metal restorations are preferred instead of porcelain for patients in whom bruxism is presumed on the basis of tooth wear. The purpose of this paper is to discuss the importance of the occlusal scheme used in implant restorations for implant longevity and to suggest a clinical approach and occlusal materials for implant prostheses in order to prevent complications related to bruxism. PMID:22701484

Measurement and evaluation of national family planning programs.

PubMed

Mauldin, W P

1967-03-01

RESUMEN: En los últimos quince años diez paises han inaugurado programas nacionales de planeamiento familiar: India, Pakistán, Corea del Sur, Taiwan, Turquía, Malasia, Ceilán, Túez, la República Arabe Unida, y Marruecos. Otros paises, incluyendo Tailandia, Hong Kong, Singapur, Kenya, Barbados, Trinidad y los Estados Unidos, apoyan y/o estimulan actividades de planeamiento familiar. En la mayor parte de los casos la razón fundamental del programa ha sido que si la tasa de crecimiento poblacional disminuyera, aumentaría la tasa de crecimiento económico.Las metas de largo alcance, expresadas típicamente en términos de reducir las tasa.de de natalidad o de crecimiento, tienen su ejemplo en el propósito de Pakistán de reducir su tasa de crecimiento a 26 para 1970; el de Corea de reducir su tasa de natalidad a 20 para 1971; y el de India de reducir su tasa de natalidad a 25 para 1973.Los objectivos intermedios, que cubren diversos aspectos del pro grama, incluyen metas específicas para un determinado mes a año, considerando personal, la adquisición de anticonceptivos, y el número de usarios por método. Las metas específicas anuales de aceptantes de dispositivos intrauterinos (IUD), para Taiwán, Corea, Túnez, Pakistán e India, son comunes, tanto por la naturaleza del artefacto, como por la facilidad de medición de los que continúan utilizándolos. El programa de evaluación en Taiwán, que trata de medir por diversos medios los efectos inmediatos, mediatos y de largo plazo del programa de planeamiento familiar sirve de modelo. El propósito de la evaiuación de un programa de planeamiento familiar es contribuir a la efectividad y eficiencia del programa, midiendo y analizando su progreso. Las áreas a medir pueden ser clasificadas como- (1) conocimiento acerca de; (2) actitudes hacia; (3) práctica de control de natalidad; y (4) nivel de fecundidad.Un buen sistema de evaluación debería incluir: A. Un buen conjunto de estadísticas de servicio presentadas en formularios estandarizados, en las siguienies formas: 1. Informes nensuales por áreas administrativas, sobre los actuales servicios de planeamiento familiar proporcionados en la actualidad, de carácter permanente o de larga duración (al presente, esterilización y IUD de acuerdo a las siguientes características del receptor: residencia, edad, paridad (número de hijos vivos por sexo), y donde se enteró del programa, si es posible "clase";(probablemente educación de la madre, pero posiblemente ocupación del esposo, ingreso, o equivalente); prácticas anticonceptivas anteriores; intervalo; y deseo de tener más hijos. En un programa grande estos datos pueden obtenerse en base a una muestra. 2. Informes mensuales sobre la distribución de suministros anticonceptivos (condones, píldoras, sustancias efervescentes, etc.), los primeros suministros deben ir acompañados de un registro de las características del recipiente, como anteriormente; los suministros subsecuentes se regietrarán sólo en volumen bruto. Esto también se aplicará al ritmo, donde éste método se enseñe a un número considerable de mujeres. 3. Informes regulares sobre las actividades de planeamiento familiar de médicos privados, como una estimación del efecto catalítico del programa del gobierno sobre ci sector privado. 4. Datos generates mensuales, ppr áreas admirtistrativas importantes, sabre: visitas domiciliarias, reuniones, cuñas radiates y televisadas, avisos en los periódicos y personal que trabaja. 5. Para propósitos de seguimiento una entrevi eta de campo cada 6 a 12 meses a cada N mujer de las listas para (1) y (2) arriba, en un total de 300 o 400, para conocer las tasas de continuación y las razones de abandono (ej: desea otro hijo, insatisfecha can ci método, otras). Las mue.stras podrían ser de 300 cada una, con una supuesta experiencia de 6, 12, 18 y 24 meses. B. Un buen conjunto de datos sobre costa (datos sobre cotos actulaes atribuíbles directamente al programa de planeamiento familiar) fraccionados par áreas principales y cinco a seis categorías de costos importantes tales coma: adminietración, personal de campo, publicidad, suministros, etc. C. Un buen conjunto de dates globales sobre la distribución de los suministros comerciales que puedan llegar tan cerca como sea posible del último consumidor, to cual significa probablemente obtener información de los mayoristas. D. Una encuesta de conocimientos, actitudes y prácticas (KAP) para una evaluación general cada dos años. Las preguntas básicas (además de las antes mencionadas y estatus marital y étnico cuando sea pertinente) son: actitud hacia e interés por la anticoncepción, número de niños por sexo, deseo de tener más hijos, prácticas anticonceptivas, experiencia sobre abortos, tal vez historia de embarazo (especialmente si esta producirá una tasa de fecundidad válida), aprobación del programa gubernamental (para uso politico), y si está actualmente embarazada (la única y mejor pregunta cuya respuesta habla del efecto sobre la tasa de natalidad). Administrativamente, la responsabilidad por la evalucion debe estar cerca al director, se debe tomar provisiones para obtener informes regulares (meneulaes) y especiales dirigidos a preguntar sobre política. El corolario es que el jefe de evaluación debe tener la confianza del director y debe estar al día en cuanto a las decisiones sabre la politics a seguir. Su trabajo consiste en extractar los aspectos principales que funcionan bien y los no operantes. En cuanto a costos, la evaluación debe hacerse sobre no más del 10 par ciento del costa del programa en paises pequeños (de menos de 30 milliones) y sabre no más del 5 per ciento en paises más grandes.Para medir en que forma el programa satisface el criterio final-la magnitud en que cambia la fecundidad-se debe realizar un trabajo más elaborado en el centro (Universidades, Consejos de población, etc.) para desarrollar una forma (a formas) segura de traducir las estadísticas de servicio en práticas y tal vez aún datos sobre suministro comercial en datos sabre tasas de natalidad. Esto incluye, par ejemplo, los esfuerzos para consolidar observaciones coma "cinco años-mujer de usa de IUD, a 400 condones equivalen a la prevención de un nacimiento," y esfuerzos como los de Pakistán de calcular tasas coma "años de protección de una pareja contra el embarazo."In the belief that a decrease in the rate of population growth will increase economic development, more than ten countries have inaugurated family planning programs in the past fifteen years. To provide a model for measuring the immediate, intermediate, and long-term effects of any such program, the authors use the Taiwan evaluation.The model suggests that a good system of evaluation should include monthly statistics on (1) participants, who are grouped by characteristics; (2) the distribution of supplies, reported at first by the characteristics of recipients, but after by gross volume only; (3) family planning activities of private physicians to measure the catalytic effect on the private sector; (4) new contacts and amount of advertising in mass media; (5) costs broken down by areas and by cost categories; and (6) distribution of commercial supplies. In addition, the program should conduct 300-400 interviews every 6-12 months to learn the rates of continuation and the rates and reasons for discontinuation. Finally, a KAP survey should be conducted every two years.The administration of the evaluation should be close to the director for policy decisions and for the ultimate work of evaluation-the finding of new ways to measure the main goal of change in fertility by the translation of statistics on Services provided and commercial supplies into birth rate data.

Sensitivity of Magnetospheric Multi-Scale (MMS) Mission Navigation Accuracy to Major Error Sources

NASA Technical Reports Server (NTRS)

Olson, Corwin; Long, Anne; Car[emter. Russell

2011-01-01

The Magnetospheric Multiscale (MMS) mission consists of four satellites flying in formation in highly elliptical orbits about the Earth, with a primary objective of studying magnetic reconnection. The baseline navigation concept is independent estimation of each spacecraft state using GPS pseudorange measurements referenced to an Ultra Stable Oscillator (USO) with accelerometer measurements included during maneuvers. MMS state estimation is performed onboard each spacecraft using the Goddard Enhanced Onboard Navigation System (GEONS), which is embedded in the Navigator GPS receiver. This paper describes the sensitivity of MMS navigation performance to two major error sources: USO clock errors and thrust acceleration knowledge errors.

Sensitivity of Magnetospheric Multi-Scale (MMS) Mission Naviation Accuracy to Major Error Sources

NASA Technical Reports Server (NTRS)

Olson, Corwin; Long, Anne; Carpenter, J. Russell

2011-01-01

The Magnetospheric Multiscale (MMS) mission consists of four satellites flying in formation in highly elliptical orbits about the Earth, with a primary objective of studying magnetic reconnection. The baseline navigation concept is independent estimation of each spacecraft state using GPS pseudorange measurements referenced to an Ultra Stable Oscillator (USO) with accelerometer measurements included during maneuvers. MMS state estimation is performed onboard each spacecraft using the Goddard Enhanced Onboard Navigation System (GEONS), which is embedded in the Navigator GPS receiver. This paper describes the sensitivity of MMS navigation performance to two major error sources: USO clock errors and thrust acceleration knowledge errors.

Launch and Landing of Russian Soyuz - Medical Support for US and Partner Astronauts

NASA Technical Reports Server (NTRS)

Menon, Anil

2017-01-01

Launching, landing, flight route, expeditions, Soyuz, near Kazakhstan USOS Crew Surgeon -Quarantine and direct care to crew before launch, then present in close proximity to launch for abort. IP Crew Surgeon -same Deputy Crew Surgeon -Back up for crew surgeon, care for immediate family, stationed at airport for helicopter abort response Russian based US doctor -Coordinate with SOS staff USOS Crew Surgeon -Nominal helicopter response and initial medical care and support during return on gulfstreamIPcenter dotP Crew Surgeon -same Deputy Crew Surgeon -Ballistic helicopter support Russian based US doctor -Coordinate with SOS staff Direct return doctor -Direct medical care on return flight

Uso de la punción lumbar en la evaluación de sepsis neonatal tardía en recién nacidos de bajo peso al nacer

PubMed Central

Zea-Vera, A; Turín, CG; Rueda, MS; Guillén-Pinto, D; Medina-Alva, P; Tori, A; Rivas, M; Zegarra, J; Castañeda, A; Cam, L; Ochoa, TJ

2017-01-01

RESUMEN El objetivo de este estudio fue analizar el uso de la punción lumbar (PL) en las sospechas de sepsis neonatal tardía. Se recomienda realizar una PL en la evaluación de toda sospecha de sepsis neonatal tardía. Se utilizó una cohorte de 414 neonatos con peso al nacer <2000g en tres hospitales de Lima. Se realizó la PL en 45/214 (21,0%) sospechas de sepsis y en 13/48 (27,1%) sepsis confirmadas por hemocultivo. Se diagnosticó meningitis en 8/214 (3,7%) sospechas y en 8/45 (17,5%) episodios en los que se realizó la PL. El tiempo de tratamiento de los episodios sin PL fue similar a los episodios de sepsis con meningitis descartada y menor a los episodios de meningitis. El uso de la PL es bajo, lo que puede resultar en meningitis no diagnosticadas y tratadas inadecuadamente. Es necesario reforzar la importancia de la PL en la evaluación de sepsis neonatal. PMID:27656928

Motivational and Skills Training HIV/STI Sexual Risk Reduction Groups for Men

PubMed Central

Calsyn, Donald A.; Hatch-Maillette, Mary; Tross, Susan; Doyle, Suzanne R.; Crits-Christoph, Paul; Song, Yong S.; Harrer, Judy M.; Lalos, Genise; Berns, Sara B.

2009-01-01

The effectiveness of a motivational and skills training HIV/AIDS group intervention designed for men in substance abuse treatment was evaluated. Men in methadone maintenance (n=288) or outpatient psychosocial treatment (n=302) completed assessments at baseline, 2 weeks, 3- and 6-months post intervention. Participants were randomly assigned to attend either “Real Men Are Safe” (REMAS; five sessions containing information, motivational exercises and skills training), or HIV education (HIV-Ed; one session containing HIV prevention information). REMAS participants engaged in significantly fewer unprotected vaginal and anal sexual intercourse occasions (USO) during the 90 days prior to the 3- and 6-month follow-ups than HIV-Ed participants. Completing REMAS resulted in an even stronger effect: completers reduced their number of USO by 21% from baseline to 6-month follow-up. In contrast, HIV-Ed completers increased the number of USO by 2%. A motivational and skills training HIV prevention intervention designed for men was associated with greater sexual risk reduction over standard HIV education. Substance abuse treatment programs can therefore help reduce sexual risk among their clientele by providing a more intensive intervention than what is traditionally provided. PMID:19150206

Spectral-Temporal Modulated Ripple Discrimination by Children With Cochlear Implants.

PubMed

Landsberger, David M; Padilla, Monica; Martinez, Amy S; Eisenberg, Laurie S

A postlingually implanted adult typically develops hearing with an intact auditory system, followed by periods of deafness (or near deafness) and adaptation to the implant. For an early implanted child whose brain is highly plastic, the auditory system matures with consistent input from a cochlear implant. It is likely that the auditory system of early implanted cochlear implant users is fundamentally different than postlingually implanted adults. The purpose of this study is to compare the basic psychophysical capabilities and limitations of these two populations on a spectral resolution task to determine potential effects of early deprivation and plasticity. Performance on a spectral resolution task (Spectral-temporally Modulated Ripple Test [SMRT]) was measured for 20 bilaterally implanted, prelingually deafened children (between 5 and 13 years of age) and 20 hearing children within the same age range. Additionally, 15 bilaterally implanted, postlingually deafened adults, and 10 hearing adults were tested on the same task. Cochlear implant users (adults and children) were tested bilaterally, and with each ear alone. Hearing listeners (adults and children) were tested with the unprocessed SMRT and with a vocoded version that simulates an 8-channel cochlear implant. For children with normal hearing, a positive correlation was found between age and SMRT score for both the unprocessed and vocoded versions. Older hearing children performed similarly to hearing adults in both the unprocessed and vocoded test conditions. However, for children with cochlear implants, no significant relationship was found between SMRT score and chronological age, age at implantation, or years of implant experience. Performance by children with cochlear implants was poorer than performance by cochlear implanted adults. It was also found that children implanted sequentially tended to have better scores with the first implant compared with the second implant. This difference was not observed for adults. An additional finding was that SMRT score was negatively correlated with age for adults with implants. Results from this study suggest that basic psychophysical capabilities of early implanted children and postlingually implanted adults differ when assessed in the sound field using their personal implant processors. Because spectral resolution does not improve with age for early implanted children, it seems likely that the sparse representation of the signal provided by a cochlear implant limits spectral resolution development. These results are supported by the finding that postlingually implanted adults, whose auditory systems matured before the onset of hearing loss, perform significantly better than early implanted children on the spectral resolution test.

The role of economic analysis in groundwater management in semi-arid regions: the case of Nigeria

NASA Astrophysics Data System (ADS)

Acharya, Gayatri

The aim of this paper is to use an economic framework to derive decision making rules for river basin management with a focus on groundwater resources. Using an example from northern Nigeria, the paper provides an example of how decision making for sustainable water resources management may be facilitated by comparing net benefits and costs across a river basin. It is argued that economic tools can be used to assess the value of water resources in different uses, identify and analyze management scenarios, and provide decision rules for the sustainable use and management of surface and ground water resources in the region. L'objet de cet article est l'utilisation d'un cadre économique pour établir des règles de prise de décision pour la gestion d'un bassin versant prenant en compte les ressources en eau souterraine. À partir d'un exemple du Nigéria septentrional, cet article explique comment une prise de décision pour la gestion durable de ressources en eau peut être facilitée en comparant les bénéfices nets et les coûts sur tout le bassin versant. Il est montré que les outils économiques peuvent être utilisés pour établir la valeur des ressources en eau dans les différents usages, pour identifier et analyser des scénarios de gestion et pour fournir des règles de décision pour un usage et une gestion durables des ressources en eaux de surface et souterraines dans la région. El objetivo de este artículo es utilizar un enfoque económico para deducir reglas de toma de decisión en la gestión de cuencas, haciendo énfasis en los recursos subterráneos. Por medio de un ejemplo del Norte de Nigeria, se ilustra cómo la toma de decisiones orientadas a la gestión sustentable de los recursos hídricos puede ser facilitada si se compara los beneficios netos y los costes en toda la cuenca. Se argumenta que las herramientas económicas pueden servir para establecer el valor de los recursos hídricos destinados a usos diferentes, para identificar y analizar escenarios de gestión, y para proporcionar reglas de decisión que posibiliten el uso sustentable y la gestión de los recursos superficiales y subterráneos en la región.

Effect of implant macro-design on primary stability: A prospective clinical study

PubMed Central

Lozano-Carrascal, Naroa; Salomó-Coll, Oscar; Gilabert-Cerdà, Marta; Farré-Pagés, Nuria; Hernández-Alfaro, Federico

2016-01-01

Background Implant restorations have become a high predictable treatment option. Several caracteristics such as surgical technique and implant design can influence the treatment outcomes. The aim of the present study was to evaluate the influence of implant macro-design on primary stability measured with resonance frequency analysis (RFA) and insertion torque (IT). Material and Methods A total of 47 implants divided in two groups: Test group (TI): 22 Tapered MIS® Seven implants; Control group (CI): 25 cylindrical Astra® Osseospeed implants. All implants were inserted following the manufacturers’ standard protocols. Implant primary stability was measured at the moment of implant placement by registering insertion torque values (ITv) and ISQ values by means of Osstell™ Mentor (ISQv) (Integration Diagnostic Ltd., Goteborg, Sweden). Results In the mandible, mean ISQv for tapered implants (TI) was 71.67±5.16 and for cylindrical implants (CI) 57.15±4.83 (p=0.01). Mean insertion torque was 46.67±6.85 Ncm for TI and 35.77±6.72 Ncm for CI (p=0.01). In the maxilla, mean ISQ was 67.2±4.42 for tapered implants and 49.17±15.30 for cylindrical implants (p=0.01). Mean insertion torque for TI was 41.5±6.26 Ncm and for CI 39.17±6.34 Ncm (p>0.05). For tapered implants, no correlation could be found between implant diameter and primary stability. But for cylindrical implants there was a statistically significant correlation between implant diameter and primary stability: ITv (p=0.03); ISQv (p=0.04). Conclusions Within the limits of the present study, tapered shaped implants achieve higher primary stability measured through ISQ and insertion torque values. Moreover, for cylindrical implants positive correlation has been established between implant diameter and primary stability. Key words:Primary stability, tapered, cylindrical, conical, implant macro-design. PMID:26827067

Effect of implant number and distribution on load transfer in implant-supported partial fixed dental prostheses for the anterior maxilla: A photoelastic stress analysis study.

PubMed

Lee, Jae-In; Lee, Yoon; Kim, Yu-Lee; Cho, Hye-Won

2016-02-01

The 4-, 3- or even 2-implant-supported partial fixed dental prosthesis (PFDP) designs have been used to rehabilitate the anterior edentulous maxilla. The purpose of this in vitro study was to compare the stress distribution in the supporting tissues surrounding implants placed in the anterior maxilla with 5 PFDP designs. A photoelastic model of the human maxilla with an anterior edentulous region was made with photoelastic resin (PL-2; Vishay Micro-Measurements), and 6 straight implants (OsseoSpeed; Astra Tech AB) were placed in the 6 anterior tooth positions. The 5 design concepts based on implant location were as follows: model 6I: 6 implants; model 2C2CI: 4 implants (2 canines and 2 central incisors); model 2C2LI: 4 implants (2 canines and 2 lateral incisors); model 2C1CI: 3 implants (2 canines and 1 central incisor); and model 2C: 2 canines. A load of 127.4 N was applied on the cingulum of 3 teeth at a 30-degree angle to the long axis of the implant. Stresses that developed in the supporting structure were recorded photographically. The 6-implant-supported PFDP exhibited the most even and lowest distribution of stresses in all loading conditions. When the canine was loaded, the 2- or 3-implant-supported PFDP showed higher stresses around the implant at the canine position than did the 4- or 6-implant-supported PFDP. When the central incisor or lateral incisor was loaded, the two 4-implant-supported PFDPs exhibited similar levels of stresses around the implants and showed lower stresses than did the 2- or 3-implant-supported PFDP. Implant number and distribution influenced stress distribution around the implants in the anterior maxilla. With a decrease in implant number, the stresses around the implants increased. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

United Kingdom national paediatric bilateral project: Demographics and results of localization and speech perception testing.

PubMed

Cullington, H E; Bele, D; Brinton, J C; Cooper, S; Daft, M; Harding, J; Hatton, N; Humphries, J; Lutman, M E; Maddocks, J; Maggs, J; Millward, K; O'Donoghue, G; Patel, S; Rajput, K; Salmon, V; Sear, T; Speers, A; Wheeler, A; Wilson, K

2017-01-01

To assess longitudinal outcomes in a large and varied population of children receiving bilateral cochlear implants both simultaneously and sequentially. This observational non-randomized service evaluation collected localization and speech recognition in noise data from simultaneously and sequentially implanted children at four time points: before bilateral cochlear implants or before the sequential implant, 1 year, 2 years, and 3 years after bilateral implants. No inclusion criteria were applied, so children with additional difficulties, cochleovestibular anomalies, varying educational placements, 23 different home languages, a full range of outcomes and varying device use were included. 1001 children were included: 465 implanted simultaneously and 536 sequentially, representing just over 50% of children receiving bilateral implants in the UK in this period. In simultaneously implanted children the median age at implant was 2.1 years; 7% were implanted at less than 1 year of age. In sequentially implanted children the interval between implants ranged from 0.1 to 14.5 years. Children with simultaneous bilateral implants localized better than those with one implant. On average children receiving a second (sequential) cochlear implant showed improvement in localization and listening in background noise after 1 year of bilateral listening. The interval between sequential implants had no effect on localization improvement although a smaller interval gave more improvement in speech recognition in noise. Children with sequential implants on average were able to use their second device to obtain spatial release from masking after 2 years of bilateral listening. Although ranges were large, bilateral cochlear implants on average offered an improvement in localization and speech perception in noise over unilateral implants. These data represent the diverse population of children with bilateral cochlear implants in the UK from 2010 to 2012. Predictions of outcomes for individual patients are not possible from these data. However, there are no indications to preclude children with long inter-implant interval having the chance of a second cochlear implant.

Influence of trabecular bone quality and implantation direction on press-fit mechanics.

PubMed

Damm, Niklas B; Morlock, Michael M; Bishop, Nicholas E

2017-02-01

Achieving primary stability of uncemented press-fit prostheses in patients with poor quality bone can involve axial implantation forces large enough to cause bone fracture. Radial implantation eliminates intraoperative impaction forces and could prevent this damage. Platens of two commercial implant surfaces ("Beaded" and "Flaked") were implanted onto trabecular bone specimens of varying quality in a press-fit simulator. Samples were implanted with varying interference, either axially (shear) or radially (normal). Push-in and pull-out forces were measured to assess stability. Microstructural changes in the bone were determined from μCT analysis. For force-defined implantation analysis, push-in and pull-out forces both increased proportionally with increasing radial force, independent of implantation direction, bone quality or implant surface. For position-defined implantation analysis, pull-out forces were generally found to increase with interference and to be greater for radial than axial implantation direction, and to be lower for poor quality bone. Bone density increased locally at the tested interface due to implantation, in particular for the Beaded surface under axial implantation. If a safe radial stress can be determined for cortical bone in a particular patient, the associated implantation force, and pull-out force which represents primary stability, can be directly derived, regardless of implantation direction, bone quality or implant surface. Radial implantation delivers primary stability that is no worse than that for axial implantation and may eliminate potentially damaging impaction forces. Development of implant designs based on this principal might improve implant fixation. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:224-233, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Chemical, corrosion and topographical analysis of stainless steel implants after different implantation periods.

PubMed

Chrzanowski, Wojciech; Armitage, David Andrew; Knowles, Jonathan Campbell; Szade, Jacek; Korlacki, Wojciech; Marciniak, Jan

2008-07-01

The aim of this work is to examine the corrosion properties, chemical composition, and material-implant interaction after different periods of implantation of plates used to correct funnel chest. The implants are made of 316L stainless steel. Examinations are carried out on three implants: new (nonimplanted) and two implanted for 29 and 35 months. The corrosion study reveals that in the potential range that could occur in the physiological condition the new bar has the lowest current density and the highest corrosion potential. This indicates that the new plate has the highest corrosion resistance and the corrosion resistance could be reduced during implantation by the instruments used during the operation. XPS analysis reveals changes in the surface chemistry. The longer the implantation time the more carbon and oxygen are observed and only trace of elements such as Cr, Mo are detected indicating that surface is covered by an organic layer. On some parts of the implants whitish tissue is observed: the thickness of which increased with the time of implantation. This tissue was identified as an organic layer; mainly attached to the surface on the areas close to where the implant was bent to attain anatomical fit and thus where the implant has higher surface roughness. The study indicates that the chest plates are impaired by the implantation procedure and contact with biological environment. The organic layer on the surface shows that the implant did not stay passive but some reactions at the tissue-implant interface occurred. These reactions should be seen as positive, as it indicates that the implants were accepted by the tissues. Nevertheless, if the implants react, they may continue to release chromium, nickel, and other harmful ions long term as indicated by lower corrosion resistance of the implants following implantation.

Are marginal bone levels and implant stability/mobility affected by single-stage platform switched dental implants? A comparative clinical study.

PubMed

Dursun, Erhan; Tulunoglu, Ibrahim; Canpınar, Pınar; Uysal, Serdar; Akalın, Ferda Alev; Tözüm, Tolga F

2012-10-01

The aim of this study was to evaluate short-term bone level and stability/mobility measurement alterations at platform switched (PS) and standard platform (SP) implants placed in mandibular premolar/molar regions using a single-stage protocol. Sixteen PS and 16 SP implants restorated with fixed prosthesis were included. Standard implant dimensions were used for both implant systems. After 3 months of osseointegration, implants were connected to abutments and final restorations were performed. Marginal bone loss was measured by standardized periapical radiographs. Implant stability/mobility was determined by resonance frequency analysis (RFA) and mobility measuring (MM) device values. Peri-implant parameters were evaluated with clinical periodontal indices and all parameters were assessed at baseline, 1, 3, and 6 months after the surgery. After 6 months, all implants showed uneventful healing. Radiographic evaluation showed a mean bone loss of 0.72 mm for PS and 0.56 mm for SP implants, and there were no significant differences between implant types. At 6 months, mean implant stability quotient (ISQ) values were 73.38 and 77 for PS and SP implants, respectively. Mean MM values were -4.75 for PS and -6.38 for SP implants. Mean MM values were lower for SP implants compared to PS implants at all time points. No significant differences were detected between implant types according to clinical peri-implant parameters. The micro-gap at crestal level which immediately exposed to the oral cavity in non-submerged two part implants seems to have adverse influence on the marginal bone level. © 2011 John Wiley & Sons A/S.

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection: a Systematic Review and Meta-Analysis

PubMed Central

Christensen, Ann-Eva; Lorenzen, Henning

2017-01-01

ABSTRACT Objectives The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. Material and Methods A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted. No language or year of publication restriction was applied. Results The search provided 298 titles. Three studies fulfilled the inclusion criteria. The included studies were characterized by low or moderate risk of bias. Survival of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone loss around implants with a scalloped implant-abutment connection. Conclusions A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must be rejected. However, further long-term randomized controlled trials assessing implant treatment outcome with the two treatment modalities are needed before definite conclusions can be provided about the beneficial use of implants with a scalloped implant-abutment connection on preservation of the peri-implant marginal bone level. PMID:28496962

Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection: a Systematic Review and Meta-Analysis.

PubMed

Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

2017-01-01

The objective was to test the hypothesis of no difference in implant treatment outcome after installation of implants with a scalloped implant-abutment connection compared to a flat implant-abutment connection. A MEDLINE (PubMed), Embase and Cochrane library search in combination with a hand-search of relevant journals was conducted. No language or year of publication restriction was applied. The search provided 298 titles. Three studies fulfilled the inclusion criteria. The included studies were characterized by low or moderate risk of bias. Survival of suprastructures has never been compared within the same study. High implant survival rate was reported in all the included studies. Significantly more peri-implant marginal bone loss, higher probing depth score, bleeding score and gingival score was observed around implants with a scalloped implant-abutment connection. There were no significant differences between the two treatment modalities regarding professional or patient-reported outcome measures. Meta-analysis disclosed a mean difference of peri-implant marginal bone loss of 1.56 mm (confidence interval: 0.87 to 2.25), indicating significant more bone loss around implants with a scalloped implant-abutment connection. A scalloped implant-abutment connection seems to be associated with higher peri-implant marginal bone loss compared to a flat implant-abutment connection. Therefore, the hypothesis of the present systematic review must be rejected. However, further long-term randomized controlled trials assessing implant treatment outcome with the two treatment modalities are needed before definite conclusions can be provided about the beneficial use of implants with a scalloped implant-abutment connection on preservation of the peri-implant marginal bone level.

Biomechanical evaluation of one-piece and two-piece small-diameter dental implants: In-vitro experimental and three-dimensional finite element analyses.

PubMed

Wu, Aaron Yu-Jen; Hsu, Jui-Ting; Chee, Winston; Lin, Yun-Te; Fuh, Lih-Jyh; Huang, Heng-Li

2016-09-01

Small-diameter dental implants are associated with a higher risk of implant failure. This study used both three-dimensional finite-element (FE) simulations and in-vitro experimental tests to analyze the stresses and strains in both the implant and the surrounding bone when using one-piece (NobelDirect) and two-piece (NobelReplace) small-diameter implants, with the aim of understanding the underlying biomechanical mechanisms. Six experimental artificial jawbone models and two FE models were prepared for one-piece and two-piece 3.5-mm diameter implants. Rosette strain gauges were used for in-vitro tests, with peak values of the principal bone strain recorded with a data acquisition system. Implant stability as quantified by Periotest values (PTV) were also recorded for both types of implants. Experimental data were analyzed statistically using Wilcoxon's rank-sum test. In FE simulations, the peak value and distribution of von-Mises stresses in the implant and bone were selected for evaluation. In in-vitro tests, the peak bone strain was 42% lower for two-piece implants than for one-piece implants. The PTV was slightly lower for one-piece implants (PTV = -6) than for two-piece implants (PTV = -5). In FE simulations, the stresses in the bone and implant were about 23% higher and 12% lower, respectively, for one-piece implants than those for two-piece implants. Due to the higher peri-implant bone stresses and strains, one-piece implants (NobelDirect) might be not suitable for use as small-diameter implants. Copyright © 2016. Published by Elsevier B.V.

Survival of dental implants placed in sites of previously failed implants.

PubMed

Chrcanovic, Bruno R; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

2017-11-01

To assess the survival of dental implants placed in sites of previously failed implants and to explore the possible factors that might affect the outcome of this reimplantation procedure. Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Descriptive statistics were used to describe the patients and implants; survival analysis was also performed. The effect of systemic, environmental, and local factors on the survival of the reoperated implants was evaluated. 175 of 10,096 implants in 98 patients were replaced by another implant at the same location (159, 14, and 2 implants at second, third, and fourth surgeries, respectively). Newly replaced implants were generally of similar diameter but of shorter length compared to the previously placed fixtures. A statistically significant greater percentage of lost implants were placed in sites with low bone quantity. There was a statistically significant difference (P = 0.032) in the survival rates between implants that were inserted for the first time (94%) and implants that replaced the ones lost (73%). There was a statistically higher failure rate of the reoperated implants for patients taking antidepressants and antithrombotic agents. Dental implants replacing failed implants had lower survival rates than the rates reported for the previous attempts of implant placement. It is suggested that a site-specific negative effect may possibly be associated with this phenomenon, as well as the intake of antidepressants and antithrombotic agents. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect on Bone Architecture of Marginal Grooves in Dental Implants Under Occlusal Loaded Conditions in Beagle Dogs.

PubMed

Kato, Hatsumi; Kuroshima, Shinichiro; Inaba, Nao; Uto, Yusuke; Sawase, Takashi

2018-02-01

The aim of this study was to clarify whether marginal grooves on dental implants affect osseointegration, bone structure, and the alignment of collagen fibers to determine bone quality under loaded conditions. Anodized Ti-6Al-4V alloy dental implants, with and without marginal grooves (test and control implants, respectively), were used (3.7 × 8.0 mm). Fourth premolars and first molars of 6 beagle mandibles were extracted. Two control and test implants were placed in randomly selected healed sites at 12 weeks after tooth extraction. Screw-retained single crowns for first molars were fabricated. Euthanasia was performed at 8 weeks after the application of occlusal forces. Implant marginal bone level, bone to implant contact (BIC), bone structure around dental implants, and the alignment of collagen fibers determining bone quality were analyzed. The marginal bone level in test implants was significantly higher than that in control implants. Occlusal forces significantly increased BIC in test implants ( P = .007), whereas BIC did not change in control implants, irrespective of occlusal forces ( P = .303). Moreover, occlusal forces significantly increased BIC in test implants compared with control implants ( P = .032). Additionally, occlusal forces preferentially aligned collagen fibers in test implants, but not control implants. Hence, marginal grooves on dental implants have positive effects on increased osseointegration and adapted bone quality based on the preferential alignment of collagen fibers around dental implants under loaded conditions.

Dental Implants in the Elderly Population: A Long-Term Follow-up.

PubMed

Compton, Sharon M; Clark, Danielle; Chan, Stephanie; Kuc, Iris; Wubie, Berhanu A; Levin, Liran

The objectives of this study were to evaluate implant survival and success in the elderly population and to assess indicators and risk factors for success or failure of dental implants in older adults (aged 60 years and older). This historical prospective study was developed from a cohort of patients born prior to 1950 who received dental implants in a single private dental office. Implant survival and marginal bone levels were recorded and analyzed with regard to different patient- and implant-related factors. The study examined 245 patient charts and 1,256 implants from one dental clinic. The mean age at the time of implant placement was 62.18 ± 8.6 years. Smoking was reported by 9.4% of the cohort studied. The overall survival rate of the implants was 92.9%; 7.1% of the implants had failed. Marginal bone loss depicted by exposed threads was evident in 23.3% of the implants. Presenting with generalized periodontal disease and/or severe periodontal disease negatively influenced the survival probability of the implant. Implants placed in areas where bone augmentation was performed prior to or during implant surgery did not have the same longevity compared with those that did not have augmentation prior to implantation. The overall findings concluded that implants can be successfully placed in older adults. A variety of factors are involved in the long-term success of the implant, and special consideration should be taken prior to placing implants in older adults to limit the influence of those risk factors.

What do sales data tell us about implant survival?

PubMed

Seemann, Rudolf; Jirku, Alexander; Wagner, Florian; Wutzl, Arno

2017-01-01

The aim of this study was to evaluate the influence of implant diameter, length and shape on a surrogate parameter of implant survival; i.e. the implant return rate in a big data analysis. A retrospective study was conducted and the factors influencing the success rates of 69,377 sold implants over a seven-year period were evaluated. The osseointegration program of a reseller provides reliable data of a single country. Implant loss rates were investigated using logistic regression models and regressed by implant type, diameter, and length. The return rate of 69,377 sold implants was 2.78% and comparable to implant loss rates in previous published prospective studies as its surrogate parameter. A total of 80% of implant returns had occurred within 157 days, and an additional 15% within 750.25 days. Diameters of 3.8 to 5.0mm showed the lowest return rates with its bottom in the 4.3mm implant whilst 6.0mm implants had significantly higher return rates. In comparison to the most sold implant length (13mm) shorter implants showed significantly higher early return rates. The study provides evidence that in cases of standard indications and sufficient bone, the use of screw typed dental implants with 3.8 or 4.3 diameter and 11 or 13 mm length shows the lowest implant return rates. Other implants may be selected only in specific indications.

Impact of crestal and subcrestal implant placement in peri-implant bone: A prospective comparative study

PubMed Central

Pellicer-Chover, Hilario; Peñarrocha-Diago, María; Peñarrocha-Oltra, David; Gomar-Vercher, Sonia; Agustín-Panadero, Rubén

2016-01-01

Background To assess the influence of the crestal or subcrestal placement of implants upon peri-implant bone loss over 12 months of follow-up. Material and Methods Twenty-six patients with a single hopeless tooth were recruited in the Oral Surgery Unit (Valencia University, Valencia, Spain). The patients were randomized into two treatment groups: group A (implants placed at crestal level) or group B (implants placed at subcrestal level). Control visits were conducted by a trained clinician at the time of implant placement and 12 months after loading. A previously established standard protocol was used to compile general data on all patients (sex and age, implant length and diameter, and brushing frequency). Implant success rate, peri-implant bone loss and the treatment of the exposed implant surface were studied. The level of statistical significance was defined as 5% (α=0.05). Results Twenty-three patients (8 males and 15 females, mean age 49.8±11.6 years, range 28-75 years) were included in the final data analyses, while three were excluded. All the included subjects were nonsmokers with a brushing frequency of up to twice a day in 85.7% of the cases. The 23 implants comprised 10 crestal implants and 13 subcrestal implants. After implant placement, the mean bone position with respect to the implant platform in group A was 0.0 mm versus 2.16±0.88 mm in group B. After 12 months of follow-up, the mean bone positions were -0.06±1.11 mm and 0.95±1.50 mm, respectively - this representing a bone loss of 0.06±1.11 mm in the case of the crestal implants and of 1.22±1.06 mm in the case of the subcrestal implants (p=0.014). Four crestal implants and 5 subcrestal implants presented peri-implant bone levels below the platform, leaving a mean exposed treated surface of 1.13 mm and 0.57 mm, respectively. The implant osseointegration success rate at 12 months was 100% in both groups. Conclusions Within the limitations of this study, bone loss was found to be greater in the case of the subcrestal implants, though from the clinical perspective these implants presented bone levels above the implant platform after 12 months of follow-up. Key words:Immediate implants, tooth extraction, dental implants, single-tooth, crestal bone, placement level. PMID:26615504

Presence of Biofilms on Polyurethane-Coated Breast Implants: Preliminary Results.

PubMed

Rieger, Ulrich M; Djedovic, Gabriel; Pattiss, Alexander; Raschke, Gregor F; Frei, Reno; Pierer, Gerhard; Trampuz, Andrej

2016-01-01

Polyurethane-coated breast implants seem to be associated with lower medium- and long-term capsular contracture rates in comparison to textured or smooth implant surfaces. Although the etiology of capsular contracture is uncertain, bacterial biofilms have been suggested to trigger chronic peri-implant inflammation, eventually leading to capsular contracture. It is unknown whether polyurethane-coated implants are less prone to biofilm colonization than other implant surfaces. We extracted data from patient records included in a prospective cohort between 2008 and 2011. All patients who underwent removal of polyurethane-coated implants were included in this current study and screened for presence of biofilms by sonication. In addition, implant- and patient-related data were analyzed. Of the ten included polyurethane-coated breast implants, six had been inserted for reconstructive purposes and four for aesthetic reasons. The median implant indwelling time was 28.3 mo. Overall, sonication cultures were positive in 50% of implants. Propionibacterium acnes and coagulase-negative staphylococci were the predominant pathogens isolated from biofilm cultures. Like other implant surfaces, polyurethane-coated implants are prone to biofilm colonization. Further investigations are needed to determine why capsular contracture rates seem to be lower in polyurethane implants than in other implant surfaces. Notably, in this study, 40% of the implants were explanted from breasts with severe capsular contracture.

Single- and double- lumen silicone breast implant integrity: prospective evaluation of MR and US criteria.

PubMed

Berg, W A; Caskey, C I; Hamper, U M; Kuhlman, J E; Anderson, N D; Chang, B W; Sheth, S; Zerhouni, E A

1995-10-01

To evaluate the accuracy of magnetic resonance (MR) and ultrasound (US) criteria for breast implant integrity. One hundred twenty-two single-lumen silicone breast implants and 22 bilumen implants were evaluated with surface coil MR imaging and US and surgically removed. MR criteria for implant failure were a collapsed implant shell ("linguine sign"), foci of silicone outside the shell ("noose sign"), and extracapsular gel, US criteria were collapsed shell, low-level echoes within the gel, and "snowstorm" echoes of extracapsular silicone. Among single-lumen implants, MR imaging depicted 39 of 40 ruptures, 14 of 28 with minimal leakage; 49 of 54 intact implants were correctly interpreted. US depicted 26 of 40 ruptured implants, four of 28 with minimal leakage, and 30 of 54 intact implants. Among bilumen implants, MR imaging depicted four of five implants with rupture of both lumina and nine of 10 as intact; US depicted one rupture and helped identify two of 10 as intact. Mammography accurately depicted the status of 29 of 30 bilumen implants with MR imaging correlation. MR imaging depicts implant integrity more accurately than US; neither method reliably depicts minimal leakage with shell collapse. Mammography is useful in screening bilumen implant integrity.

Role of clinician's experience and implant design on implant stability. An ex vivo study in artificial soft bones.

PubMed

Romanos, Georgios E; Basha-Hijazi, Abdulaziz; Gupta, Bhumija; Ren, Yan-Fang; Malmstrom, Hans

2014-04-01

Clinical experience in implant placement is important in order to prevent implant failures. However, the implant design affects the primary implant stability (PS) especially in poor quality bones. Therefore, the aim of this study was to compare the effect of clinician surgical experience on PS, when placing different type of implant designs. A total of 180 implants (90 parallel walled-P and 90 tapered-T) were placed in freshly slaughtered cow ribs. Bone quality was evaluated by two examiners during surgery and considered as 'type IV' bone. Implants (ø 5 mm, length: 15 mm, Osseotite, BIOMET 3i, Palm Beach Gardens, FL, USA) were placed by three different clinicians (master/I, good/II, non-experienced/III, under direct supervision of a manufacturer representative; 30 implants/group). An independent observer assessed the accuracy of placement by resonance frequency analysis (RFA) with implant stability quotient (ISQ) values. Two-way analysis of variance (ANOVA) and Tukey's post hoc test were used to detect the surgical experience of the clinicians and their interaction and effects of implant design on the PS. All implants were mechanically stable. The mean ISQ values were: 49.57(± 18.49) for the P-implants and 67.07(± 8.79) for the T-implants. The two-way ANOVA showed significant effects of implant design (p < .0001), clinician (p < .0001), and their interaction (p < .0001). The Tukey's multiple comparison test showed significant differences in RFA for the clinician group I/II (p = .015) and highly significant (p < .0001) between I/III and II/III. The P-implants presented (for I, II, and III) mean ISQ values 31.25/49.18/68.17 and the T-implants showed higher ISQ values, 70.15/62.08/68.98, respectively. Clinicians I and II did not show extreme differences for T-implants (p = .016). In contrast, clinician III achieved high ISQ values using P- and T-implants following the exact surgical protocol based on the manufacturer guidelines. T-implants provided high stability for experienced clinicians compared with P-implants. T-implants achieved greater PS than the P-implants. All clinicians consistently achieved PS; however, experienced clinicians achieved higher ISQ values with T-implants in poor quality bone. © 2012 Wiley Periodicals, Inc.

Tilted orthodontic micro implants: a photoelastic stress analysis.

PubMed

Çehreli, Seçil; Özçırpıcı, Ayça Arman; Yılmaz, Alev

2013-10-01

The aim of this study was to examine peri-implant stresses around orthodontic micro implants upon torque-tightening and static load application by quasi-three-dimensional photoelastic stress analysis. Self-tapping orthodontic micro implants were progressively inserted into photoelastic models at 30, 45, 70, and 90 degrees and insertion torques were measured. Stress patterns (isochromatic fringe orders) were recorded by the quasi-three-dimensional photoelastic method using a circular polariscope after insertion and 250 g static force application. Torque-tightening of implants generated peri-implant stresses. Upon insertion, 90 degree placed implants displayed the lowest and homogeneous stress distribution followed by 30, 70, and 45 degree tilted implants. Static loading did not dramatically alter stress fields around the implants tested. The highest alteration in stress distribution was observed for the 90 degree placed implant, while 70 degree tilted implant had the lowest stresses among tilted implants. Torque-tightening of orthodontic micro implants creates a stress field that is not dramatically altered after application of static lateral moderate orthodontic loads, particularly at the cervical region of tilted implants.

Prevalences of peri-implantitis and peri-implant mucositis: systematic review and meta-analysis.

PubMed

Lee, Chun-Teh; Huang, Yen-Wen; Zhu, Liang; Weltman, Robin

2017-07-01

Due to the inconsistent definitions, reporting methods and study characteristics, prevalences of peri-implant diseases significantly varied in studies. This study aimed to systematically analyze implant-based and subject-based prevalences of peri-implant diseases and assess clinical variables potentially affecting the prevalence. Electronic search of studies was conducted using MEDLINE (PubMed), EMBASE and Web of Science. Publication screening, data extraction, and quality assessment were performed. Clinical studies having an at least average three-year follow-up period were selected. The numbers of subjects and implants in the studies had to be equal to or more than thirty. Forty seven studies were selected and prevalences of peri-implant diseases were analyzed. Since heterogeneity existed in each outcome (I 2 =94.7, 95.7, 95.3, and 99.3 for implant-based and subject-based peri-implantitis and peri-implant mucositis, respectively), the random-effects model based on the DerSimonian and Laird method, which incorporate an estimate of heterogeneity in the weighting, was applied to obtain the pooled prevalence. Weighted mean implant-based and subject-based peri-implantitis prevalences were 9.25% (95% Confidence Interval (CI): [7.57, 10.93]) and 19.83% (CI [15.38, 24.27) respectively. Weighted mean implant-based and subject-based peri-implant mucositis prevalences were 29.48% (CI: [22.65, 36.32]) and 46.83% (CI: [38.30, 55.36]) respectively. Functional time and implant to subject ratio were associated with subject-based peri-implantitis prevalence, but not peri-implant mucositis prevalences. Peri-implant diseases were prevalent and prevalence of peri-implantitis increased over time. Prevalences of peri-implantitis and peri-implant mucositis might not be highly associated since the prevalences were influenced by distinct variables. The results should be carefully interpreted because of data heterogeneity. Peri-implant diseases affect a significant number of dental implants and patients. It is important to understand the difficulties in diagnosis of these diseases and risk factors which may be modified to reduce the potential for disease occurrence or progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

PubMed

Berglundh, Tord; Armitage, Gary; Araujo, Mauricio G; Avila-Ortiz, Gustavo; Blanco, Juan; Camargo, Paulo M; Chen, Stephen; Cochran, David; Derks, Jan; Figuero, Elena; Hämmerle, Christoph H F; Heitz-Mayfield, Lisa J A; Huynh-Ba, Guy; Iacono, Vincent; Koo, Ki-Tae; Lambert, France; McCauley, Laurie; Quirynen, Marc; Renvert, Stefan; Salvi, Giovanni E; Schwarz, Frank; Tarnow, Dennis; Tomasi, Cristiano; Wang, Hom-Lay; Zitzmann, Nicola

2018-06-01

A classification for peri-implant diseases and conditions was presented. Focused questions on the characteristics of peri-implant health, peri-implant mucositis, peri-implantitis, and soft- and hard-tissue deficiencies were addressed. Peri-implant health is characterized by the absence of erythema, bleeding on probing, swelling, and suppuration. It is not possible to define a range of probing depths compatible with health; Peri-implant health can exist around implants with reduced bone support. The main clinical characteristic of peri-implant mucositis is bleeding on gentle probing. Erythema, swelling, and/or suppuration may also be present. An increase in probing depth is often observed in the presence of peri-implant mucositis due to swelling or decrease in probing resistance. There is strong evidence from animal and human experimental studies that plaque is the etiological factor for peri-implant mucositis. Peri-implantitis is a plaque-associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Peri-implantitis sites exhibit clinical signs of inflammation, bleeding on probing, and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss. The evidence is equivocal regarding the effect of keratinized mucosa on the long-term health of the peri-implant tissue. It appears, however, that keratinized mucosa may have advantages regarding patient comfort and ease of plaque removal. Case definitions in day-to-day clinical practice and in epidemiological or disease-surveillance studies for peri-implant health, peri-implant mucositis, and peri-implantitis were introduced. The proposed case definitions should be viewed within the context that there is no generic implant and that there are numerous implant designs with different surface characteristics, surgical and loading protocols. It is recommended that the clinician obtain baseline radiographic and probing measurements following the completion of the implant-supported prosthesis. © 2018 American Academy of Periodontology and European Federation of Periodontology.

Fortifying the Bone-Implant Interface Part 2: An In Vivo Evaluation of 3D-Printed and TPS-Coated Triangular Implants

PubMed Central

Lindsey, Derek P.; Woods, Shane A.; Lalor, Peggy A.; Gundanna, Mukund I.; Yerby, Scott A.

2017-01-01

Background Minimally invasive surgical fusion of the sacroiliac (SI) joint using machined solid triangular titanium plasma spray (TPS) coated implants has demonstrated positive clinical outcomes in SI joint pain patients. Additive manufactured (AM), i.e. 3D-printed, fenestrated triangular titanium implants with porous surfaces and bioactive agents, such as nanocrystalline hydroxyapatite (HA) or autograft, may further optimize bony fixation and subsequent biomechanical stability. Methods A bilateral ovine distal femoral defect model was used to evaluate the cancellous bone-implant interfaces of TPS-coated and AM implants. Four implant groups (n=6/group/time-point) were included: 1)TPS-coated, 2)AM, 3)AM+HA, and 4)AM+Autograft. The bone-implant interfaces of 6- and 12-week specimens were investigated via radiographic, biomechanical, and histomorphometric methods. Results Imaging showed peri-implant bone formation around all implants. Push-out testing demonstrated forces greater than 2500 N, with no significant differences among groups. While TPS implants failed primarily at the bone-implant interface, AM groups failed within bone ~2-3mm away from implant surfaces. All implants exhibited bone ongrowth, with no significant differences among groups. AM implants had significantly more bone ingrowth into their porous surfaces than TPS-coated implants (p<0.0001). Of the three AM groups, AM+Auto implants had the greatest bone ingrowth into the porous surface and through their core (p<0.002). Conclusions Both TPS and AM implants exhibited substantial bone ongrowth and ingrowth, with additional bone through growth into the AM implants’ core. Overall, AM implants experienced significantly more bone infiltration compared to TPS implants. While HA-coating did not further enhance results, the addition of autograft fostered greater osteointegration for AM implants. Clinical Relevance Additive manufactured implants with a porous surface provide a highly interconnected porous surface that has comparatively greater surface area for bony integration. Results suggest this may prove advantageous toward promoting enhanced biomechanical stability compared to TPS-coated implants for SI joint fusion procedures. PMID:28765800

Macro design morphology of endosseous dental implants.

PubMed

Sahiwal, Indira G; Woody, Ronald D; Benson, Byron W; Guillen, Guillermo E

2002-05-01

The identification of dental implant bodies in patients without available records is a considerable problem due to increased patient mobility and to the large number of implant systems with different designs. The purpose of this study was to document the designs of selected implants to help clinicians identify these implants from their radiographic images. More than 50 implant manufacturers were contacted and asked to provide implants with dimensions as close as possible to 3.75 mm (diameter) x 10 mm (length). Forty-four implants were donated, separated into threaded and non-threaded categories, and further sorted into tapered and non-tapered categories. The implants were examined visually, and features on the entire circumference and length of each implant were recorded and categorized as coronal, midbody, or apical. A series of tables describe the 44 implants according to coronal, midbody, and apical features. The results of this project offer dentists basic knowledge of the design of selected dental implants. Such knowledge can aid the radiographic identification of these implants.

Ultrastructural investigation of intact orbital implant surfaces using atomic force microscopy.

PubMed

Choi, Samjin; Lee, Seung Jun; Shin, Jae-Ho; Cheong, Youjin; Lee, Hui-Jae; Paek, Joo Hee; Kim, Jae Sik; Jin, Kyung-Hyun; Park, Hun-Kuk

2011-01-01

This study examined the surface nanostructures of three orbital implants: nonporous poly(methyl methacrylate) (PMMA), porous aluminum oxide and porous polyethylene. The morphological characteristics of the orbital implants surfaces were observed by atomic force microscopy (AFM). The AFM topography, phase shift and deflection images of the intact implant samples were obtained. The surface of the nonporous PMMA implant showed severe scratches and debris. The surface of the aluminum oxide implant showed a porous structure with varying densities and sizes. The PMMA implant showed nodule nanostructures, 215.56 ± 52.34 nm in size, and the aluminum oxide implant showed crystal structures, 730.22 ± 341.02 nm in size. The nonporous PMMA implant showed the lowest roughness compared with other implant biomaterials, followed by the porous aluminum oxide implant. The porous polyethylene implant showed the highest roughness and severe surface irregularities. Overall, the surface roughness of orbital implants might be associated with the rate of complications and cell adhesion. Copyright © 2011 Wiley Periodicals, Inc.

Implant and prosthesis movement after enucleation: a randomized controlled trial.

PubMed

Shome, Debraj; Honavar, Santosh G; Raizada, Kuldeep; Raizada, Deepa

2010-08-01

To evaluate implant and prosthesis movement after myoconjunctival enucleation and subsequent polymethyl methacrylate (PMMA) implantation, compared with the traditional enucleation with muscle imbrication using a PMMA implant and with enucleation accompanied by porous polyethylene implantation. Randomized, controlled, observer-masked, interventional study. One hundred fifty patients, equally and randomly allocated to the 3 groups. Group 1 consisted of patients in whom a PMMA implant was used after enucleation with muscle imbrication (traditional PMMA group). Group 2 consisted of patients in whom a PMMA implant was used after enucleation with a myoconjunctival technique (myoconjunctival PMMA group). Group 3 consisted of patients in whom a porous polyethylene implant was used after enucleation by the scleral cap technique (porous polyethylene group). Fifty patients were included in each group. Patients were allocated to 1 of the 3 groups using stratified randomization. Informed consent was obtained. Acrylic prostheses custom made by a trained ocularist were fitted 6 weeks after surgery in all patients. A masked observer measured implant and prosthesis movement 6 weeks after surgery using a slit-lamp device with real-time video and still photographic documentation. Analysis of implant and prosthesis movement was carried out using the Mann-Whitney U test, and a P value of < or =0.03 was considered significant. Complications including implant displacement and exposure also were noted. Implant and prosthesis movement. Myoconjunctival PMMA implant movement was better than the traditional PMMA implant (P = 0.001), but was similar to that of the porous polyethylene implant. Prosthesis movement with the myoconjunctival PMMA implant was better than that of either the traditional PMMA (P = 0.001) or porous polyethylene (P = 0.002) implants. Myoconjunctival enucleation technique with a PMMA implant provides statistically and clinically significantly better implant and prosthesis movement than the traditional PMMA implant and better prosthesis movement than the porous polyethylene implant. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

A prospective, split-mouth study comparing tilted implants with angulated connection versus conventional implants with angulated abutment.

PubMed

Van Weehaeghe, Manú; De Bruyn, Hugo; Vandeweghe, Stefan

2017-12-01

An angulation of the implant connection could overcome the problems related to angulated abutments. This study compares conventional implants with angulated abutment to tilted implants with an angulated connection. Twenty patients were treated in the edentulous mandible. In the posterior jaw locations, one conventional tilted implant with angulated abutment and one angulated implant without abutment were placed. In the anterior jaw, two conventional implants were placed, one with and one without abutment. Implants were immediately loaded and 3 months later, the final bridge (PFM or monolithic zirconia) was placed. After a follow-up of 48 months, 17 patients were available for clinical examination. The mean overall marginal bone loss (MBL) was 1.26 mm. No significant differences in implant survival, MBL, periodontal indices, patients' satisfaction, or complications was found between implants restored on abutment or implant level, between the posteriorly located angulated implant nor angulated abutment, and between both anterior implants with or without abutment. The posterior implants demonstrated less MBL compared to the anterior implants (P < .001). There was no significant difference in MBL between the implants restored with zirconia or PFM bridges (P = .294). Overall mean pocket depth was 2.83 mm. More plaque was found in the PFM group compared to the full-zirconia group, at the bridge (P = .042) and the implants (P = .029). There was no difference between both materials in pocket depth (P = .635) or bleeding (P = .821). One zirconia bridge fractured, two angulated abutment were replaced and four loose bridge screws connected to the angulated abutments had to be tightened. Patients were overall satisfied (4.74/5). An implant with angulated connection may results in a stronger connection but does not affect the marginal bone loss. No difference in MBL was seen between implants restored on abutment or implant level. Zirconia seems to reduce the amount of plaque. © 2017 Wiley Periodicals, Inc.

One-year results of maxillary overdentures supported by 2 titanium-zirconium implants - implant survival rates and radiographic outcomes.

PubMed

Zembic, Anja; Tahmaseb, Ali; Jung, Ronald E; Wismeijer, Daniel

2017-07-01

To assess implant survival rates and peri-implant bone loss of 2 titanium-zirconium implants supporting maxillary overdentures at 1 year of loading. Twenty maxillary edentulous patients (5 women and 15 men) being dissatisfied with their complete dentures were included. In total, 40 diameter-reduced titanium-zirconium implants were placed in the anterior maxilla. Local guided bone regeneration (GBR) was allowed if the treatment did not compromise implant stability. Following 3 to 5 months of healing, implant-supported overdentures were inserted on two ball anchors. Implants and overdentures were assessed at 1, 2, 4, and 8 weeks after implant insertion and 2, 4, and 12 months after insertion of overdentures (baseline). Standardized radiographs were taken at implant loading and 1 year. Implant survival rates and bone loss were the primary outcomes. Nineteen patients (1 dropout) with 38 implants were evaluated at a mean follow-up of 1.1 years (range 1.0-1.7 years). One implant failed resulting in an implant survival rate of 97.3%. There was a significant peri-implant bone loss of the implants at 1 year of function (mean, 0.7 mm, SD = 1.1 mm; median: 0.48 mm, IQR = 0.56 mm). There was a high 1-year implant survival rate for edentulous patients receiving 2 maxillary implants and ball anchors as overdenture support. However, several implants exhibited an increased amount of bone loss of more than 2 mm. Overdentures supported by 2 maxillary implants should thus be used with caution as minimally invasive treatment for specific patients encountering problems with their upper dentures until more long-term data is available. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Periotest values of implants placed in sockets augmented with calcium phosphosilicate putty graft: a comparative analysis against implants placed in naturally healed sockets.

PubMed

Mahesh, Lanka; Narayan, Tv; Kostakis, Georgios; Shukla, Sagrika

2014-03-01

To measure implant stability using periotest values of implants placed in sockets augmented with calcium phospho-silicate putty (CPS Putty) as compared with implant stability in naturally healed sockets. Twenty two sockets were implanted with CPS Putty immediately after extraction. The sockets were re-entered after a healing period at 5 to 6 months (average 5.3 months) for implant placement. Periotest values were recorded during implant insertion to assess primary stability. These were compared with the Periotest values of 26 implants placed in 22 patients, with naturally healed sockets. Periotest values were significantly lower in the grafted group, indicating better implant stability in sites grafted with CPS putty. Implant stability seems to be significantly higher in sockets augmented using CPS putty when compared to nongrafted sites. This suggests that socket grafting with CPS putty may enhance the quality of available bone for implantation.

Oral rehabilitation with tilted dental implants: A metaanalysis

PubMed Central

Peñarrocha-Oltra, David; Candel-Marti, Eugenia; Peñarrocha-Diago, Maria

2012-01-01

Objective: To compare the course of patients treated with tilted implants versus those treated conventionally with axial implants, analyzing the success rate and marginal bone loss. Material and Methods: A PubMed search was made using the key words “tilted implants”, “angled implants”, “angulated implants”, “inclined implants” and “maxillary atrophy.” A review was made of the articles published between 1999-2010. The inclusion criteria were the use of tilted implants, clinical series involving at least 10 patients, and a minimum follow-up of 12 months after prosthetic loading. The exclusion criteria were isolated clinical cases, studies with missing data, and publications in languages other than English or Spanish. The metaanalysis finally included 13 articles: 7 retrospective studies and 6 prospective studies. Results: On analyzing the success rate in the retrospective studies, two reported a higher success rate with tilted implants; one a higher success rate with axial implants; and two reported similar success rates with both implants. On analyzing the success rate in the prospective studies, two reported a higher success rate with tilted implants; two a higher success rate with axial implants; and two reported similar success rates with both implants. On examining marginal bone loss, three studies reported greater bone loss with axial implants and one with tilted implants. Conclusions: There was no evidence of differences in success rate between tilted and axial implants in either the prospective or retrospective studies subjected to review. The marginal bone loss observed with the tilted and axial implants likewise proved very similar. It thus can be deduced that tilted implants exhibit the same evolutive behavior as axial implants. Key words:Axial implants, tilted implants, maxillary atrophy, tilted implants. PMID:22322494

Three-dimensional finite element analysis of stress distribution on different bony ridges with different lengths of morse taper implants and prosthesis dimensions.

PubMed

Toniollo, Marcelo Bighetti; Macedo, Ana Paula; Rodrigues, Renata Cristina Silveira; Ribeiro, Ricardo Faria; de Mattos, Maria da Gloria Chiarello

2012-11-01

This finite element analysis (FEA) compared stress distribution on different bony ridges rehabilitated with different lengths of morse taper implants, varying dimensions of metal-ceramic crowns to maintain the occlusal alignment. Three-dimensional FE models were designed representing a posterior left side segment of the mandible: group control, 3 implants of 11 mm length; group 1, implants of 13 mm, 11 mm and 5 mm length; group 2, 1 implant of 11 mm and 2 implants of 5 mm length; and group 3, 3 implants of 5 mm length. The abutments heights were 3.5 mm for 13- and 11-mm implants (regular), and 0.8 mm for 5-mm implants (short). Evaluation was performed on Ansys software, oblique loads of 365N for molars and 200N for premolars. There was 50% higher stress on cortical bone for the short implants than regular implants. There was 80% higher stress on trabecular bone for the short implants than regular implants. There was higher stress concentration on the bone region of the short implants neck. However, these implants were capable of dissipating the stress to the bones, given the applied loads, but achieving near the threshold between elastic and plastic deformation to the trabecular bone. Distal implants and/or with biggest occlusal table generated greatest stress regions on the surrounding bone. It was concluded that patients requiring short implants associated with increased proportions implant prostheses need careful evaluation and occlusal adjustment, as a possible overload in these short implants, and even in regular ones, can generate stress beyond the physiological threshold of the surrounding bone, compromising the whole system.

Stress distribution of various designs of prostheses on short implants or standard implants in posterior maxilla: a three dimensional finite element analysis

PubMed Central

JOMJUNYONG, K.; RUNGSIYAKULL, P.; RUNGSIYAKULL, C.; AUNMEUNGTONG, W.; CHANTARAMUNGKORN, M.; KHONGKHUNTHIAN, P.

2017-01-01

SUMMARY Introduction. Although many previous studies have reported on the high success rate of short dental implants, prosthetic design still plays an important role in the long-term implant treatment results. This study aims to evaluate stress distribution characteristics involved with various prosthetic designs on standard implants or short implants in the posterior maxilla. Materials and methods. Six finite element models were simulated representing the missing first and second maxillary molars. A standard implant (PW+ implant: 5.0×10 mm) and a short implant (PW+ implant: 5.0×6.0 mm) were applied under the various prosthetic conditions. The peri-implant maximum bone stress (V on mises stress) was evaluated when 200 N 30° oblique load was applied. A type III bone was approximated and complete osseous integration was assumed. Results. Maximum Von mises stress was numerically located at the cortical bone around the implant neck in all models. In every standard implant model shows better stress distribution. Stress values and concentration area decreased in the cortical and cancellous bone when implants were splinted in both the standard and short implant models. With regard to the non-replacing second molar models found that the area of stress at the cortical bone around the first molar implant to be more intensive. Moreover, in the non-replacing second molar models, the stress also spread to the second pre-molar in both the standard and short implant models. Conclusions. The length of the implant and prosthetics designs both affect the stress value and distribution of stress to the cortical and cancellous bones around the implant. PMID:29682254

Recall management of patients with Rofil Medical breast implants.

PubMed

Schott, Sarah; Bruckner, Thomas; Golatta, Michael; Wallwiener, Markus; Küffner, Livia; Mayer, Christine; Paringer, Carmen; Domschke, Christoph; Blumenstein, Maria; Schütz, Florian; Sohn, Christof; Heil, Joerg

2014-07-01

Some Rofil Medical breast implants are relabelled Poly Implant Prothèse (PIP) implants, and it is recommended that Rofil implants be managed in the same way as PIP implants. We report the results of a systematic recall of patients who had received Rofil implants. All patients who received Rofil implants at our centre were identified and invited for specialist consultation. In patients who opted for explantation, preoperative and intraoperative work-up was performed in accordance with national guidelines and analysed. In cases suspicious for rupture, an MRI scan was performed. Two-hundred and twenty-five patients (average age 56; range 28-80) received a total of 321 Rofil implants an average of 5.8 (range 1-11) years previously, 225/321 (70%) implants were used for reconstruction after breast cancer. A total of 43 implants were removed prior to 2011, mainly due to capsular contracture (CC). A total of 188 patients were still affected at the time of recall. Of the 188 patients, 115 (61%) attended for specialist consultation, of which 50 (44%) requested immediate implant removal. To date, 72 of 115 (63%) women attending consultation (38% of all affected) have chosen explantation, 66 of 72 (92%) opting for new implants. Of the 108 explanted implants, 25 (23%) had capsular rupture and 57 (53%) had implant bleeding. Preoperative clinical assessment was unreliable for predicting CC or rupture. The majority of patients attended for consultation and requested explantation. The quality of the explanted Rofil implants was comparable to PIP implants, with a higher rupture prevalence compared with other, non-affected implants. Nevertheless, the acceptance of breast implants for reimplantation remained high. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Macrotextured Breast Implants with Defined Steps to Minimize Bacterial Contamination around the Device: Experience in 42,000 Implants.

PubMed

Adams, William P; Culbertson, Eric J; Deva, Anand K; R Magnusson, Mark; Layt, Craig; Jewell, Mark L; Mallucci, Patrick; Hedén, Per

2017-09-01

Bacteria/biofilm on breast implant surfaces has been implicated in capsular contracture and breast implant-associated anaplastic large-cell lymphoma (ALCL). Macrotextured breast implants have been shown to harbor more bacteria than smooth or microtextured implants. Recent reports also suggest that macrotextured implants are associated with a significantly higher incidence of breast implant-associated ALCL. Using techniques to reduce the number of bacteria around implants, specifically, the 14-point plan, has successfully minimized the occurrence of capsular contracture. The authors hypothesize that a similar effect may be seen in reducing the risk of breast implant-associated ALCL. Pooled data from eight plastic surgeons assessed the use of macrotextured breast implants (Biocell and polyurethane) and known cases of breast implant-associated ALCL. Surgeon adherence to the 14-point plan was also analyzed. A total of 42,035 Biocell implants were placed in 21,650 patients; mean follow-up was 11.7 years (range, 1 to 14 years). A total of 704 polyurethane implants were used, with a mean follow-up of 8.0 years (range, 1 to 20 years). The overall capsular contracture rate was 2.2 percent. There were no cases of implant-associated ALCL. All surgeons routinely performed all 13 perioperative components of the 14-point plan; two surgeons do not routinely prescribe prophylaxis for subsequent unrelated procedures. Mounting evidence implicates the role of a sustained T-cell response to implant bacteria/biofilm in the development of breast implant-associated ALCL. Using the principles of the 14-point plan to minimize bacterial load at the time of surgery, the development and subsequent sequelae of capsular contracture and breast implant-associated ALCL may be reduced, especially with higher-risk macrotextured implants. Therapeutic, IV.

Finite element analysis of a novel implant distribution to support maxillary overdentures.

PubMed

Osman, Reham B; Elkhadem, Amr H; Ma, Sunyoung; Swain, Michael V

2013-01-01

To evaluate the biomechanics of a novel implant placement distribution and compare it with that of conventional maxillary overdenture support using three-dimensional finite element analysis (FEA). The application of zirconia implants in the context of this novel design was also evaluated. Detailed FEA models were created to analyze the loading responses of two different distributions of implants to support maxillary overdentures. The two implant distributions were as follows: the conventional design (D1) included four unsplinted implants in the premolar regions, whereas the novel design (D2) included one midpalatal implant, bilateral canine/premolar implants, and one anterior off-center crestal implant. Anatomical models were created with computed tomographic data and static loads were applied axially and obliquely. Von Mises stresses and equivalent strains generated in peri-implant bone and first principal stresses in the implants were calculated, including any denture displacement. Comparable stress and strain values were seen in the peri-implant bone for both designs. A significant decrease in the first principal stresses of D2 implants was observed with oblique loads. The maximum equivalent strain produced in the peri-implant region was mostly within the range for bone augmentation. D2 displayed lower maximum displacement values than D1. Maximum tensile stresses in the zirconia implants for either design were well below their fracture strength. A novel four-implant distribution involving midpalatal and crestal implants may be an alternative to the conventional design used for maxillary overdentures. This is particularly relevant when anatomical considerations prevent the placement of four anterior crestal implants. Zirconia implants may also be a valid option for a selected group of patients or for those requesting metal-free restorations. Prospective clinical studies are required to confirm these in vitro results.

Silicone gel breast implants: science and testing.

PubMed

Kinney, Brian M; Jeffers, Lynn L C; Ratliff, Gregory E; Carlisle, Dan A

2014-07-01

Since the first generation of breast implants, major design innovations, including consistency of the gel, palpability and thickness of the shell, and barrier materials in the shell, have been introduced. Surgeons have not had metrics to assess and compare available implants. Research at independent laboratories included 4 tests: gel elasticity (the gel's ability to retain its shape), gel compression fracture (the resistance to permanent gel deformation), gel-shell peel (the integration of the gel with shell as a cohesive unit), and morphological analysis. Sientra's round High-Strength Cohesive (HSC) experienced the least gel elasticity (5.805 mm), whereas Allergan's round implants experienced the most (7.465 mm). Among shaped implants, Allergan 410 experienced the least gel elasticity (3.242 mm), whereas the Sientra HSC+ implant experienced the most (4.270 mm). Sientra's round (36.32 lbf) and shaped (44.16 lbf) implants demonstrated the highest resistance to gel fracture, with Allergan's implants demonstrating the least among round (23.06 lbf) implants and Mentor Contour Profile Gel (CPG) among shaped (30.45 lbf) implants. For the gel-shell peel test, Sientra's implant required over 26% greater force than Allergan's implant and over 35% greater force than Mentor's implant. Sientra's shaped implants required more than double the peel force than Allergan 410 (119% greater) and Mentor CPG (130% greater). Morphological results showed Sientra's implants preserved structural integrity (-1.10% change). The initial findings show that these implant characteristics are individual factors to be considered separately and are not necessarily correlative. Further study of implants using these and other testing techniques will help clinicians choose between implants.

CO2 laser surface treatment of failed dental implants for re-implantation: an animal study.

PubMed

Kasraei, Shahin; Torkzaban, Parviz; Shams, Bahar; Hosseinipanah, Seyed Mohammad; Farhadian, Maryam

2016-07-01

The aim of the present study was to evaluate the success rate of failed implants re-implanted after surface treatment with CO2 laser. Despite the widespread use of dental implants, there are many incidents of failures. It is believed that lasers can be applied to decontaminate the implant surface without damaging the implant. Ten dental implants that had failed for various reasons other than fracture or surface abrasion were subjected to CO2 laser surface treatment and randomly placed in the maxillae of dogs. Three failed implants were also placed as the negative controls after irrigation with saline solution without laser surface treatment. The stability of the implants was evaluated by the use of the Periotest values (PTVs) on the first day after surgery and at 1, 3, and 6 months post-operatively. The mean PTVs of treated implants increased at the first month interval, indicating a decrease in implant stability due to inflammation followed by healing of the tissue. At 3 and 6 months, the mean PTVs decreased compared to the 1-month interval (P < 0.05), indicating improved implant stability. The mean PTVs increased in the negative control group compared to baseline (P < 0.05). Independent t-test showed that the mean PTVs of treated implants were significantly lower than control group at 3 and 6 months after implant placement (P < 0.05). Based on the PTVs, re-implantation of failed implants in Jack Russell Terrier dogs after CO2 laser surface debridement is associated with a high success rate in terms of implant stability.

Retrospective Analysis on Survival Rate, Template-Related Complications, and Prevalence of Peri-implantitis of 694 Anodized Implants Placed Using Computer-Guided Surgery: Results Between 1 and 10 Years of Follow-Up.

PubMed

Tallarico, Marco; Meloni, Silvio Mario

To report survival rate, early surgical template-related complications, and prevalence of peri-implantitis of dental implants placed in private practices using computer-guided, template-assisted surgery and followed between 1 and 10 years. The present retrospective multicenter study evaluated data collected from fully or partially edentulous patients, with anodized-surface implants placed using computer-guided, template-assisted surgery between January 2006 and December 2015. The outcome measures were implant cumulative survival rate (CSR), early surgical complications involving the surgical template, and prevalence of peri-implantitis. A total of 694 implants were placed in 141 patients. Ten patients (7.1%) with 48 implants (6.9%) dropped out during the study period. One hundred seventeen patients, who received 121 surgical and prosthetic procedures, were treated according to a double-scan protocol, while the remaining 24 patients were treated by using the integrated treatment workflow. Most of the implants were immediately loaded (528 implants, 76.1%; 112 patients, 79.4%). Overall, 107 complete full-arch restorations (supported by four to eight implants each) were delivered in 103 patients (73%) with 595 implants (85.7%), while 13 single and 30 partial restorations (two to five implants each) were delivered in 38 patients (27%) with 99 implants (14.3%). Patients were followed for up to 10 years (mean: 58.2 months, range: 12 to 120 months). Implant- and patient-level CSR (Kaplan-Meier estimation) at the 10-year follow-up was 97.4% (95% CI: 1.0309 to 0.9161) and 92.1% (95% CI: 1.1575 to 0.6836), respectively. All failed implants were lost before definitive prosthesis delivery (early failure). Ten (7.1%) minor template-related complications were experienced and resolved chairside. Over the entire follow-up period, four patients (2.8%) with 12 implants (1.7%) showed signs of peri-implantitis at the 1- (four implants), 2- (four implants), and 4-year (four implants) visits. High long-term survival rates and low complications and prevalence of peri-implantitis were observed for a large cohort of anodized-surface implants placed in private practices. Further studies are needed to confirm these preliminary results.

What do sales data tell us about implant survival?

PubMed Central

Seemann, Rudolf; Jirku, Alexander; Wagner, Florian; Wutzl, Arno

2017-01-01

Objective The aim of this study was to evaluate the influence of implant diameter, length and shape on a surrogate parameter of implant survival; i.e. the implant return rate in a big data analysis. Materials and methods A retrospective study was conducted and the factors influencing the success rates of 69,377 sold implants over a seven-year period were evaluated. The osseointegration program of a reseller provides reliable data of a single country. Implant loss rates were investigated using logistic regression models and regressed by implant type, diameter, and length. Results The return rate of 69,377 sold implants was 2.78% and comparable to implant loss rates in previous published prospective studies as its surrogate parameter. A total of 80% of implant returns had occurred within 157 days, and an additional 15% within 750.25 days. Diameters of 3.8 to 5.0mm showed the lowest return rates with its bottom in the 4.3mm implant whilst 6.0mm implants had significantly higher return rates. In comparison to the most sold implant length (13mm) shorter implants showed significantly higher early return rates. Conclusions The study provides evidence that in cases of standard indications and sufficient bone, the use of screw typed dental implants with 3.8 or 4.3 diameter and 11 or 13 mm length shows the lowest implant return rates. Other implants may be selected only in specific indications. PMID:28222128

The Effects of Subcrestal Implant Placement on Crestal Bone Levels and Bone-to-Abutment Contact: A Microcomputed Tomographic and Histologic Study in Dogs.

PubMed

Fetner, Michael; Fetner, Alan; Koutouzis, Theofilos; Clozza, Emanuele; Tovar, Nick; Sarendranath, Alvin; Coelho, Paulo G; Neiva, Kathleen; Janal, Malvin N; Neiva, Rodrigo

2015-01-01

Implant design and the implant-abutment interface have been regarded as key influences on crestal bone maintenance over time. The aim of the present study was to determine crestal bone changes around implants placed at different depths in a dog model. Thirty-six two-piece dental implants with a medialized implant-abutment interface and Morse taper connection (Ankylos, Dentsply) were placed in edentulous areas bilaterally in six mongrel dogs. On each side of the mandible, three implants were placed randomly at the bone crest, 1.5 mm subcrestally, or 3.0 mm subcrestally. After 3 months, the final abutments were torqued into place. At 6 months, the animals were sacrificed and samples taken for microcomputed tomographic (micro-CT) and histologic evaluations. Micro-CT analysis revealed similar crestal or marginal bone loss among groups. Both subcrestal implant groups lost significantly less crestal and marginal bone than the equicrestal implants. Bone loss was greatest on the buccal of the implants, regardless of implant placement depth. Histologically, implants placed subcrestally were found to have bone in contact with the final abutment and on the implant platform. Implants with a centralized implant-abutment interface and Morse taper connection can be placed subcrestally without significant loss of crestal or marginal bone. Subcrestal placement of this implant system appears to be advantageous in maintaining bone height coronal to the implant platform.

Comparison of the Explantation Rate of Poly Implant Prothèse, Allergan, and Pérouse Silicone Breast Implants within the First Four Years after Reconstructive Surgery before the Poly Implant Prothèse Alert by the French Regulatory Authority.

PubMed

Leduey, Alexandre; Mazouni, Chafika; Leymarie, Nicolas; Alkhashnam, Heba; Sarfati, Benjamin; Garbay, Jean-Rémi; Gaudin, Amélie; Kolb, Frédéric; Rimareix, Françoise

2015-01-01

Background. In March 2010, ANSM (Agence Nationale de Sécurité du Medicament), the French Medical Regulatory Authority, withdrew Poly Implant Prothèse (PIP) breast implants from the market due to the use of non-medical-grade silicone gel. The aim of this study was to compare the removal rate (and reasons thereof) of breast implants produced by different manufacturers before the ANSM alert. Materials and Methods. From October 2006 to January 2010, 652 women received 944 implants after breast cancer surgery at the Gustave Roussy Comprehensive Cancer Center, Paris (France). The complications and removal rates of the different implant brands used (PIP, Allergan, and Pérouse) were evaluated and compared. Results. PIP implants represented 50.6% of the used implants, Allergan 33.4%, and Pérouse 16%. The main reasons for implant removal were patient dissatisfaction due to aesthetic problems (43.2%), infection (22.2%), and capsular contracture (13.6%). Two years after implantation, 82% of Pérouse implants, 79% of PIP, and 79% of Allergan were still in situ. There was no difference in removal rate among implant brands. Conclusion. Before the ANSM alert concerning the higher rupture rate of PIP breast implants, our implant removal rate did not predict PIP implant failure related to the use of nonapproved silicone gel.

Comparison of the Explantation Rate of Poly Implant Prothèse, Allergan, and Pérouse Silicone Breast Implants within the First Four Years after Reconstructive Surgery before the Poly Implant Prothèse Alert by the French Regulatory Authority

PubMed Central

Leduey, Alexandre; Mazouni, Chafika; Leymarie, Nicolas; Alkhashnam, Heba; Sarfati, Benjamin; Garbay, Jean-Rémi; Gaudin, Amélie; Kolb, Frédéric; Rimareix, Françoise

2015-01-01

Background. In March 2010, ANSM (Agence Nationale de Sécurité du Medicament), the French Medical Regulatory Authority, withdrew Poly Implant Prothèse (PIP) breast implants from the market due to the use of non-medical-grade silicone gel. The aim of this study was to compare the removal rate (and reasons thereof) of breast implants produced by different manufacturers before the ANSM alert. Materials and Methods. From October 2006 to January 2010, 652 women received 944 implants after breast cancer surgery at the Gustave Roussy Comprehensive Cancer Center, Paris (France). The complications and removal rates of the different implant brands used (PIP, Allergan, and Pérouse) were evaluated and compared. Results. PIP implants represented 50.6% of the used implants, Allergan 33.4%, and Pérouse 16%. The main reasons for implant removal were patient dissatisfaction due to aesthetic problems (43.2%), infection (22.2%), and capsular contracture (13.6%). Two years after implantation, 82% of Pérouse implants, 79% of PIP, and 79% of Allergan were still in situ. There was no difference in removal rate among implant brands. Conclusion. Before the ANSM alert concerning the higher rupture rate of PIP breast implants, our implant removal rate did not predict PIP implant failure related to the use of nonapproved silicone gel. PMID:26543648

Short Implants: New Horizon in Implant Dentistry.

PubMed

Jain, Neha; Gulati, Manisha; Garg, Meenu; Pathak, Chetan

2016-09-01

The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration.

Short Implants: New Horizon in Implant Dentistry

PubMed Central

Gulati, Manisha; Garg, Meenu; Pathak, Chetan

2016-01-01

The choice of implant length is an essential factor in deciding the survival rates of these implants and the overall success of the prosthesis. Placing an implant in the posterior part of the maxilla and mandible has always been very critical due to poor bone quality and quantity. Long implants can be placed in association with complex surgical procedures such as sinus lift and bone augmentation. These techniques are associated with higher cost, increased treatment time and greater morbidity. Hence, there is need for a less invasive treatment option in areas of poor bone quantity and quality. Data related to survival rates of short implants, their design and prosthetic considerations has been compiled and structured in this manuscript with emphasis on the indications, advantages of short implants and critical biomechanical factors to be taken into consideration when choosing to place them. Studies have shown that comparable success rates can be achieved with short implants as those with long implants by decreasing the lateral forces to the prosthesis, eliminating cantilevers, increasing implant surface area and improving implant to abutment connection. Short implants can be considered as an effective treatment alternative in resorbed ridges. Short implants can be considered as a viable treatment option in atrophic ridge cases in order to avoid complex surgical procedures required to place long implants. With improvement in the implant surface geometry and surface texture, there is an increase in the bone implant contact area which provides a good primary stability during osseo-integration. PMID:27790598

Clinical outcomes of implant therapy in ectodermal dysplasia patients: a systematic review.

PubMed

Wang, Y; He, J; Decker, A M; Hu, J C; Zou, D

2016-08-01

The purpose of this review was to determine the outcome of oral function reconstruction in ectodermal dysplasia (ED) patients who have received dental implant therapy. A search was made of the PubMed and Web of Science databases; key words used were "(ectodermal dysplasia) AND (implant OR implants)", with supplementary retrieval key words "dental implant", "zygomatic implant", "anodontia", and "edentulous". Patient age, use of bone graft, implant site, type of implant, and survival rate of the implants were included in the subsequent data analysis. Forty-five articles published between 1988 and October 2015 were included in this analysis. The cases of a total of 96 patients were retrieved (22 children and 74 adults); these patients received a total of 701 implants. Fourteen implants were removed during a median follow-up time of 24 months. The 24-month implant survival rate was 97.9% in adult subjects and 98.6% in children. Sixty-eight percent of adult patients underwent bone augmentation prior to implant placement. Based on this review, dental implants are commonly used in the oral reconstruction of ED patients. However, long-term data on bone augmentation and implant success are needed, as well as additional clinical evidence on bone resorption, the esthetic outcomes of implant therapy, and physiological considerations in ED patients. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Three-dimensional finite element analyses of four designs of a high-strength silicon nitride implant.

PubMed

Lin, S; Shi, S; LeGeros, R Z; LeGeros, J P

2000-01-01

The effects of implant shape and size on the stress distribution around high-strength silicon nitride implants under vertical and oblique forces were determined using a three-dimensional finite element analysis. Finite element models were designed using as a basis the serial sections of the mandible. Using Auto-CAD software, the model simulated the placement of implants in the molar region of the left mandible. Results of the analyses demonstrated that mainly the implant root shape and the directions of bite forces influence the stress distributions in the supporting bone around each implant. Implant size is a lesser factor. The serrated implants presented a larger surface area to the bone than either the cylindrical or tapered implants, which resulted in lower compressive stress around the serrated implants. With increasing implant diameter and length, compressive stress decreased. The mean compressive stress distribution on the serrated implants was more flat (platykurtic) than on either the cylindrical or tapered implants. Results of studies on two load directions (vertical and oblique) showed that, in either case, the compressive stress in the cortical bone around the neck of the implant was higher than in the cancellous bone along the length of the implant. The most extreme principal compressive stress was found with oblique force. This study provides the first information on the relationship between shape of the silicon nitride implant and stress on the supporting bone.

Maxillary overdentures supported by four splinted direct metal laser sintering implants: a 3-year prospective clinical study.

PubMed

Mangano, Francesco; Luongo, Fabrizia; Shibli, Jamil Awad; Anil, Sukumaran; Mangano, Carlo

2014-01-01

Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS) technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females) to support bar-retained maxillary overdentures (ODs). Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB). Results. The 3-year implant survival rate was 97.4% (implant-based) and 92.9% (patient-based). Three implants failed. The incidence of biological complication was 3.5% (implant-based) and 7.1% (patient-based). The incidence of prosthetic complication was 17.8% (patient-based). No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results.

Maxillary Overdentures Supported by Four Splinted Direct Metal Laser Sintering Implants: A 3-Year Prospective Clinical Study

PubMed Central

Mangano, Francesco; Shibli, Jamil Awad; Anil, Sukumaran

2014-01-01

Purpose. Nowadays, the advancements in direct metal laser sintering (DMLS) technology allow the fabrication of titanium dental implants. The aim of this study was to evaluate implant survival, complications, and peri-implant marginal bone loss of DMLS implants used to support bar-retained maxillary overdentures. Materials and Methods. Over a 2-year period, 120 implants were placed in the maxilla of 30 patients (18 males, 12 females) to support bar-retained maxillary overdentures (ODs). Each OD was supported by 4 implants splinted by a rigid cobalt-chrome bar. At each annual follow-up session, clinical and radiographic parameters were assessed. The outcome measures were implant failure, biological and prosthetic complications, and peri-implant marginal bone loss (distance between the implant shoulder and the first visible bone-to-implant contact, DIB). Results. The 3-year implant survival rate was 97.4% (implant-based) and 92.9% (patient-based). Three implants failed. The incidence of biological complication was 3.5% (implant-based) and 7.1% (patient-based). The incidence of prosthetic complication was 17.8% (patient-based). No detrimental effects on marginal bone level were evidenced. Conclusions. The use of 4 DMLS titanium implants to support bar-retained maxillary ODs seems to represent a safe and successful procedure. Long-term clinical studies on a larger sample of patients are needed to confirm these results. PMID:25580124

Short dental implants: an emerging concept in implant treatment.

PubMed

Al-Hashedi, Ashwaq Ali; Taiyeb Ali, Tara Bai; Yunus, Norsiah

2014-06-01

Short implants have been advocated as a treatment option in many clinical situations where the use of conventional implants is limited. This review outlines the effectiveness and clinical outcomes of using short implants as a valid treatment option in the rehabilitation of edentulous atrophic alveolar ridges. Initially, an electronic search was performed on the following databases: Medline, PubMed, Embase, Cochrane Database of Systematic Reviews, and DARE using key words from January 1990 until May 2012. An additional hand search was included for the relevant articles in the following journals: International Journal of Oral and Maxillofacial Implants, Clinical Oral Implants Research, Journal of Clinical Periodontology, International Journal of Periodontics, Journal of Periodontology, and Clinical Implant Dentistry and Related Research. Any relevant papers from the journals' references were hand searched. Articles were included if they provided detailed data on implant length, reported survival rates, mentioned measures for implant failure, were in the English language, involved human subjects, and researched implants inserted in healed atrophic ridges with a follow-up period of at least 1 year after implant-prosthesis loading. Short implants demonstrated a high rate of success in the replacement of missing teeth in especially atrophic alveolar ridges. The advanced technology and improvement of the implant surfaces have encouraged the success of short implants to a comparable level to that of standard implants. However, further randomized controlled clinical trials and prospective studies with longer follow-up periods are needed.

Effects of pore size, implantation time and nano-surface properties on rat skin ingrowth into percutaneous porous titanium implants

PubMed Central

Farrell, Brad J.; Prilutsky, Boris I.; Ritter, Jana M.; Kelley, Sean; Popat, Ketul; Pitkin, Mark

2013-01-01

The main problem of percutaneous osseointegrated implants is poor skin-implant integration, which may cause infection. This study investigated the effects of pore size (Small, 40–100 microns and Large, 100–160 microns), nanotubular surface treatment (Nano), and duration of implantation (3 and 6 weeks) on skin ingrowth into porous titanium. Each implant type was percutaneously inserted in the back of 35 rats randomly assigned to 7 groups. Implant extrusion rate was measured weekly and skin ingrowth into implants was determined histologically after harvesting implants. It was found that all 3 types of implants demonstrated skin tissue ingrowth of over 30% (at week 3) and 50% (at weeks 4–6) of total implant porous area under the skin; longer implantation resulted in greater skin ingrowth (p<0.05). Only one case of infection was observed (infection rate 2.9%). Small and Nano groups showed the same implant extrusion rate which was lower than the Large group rate (0.06±0.01 vs. 0.16 ± 0.02 cm/week; p<0.05). Ingrowth area was comparable in the Small, Large and Nano implants. However, qualitatively, the Nano implants showed greatest cellular inhabitation within first three weeks. We concluded that percutaneous porous titanium implants allow for skin integration with the potential for a safe seal. PMID:23703928

A retrospective study on clinical and radiological outcomes of oral implants in patients followed up for a minimum of 20 years.

PubMed

Chrcanovic, Bruno Ramos; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

2018-04-01

Very long-term follow-up of oral implants is seldom reported in the literature. To assess oral implant failure rates and marginal bone loss (MBL) of patients followed up for a minimum of 20 years. Implants placed in patients followed up for 20+ years were included. Descriptive statistics, survival analyses, generalized estimating equations were performed. Three-hundred implants were randomly selected for MBL. 1,045 implants (227 patients) were included. Implant location, irradiation, and bruxism affected the implant survival rate. Thirty-five percent of the failures occurred within the first year after implantation, and another 26.8% in the second/third year. There was a cumulative survival rate of 87.8% after 36 years of follow-up. In the last radiological follow up, 35 implants (11.7%) had bone gain, and 35 implants (11.7%) presented at least 3 mm of MBL. Twenty-six out of 86 failed implants with available radiograms presented severe MBL in the last radiological register before implant failure. Most of the implant failures occurred at the first few years after implantation, regardless of a very long follow up. MBL can be insignificant in long-term observations, but it may, nevertheless, be the cause of secondary failure of oral implants in some cases. © 2017 Wiley Periodicals, Inc.

Implant-bone interface stress distribution in immediately loaded implants of different diameters: a three-dimensional finite element analysis.

PubMed

Ding, Xi; Zhu, Xing-Hao; Liao, Sheng-Hui; Zhang, Xiu-Hua; Chen, Hong

2009-07-01

To establish a 3D finite element model of a mandible with dental implants for immediate loading and to analyze stress distribution in bone around implants of different diameters. Three mandible models, embedded with thread implants (ITI, Straumann, Switzerland) with diameters of 3.3, 4.1, and 4.8 mm, respectively, were developed using CT scanning and self-developed Universal Surgical Integration System software. The von Mises stress and strain of the implant-bone interface were calculated with the ANSYS software when implants were loaded with 150 N vertical or buccolingual forces. When the implants were loaded with vertical force, the von Mises stress concentrated on the mesial and distal surfaces of cortical bone around the neck of implants, with peak values of 25.0, 17.6 and 11.6 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains (5854, 4903, 4344 muepsilon) were located on the buccal cancellous bone around the implant bottom and threads of implants. The stress and strain were significantly lower (p < 0.05) with the increased diameter of implant. When the implants were loaded with buccolingual force, the peak von Mises stress values occurred on the buccal surface of cortical bone around the implant neck, with values of 131.1, 78.7, and 68.1 MPa for 3.3, 4.1, and 4.8 mm diameters, respectively, while the maximum strains occurred on the buccal surface of cancellous bone adjacent to the implant neck, with peak values of 14,218, 12,706, and 11,504 microm, respectively. The stress of the 4.1-mm diameter implants was significantly lower (p < 0.05) than those of 3.3-mm diameter implants, but not statistically different from that of the 4.8 mm implant. With an increase of implant diameter, stress and strain on the implant-bone interfaces significantly decreased, especially when the diameter increased from 3.3 to 4.1 mm. It appears that dental implants of 10 mm in length for immediate loading should be at least 4.1 mm in diameter, and uniaxial loading to dental implants should be avoided or minimized.

Two-stage implant systems.

PubMed

Fritz, M E

1999-06-01

Since the advent of osseointegration approximately 20 years ago, there has been a great deal of scientific data developed on two-stage integrated implant systems. Although these implants were originally designed primarily for fixed prostheses in the mandibular arch, they have been used in partially dentate patients, in patients needing overdentures, and in single-tooth restorations. In addition, this implant system has been placed in extraction sites, in bone-grafted areas, and in maxillary sinus elevations. Often, the documentation of these procedures has lagged. In addition, most of the reports use survival criteria to describe results, often providing overly optimistic data. It can be said that the literature describes a true adhesion of the epithelium to the implant similar to adhesion to teeth, that two-stage implants appear to have direct contact somewhere between 50% and 70% of the implant surface, that the microbial flora of the two-stage implant system closely resembles that of the natural tooth, and that the microbiology of periodontitis appears to be closely related to peri-implantitis. In evaluations of the data from implant placement in all of the above-noted situations by means of meta-analysis, it appears that there is a strong case that two-stage dental implants are successful, usually showing a confidence interval of over 90%. It also appears that the mandibular implants are more successful than maxillary implants. Studies also show that overdenture therapy is valid, and that single-tooth implants and implants placed in partially dentate mouths have a success rate that is quite good, although not quite as high as in the fully edentulous dentition. It would also appear that the potential causes of failure in the two-stage dental implant systems are peri-implantitis, placement of implants in poor-quality bone, and improper loading of implants. There are now data addressing modifications of the implant surface to alter the percentage of osseointegration. New types of reinforcements for dental implants and the use of growth factors to augment bone regeneration so that implants can be placed more easily are now being actively investigated.

Treatment of peri-implant diseases: a review of the literature and protocol proposal.

PubMed

Armas, Joshé; Culshaw, Shauna; Savarrio, Lee

2013-01-01

Over 100,000 implants were placed in the UK in 2010. As the numbers of patients with implant-retained prostheses increases, operators are encountering an increasing number of biological implant complications, most commonly peri-implant mucositis and peri-implantitis. The effective management of these complications is crucial to maintain patients' oral health. In particular, in contrast to common periodontal infections, some peri-implant infections may benefit from surgical intervention as a first line approach. This article reviews the literature on the treatment options for peri-implant mucositis and peri-implantitis and proposes a protocol for their treatment.

The Key Points of Maintenance Therapy for Dental Implants: A Literature Review.

PubMed

Pirc, Miha; Dragan, Irina F

2017-04-01

Dental implants require lifelong maintenance and care. Success is defined by biologic factors (presence of inflamed soft tissues surrounding dental implants and radiographic changes in the crestal bone levels) and mechanical factors (stability of the implant fixture and implant supported restoration, etc). Most implant failures are initiated by incipient stages of inflammatory processes, which lead to peri-mucositis and peri-implantitis. The evidence regarding the value of maintenance protocol regarding implants is sparse compared with the one for teeth. This article addresses the existing literature on processes for oral hygiene for implant care.

[Application of plasma sprayed zirconia coating in dental implant: study in implant].

PubMed

Huang, Z F; Wang, Z F; Li, C H; Hao, D; Lan, J

2018-04-09

Objective: To investigate the osseointegration of a novel coating-plasma-sprayed zirconia in dental implant. Methods: Zirconia coating on non-thread titanium implant was prepared using plasma spraying, the implant surface morphology, surface roughness and wettability were measured. In vivo , zirconia coated implants were inserted in rabbit tibia and animals were respectively sacrificed at 2, 4, 8 and 12 weeks after implantation. The bond strength between implant and bone was measured by push-out test. The osseointegration was observed by scanning electron microscopy (SEM), micro CT and histological analyses. Quantified parameters including removal torque, and bone-implant contact (BIC) percentage were calculated. Results: The surface roughness (1.6 µm) and wettability (54.6°) of zirconia coated implant was more suitable than those of titanium implant (0.6 µm and 74.4°) for osseointegration. At 12 weeks, the push-out value of zirconia coated implant and titanium implant were (64.9±3.0) and (50.4±2.9) N, and BIC value of these two groups were (54.7±3.6)% and (41.5±3.6)%. All these differences had statistical significance. Conclusions: The surface characters of zirconia coated implant were more suitable for osseointegration and present better osseointegration than smooth titanium implant in vivo , especially at early stage.

The formation of an organic coat and the release of corrosion microparticles from metallic magnesium implants.

PubMed

Badar, Muhammad; Lünsdorf, Heinrich; Evertz, Florian; Rahim, Muhammad Imran; Glasmacher, Birgit; Hauser, Hansjörg; Mueller, Peter P

2013-07-01

Magnesium alloys have been proposed as prospective degradable implant materials. To elucidate the complex interactions between the corroding implants and the tissue, magnesium implants were analyzed in a mouse model and the response was compared to that induced by Ti and by the resorbable polymer polyglactin, respectively. One month after implantation, distinct traces of corrosion were apparent but the magnesium implants were still intact, whereas resorbable polymeric wound suture implants were already fragmented. Analysis of magnesium implants 2weeks after implantation by energy-dispersive X-ray spectroscopy indicated that magnesium, oxygen, calcium and phosphate were present at the implant surface. One month after implantation, the element composition of the outermost layer of the implant was indicative of tissue without detectable levels of magnesium, indicating a protective barrier function of this organic layer. In agreement with this notion, gene expression patterns in the surrounding tissue were highly similar for all implant materials investigated. However, high-resolution imaging using energy-filtered transmission electron microscopy revealed magnesium-containing microparticles in the tissue in the proximity of the implant. The release of such corrosion particles may contribute to the accumulation of calcium phosphate in the nearby tissue and to bone conductive activities of magnesium implants. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Intracapsular implant rupture: MR findings of incomplete shell collapse.

PubMed

Soo, M S; Kornguth, P J; Walsh, R; Elenberger, C; Georgiade, G S; DeLong, D; Spritzer, C E

1997-01-01

The objective of this study was to determine the frequency and significance of the MR findings of incomplete shell collapse for detecting implant rupture in a series of surgically removed breast prostheses. MR images of 86 breast implants in 44 patients were studied retrospectively and correlated with surgical findings at explantation. MR findings included (a) complete shell collapse (linguine sign), 21 implants; (b) incomplete shell collapse (subcapsular line sign, teardrop sign, and keyhole sign), 33 implants; (c) radial folds, 31 implants; and (d) normal, 1 implant. The subcapsular line sign was seen in 26 implants, the teardrop sign was seen in 27 implants, and the keyhole sign was seen in 23 implants. At surgery, 48 implants were found to be ruptured and 38 were intact. The MR findings of ruptured implants showed signs of incomplete collapse in 52% (n = 25), linguine sign in 44% (n = 21), and radial folds in 4% (n = 2). The linguine sign perfectly predicted implant rupture, but sensitivity was low. Findings of incomplete shell collapse improved sensitivity and negative predictive values, and the subcapsular line sign produced a significant incremental increase in predictive ability. MRI signs of incomplete shell collapse were more common than the linguine sign in ruptured implants and are significant contributors to the high sensitivity and negative predictive values of MRI for evaluating implant integrity.

Longer-term functional outcomes and everyday listening performance for young children through to young adults using bilateral implants.

PubMed

Galvin, Karyn Louise; Holland, Jennifer Frances; Hughes, Kathryn Clare

2014-01-01

First, to document a broad range of functional outcomes of bilateral implantation for young children through young adults at a postoperative point at which stable outcomes could be expected. Second, to evaluate the relationship between functional outcomes and age at bilateral implantation and time between implants. A study-specific questionnaire was administered to parents in an interview 3.5 years or more after sequential (n = 50) or simultaneous (n = 7) implants were received by their child. Median age at bilateral implantation was 4.1 years (range 0.7 to 19.8) and time between implants was 2.7 years (range 0.0 to 16.7). On the basis of parent report, 72% of the sequentially implanted children and young adults found it easy/only "a bit difficult" to adapt to the second implant, and were "happily wearing both implants together most of the time" by 6 months or before; 26% had not adapted, with both implants not worn most of the time or worn as a parental requirement. Seventy-two percent of sequentially implanted children and young adults had a positive attitude toward the second implant, including 9 whose early postoperative attitude was negative or neutral. The majority of children and young adults preferred bilateral implants (70%) and used the two full time (72%), while around half demonstrated similar performance with each implant alone. The proportion of nonusers or very minimal users of the second implant was just 9%. Eighty-eight percent of parents reported superior performance with bilateral versus a unilateral implant (n = 40), or that only bilateral implants were worn (n = 10) so performance could not be compared. The most commonly identified areas of superiority were localization, less need for repetition, and increased responsiveness. In balancing risks and costs with benefits, most parents (86%) considered the second implant worthwhile. Regarding the relationship between outcomes and demographic factors, the group achieving similar performance with each implant alone was younger at bilateral implantation and had less time between implants, and the group bilaterally implanted before 3.5 years of age (who also had less than 2 years between implants) had a higher proportion of positive outcomes on all functional outcome measures. Overall, the results indicate primarily positive functional outcomes for children and young adults receiving bilateral implants at all ages, including when the delay between implants is long. The results are important for evidence-based preoperative counseling, which helps families to make informed decisions and develop appropriate expectations. The results are also important for the development of clinical management practices that support and encourage the minority of recipients who have difficulty adapting to bilateral implants or achieving full-time use.

Immediate provisionalization of dental implants placed in healed alveolar ridges and extraction sockets: a 5-year prospective evaluation.

PubMed

Cooper, Lyndon F; Reside, Glenn J; Raes, Filiep; Garriga, Joan Soliva; Tarrida, Luis Giner; Wiltfang, Jörg; Kern, Matthias; De Bruyn, Hugo

2014-01-01

This 5-year prospective multicenter study compared implant survival and success, peri-implant health and soft tissue responses, crestal bone level stability, and complication rates following immediate loading of single OsseoSpeed implants placed in anterior maxillary healed ridges or extraction sockets. Individuals requiring anterior tooth replacement with single implants were treated and immediately provisionalized. Definitive all-ceramic crowns were placed at 12 weeks. Implant survival, bone levels, soft tissue levels, and peri-implant health were monitored for 5 years. One hundred thirteen patients received implants in fresh sockets (55) and healed ridges (58). After 5 years, 45 and 49 patients remained for evaluation, respectively. During the first year, three implants failed in the extraction socket group (94.6% survival) and one implant failed in the healed ridge group (98.3% survival); this difference was not significant. No further implant failures were recorded. After 5 years, the interproximal crestal bone levels were located a mean of 0.43 ± 0.63 mm and 0.38 ± 0.62 mm from the reference points of implants in sockets and healed ridges (not a significant difference). In both groups, papillae increased over time and peri-implant mucosal zenith positions were stable from the time of definitive crown placement in sockets and healed ridges. Compared to flap surgery for implants in healed ridges, flapless surgery resulted in increased peri-implant mucosal tissue dimension (average, 0.78 ± 1.34 mm vs 0.19 ± 0.79 mm). After 5 years, the bone and soft tissue parameters that characterize implant success and contribute to dental implant esthetics were similar following the immediate provisionalization of implants in sockets and healed ridges. The overall tissue responses and reported implant survival support the immediate provisionalization of dental implants in situations involving healed ridges and, under ideal circumstances, extraction sockets.

The Influence of the Crown-Implant Ratio on the Crestal Bone Level and Implant Secondary Stability: 36-Month Clinical Study.

PubMed

Hadzik, Jakub; Krawiec, Maciej; Sławecki, Konstanty; Kunert-Keil, Christiane; Dominiak, Marzena; Gedrange, Tomasz

2018-01-01

When the era of dental implantology began, the pioneers defined some gold standards used in dental prosthetics treatment for implant-supported restorations. Referring to traditional prosthetics, it was taken for granted that the length of an implant placed in the alveolar bone (the equivalent of the root) should exceed the length of the superstructure. The aim of the study was to determine whether implant length and the crown-to-implant ( C / I ) ratio influence implant stability and the loss of the surrounding marginal bone and whether short implants can be used instead of sinus augmentation procedures. The patients participating in the study ( n = 30) had one single tooth implant, a short (OsseoSpeed™ L6 Ø4 mm, Implants) or a regular implant (OsseoSpeed L11 and L13 Ø4 mm, DENTSPLY Implants), placed in the maxilla. The evaluation was based on clinical and radiological examination. The crown-to-implant ratio was determined by dividing the length of the crown together with the abutment by the length of the implant placed crestally. Mean crown-to-implant ratios were calculated separately for each group and its correlation with the MBL (marginal bone loss) and stability was assessed. The authors compared the correlation between the C / I ratio values, MBL, and secondary implant stability. Positive results in terms of primary and secondary stability were achieved with both (short and conventional) implants. The MBL was low for short and conventional implants being 0.34 ± 0.24 mm and 0.22 ± 0.46 mm, respectively. No significant correlation was found between the C / I ratio and secondary stability as well as the C / I ratio and the marginal bone loss. Short implants can be successfully used to support single crowns. The study has revealed no significant differences in the clinical performance of prosthetic restorations supported by short implants. Clinical trial registration number is NCT03471000.

A resonance frequency analysis of sandblasted and acid-etched implants with different diameters: a prospective clinical study during the initial healing period

PubMed Central

2017-01-01

Purpose The possibility of immediate or early loading has become popular in implant dentistry. A prerequisite for the immediate or early loading of an implant prosthesis is the achievement of initial stability in the implant. Moreover, in response to clinicians' interest in verifying clinical stability to determine the optimal time point for functional loading, a non-invasive method to assess implant stability has been developed on the basis of resonance frequency analysis (RFA). The primary objective of this study was to monitor the stability of sandblasted, large-grit, and acid-etched (SLA) implants with different diameters during the early phases of healing by RFA. The secondary objective was to evaluate how the initial stability of implants varied depending on different surface modifications and other contributing factors. Methods Thirty-five implants (25 SLA implants and 10 resorbable blasting media [RBM] implants) placed in 20 subjects were included. To measure implant stability, RFA was performed at baseline and at 1, 2, 3, 4, 6, and 10 weeks after surgery. Results The longitudinal changes in the implant stability quotient (ISQ) values were similar for the SLA implants with different diameters and for the RBM implants. During the initial healing period, the ISQ decreased after installation and reached its lowest values at 1 week and 2 weeks, respectively. The mean ISQ values in the SLA implants were significantly higher in Ø 5.0 mm implants than in Ø 4.0 mm implants. Men showed a higher ISQ than women. Mandibular sites showed a higher ISQ than maxillary sites. Conclusions All implants used in this study are suitable for immediate or early loading under appropriate indications. A wider diameter and SLA surface treatment of implants could improve the stability, if the implant is fixed with at least 30 Ncm of insertion torque. PMID:28462009

Short dental implants versus standard dental implants placed in the posterior jaws: A systematic review and meta-analysis.

PubMed

Lemos, Cleidiel Aparecido Araujo; Ferro-Alves, Marcio Luiz; Okamoto, Roberta; Mendonça, Marcos Rogério; Pellizzer, Eduardo Piza

2016-04-01

The purpose of the present systematic review and meta-analysis was to compare short implants (equal or less than 8mm) versus standard implants (larger than 8mm) placed in posterior regions of maxilla and mandible, evaluating survival rates of implants, marginal bone loss, complications and prosthesis failures. This review has been registered at PROSPERO under the number CRD42015016588. Main search terms were used in combination: dental implant, short implant, short dental implants, short dental implants posterior, short dental implants maxilla, and short dental implants mandible. An electronic search for data published up until September/2015 was undertaken using the PubMed/Medline, Embase and The Cochrane Library databases. Eligibility criteria included clinical human studies, randomized controlled trials and/or prospective studies, which evaluated short implants in comparison to standard implants in the same study. The search identified 1460 references, after inclusion criteria 13 studies were assessed for eligibility. A total of 1269 patients, who had received a total of 2631 dental implants. The results showed that there was no significant difference of implants survival (P=.24; RR:1.35; CI: 0.82-2.22), marginal bone loss (P=.06; MD: -0.20; CI: -0.41 to 0.00), complications (P=.08; RR:0.54; CI: 0.27-1.09) and prosthesis failures (P=.92; RR:0.96; CI: 0.44-2.09). Short implants are considered a predictable treatment for posterior jaws. However, short implants with length less than 8 mm (4-7 mm) should be used with caution because they present greater risks to failures compared to standard implants. Short implants are frequently placed in the posterior area in order to avoid complementary surgical procedures. However, clinicians need to be aware that short implants with length less than 8mm present greater risk of failures. Copyright © 2016. Published by Elsevier Ltd.

10-year survival rate and the incidence of peri-implant disease of 374 titanium dental implants with a SLA surface: a prospective cohort study in 177 fully and partially edentulous patients.

PubMed

van Velzen, Frank J J; Ofec, Ronen; Schulten, Engelbert A J M; Ten Bruggenkate, Christiaan M

2015-10-01

This prospective cohort study evaluates the 10-year survival and incidence of peri-implant disease at implant and patient level of sandblasted, large grid, and acid-etched titanium dental implants (Straumann, soft tissue level, SLA surface) in fully and partially edentulous patients. Patients who had dental implant surgery in the period between November 1997 and June 2001, with a follow-up of at least 10 years, were investigated for clinical and radiological examination. Among the 506 inserted dental implants in 250 patients, 10-year data regarding the outcome of implants were available for 374 dental implants in 177 patients. In the current study, peri-implantitis was defined as advanced bone loss (≧1.5 mm. postloading) in combination with bleeding on probing. At 10-year follow-up, only one implant was lost (0.3%) 2 months after implant surgery due to insufficient osseointegration. The average bone loss at 10 year postloading was 0.52 mm. Advanced bone loss at 10-year follow-up was present in 35 dental implants (9.8%). Seven percent of the observed dental implants showed bleeding on probing in combination with advanced bone loss and 4.2% when setting the threshold for advanced bone loss at 2.0 mm. Advanced bone loss without bleeding on probing was present in 2.8% of all implants. In this prospective study, the 10-year survival rate at implant and patient level was 99.7% and 99.4%, respectively. Peri-implantitis was present in 7% of the observed dental implants according to the above-mentioned definition of peri-implantitis. This study shows that SLA implants offer predictable long-term results as support in the treatment of fully and partially edentulous patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Longitudinal Study in Children with Sequential Bilateral Cochlear Implants: Time Course for the Second Implanted Ear and Bilateral Performance

ERIC Educational Resources Information Center

Reeder, Ruth M.; Firszt, Jill B.; Cadieux, Jamie H.; Strube, Michael J.

2017-01-01

Purpose: Whether, and if so when, a second-ear cochlear implant should be provided to older, unilaterally implanted children is an ongoing clinical question. This study evaluated rate of speech recognition progress for the second implanted ear and with bilateral cochlear implants in older sequentially implanted children and evaluated localization…

Brief Assessment of Parental Perception (BAPP): Development and validation of a new measure for assessing paediatric outcomes after bilateral cochlear implantation.

PubMed

Samuel, V; Gamble, C; Cullington, H; Bathgate, F; Bennett, E; Coop, N; Cropper, J; Emond, A; Kentish, R; Edwards, L

2016-11-01

In contrast to previous clinical practice, current guidelines recommend bilateral cochlear implantation in children, resulting in a cohort of children who initially received one implant, but have subsequently had a second, contralateral implant. This study aimed to explore satisfaction and quality of life in children implanted simultaneously or sequentially. A novel measure of satisfaction and quality of life following paediatric bilateral cochlear implantation (the Brief Assessment of Parental Perception; BAPP) was developed and preliminary validation undertaken as part of a large, national project of bilateral implantation. Children's parents completed the measure yearly for up to three years following implantation. Children from 14 UK implant centres were recruited into the study; data were available for 410 children one year post-implantation. The BAPP was found to have good face and convergent validity, and internal consistency. Results indicated very high levels of satisfaction with the devices, and improvements in quality of life. However there was evidence that children implanted sequentially were less willing to wear their second implant in the first two years than those children receiving simultaneous implants. Simultaneous and sequential cochlear implants have a positive impact on the quality of life of deaf children.

Hydroxyapatite ocular implant and non-integrated implants in eviscerated patients

PubMed Central

Gradinaru, S; Popescu, V; Leasu, C; Pricopie, S; Yasin, S; Ciuluvica, R; Ungureanu, E

2015-01-01

Introduction: This study compares the outcomes and complications of hydroxyapatite ocular implant and non-integrated ocular implants following evisceration. Materials and Methods: This is a retrospective study of 90 patients who underwent evisceration for different ocular affections, in the Ophthalmology Department of the University Emergency Hospital Bucharest, between January 2009 and December 2013. The outcomes measured were conjunctival dehiscence, socket infection, implant exposure and extrusion rate. Results: Forty-three patients had the hydroxyapatite implant (coralline–Integrated Ocular Implants, USA or synthetic–FCI, France) and forty-seven received non-integrated ocular implants (24 acrylic and 23 silicone). Five cases of socket infection, thirteen cases of extrusion and two cases of conjunctival dehiscence were encountered. Conclusions: There was a higher rate of conjunctival dehiscence with hydroxyapatite ocular implant, but implant extrusion and socket infection were found in non-integrated ocular implants. PMID:25914747

DEALING WITH DENTAL IMPLANT FAILURES

PubMed Central

Levin, Liran

2008-01-01

An implant-supported restoration offers a predictable treatment for tooth replacement. Reported success rates for dental implants are high. Nevertheless, failures that mandate immediate implant removal do occur. The consequences of implant removal jeopardize the clinician's efforts to accomplish satisfactory function and esthetics. For the patient, this usually involves further cost and additional procedures. The aim of this paper is to describe different methods and treatment modalities to deal with dental implant failure. The main topics for discussion include identifying the failing implant, implants replacing failed implants at the exact site, and the use of other restorative options. When an implant fails, a tailor made treatment plan should be provided to each patient according to all relevant variables. Patients should be informed regarding all possible treatment modalities following implant failure and give their consent to the most appropriate treatment option for them. PMID:19089213

Decontamination of dental implant surface in peri-implantitis treatment: A literature review

PubMed Central

Buitrago-Vera, Pedro; Solá-Ruiz, María F.; Ferrer-García, Juan C.

2013-01-01

Etiological treatment of peri-implantitis aims to reduce the bacterial load within the peri-implant pocket and decontaminate the implant surface in order to promote osseointegration. The aim of this literature review was to evaluate the efficacy of different methods of implant surface decontamination. A search was conducted using the PubMed (Medline) database, which identified 36 articles including in vivo and in vitro studies, and reviews of different decontamination systems (chemical, mechanical, laser and photodynamic therapies). There is sufficient consensus that, for the treatment of peri-implant infections, the mechanical removal of biofilm from the implant surface should be supplemented by chemical decontamination with surgical access. However, more long-term research is needed to confirm this and to establish treatment protocols responding to different implant characterics. Key words:Peri-implantitis, treatment, decontamination, implant surface, laser. PMID:23986023

Synthesis of Pure Ca(OH)2 Nanoparticles and Superhydrophobic Suspensions: Consolidation and Waterproofing of Architectural Heritage Materials

NASA Astrophysics Data System (ADS)

Madrid Mendoza, Juan Antonio

El objetivo de esta tesis es investigar sobre la sintesis, propiedades y aplicaciones de las nanoparticulas de Ca(OH)2 para consolidar materiales patrimoniales arquitectonicos. Las nanoparticulas de Ca(OH)2 se han utilizado recientemente en la conservacion del patrimonio, aunque algunos aspectos de la sintesis no son completamente comprendidos. En el presente estudio, hemos desarrollado metodos optimizados para obtener nanoparticulas de alta pureza mediante sintesis de fase homogenea y heterogenea utilizando diferentes materiales de partida. Se han realizado del orden de cien sintesis en diferentes condiciones para comprobar la validez y fiabilidad del metodo sintetico. Los resultados confirman que la temperatura de reaccion tiene una gran influencia en el tamano y la morfologia de las nanoparticulas de Ca(OH)2. Ademas, se ha investigado la estabilidad de las nanoparticulas a lo largo del tiempo en mezclas de 2-propanol / agua, en las que se encontro que la ausencia de agua era critica para evitar la aglomeracion de Ca(OH)2. Una vez dispersas en 2-propanol, las nanoparticulas se han utilizado para consolidar sustratos reales (piedra, adobe y estuco) confirmando su alto rendimiento en terminos de consolidacion superficial y - cuando se mezcla con ciertos surfactantes - en reduccion de la absorcion de agua. Asimismo, se ha investigado el uso de nanoparticulas modificadas basadas en M(OH)2, donde M=Ca2+, Mg2+, con el objetivo de mejorar tanto la cohesion superficial como la durabilidad de los materiales patrimoniales (p. ej. piedra Tabaire). Finalmente, el tratamiento de consolidacion basado en nanoparticulas puras de Ca(OH)2 se utilizo en emplazamientos con valor patrimonial, como edificios historicos y yacimientos arqueologicos (Teatro Romano de Cartagena) obteniendo resultados satisfactorios. The aim of this thesis is to investigate on the synthesis, properties and applications of Ca(OH)2 nanoparticles to consolidate architectural heritage materials. Ca(OH)2 nanoparticles have recently been used in heritage conservation, although some aspects of the synthesis are not fully-understood. In the present study, we have developed optimised methods for obtaining high-purity nanoparticles based on homogenous and heterogeneous phase synthesis using different starting materials. Around one hundred syntheses have been performed to test the validity and reliability of the synthetic method in different conditions. The results confirm that the reaction temperature has a great influence on the size and morphology of Ca(OH)2 nanoparticles. Besides, the nanoparticles stability has been investigated over time in 2-propanol / water mixtures, in which the absence of water was found to be critical to avoid Ca(OH)2 agglomeration. Once dispersed in 2-propanol, the nanoparticles have been used to consolidate real substrates (stone, adobe and stucco) confirming their high performance in terms of surface consolidation and - when mixed with certain surfactants - water absorption. Likewise, the use of modified nanoparticles based on M(OH)2, where M=Ca2+, Mg2+, has been investigated with the aim of improving both the surface cohesion and durability of heritage materials (e.g. Tabaire stone). Finally, the consolidation treatment consisting in pure Ca(OH)2 nanoparticles has been used in cultural heritage sites, such as historical buildings and archaeological monuments (Roman Theatre of Cartagena) leading to satisfactory results.

Inverse problem in hydrogeology

NASA Astrophysics Data System (ADS)

Carrera, Jesús; Alcolea, Andrés; Medina, Agustín; Hidalgo, Juan; Slooten, Luit J.

2005-03-01

The state of the groundwater inverse problem is synthesized. Emphasis is placed on aquifer characterization, where modelers have to deal with conceptual model uncertainty (notably spatial and temporal variability), scale dependence, many types of unknown parameters (transmissivity, recharge, boundary conditions, etc.), nonlinearity, and often low sensitivity of state variables (typically heads and concentrations) to aquifer properties. Because of these difficulties, calibration cannot be separated from the modeling process, as it is sometimes done in other fields. Instead, it should be viewed as one step in the process of understanding aquifer behavior. In fact, it is shown that actual parameter estimation methods do not differ from each other in the essence, though they may differ in the computational details. It is argued that there is ample room for improvement in groundwater inversion: development of user-friendly codes, accommodation of variability through geostatistics, incorporation of geological information and different types of data (temperature, occurrence and concentration of isotopes, age, etc.), proper accounting of uncertainty, etc. Despite this, even with existing codes, automatic calibration facilitates enormously the task of modeling. Therefore, it is contended that its use should become standard practice. L'état du problème inverse des eaux souterraines est synthétisé. L'accent est placé sur la caractérisation de l'aquifère, où les modélisateurs doivent jouer avec l'incertitude des modèles conceptuels (notamment la variabilité spatiale et temporelle), les facteurs d'échelle, plusieurs inconnues sur différents paramètres (transmissivité, recharge, conditions aux limites, etc.), la non linéarité, et souvent la sensibilité de plusieurs variables d'état (charges hydrauliques, concentrations) des propriétés de l'aquifère. A cause de ces difficultés, le calibrage ne peut êtreséparé du processus de modélisation, comme c'est le cas dans d'autres cas de figure. Par ailleurs, il peut être vu comme une des étapes dans le processus de détermination du comportement de l'aquifère. Il est montré que les méthodes d'évaluation des paramètres actuels ne diffèrent pas si ce n'est dans les détails des calculs informatiques. Il est montré qu'il existe une large panoplie de techniques d'inversion : codes de calcul utilisables par tout-un-chacun, accommodation de la variabilité via la géostatistique, incorporation d'informations géologiques et de différents types de données (température, occurrence, concentration en isotopes, âge, etc.), détermination de l'incertitude. Vu ces développements, la calibration automatique facilite énormément la modélisation. Par ailleurs, il est souhaitable que son utilisation devienne une pratique standardisée. Se sintetiza el estado del problema inverso en aguas subterráneas. El énfasis se ubica en la caracterización de acuíferos, donde los modeladores tienen que enfrentar la incertidumbre del modelo conceptual (principalmente variabilidad temporal y espacial), dependencia de escala, muchos tipos de parámetros desconocidos (transmisividad, recarga, condiciones limitantes, etc), no linealidad, y frecuentemente baja sensibilidad de variables de estado (típicamente presiones y concentraciones) a las propiedades del acuífero. Debido a estas dificultades, no puede separarse la calibración de los procesos de modelado, como frecuentemente se hace en otros campos. En su lugar, debe de visualizarse como un paso en el proceso de enten dimiento del comportamiento del acuífero. En realidad, se muestra que los métodos reales de estimación de parámetros no difieren uno del otro en lo esencial, aunque sí pueden diferir en los detalles computacionales. Se discute que existe amplio espacio para la mejora del problema inverso en aguas subterráneas: desarrollo de códigos amigables alusuario, acomodamiento de variabilidad a través de geoestadística, incorporación de información geológica y diferentes tipos de datos (temperatura, presencia y concentración de isótopos, edad, etc), explicación apropiada de incertidumbre, etc. A pesar de esto, aún con los códigos existentes, la calibración automática facilita enormemente la tarea de modelado. Por lo tanto, se sostiene que su uso debería de convertirse en práctica standard.

Spatial characteristics of groundwater temperature in the Ishikari Lowland, Hokkaido, northern Japan: analytical and numerical applications

NASA Astrophysics Data System (ADS)

Dim, J. R.; Sakura, Y.; Fukami, H.; Miyakoshi, A.

2002-03-01

In porous sediments of the Ishikari Lowland, there is a gradual increase in the background geothermal gradient from the Ishikari River (3-4 °C 100 m-1) to the southwest highland area (10 °C 100 m-1). However, the geothermal gradient at shallow depths differs in detail from the background distribution. In spite of convective heat-flow loss generally associated with groundwater flow, heat flow remains high (100 mW m-2) in the recharge area in the southwestern part of the Ishikari basin, which is part of an active geothermal field. In the northeastern part of the lowland, heat flow locally reaches 140 mW m-2, probably due to upward water flow from the deep geothermal field. Between the two areas the heat flow is much lower. To examine the role of hydraulic flow in the distortion of the isotherms in this area, thermal gradient vs. temperature analyses were made, and they helped to define the major components of the groundwater-flow system of the region. Two-dimensional simulation modeling aided in understanding not only the cause of horizontal heat-flow variations in this field but also the contrast between thermal properties of shallow and deep groundwater reservoirs. Résumé. Dans les sédiments poreux des basses terres d'Ishikari, on observe une augmentation graduelle du gradient géothermal général depuis la rivière Ishikari (3-4 °C 100 m-1) vers la zone élevée située au sud-ouest (10 °C 100 m-1). Toutefois, le gradient géothermal aux faibles profondeurs diffère dans le détail de la distribution générale. Malgré la perte de flux de chaleur par convection, généralement associée aux écoulements souterrains, le flux de chaleur reste élevé (100 mW m-2) dans la zone de recharge de la partie sud-ouest du bassin de l'Ishikari, qui appartient à un champ géothermal actif. Dans la partie nord-est des basses terres, le flux de chaleur atteint localement 140 mW m-2, probablement à cause d'un écoulement souterrain ascendant depuis le champ géothermal profond. Entre les deux zones, le flux de chaleur est beaucoup plus faible. Afin de déterminer le rôle du flux d'eau souterraine dans la distorsion des isothermes dans cette zone, des analyses du gradient thermal en fonction de la température ont été réalisées elles ont permis de définir les composantes majeures du système aquifère régional. Une modélisation deux-dimensionnelle pour la simulation a ensuite contribué à la compréhension non seulement de la cause des variations horizontales du flux de chaleur dans cette région, mais également du contraste entre les propriétés des réservoirs superficiel et profond. Resumen. En los sedimentos porosos de las tierras bajas de Ishikari, hay un incremento gradual en el gradiente geotérmico desde el río Ishikari (3-4 °C 100 m-1) hacia la zona elevada del sudoeste (10 °C 100 m-1). Sin embargo, el gradiente geotérmico a profundidades someras difiere de la distribución de fondo. A pesar de las pérdidas por el flujo convectivo de calor asociadas generalmente al flujo de aguas subterráneas, el flujo de calor permanece elevado (100 mW m-2) en el área de recarga, hacia el sudoeste de la cuenca del Ishikari, la cual pertenece a un campo geotérmico activo. Al nordeste de las tierras bajas, el flujo de calor alcanza 140 mW m-2, probablemente por el flujo ascendente de agua procedente del campo geotérmico profundo. Entre ambas áreas, el flujo de calor es mucho menor. Para examinar el papel del flujo hidráulico en la distorsión de las isotermas de esta región, se ha comparado el gradiente térmico con la temperatura, con lo cual se ha podido definir los componentes mayoritarios del sistema de flujo de las aguas subterráneas. El uso de modelos bidimensionales ha servido para comprender no sólo del origen de las variaciones horizontales del flujo de calor en este campo, sino también el contraste entre las propiedades térmicas de los reservorios someros y profundos de aguas subterráneas.

Effect of phosphate treatment of Acid-etched implants on mineral apposition rates near implants in a dog model.

PubMed

Foley, Christine Hyon; Kerns, David G; Hallmon, William W; Rivera-Hidalgo, Francisco; Nelson, Carl J; Spears, Robert; Dechow, Paul C; Opperman, Lynne A

2010-01-01

This study evaluated the effects of phosphate coating of acid-etched titanium on the mineral apposition rate (MAR) and new bone-to-implant contact (BIC) in a canine model. Titanium implants (2.2 3 4 mm) with acid-etched surfaces that were electrolytically phosphated or not were placed in 48 mandibular sites in six foxhounds. Tetracycline and calcein dyes were administered 1 week after implant placement and 1 week before sacrifice. At 12 weeks after implant placement, the animals were sacrificed. MAR and BIC were evaluated using fluorescence microscopy. Light microscopic and histologic evaluations were performed on undecalcified sections. Microscopic evaluation showed the presence of healthy osteoblasts lining bone surfaces near implants. Similar BIC was observed in phosphated and nonphosphated titanium implant sites. MAR was significantly higher around the nonphosphated titanium implant surfaces than around the phosphated titanium samples. No significant differences were found between dogs or implant sites. Acid-etched implants showed significantly higher MARs compared to acid-etched, phosphate-coated implants. Int J Maxillofac Implants 2010;25:278-286.

Reliability of implant placement with stereolithographic surgical guides generated from computed tomography: clinical data from 94 implants.

PubMed

Ersoy, Ahmet Ersan; Turkyilmaz, Ilser; Ozan, Oguz; McGlumphy, Edwin A

2008-08-01

Dental implant placement requires precise planning with regard to anatomic limitations and restorative goals. The aim of this study was to evaluate the match between the positions and axes of the planned and placed implants using stereolithographic (SLA) surgical guides. Ninety-four implants were placed using SLA surgical guides generated from computed tomography (CT) between 2005 and 2006. Radiographic templates were used for all subjects during CT imaging. After obtaining three-dimensional CT images, each implant was virtually placed on the CT images. SLA surgical guides, fabricated using an SLA machine with a laser beam to polymerize the liquid photo-polymerized resin, were used during implant placement. A new CT scan was taken for each subject following implant placement. Special software was used to fuse the images of the planned and placed implants, and the locations and axes were compared. Compared to the planned implants, the placed implants showed angular deviation of 4.9 degrees+/-2.36 degrees, whereas the mean linear deviation was 1.22+/-0.85 mm at the implant neck and 1.51+/-1 mm at the implant apex. Compared to the implant planning, the angular deviation and linear deviation at the neck and apex of the placed maxillary implants were 5.31 degrees+/-0.36 degrees, 1.04+/-0.56 mm, and 1.57+/-0.97 mm, respectively, whereas corresponding figures for placed mandibular implants were 4.44 degrees+/-0.31 degrees, 1.42+/-1.05 mm, and 1.44+/-1.03 mm, respectively. SLA surgical guides using CT data may be reliable in implant placement and make flapless implant placement possible.

The clinical and diagnostic consequences of Poly Implant Prothèse silicone breast implants, recalled from the European market in 2010.

PubMed

Maijers, Maria C; Niessen, Francisus B

2013-03-01

Recently, Poly Implant Prothèse silicone breast implants were recalled from the European market. The authors studied 112 women and previously published data on rupture prevalence. Women are presenting with symptoms they feel may be a result of ruptured implants. The authors' aim was to study the clinical consequences of Poly Implant Prothèse implants. One hundred twelve women with 224 proven Poly Implant Prothèse implants after 10 years of implantation were enrolled in this study. All women underwent physical examination and magnetic resonance imaging and were interviewed regarding symptoms. Details of the explantations of 35 women with at least one ruptured implant were documented. Tissue from 10 women was sent for pathologic investigation. Of 112 women, 34 (30.4 percent) had symptoms attributable to their implants. Physical examination showed that 12 of the 121 women (10.7 percent) had findings suggestive of rupture, most commonly pain. Three had lymphadenopathy that seemed to correlate with implant rupture or excessive "gel bleed." Pathologic findings showed no malignancies. Eight women who underwent explantation had no implant rupture. Excessive gel bleed was documented in half of them. Clinical consequences of women with Poly Implant Prothèse implants are comparable to those reported in the literature of other manufacturers. Neither complaints nor findings at physical examination had a significant correlation with implant rupture at explantation. Magnetic resonance imaging is still the preferred method compared with physical examination for diagnosing rupture. The low specificity was probably caused by the difficulty in differentiating between rupture and excessive gel bleed in these implants.

The influence of bone graft procedures on primary stability and bone change of implants placed in fresh extraction sockets.

PubMed

Jun, Sang Ho; Park, Chang-Joo; Hwang, Suk-Hyun; Lee, Youn Ki; Zhou, Cong; Jang, Hyon-Seok; Ryu, Jae-Jun

2018-12-01

This study was to evaluate the effect of bone graft procedure on the primary stability of implants installed in fresh sockets and assess the vertical alteration of peri-implant bone radiographically. Twenty-three implants were inserted in 18 patients immediately after tooth extraction. The horizontal gap between the implant and bony walls of the extraction socket was grafted with xenografts. The implant stability before and after graft procedure was measured by Osstell Mentor as implant stability quotient before bone graft (ISQ bbg) and implant stability quotient after bone graft (ISQ abg). Peri-apical radiographs were taken to measure peri-implant bone change immediately after implant surgery and 12 months after implant placement. Data were analyzed by independent t test; the relationships between stability parameters (insertion torque value (ITV), ISQ abg, and ISQ bbg) and peri-implant bone changes were analyzed according to Pearson correlation coefficients. The increase of ISQ in low primary stability group (LPSG) was 6.87 ± 3.62, which was significantly higher than the increase in high primary stability group (HPSG). A significant correlation between ITV and ISQ bbg ( R  = 0.606, P  = 0.002) was found; however, age and peri-implant bone change were not found significantly related to implant stability parameters. It was presented that there were no significant peri-implant bone changes at 1 year after bone graft surgery. Bone graft procedure is beneficial for increasing the primary stability of immediately placed implants, especially when the ISQ of implants is below 65 and that bone grafts have some effects on peri-implant bone maintenance.

Revisiting the stability of mini-implants used for orthodontic anchorage.

PubMed

Yao, Chung-Chen Jane; Chang, Hao-Hueng; Chang, Jenny Zwei-Chieng; Lai, Hsiang-Hua; Lu, Shao-Chun; Chen, Yi-Jane

2015-11-01

The aim of this study is to comprehensively analyze the potential factors affecting the failure rates of three types of mini-implants used for orthodontic anchorage. Data were collected on 727 mini-implants (miniplates, predrilled titanium miniscrews, and self-drilling stainless steel miniscrews) in 220 patients. The factors related to mini-implant failure were investigated using a Chi-square test for univariate analysis and a generalized estimating equation model for multivariate analysis. The failure rate for miniplates was significantly lower than for miniscrews. All types of mini-implants, especially the self-drilling stainless steel miniscrews, showed decreased stability if the previous implantation had failed. The stability of predrilled titanium miniscrews and self-drilling stainless steel miniscrews were comparable at the first implantation. However, the failure rate of stainless steel miniscrews increased at the second implantation. The univariate analysis showed that the following variables had a significant influence on the failure rates of mini-implants: age of patient, type of mini-implant, site of implantation, and characteristics of the soft tissue around the mini-implants. The generalized estimating equation analysis revealed that mini-implants with miniscrews used in patients younger than 35 years, subjected to orthodontic loading after 30 days and implanted on the alveolar bone ridge, have a significantly higher risk of failure. This study revealed that once the dental surgeon becomes familiar with the procedure, the stability of orthodontic mini-implants depends on the type of mini-implant, age of the patient, implantation site, and the healing time of the mini-implant. Miniplates are a more feasible anchorage system when miniscrews fail repeatedly. Copyright © 2014. Published by Elsevier B.V.

Influence of implant number on the biomechanical behaviour of mandibular implant-retained/supported overdentures: a three-dimensional finite element analysis.

PubMed

Liu, Jingyin; Pan, Shaoxia; Dong, Jing; Mo, Zhongjun; Fan, Yubo; Feng, Hailan

2013-03-01

The aim of this study was to evaluate strain distribution in peri-implant bone, stress in the abutments and denture stability of mandibular overdentures anchored by different numbers of implants under different loading conditions, through three-dimensional finite element analysis (3D FEA). Four 3D finite element models of mandibular overdentures were established, using between one and four Straumann implants with Locator attachments. Three types of load were applied to the overdenture in each model: 100N vertical and inclined loads on the left first molar and a 100N vertical load on the lower incisors. The biomechanical behaviours of peri-implant bone, implants, abutments and overdentures were recorded. Under vertical load on the lower incisors, the single-implant overdenture rotated over the implant from side to side, and no obvious increase of strain was found in peri-implant bone. Under the same loading conditions, the two-implant-retained overdenture showed more apparent rotation around the fulcrum line passing through the two implants, and the maximum equivalent stress in the abutments was higher than in the other models. In the three-implant-supported overdenture, no strain concentration was found in cortical bone around the middle implant under three loading conditions. Single-implant-retained mandibular overdentures do not show damaging strain concentration in the bone around the only implant and may be a cost-effective treatment option for edentulous patients. A third implant can be placed between the original two when patients rehabilitated by two-implant overdentures report constant and obvious denture rotation around the fulcrum line. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of Implant Positions and Occlusal Forces on Peri-Implant Bone Stress in Mandibular Two-Implant Overdentures: A 3-Dimensional Finite Element Analysis.

PubMed

Alvarez-Arenal, Angel; Gonzalez-Gonzalez, Ignacio; deLlanos-Lanchares, Hector; Brizuela-Velasco, Aritza; Dds, Elena Martin-Fernandez; Ellacuria-Echebarria, Joseba

2017-12-01

The aim of this study was to evaluate and compare the bone stress around implants in mandibular 2-implant overdentures depending on the implant location and different loading conditions. Four 3-dimensional finite element models simulating a mandibular 2-implant overdenture and a Locator attachment system were designed. The implants were located at the lateral incisor, canine, second premolar, and crossed-implant levels. A 150 N unilateral and bilateral vertical load of different location was applied, as was 40 N when combined with midline load. Data for von Mises stress were produced numerically, color coded, and compared between the models for peri-implant bone and loading conditions. With unilateral loading, in all 4 models much higher peri-implant bone stress values were recorded on the load side compared with the no-load side, while with bilateral occlusal loading, the stress distribution was similar on both sides. In all models, the posterior unilateral load showed the highest stress, which decreased as the load was applied more mesially. In general, the best biomechanical environment in the peri-implant bone was found in the model with implants at premolar level. In the crossed-implant model, the load side greatly altered the biomechanical environment. Overall, the overdenture with implants at second premolar level should be the chosen design, regardless of where the load is applied. The occlusal loading application site influences the bone stress around the implant. Bilateral occlusal loading distributes the peri-implant bone stress symmetrically, while unilateral loading increases it greatly on the load side, no matter where the implants are located.

Prospective randomized clinical trial of hydrophilic tapered implant placement at maxillary posterior area: 6 weeks and 12 weeks loading

PubMed Central

2016-01-01

PURPOSE Early loading of implant can be determined by excellent primary stability and characteristic of implant surface. The implant system with recently improved surface can have load application 4-6 weeks after installing in maxilla and mandible. This study evaluated the effect of healing period to the stability of hydrophilic tapered-type implant at maxillary posterior area. MATERIALS AND METHODS This study included 30 patients treated by hydrophilic tapered-type implants (total 41 implants at maxilla) and classified by two groups depending on healing period. Group 1 (11 patients, 15 implants) was a control group and the healing period was 12 weeks, and Group 2 (19 patients, 26 implants) was test group and the healing period was 6 weeks. Immediately after implant placement, at the first impression taking, implant stability was measured using Osstell Mentor. The patients also took periapical radiographs after restoration delivery, 12 months after restoration and final followup period. The marginal bone loss around the implants was measured using the periapical radiographs. RESULTS All implants were survived and success rate was 97.56%. The marginal bone loss was less than 1mm after 1 year postoperatively except the one implant. The stabilities of the implants were not correlated with age, healing period until loading, insertion torque (IT), the diameter of fixture and the location of implant. Only the quality of bone in group 2 (6 week) was correlated with the stability of implant. CONCLUSION Healing period of 6 weeks can make the similar clinical prognosis of implants to that of healing period of 12 weeks if bone quality is carefully considered in case of early loading. PMID:27826390

Comparison of Reconstructive Outcomes in Breast Cancer Patients With Preexisting Subpectoral Implants: Implant-Sparing Mastectomy With Delayed Implant Exchange Versus Immediate Tissue Expander Reconstruction.

PubMed

Parabkaharan, Sangeetha; Melody, Megan; Trotta, Rose; Lleshi, Amina; Sun, Weihong; Smith, Paul D; Khakpour, Nazanin; Dayicioglu, Deniz

2016-06-01

Women who have undergone prior augmentation mammoplasty represent a unique subset of breast cancer patients with several options available for breast reconstruction. We performed a single institution review of surgical outcomes of breast reconstruction performed in patients with breast cancer with prior history of subpectoral breast augmentation. Institutional review board-approved retrospective review was conducted among patients with previously mentioned criteria treated at our institution between 2000 and 2014. Reconstructions were grouped into 2 categories as follows: (1) removal of preexisting subpectoral implant during mastectomy with immediate tissue expander placement and (2) implant-sparing mastectomy followed by delayed exchange to a larger implant. We reviewed demographics, tumor features, and reconstruction outcomes of these groups. Fifty-three patients had preexisting subpectoral implants. Of the 63 breast reconstructions performed, 18 (28.6%) had immediate tissue expander placed and 45 (71.4%) had implant-sparing mastectomy followed by delayed implant exchange. The groups were comparable based on age, body mass index, cancer type, tumor grade, TNM stage at presentation, and hormonal receptor status. No significant difference was noted between tumor margins or subsequent recurrence, mastectomy specimen weight, removed implant volume, volume of implant placed during reconstruction, or time from mastectomy to final implant placement. Rates of complications were significantly higher in the tissue expander group compared to the implant-sparing mastectomy group 7 (38.9%) versus 4 (8.9%) (P = 0.005). Implant-sparing mastectomy with delayed implant exchange in patients with preexisting subpectoral implants is safe and has fewer complications compared to tissue expander placement. There was no difference noted in the final volume of implant placed, time interval for final implant placement, or tumor margins.

Assessment and Evaluation of Quality of Life (OHRQoL) of Patients with Dental Implants Using the Oral Health Impact Profile (OHIP-14) - A Clinical Study.

PubMed

Alzarea, Bader K

2016-04-01

Peri-implant tissue health is a requisite for success of dental implant therapy. Plaque accumulation leads to initiation of gingivitis around natural teeth and peri-implantitis around dental implants. Peri-implantitis around dental implants may result in implant placement failure. For obtaining long-term success, timely assessment of dental implant site is mandatory. To assess and evaluate Quality of Life (OHRQoL) of individuals with dental implants using the Oral Health Impact Profile (OHIP-14). Total 92 patients were evaluated for assessment of the health of peri-implant tissues by recording, Plaque Index (PI), Probing Pocket Depth (PD), Bleeding On Probing (BOP) and Probing Attachment Level (PAL) as compared to contra-lateral natural teeth (control). In the same patients Quality of Life Assessment was done by utilizing Oral Health Impact Profile Index (OHIP-14). The mean plaque index around natural teeth was more compared to implants and it was statistically significant. Other three dimensions mean bleeding on probing; mean probing attachment level and mean pocket depth around both natural teeth and implant surfaces was found to be not statistically significant. OHIP-14 revealed that patients with dental implants were satisfied with their Oral Health-Related Quality of Life (OHRQoL). Similar inflammatory conditions are present around both natural teeth and implant prostheses as suggested by results of mean plaque index, mean bleeding on probing, mean pocket depth and mean probing attachment level, hence reinforcing the periodontal health maintenance both prior to and after incorporation of dental implants. Influence of implant prostheses on patient's oral health related quality of life (as depicted by OHIP-14) and patients' perceptions and expectations may guide the clinician in providing the best implant services.

Retrospective analysis of survival rates and marginal bone loss on short implants in the mandible.

PubMed

Draenert, Florian G; Sagheb, Keyvan; Baumgardt, Katharina; Kämmerer, Peer W

2012-09-01

Short implants have become an interesting alternative to bone augmentation in dental implantology. Design of shorter implants and longer surveillance times are a current research issue. The goal of this study was to show the survival rates of short implants below 9 mm in the partly edentulous mandibular premolar and molar regions with fixed prosthetics. Marginal vertical and 2D bone loss was evaluated additionally. Different implant designs are orientationally evaluated. A total of 247 dental implants with fixed prosthetics (crowns and bridges) in the premolar and molar region of the mandible were evaluated; 47 implants were 9 mm or shorter. Patient data were evaluated to acquire implant survival rates, implant diameter, gender and age. Panoramic X-rays were analysed for marginal bone loss. Average surveillance time was 1327 days. Cumulative survival rate (CSR) of short implants was 98% (1 implants lost) compared to 94% in the longer implants group without significance. Thirty-five of the short implants were Astratech (0 losses) and 12 were Camlog Screw Line Promote Plus (1 loss). Early vertical and two-dimensional marginal bone loss was not significantly different in short and regular length implant group with an average of 0.6 mm and 0.7 mm(2) in short implants over the observation period. Within the limitations of this study, we conclude that short implants with a length of 9 mm or less have equal survival rates compared with longer implants over the observation period of 1-3 years. © 2011 John Wiley & Sons A/S.

Oral Health-Related Quality of Life in Edentulous Patients with Two- vs Four-Locator-Retained Mandibular Overdentures: A Prospective, Randomized, Crossover Study.

PubMed

Karbach, Julia; Hartmann, Sinsa; Jahn-Eimermacher, Antje; Wagner, Wilfried

2015-01-01

To compare the oral health-related quality of life (OHRQoL) in a prospective, randomized crossover trial in patients with mandibular overdentures retained with two or four locators. In 30 patients with edentulous mandibles, four implants (ICX-plus implants [Medentis Medical]) were placed in the intraforaminal area. Eight weeks after transgingival healing, patients were randomly assigned to have two or four implants incorporated in the prosthesis. After 3 months, the retention concepts were switched. The patients with a two-implant-supported overdenture had four implants incorporated, whereas patients with a four-implant-supported overdenture had two retention locators taken out. After 3 more months, all four implants were retained in the implant-supported overdenture in every patient. To measure OHRQoL of the patients, the Oral Health Impact Profile 14, German version (OHIP-14 G), was used. A considerable increase in OHRQoL could be seen in all patients after the prosthesis was placed on the implants. Also, a statistically significant difference of OHRQoL could be seen in the OHIP-14 G scores between two-implant and four-implant overdentures. Patients had a higher OHRQoL after incorporation of four implants in the overdenture compared with only two implants. Patients with implant-retained overdentures had better OHRQoL compared with those with conventional dentures. The number of incorporated implants in the locator-retained overdenture also influenced the increase in OHRQoL, with four implants having a statistically significant advantage over two implants.

Biomechanical interactions of endodontically treated tooth implant-supported prosthesis under fatigue test with acoustic emission monitoring.

PubMed

Huang, Shao-Fu; Chen, Wan-Rung; Lin, Chun-Li

2016-02-24

This study investigated the biomechanical interactions in endodontically treated tooth implant-supported prosthesis (TISP) with implant system variations under dynamic cyclic loads monitored using the acoustic emission (AE) technique. Macrostructure implants using a taper integrated screw-in (TIS; 2-piece implant) and a retaining-screw (RS; 3-piece implant) connected to an abutment were used for this investigation and their corresponding mechanical resistances in conformity with the ISO 14801 standard were evaluated. The endodontically treated TISP samples were constructed containing TIS and RS implants splinted to the second premolar with fatigue tests performed by applying occlusal force onto the premolar simulating the bending moment effect. The numbers of accumulated AE signals in the fatigue tests and failure modes for the sample were recorded to evaluate the mechanical resistance. The maximum load in the static test for RS (3-piece) implant (797N) was significantly higher than that for the TIS (2-piece) implant (559N). Large deformations were found at abutment screws in both RS and TIS implants. Although the numbers of accumulated AE signals for the TIS implant (72511) were higher than those for the RS implant (437), statistical non-significant differences were found between TIS and RS implants. No obvious damage was noted in endodontically treated TISP samples using RS implants but two of the corresponding TIS implants fractured in the abutment screws. Splints with RS (3-piece) implant prosthesis produce better mechanical responses than the TIS (2-piece) implant when connected to an endodontically treated tooth restored with a post core and crown.

Micromotion-induced strain fields influence early stages of repair at bone-implant interfaces

PubMed Central

Wazen, Rima M.; Currey, Jennifer A.; Guo, Hongqiang; Brunski, John B.; Helms, Jill A.; Nanci, Antonio

2013-01-01

Implant loading can create micromotion at the bone-implant interface. The interfacial strain associated with implant micromotion could contribute to regulating the tissue healing response. Excessive micromotion can lead to fibrous encapsulation and implant loosening. Our objective was to characterize the influence of interfacial strain on bone regeneration around implants in mouse tibiae. A micromotion system was used to create strain under conditions of (1) no initial contact between implant and bone, and (2) a direct bone-implant contact. Pin- and screw-shaped implants were subjected to displacements of 150 μm or 300 μm, 60 cycles/day, for 7 days. Pin-shaped implants placed in 5 animals were subjected to 3 sessions of 150 μm displacement per day, with 60 cycles per session. Control implants in both types of interfaces were stabilized throughout the healing period. Experimental strain analyses, microtomography, image-based displacement mapping, and finite element simulations were used to characterize interfacial strain fields. Calcified tissue sections were prepared and stained with Goldner to evaluate tissue reaction in higher and lower strain regions. In stable implants, bone formation occurred consistently around the implants. In implants subjected to micromotion, bone regeneration was disrupted in areas of high strain concentrations (e.g. > 30%), whereas lower strain values were permissive of bone formation. Increasing implant displacement or number of cycles per day also changed the strain distribution and disturbed bone healing. These results indicate that not only implant micromotion but also the associated interfacial strain field contributes to regulating the interfacial mechanobiology at healing bone-implant interfaces. PMID:23337705

Retrospective analysis of dental implants placed and restored by advanced prosthodontic residents.

PubMed

Barias, Pamela A; Lee, Damian J; Yuan, Judy Chia-Chun; Sukotjo, Cortino; Campbell, Stephen D; Knoernschild, Kent L

2013-02-01

The purposes of this retrospective clinical review were to: (1) describe the demographics of implant patients, types of implant treatment and implant-supported prostheses in an Advanced Education in Prosthodontic Program, (2) evaluate the survival rate of dental implants placed by prosthodontic residents from 2006 to 2008, and (3) analyze the relationship between resident year of training and implant survival rate. All patients who received dental implants placed by prosthodontic residents from January 2006 to October of 2008 in the Advanced Prosthodontic Program at the University of Illinois at Chicago College of Dentistry were selected for this study. Age, gender, implant diameter, length, implant locations, surgical and restorative detail, and year of prosthodontic residency training were collected and analyzed. Life-table and Kaplan-Meier survival analyses were performed based on implants overall, locations, year of training, and use of a computer-generated surgical guide. A Logrank statistic was performed between implant survival and year of prosthodontic residency training, location, and use of computer-generated surgical guide (α= 0.05). Three hundred and six implants were placed, and of these, seven failed. Life-table and Kaplan-Meier analyses computed a cumulative survival rate (CSR) of 97% for overall implants and implants placed with a computer-generated surgical guide. No statistical difference was found in implant survival rates as a function of year of training (P= 0.85). Dental implants placed by prosthodontic residents had a CSR comparable to previously published studies by other specialties. The year of prosthodontic residency training and implant failure rate did not have any significant relationship. © 2012 by the American College of Prosthodontists.

A Ballistics Examination of Firearm Injuries Involving Breast Implants.

PubMed

Pannucci, Christopher J; Cyr, Adam J; Moores, Neal G; Young, Jason B; Szegedi, Martin

2018-03-01

This ballistics study examines whether saline breast implants can decrease tissue penetration in firearm injuries. We hypothesize that the fluid column within a saline breast implant can alter bullet velocity and/or bullet pattern of mushrooming. The two experimental groups included saline implants with 7.4 cm projection and a no implant group. The experimental design allowed the bullet to pass-through an implant and into ballistics gel (n = 10) or into ballistics gel without passage through an implant (n = 11). Shots that passed through an implant had 20.6% decreased penetration distance when compared to shots that did not pass-through an implant; this difference was statistically significant (31.9 cm vs. 40.2 cm, p < 0.001). Implant group bullets mushroomed prior to gel entry, but the no implant group mushroomed within the gel. Bullet passage through a saline breast implant results in direct bullet velocity reduction and earlier bullet mushrooming; this causes significantly decreased ballistics gel penetration. © 2017 American Academy of Forensic Sciences.

Why do dental implants fail? Part I.

PubMed

el Askary, A S; Meffert, R M; Griffin, T

1999-01-01

Many factors are attributed to failure of the dental implant, either directly or indirectly. The focus of this article is to define the causation of dental implant failure, as well as to present an evaluation of the implant literature regarding etiology, classification, management, and treatment of implant failures. This article will highlight the initial signs of implant failure with a view of some clinical cases in terms of classification and degrees of implant failure. Finally, a dental implant failure checklist is formulated to guide the practitioner in defining the cause of implant failure, be it infective or noninfective, and to establish percentages and frequency of occurrence. The checklist applies to all implant systems and will help to determine the factors responsible for causation and the repair procedures, whether they are at the surgical or restorative phases. The definition of implant failure is set forth in terms of ailing, failing, failed, and surviving implants, and the appropriate treatments and dispositions are outlined.

Benefits and Limitations of Macrotextured Breast Implants and Consensus Recommendations for Optimizing Their Effectiveness.

PubMed

Maxwell, G Patrick; Scheflan, Michael; Spear, Scott; Nava, Maurizio B; Hedén, Per

2014-08-01

Implant texture is an important factor influencing implant selection for breast augmentation. Natrelle Biocell implants are characterized by macrotextured shell surfaces containing irregularly arranged concavities with large open-pore diameters and depths. These properties facilitate adhesion of the implant to the surrounding tissue, thereby promoting implant immobilization. Relative to implants with other surfaces, macrotextured implants offer low rates of capsular contracture; low rates of malposition, rotation, and rippling; and high rates of patient satisfaction. However, macrotextured implants are associated with a slightly higher risk of double capsule and late seroma. The surgeon can minimize these risks with straightforward techniques that encourage tissue adhesion. This report presents experience-based recommendations to optimize the effectiveness of Biocell anatomic implants. The authors discuss the application of best practices to all aspects of the breast implantation process, from implant selection and surgical planning to operative technique and postoperative management. LEVEL OF EVIDENCE 3. © 2014 The American Society for Aesthetic Plastic Surgery, Inc.

Groundwater demand management at local scale in rural areas of India: a strategy to ensure water well sustainability based on aquifer diffusivity and community participation

NASA Astrophysics Data System (ADS)

Kulkarni, Himanshu; Vijay Shankar, P. S.; Deolankar, S. B.; Shah, Mihir

Watershed development programmes provide an opportunity for sustainable management strategies, although currently, they remain largely `supply-side' mechanisms of water resources development. Hydrogeological conditions, community participation and status of groundwater usage are important in evolving strategies on `demand-side' groundwater management. Neemkheda aquifer is a typical low-storage, low-hydraulic conductivity aquifer from a watershed in the dryland regions of Madhya Pradesh State of central India. A shallow unconfined aquifer, it consists of an upper coarse, calcareous sandstone unit underlain by a fine-grained sandstone unit. A `well commune' of seven wells is poised to test the concept of joint groundwater management, wherein wells are mechanisms of tapping a common water source, the Neemkheda aquifer. The strategy for systematic groundwater management in the Neemkheda well commune is based upon the relationship between Transmissivity (T) and Storage coefficient (S), i.e. aquifer diffusivity, and its variation within the aquifer. Wells within a high diffusivity domain tend to dewater more quickly than wells within a low diffusivity domain. A well-use schedule during the dry season, based upon aquifer diffusivity forms the basis of the groundwater management concept. The distribution of local aquifer diffusivities governs the relationship between local and regional aquifer depletion times and forms the basis of the groundwater management exercise being proposed for the Neemkheda aquifer. Los programas de desarrollo de una cuenca hídrica son una oportunidad para el uso de estrategias de gestión sostenible, aunque hoy en día estas siguen siendo principalmente mecanismos para el desarrollo de recursos hídricos con énfasis en la ``oferta''. Las condiciones hidrogeológicas, la participación comunitaria y la condición de utilización del agua subterránea, son importantes en el desarrollo de estrategias para la gestión del agua subterránea, desde el punto de vista de la ``demanda''. El acuífero de Neemkheda es un acuífero típico de almacenamiento bajo y conductividad hidráulica baja, perteneciente a una cuenca hídrica ubicada en las regiones secas del Estado de Madhya Pradesh, en la parte central de India. Un acuífero de tipo libre, somero, formado por una unidad superior de arenisca calcárea de grano grueso, subyacida por una unidad de arenisca de grano fino. Un campo de pozos comunitario compuesto por siete pozos, pone a prueba el concepto de gestión conjunta del agua subterránea, dentro del cual los pozos son mecanismos para usar una fuente de agua común: El acuífero de Neemkheda. La estrategia usada para la gestión sistemática del agua subterránea, en el campo de pozos comunitario de Neemkheda, se basa en la relación existente entre Transmisividad (T) y Coeficiente de Almacenamiento (S), es decir en la Difusividad del Acuífero y en su variación observada dentro del mismo acuífero. Los pozos cuya difusividad esta dentro de un rango alto, tienden a experimentar un descenso en su nivel mas rápidamente que aquellos pozos con una difusividad baja. El concepto de gestión de agua subterránea se basa en un programa especial de operación para cada pozo durante la estación seca, el cual a su vez se basa en la difusividad del acuífero. La distribución de difusividades locales del acuífero rige las relaciones entre las épocas de descensos de nivel en el acuífero a escala regional y local, y además constituyen la base del ejercicio de la gestión del agua subterránea que se esta proponiendo para el acuífero de Neemkheda. Les programmes de développement des bassins versants offrent une occasion de développer des stratégies pour une gestion durable, bien qu' à présent elles restent en grande mesure `le terme source' dans le mécanisme de développement de la ressource en eau. Les conditions hydrogéologiques, la participation de la communauté et l'usage des eaux souterraines sont importants pour le `terme demande' dans les stratégies de gestion des eaux souterraines. L'aquifère de Neemkheda presents des caractéristiques typiques pour un bassin versant dans les régions arides de l'état Madhya Pradesh de l'Inde centrale en ce qui concerne les faible valeurs de la conductivité hydraulique et du coéfficient d'emmagasinement. Il s'agit d'un aquifère phrèatique dont la partie supérieure est constitué par des grès calcaire qui restent sur des grés plus fins. Afin d'essayer le concept de gestion integrée, on a réalisé dans l'aquifère de Neemkheda un captage ayant sept forages qui forment la ressource en eau communale. La stratégie de la gestion systématique du captage est basée sur la relation entre la transmissivité (T), le coéfficient d'emmagasinement (S), donc la diffusivité hydraulique ainsi que sa variation spatiale. Les puits forés dans les zones à grande diffusivité tendent à s'assècher plus vite que ceux creusés dans des zones à faible diffusivité. Le concept de la gestion des eaux souterraines est donc basé sur la distribution spatiale des diffusivités. À partir de ce concept on a développé un programme d'exploitation des forages pendant les saisons sèches. La relation entre les temps d' épuissment locaux et régionaux est determiné par la distribution spatiale de la diffusivitée et forme la base de l'exercice sur la gestion des eaux proposée pour l'aquifère de Neemkheda.

Clinical and radiological investigations of mandibular overdentures supported by conventional or mini-dental implants: A 2-year prospective follow-up study.

PubMed

Temizel, Sonay; Heinemann, Friedhelm; Dirk, Cornelius; Bourauel, Christoph; Hasan, Istabrak

2017-02-01

Conventional dental implants are not applicable in the mandibular interforaminal region if bone volume is limited. Mini-dental implants offer an alternative means of supporting mandibular overdentures in a narrow residual ridge, without additional surgery. The purpose of this nonrandomized clinical trial was to compare the ability of mini-dental implants with that of conventional dental implants in supporting mandibular overdentures during a 2-year clinical follow-up. Bone quality, bone resorption, implant stability, and oral health were assessed radiographically. A total of 32 participants with edentulism were included. Twenty-two participants (99 implants) received 4 to 5 mini-dental implants (diameter: 1.8-2.4 mm; length: 13-15 mm, study group), and 10 participants (35 implants) received 2 to 4 conventional dental implants (diameter: 3.3-3.7 mm; length: 11-13 mm, control group). The selection of the participants in the study or control group was based on the available bone volume in the mandible. The selection was not randomized. The density of cortical bone thickness was measured in Hounsfield units (HU) from computed tomography data, and patients were followed for 2 years. The participants were examined 3, 6, 12, and 24 months after surgery. Primary stability immediately after the insertion of dental implants (Periotest), secondary stability 6 months after implantation, modified plaque, bleeding on probing indices, and probing depth were measured and analyzed statistically (α=.05). The mean HU value 6 months after implantation in the participants who received mini-dental implants was significantly (P=.035) higher (1250 HU) than that in the participants who received conventional dental implants (1100 HU). The probing depths around the conventional dental implants (1.6 and 1.8 mm, respectively) were significantly higher than those around the mini-dental implants (1.3 and 1.2 mm, respectively) 12 and 24 months after surgery, respectively (P<.001). The mean primary and secondary stability values for conventional dental implants were -4.0 and -4.9, respectively. The primary and secondary stability values for the mini-dental implants were -0.3 and -1.4, respectively. The Periotest values of the primary (measured immediately after implant insertion) and secondary implant stabilities (measured 6 months after implant insertion) were significantly higher for the conventional dental implants than for the mini-dental implants (P<.001). Based on this 2-year clinical trial, patients receiving mini-dental implants had clinical outcomes similar to those of patients receiving conventional dental implants to support overdenture prostheses. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Bacterial colonization of the implant-abutment interface of conical connection with an internal octagon: an in vitro study using real-time PCR.

PubMed

Baj, A; Beltramini, G A; Bolzoni, A; Cura, F; Palmieri, A; Scarano, A; Ottria, L; Giannì, A B

2017-01-01

Bacterial leakage at the implant-abutment connection of a two-piece implant system is considered the main cause of peri-implantitis. Prevention of bacterial leakage at the implant-abutment connection is mandatory for reducing inflammation process around implant neck and achieving bone stability. Micro-cavities at implant-abutment connection level can favour bacterial leakage, even in modern two-piece implant systems. The conical connection with an internal octagon (CCIO) is considered to be more stable mechanically and allows a more tight link between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new two-implant system with an internal conical implant-abutment connection with internal octagon (Shiner XT, FMD Falappa Medical Devices S.p.A. Rome, Italy). To verify the ability of the implant in protecting the internal space from the external environment, the passage of genetically modified Escherichia c oli across implant-abutment interface was evaluated. Four Shiner XT implants (FMD, Falappa Medical Devices®, Rome, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 6% for P. gingivalis and 5% for T. forsythia. Other comparable studies about the tightness of the tested implant system reported similar results. The gap size at the implant-abutment connection of CCIOs was measured by other authors discovering a gap size of 1–2μm of the AstraTech system and of 4μm for the Ankylos system. Bacterial leakage along implant-abutment connection of cylindrical and tapered implants, Shiner XT, (FMD Falappa Medical Devices S.p.A. Rome, Italy) showed better results compared to other implants. Additional studies are needed to explore the relationship in terms of microbiota of the CCIO. In addition, the dynamics of internal colonization needs to be thoroughly documented in longitudinal in vivo studies.

[Bilateral cochlear implants in children: acquisition of binaural hearing].

PubMed

Ramos-Macías, Angel; Deive-Maggiolo, Leopoldo; Artiles-Cabrera, Ovidio; González-Aguado, Rocío; Borkoski-Barreiro, Silvia A; Masgoret-Palau, Elizabeth; Falcón-González, Juan C; Bueno-Yanes, Jorge

2013-01-01

Several studies have indicated the benefit of bilateral cochlear implants in the acquisition of binaural hearing and bilateralism. In children with cochlear implants, is it possible to achieve binaurality after a second implant? When is the ideal time to implant them? The objective of this study was to analyse the binaural effect in children with bilateral implants and the differences between subjects with simultaneous and sequential implants with both short and long intervals. There were 90 patients between 1 and 2 years of age (the first surgery), implanted between 2000 and 2008. Of these, 25 were unilateral users and 65 bilateral; 17 patients had received simultaneous implants, 29 had sequential implants before 12 months after the first one (short interimplant period) and 19 after 12 months (long period). All of them were tested for silent and noisy verbal perception and a tonal threshold audiometry was performed. The silent perception test showed that the simultaneous and short period sequential implant patients (mean: 84.67%) versus unilateral and long period sequential implants (mean: 79.66%), had a statistically-significant difference (P=0,23). Likewise, the noisy perception test showed a difference with statistical significance (P=0,22) comparing the simultaneous implanted and short period sequential implants (mean, 77.17%) versus unilateral implanted and long period sequential ones (mean: 69.32%). The simultaneous and sequential short period implants acquired the advantages of binaural hearing. Copyright © 2012 Elsevier España, S.L. All rights reserved.

2D FEA of evaluation of micromovements and stresses at bone-implant interface in immediately loaded tapered implants in the posterior maxilla.

PubMed

Desai, Shrikar R; Singh, Rika; Karthikeyan, I

2013-09-01

The aim of the study is to evaluate the influence implant length on stress distribution at bone implant interface in single immediately loaded implants when placed in D4 bone quality. A 2-dimensional finite element models were developed to simulate two types of implant designs, standard 3.75 mm-diameter tapered body implants of 6 and 10 mm lengths. The implants were placed in D4 bone quality with a cortical bone thickness of 0.5 mm. The implant design incorporated microthreads at the crestal part and the rest of the implant body incorporated Acme threads. The Acme thread form has a 29° thread angle with a thread height half of the pitch; the apex and valley are flat. A 100 N of force was applied vertically and in the oblique direction (at an angle of 45°) to the long axis of the implants. The respective material properties were assigned. Micro-movements and stresses at the bone implant interface were evaluated. The results of total deformation (micro-movement) and Von mises stress were found to be lower for tapered long implant (10 mm) than short implant (6 mm) while using both vertical as well as oblique loading. Short implants can be successfully placed in poor bone quality under immediate loading protocol. The novel approach of the combination of microthreads at the crestal portion and acme threads for body portion of implant fixture gave promising results.

Multiscale Analyses of the Bone-implant Interface

PubMed Central

Cha, J.Y.; Pereira, M.D.; Smith, A.A.; Houschyar, K.S.; Yin, X.; Mouraret, S.; Brunski, J.B.

2015-01-01

Implants placed with high insertion torque (IT) typically exhibit primary stability, which enables early loading. Whether high IT has a negative impact on peri-implant bone health, however, remains to be determined. The purpose of this study was to ascertain how peri-implant bone responds to strains and stresses created when implants are placed with low and high IT. Titanium micro-implants were inserted into murine femurs with low and high IT using torque values that were scaled to approximate those used to place clinically sized implants. Torque created in peri-implant tissues a distribution and magnitude of strains, which were calculated through finite element modeling. Stiffness tests quantified primary and secondary implant stability. At multiple time points, molecular, cellular, and histomorphometric analyses were performed to quantitatively determine the effect of high and low strains on apoptosis, mineralization, resorption, and collagen matrix deposition in peri-implant bone. Preparation of an osteotomy results in a narrow zone of dead and dying osteocytes in peri-implant bone that is not significantly enlarged in response to implants placed with low IT. Placing implants with high IT more than doubles this zone of dead and dying osteocytes. As a result, peri-implant bone develops micro-fractures, bone resorption is increased, and bone formation is decreased. Using high IT to place an implant creates high interfacial stress and strain that are associated with damage to peri-implant bone and therefore should be avoided to best preserve the viability of this tissue. PMID:25628271

One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study.

PubMed

Siddiqi, A; Duncan, W J; De Silva, R K; Zafar, S

2016-01-01

Reports have documented titanium (Ti) hypersensitivity after dental implant treatment. Alternative materials have been suggested including zirconia (Zr) ceramics, which have shown predictable osseointegration in animal studies and appear free of immune responses. The aim of the research was to investigate the bone-to-implant contact (BIC) of one-piece Zr, compared with one-piece Ti implants, placed in the jaws and femurs of domestic sheep. Ten New Zealand mixed breed sheep were used. A One-piece prototype Ti (control) and one Zr (test) implant were placed in the mandible, and one of each implant (Ti and Zr) was placed into the femoral epicondyle of each animal. The femur implants were submerged and unloaded; the mandibular implants were placed using a one-stage transgingival protocol and were nonsubmerged. After a healing period of 12 weeks, %BIC was measured. The overall survival rate for mandibular and femur implants combined was 87.5%. %BIC was higher for Zr implants versus Ti implants in the femur (85.5%, versus 78.9%) ( p = 0.002). Zirconia implants in the mandible showed comparable %BIC to titanium implants (72.2%, versus 60.3%) ( p = 0.087). High failure rate of both Zr and Ti one-piece implants in the jaw could be attributed to the one-piece design and surface characteristics of the implant that could have influenced osseointegration. Further clinical trials are recommended to evaluate the performance of zirconia implants under loading conditions.

Three-Dimensional Finite Element Analysis on Stress Distribution of Internal Implant-Abutment Engagement Features.

PubMed

Cho, Sung-Yong; Huh, Yun-Hyuk; Park, Chan-Jin; Cho, Lee-Ra

To investigate the stress distribution in an implant-abutment complex with a preloaded abutment screw by comparing implant-abutment engagement features using three-dimensional finite element analysis (FEA). For FEA modeling, two implants-one with a single (S) engagement system and the other with a double (D) engagement system-were placed in the human mandibular molar region. Two types of abutments (hexagonal, conical) were connected to the implants. Different implant models (a single implant, two parallel implants, and mesial and tilted distal implants with 1-mm bone loss) were assumed. A static axial force and a 45-degree oblique force of 200 N were applied as the sum of vectors to the top of the prosthetic occlusal surface with a preload of 30 Ncm in the abutment screw. The von Mises stresses at the implant-abutment and abutment-screw interfaces were measured. In the single implant model, the S-conical abutment type exhibited broader stress distribution than the S-hexagonal abutment. In the double engagement system, the stress concentration was high in the lower contact area of the implant-abutment engagement. In the tilted implant model, the stress concentration point was different from that in the parallel implant model because of the difference in the bone level. The double engagement system demonstrated a high stress concentration at the lower contact area of the implant-abutment interface. To decrease the stress concentration, the type of engagement features of the implant-abutment connection should be carefully considered.

Cone-morse implant connection system significantly reduces bacterial leakage between implant and abutment: an in vitro study.

PubMed

Baj, A; Bolzoni, A; Russillo, A; Lauritano, D; Palmieri, A; Cura, F; Silvestre, F J; Giannì, A B

2017-01-01

Osseointegrated implants are very popular dental treatments today in the world. In osseointegrated implants, the occlusal forces are transmitted from prosthesis through an abutment to a dental implant. The abutment is connected to the implant by mean of a screw. A screw is the most used mean for connecting an implant to an abutment. Frequently the screws break and are lost. There is an alternative to screw retained abutment systems: the cone-morse connection (CMC). The CMC, thanks to the absence of the abutment screw, guarantees no micro-gaps, no micro-movements, and a reduction of bacterial leakage between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new CMC implants systems (Leone Spa®, Florence, Italy). To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Four cone-morse Leone implants (Leone® Spa, Florence, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was then measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 3% for P. gingivalis and 4% for T. forsythia. Cone-morse connection implant system has very low bacterial leakage percentage and is similar to one-piece implants.

Effect of osteoporosis on fixation of osseointegrated implants in rats.

PubMed

Li, Yunfeng; He, Sheng; Hua, Yunwei; Hu, Jing

2017-11-01

The effect of osteoporosis on implant osseointegration has been widely investigated, whereas osteoporosis may also newly occur in patient with previously osseointegrated implant. This study was designed to investigate the effect of osteoporosis on implant fixation in rats after successful osseointegration had been obtained. Seventy female Sprague-Dawley rats were included, and each animal received two titanium implants in the distal metaphysis of femur bilaterally. Eight weeks later, ten rats were sacrificed to confirm the establishment of implant osseointegration. All left rats were randomly subjected to bilateral ovariectomy (OVX) or sham operation. Three, six, and twelve weeks later, implant osseointegration, peri-implant bone tissue, and biomechanical properties of implant were analyzed. Right femurs with implants were used for micro-CT and histological analysis, and left femurs with implants were used for biomechanical test. Micro-CT, histology, and biomechanical test confirmed the destructive effect of OVX on previously osseointegrated implant in rats; when compared to sham-operated rats, peri-implant bone volume, trabecular architecture, bone-to-implant contact ratio, as well as biomechanical parameters decreased progressively within 12 weeks. Results also indicated that the effect of OVX on undisturbed bone (proximal tibiae) was much stronger than that on peri-implant bone. Osteoporosis produced a progressive negative effect on previously osseointegrated implant in distal femora of rats during 12 weeks. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2426-2432, 2017. © 2016 Wiley Periodicals, Inc.

One-Piece Zirconia Ceramic versus Titanium Implants in the Jaw and Femur of a Sheep Model: A Pilot Study

PubMed Central

De Silva, R. K.; Zafar, S.

2016-01-01

Reports have documented titanium (Ti) hypersensitivity after dental implant treatment. Alternative materials have been suggested including zirconia (Zr) ceramics, which have shown predictable osseointegration in animal studies and appear free of immune responses. The aim of the research was to investigate the bone-to-implant contact (BIC) of one-piece Zr, compared with one-piece Ti implants, placed in the jaws and femurs of domestic sheep. Ten New Zealand mixed breed sheep were used. A One-piece prototype Ti (control) and one Zr (test) implant were placed in the mandible, and one of each implant (Ti and Zr) was placed into the femoral epicondyle of each animal. The femur implants were submerged and unloaded; the mandibular implants were placed using a one-stage transgingival protocol and were nonsubmerged. After a healing period of 12 weeks, %BIC was measured. The overall survival rate for mandibular and femur implants combined was 87.5%. %BIC was higher for Zr implants versus Ti implants in the femur (85.5%, versus 78.9%) (p = 0.002). Zirconia implants in the mandible showed comparable %BIC to titanium implants (72.2%, versus 60.3%) (p = 0.087). High failure rate of both Zr and Ti one-piece implants in the jaw could be attributed to the one-piece design and surface characteristics of the implant that could have influenced osseointegration. Further clinical trials are recommended to evaluate the performance of zirconia implants under loading conditions. PMID:28058261

Risk factors for implant failure: a retrospective study in an educational institution using GEE analyses.

PubMed

Borba, Marcelo; Deluiz, Daniel; Lourenço, Eduardo José Veras; Oliveira, Luciano; Tannure, Patrícia Nivoloni

2017-08-21

This study aimed to evaluate dental implant outcomes and to identify risk factors associated with implant failure over 12 years via dental records of patients attending an educational institution. Dental records of 202 patients receiving 774 dental implants from 2002 to 2014 were analyzed by adopting a more reliable statistical method to evaluate risk factors with patients as the unit [generalized estimating equation (GEE)]. Information regarding patient age at implantation, sex, use of tobacco, and history of systemic diseases was collected. Information about implant location in the arch region and implant length, diameter, and placement in a grafted area was evaluated after 2 years under load. Systemic and local risk factors for early and late implant failure were studied. A total of 18 patients experienced 25 implant failures, resulting in an overall survival rate of 96.8% (2.84% and 0.38% early and late implant failures, respectively). The patient-based survival rate was 91.8%. GEE univariate and multivariate analyses revealed that a significant risk factor for implant failure was the maxillary implant (p = 0.006 and p = 0.014, respectively). Bone grafting appeared to be a risk factor for implant failure (p = 0.054). According to GEE analyses, maxillary implants had significantly worse outcomes in this population and were considered to be a risk factor for implant failure. Our results suggested that implants placed in a bone augmentation area had a tendency to fail.

Peri-implant plastic surgery techniques to hard and soft tissue augmentation in implant rehabilitation

PubMed Central

Baltacioğlu, Esra; Korkmaz, Yavuz Tolga; Korkmaz, Fatih Mehmet; Aydin, Güven; Sukuroglu, Erkan

2017-01-01

This report presents the clinical results of peri-implant plastic surgical approaches for hard and soft tissues before and during the implant placement in a patient with vertical ridge deformation and a shallow vestibule sulcus, and the subsequently performed prosthetic rehabilitation. The surgical approaches used in this case reduced the crown-height space and crown-to-implant ratio and ensured that the implants were placed in their ideal positions, and peri-implant tissue health was maintained. In conclusion, developments in the peri-implant plastic surgery enable the successful augmentation of hard and soft tissue defects and provide the implant-supported fixed prosthetic rehabilitation. PMID:29386805

The glass spherical hollow orbital implant: a prospective study.

PubMed

Stephen, B E

1999-06-01

Various types of orbital implants are in use in the rehabilitation of anophthalmic patients. The latest is the expensive hydroxyapatite implant. The study objective was to evaluate the effectiveness of low cost glass spherical hollow implants, as primary and secondary implants. St Michaels and Frazer Private Hospitals, Colombo. 65 patients had glass sphere orbital implants between 1987 and 1995; 51 primary (evisceration 46, enucleation 5) and 14 secondary (evisceration 2, enucleation 12). At 9 to 12 months follow up, patients were evaluated for mobility of implant, prosthesis mobility, lid sulcus deformity, cosmetic results and complications. Primary glass spherical hollow implants provide excellent mobility of the implant (92%), cosmesis (88%), prosthesis mobility (67%), with a low rate of complications (9.5%). Results of primary implant was superior to that of secondary (p < 0.001). Excellent results were obtained with spherical glass spheres as primary implants following evisceration.

Histologic analysis of a failing three-part dental implant: a human case report.

PubMed

Landi, Luca; Manicone, Paolo Francesco; Piccinelli, Stefano; Raia, Roberto

2005-12-01

Two failing implants were removed for prosthetic reasons from the maxilla of a 60-year-old woman. The implants were clinically immobile but presented clear signs of peri-implant mucositis and bone destruction. One of the two implants was harvested together with the surrounding bone and analyzed histologically. The implant was threaded and consisted of three distinct components screwed together in a telescopic fashion. Histologically, bone loss reached the fourth thread, while apical to the fourth thread, osseointegration between the host bone and the implant surface was recognizable. The implant parts were not completely seated into each other, and the resulting gap was colonized by host bone. Newly formed alveolar bone penetrated deep into the implant body cavity and appeared similar in nature to the alveolar bone surrounding the implant. Histologic findings are discussed in reference to the ability of such an implant to withstand biomechanical loading over time.

Analysis of the influence of the macro- and microstructure of dental zirconium implants on osseointegration: a minipig study.

PubMed

Mueller, Cornelia Katharina; Solcher, Philipp; Peisker, Andrè; Mtsariashvilli, Maia; Schlegel, Karl Andreas; Hildebrand, Gerhard; Rost, Juergen; Liefeith, Klaus; Chen, Jiang; Schultze-Mosgau, Stefan

2013-07-01

It was the aim of this study to analyze the influence of implant design and surface topography on the osseointegration of dental zirconium implants. Six different implant designs were tested in the study. Nine or 10 test implants were inserted in the frontal skull in each of 10 miniature pigs. Biopsies were harvested after 2 and 4 months and subjected to microradiography. No significant differences between titanium and zirconium were found regarding the microradiographically detected bone-implant contact (BIC). Cylindric zirconium implants showed a higher BIC at the 2-month follow-up than conic zirconium implants. Among zirconium implants, those with an intermediate Ra value showed a significantly higher BIC compared with low and high Ra implants 4 months after surgery. Regarding osseointegration, titanium and zirconium showed equal properties. Cylindric implant design and intermediate surface roughness seemed to enhance osseointegration. Copyright © 2013 Elsevier Inc. All rights reserved.

EAO Supplement Working Group 4 - EAO CC 2015 Short implants versus sinus lifting with longer implants to restore the posterior maxilla: a systematic review.

PubMed

Thoma, D S; Zeltner, M; Hüsler, J; Hämmerle, C H F; Jung, R E

2015-09-01

To compare short implants in the posterior maxilla to longer implants placed after or simultaneously with sinus floor elevation procedures. The focused question was as follows: Are short implants superior to longer implants in the augmented sinus in terms of survival and complication rates of implants and reconstructions, patient-reported outcome measures (PROMs) and costs? A MEDLINE search (1990-2014) was performed for randomized controlled clinical studies comparing short implants (≤8 mm) to longer implants (>8 mm) in augmented sinus. The search was complimented by an additional hand search of the selected papers and reviews published between 2011 and 2014. Eligible studies were selected based on the inclusion criteria, and quality assessments were conducted. Descriptive statistics were applied for a number of outcome measures. Survival rates of dental implants were pooled simply in case of comparable studies. Eight randomized controlled clinical trials (RCTs) comparing short implants versus longer implants in the augmented sinus derived from an initial search count of 851 titles were selected and data extracted. In general, all studies were well conducted with a low risk of bias for the majority of the analyzed parameters. Based on the pooled analyses of longer follow-ups (5 studies, 16-18 months), the survival rate of longer implants amounted to 99.5% (95% CI: 97.6-99.98%) and for shorter implants to 99.0% (95% CI: 96.4-99.8%). For shorter follow-ups (3 studies, 8-9 months), the survival rates of longer implants are 100% (95% CI: 97.1-100%) and for shorter implants 98.2% (95% CI: 93.9-99.7%). Complications were predominantly of biological origin, mainly occurred intraoperatively as membrane perforations, and were almost three times as higher for longer implant in the augmented sinus compared to shorter implants. PROMs, morbidity, surgical time and costs were generally in favor of shorter dental implants. All studies were performed by surgeons in specialized clinical settings. The outcomes of the survey analyses demonstrated predictably high implant survival rates for short implants and longer implants placed in augmented sinus and their respective reconstructions. Given the higher number of biological complications, increased morbidity, costs and surgical time of longer dental implants in the augmented sinus, shorter dental implants may represent the preferred treatment alternative. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Calfplasty.

PubMed

Felício, Y

2000-01-01

The author describes a method of calf augmentation by a silicone prosthesis implant for correction of asymmetrical legs or aesthetic problems. Preference is given to the placement of soft silicone implants (Glitzentein implants); they are more natural looking than hard implants. The implants are placed over both heads of the gastrocnemius muscle or beneath the fascia cruris superficialis. Operations were performed from November 1985 to August 1999. One hundred patients were studied: 95 female and 5 male. Two hundred calf implants were performed: 188 soft implants (Glitzenstein), 6 hard implants (Aiache), and 6 together on the same leg (Glitzenstein and Aiache implants). No infection problems, prosthesis rupture, or hematomas occurred. There were four seromas, but they disappeared in 15 days. Four prostheses were removed in two patients who did not like the final result. One prosthesis changed place, to the upper part of the calf. The operation is performed under sedative and local anesthesia, with an incision of approximately 4 to 5 cm in the popliteal pleat, at the same height as the fascia cruris. To date, no functional problem or muscular dysfunction has been provoked by silicone prosthesis implants. The patient walks 8 h after the surgery. We selected 500 patients who received implants in the legs with calf prostheses, fat implants, and prosthesis and fat implant together, during 14 years of follow-up, but the focus of this paper is a calf implant with prosthesis in 100 patients with 200 calf prosthesis implants.

Qualitative and quantitative observations of bone tissue reactions to anodised implants.

PubMed

Sul, Young-Taeg; Johansson, Carina B; Röser, Kerstin; Albrektsson, Tomas

2002-04-01

Research projects focusing on biomaterials related factors; the bulk implant material, the macro-design of the implant and the microsurface roughness are routinely being conducted at our laboratories. In this study, we have investigated the bone tissue reactions to turned commercially pure (c.p.) titanium implants with various thicknesses of the oxide films after 6 weeks of insertion in rabbit bone. The control c.p. titanium implants had an oxide thickness of 17-200 nm while the test implants revealed an oxide thickness between 600 and 1000 nm. Routine histological investigations of the tissue reactions around the implants and enzyme histochemical detections of alkaline and acid phosphatase activities demonstrated similar findings around both the control and test implants. In general, the histomorphometrical parameters (bone to implant contact and newly formed bone) revealed significant quantitative differences between the control and test implants. The test implants demonstrated a greater bone response histomorphometrically than control implants and the osteoconductivity was more pronounced around the test implant surfaces. The parameters that differed between the implant surfaces, i.e. the oxide thickness, the pore size distribution, the porosity and the crystallinity of the surface oxides may represent factors that have an influence on the histomorphometrical results indicated by a stronger bone tissue response to the test implant surfaces, with an oxide thickness of more than 600 nm.

Osseointegration of titanium implants functionalised with phosphoserine-tethered poly(epsilon-lysine) dendrons: a comparative study with traditional surface treatments in sheep.

PubMed

Stübinger, Stefan; Nuss, Katja; Bürki, Alexander; Mosch, Isabel; le Sidler, Miché; Meikle, Steve T; von Rechenberg, Brigitte; Santin, Matteo

2015-02-01

The aim of this study was to analyse the osseointegrative potential of phosphoserine-tethered dendrons when applied as surface functionalisation molecules on titanium implants in a sheep model after 2 and 8 weeks of implantation. Uncoated and dendron-coated implants were implanted in six sheep. Sandblasted and etched (SE) or porous additive manufactured (AM) implants with and without additional dendron functionalisation (SE-PSD; AM-PSD) were placed in the pelvic bone. Three implants per group were examined histologically and six implants were tested biomechanically. After 2 and 8 weeks the bone-to-implant contact (BIC) total values of SE implants (43.7±12.2; 53.3±9.0%) and SE-PSD (46.7±4.5; 61.7±4.9%) as well as AM implants (20.49±5.1; 43.9±9.7%) and AM-PSD implants (19.7±3.5; 48.3±15.6%) showed no statistically significant differences. For SE-PSD and AM-PSD a separate analysis of only the cancellous BIC demonstrated a statistically significant difference after 2 and 8 weeks. Biomechanical findings proved the overall increased stability of the porous implants after 8 weeks. Overall, the great effect of implant macro design on osseointegration was further supported by additional phosphoserine-tethered dendrons for SE and AM implants.

Osseointegration of three-dimensional designed titanium implants manufactured by selective laser melting.

PubMed

Shaoki, Algabri; Xu, Jia-Yun; Sun, Haipeng; Chen, Xian-Shuai; Ouyang, Jianglin; Zhuang, Xiu-Mei; Deng, Fei-Long

2016-10-27

The selective laser melting (SLM) technique is a recent additive manufacturing (AM) technique. Several studies have reported success in the SLM-based production of biocompatible orthopaedic implants and three-dimensional bone defect constructs. In this study, we evaluated the surface properties and biocompatibility of an SLM titanium implant in vitro and compared them with those of a machined (MA) titanium control surface. In addition, we evaluated the osseointegration capability of the SLM implants in vivo and compared it with those of MA and Nobel-speedy (Nobel-S) implants. SLM microtopographical surface analysis revealed porous and high roughness with varied geometry compared with a smooth surface in MA Ti samples but with similar favourable wettability. Osteoblast proliferation and alkaline phosphatase activity were significantly enhanced on the SLM surface. Histological analysis of the bone-implant contact ratio revealed no significant difference among SLM, MA, and Nobel-S implants. Micro-CT assessment indicated that there was no significant difference in bone volume fraction around the implant among SLM implants and other types of surface modification implants. The removal torque value measurement of SLM implants was significantly lower that of than Nobel-S implants P < 0.001 and higher than that of MA implants. The study demonstrates the capability of SLM implants to integrate with living bone. The SLM technique holds promise as a new dental implant manufacturing technique.

Randomized study on the effect of single-implant versus two-implant retained overdentures on implant loss and muscle activity: a 12-month follow-up report.

PubMed

Alqutaibi, A Y; Kaddah, A F; Farouk, M

2017-06-01

The objective was to evaluate and compare single- and two-implant retained overdentures for the rehabilitation of the edentulous mandible. Fifty-six edentulous subjects were eligible for inclusion. Using a random sampling system, a single implant or two implants were placed in the mandible. After 3 months, locator attachments were connected to the implants and the denture delivered with the retentive components incorporated in the denture base. Implant failure and muscle activity were evaluated at the 3-, 6-, and 12-month follow-up examinations. The study sample comprised 56 patients (32 male, 24 female), with a mean age of 58.2 years. A total of 84 implants were placed (28 in the single-implant group and 56 in the two-implant group). All patients completed the 12 months of follow-up. No significant differences were found between subjects in the two groups with respect to implant failure. With regard to improvements in muscle activity, the two-implant group showed statistically significant but perhaps not clinically important differences. Single-implant mandibular overdentures may be suggested as an alternative treatment modality for the rehabilitation of edentulous patients who cannot afford the cost of a two-implant overdenture. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Numerical assessment of bone remodeling around conventionally and early loaded titanium and titanium-zirconium alloy dental implants.

PubMed

Akça, Kıvanç; Eser, Atılım; Çavuşoğlu, Yeliz; Sağırkaya, Elçin; Çehreli, Murat Cavit

2015-05-01

The aim of this study was to investigate conventionally and early loaded titanium and titanium-zirconium alloy implants by three-dimensional finite element stress analysis. Three-dimensional model of a dental implant was created and a thread area was established as a region of interest in trabecular bone to study a localized part of the global model with a refined mesh. The peri-implant tissues around conventionally loaded (model 1) and early loaded (model 2) implants were implemented and were used to explore principal stresses, displacement values, and equivalent strains in the peri-implant region of titanium and titanium-zirconium implants under static load of 300 N with or without 30° inclination applied on top of the abutment surface. Under axial loading, principal stresses in both models were comparable for both implants and models. Under oblique loading, principal stresses around titanium-zirconium implants were slightly higher in both models. Comparable stress magnitudes were observed in both models. The displacement values and equivalent strain amplitudes around both implants and models were similar. Peri-implant bone around titanium and titanium-zirconium implants experiences similar stress magnitudes coupled with intraosseous implant displacement values under conventional loading and early loading simulations. Titanium-zirconium implants have biomechanical outcome comparable to conventional titanium implants under conventional loading and early loading.

Predictability of short implants (< 10 mm) as a treatment option for the rehabilitation of atrophic maxillae. A systematic review

PubMed Central

García-Sala-Bonmatí, Fernando; Martínez-González, Amparo; García-Dalmau, Carlos; Mañes-Ferrer, José-Félix; Brotons-Oliver, Alejandro

2016-01-01

Background Short implants (< 10 mm) are one of the treatment options available in cases of limited vertical bone. A purpose of this paper is to evaluate the predictability of short implants as an alternative to technically molthough such implants are now widely used, there is controversy regarding their clinical reliability. There complex treatments in patients with atrophic maxillae, based on a systematic review of the literature and the analysis of the implant survival rates, changes in peri-implant bone level, and associated complications. It is postulated that short implants offer clinical results similar to those of longer implants. Material and Methods A Medline-PubMed search was made covering the period between January 2004 and December 2014 (both included). Studies in English published in indexed journals, involving at least 20 implants and with a follow-up period of at least 12 months were considered. A manual search in four high impact journals was also conducted. Results A total of 37 studies meeting the inclusion criteria were included in this review. 9792 implants placed in over 5000 patients were analyzed. Conclusions Based on the results of this review, short implants are seen to offer clinical results in terms of survival, bone loss and complications similar to those of longer implants. Key words:Survival rate, clinical results, dental implants, oral implants, short implants, short lengt PMID:26946199

Breast reconstruction - implants

MedlinePlus

Breast implants surgery; Mastectomy - breast reconstruction with implants; Breast cancer - breast reconstruction with implants ... it harder to find a tumor if your breast cancer comes back. Getting breast implants does not take ...

Heat generated during seating of dental implant fixtures.

PubMed

Flanagan, Dennis

2014-04-01

Frictional heat can be generated during seating of dental implants into a drill-prepared osteotomy. This in vitro study tested the heat generated by implant seating in dense bovine mandible ramus. A thermocouple was placed approximately 0.5 mm from the rim of the osteotomy during seating of each dental implant. Four diameters of implants were tested. The average temperature increases were 0.075°C for the 5.7-mm-diameter implant, 0.97°C for the 4.7-mm-diameter implant, 1.4°C for the 3.7-mm-diameter implant, and 8.6°C for the 2.5-mm-diameter implant. The results showed that heat was indeed generated and a small temperature rise occurred, apparently by the friction of the implant surface against the fresh-cut bone surface. Bone is a poor thermal conductor. The titanium of the implant and the steel of the handpiece are much better heat conductors. Titanium may be 70 times more heat conductive than bone. The larger diameter and displacement implant may act as a heat sink to draw away any heat produced from the friction of seating the implant at the bone-implant interface. The peak temperature duration was momentary, and not measured, but this was approximately less than 1 second. Except for the 2.5-mm-diameter implants, the temperature rises and durations were found to be below those previously deemed to be detrimental, so no clinically significant osseous damage would be expected during dental implant fixture seating of standard and large-diameter-sized implants. A 2.5-mm implant may generate detrimental heat during seating in nonvital bone, but this may be clinically insignificant in vital bone. The surface area and thermal conductivity are important factors in removing generated heat transfer at the bone-implant interface. The F value as determined by analysis of variance was 69.22, and the P value was less than .0001, demonstrating significant differences between the groups considered as a whole.

Rehabilitation of postrior atrophic edentulous jaws: prostheses supported by 5 mm short implants or by longer implants in augmented bone? One-year results from a pilot randomised clinical trial.

PubMed

Esposito, Marco; Pellegrino, Gerardo; Pistilli, Roberto; Felice, Pietro

2011-01-01

To evaluate whether 5 mm short dental implants could be an alternative to augmentation with anorganic bovine bone and placement of at least 10 mm long implants in posterior atrophic jaws. Fifteen patients with bilateral atrophic mandibles (5-7 mm bone height above the mandibular canal), and 15 patients with bilateral atrophic maxillae (4-6 mm bone height below the maxillary sinus) and bone thickness of at least 8 mm, were randomised according to a splitmouth design to receive one to three 5 mm short implants or at least 10 mm long implants in augmented bone. Mandibles were vertically augmented with interpositional bone blocks and maxillary sinuses with particulated bone via a lateral window. Implants were placed after 4 months, submerged and loaded, after 4 months, with provisional prostheses. Four months later, definitive provisionally cemented prostheses were delivered. Outcome measures were: prosthesis and implant failures, any complication and peri-implant marginal bone level changes. In 5 augmented mandibles, the planned 10 mm long implants could not be placed and shorter implants (7 and 8.5 mm) had to be used instead. One year after loading no patient dropped out. Two long (8.5 mm in the mandible and 13 mm in the maxilla) implants and one 5 mm short maxillary implant failed. There were no statistically significant differences in failures or complications. Patients with short implants lost on average 1 mm of peri-implant bone and patients with longer implants lost 1.2 mm. This difference was statistically significant. This pilot study suggests that 1 year after loading, 5 mm short implants achieve similar if not better results than longer implants placed in augmented bone. Short implants might be a preferable choice to bone augmentation since the treatment is faster, cheaper and associated with less morbidity, however their long-term prognosis is unknown.

Comparison of marginal bone loss between internal- and external-connection dental implants in posterior areas without periodontal or peri-implant disease.

PubMed

Kim, Dae-Hyun; Kim, Hyun Ju; Kim, Sungtae; Koo, Ki-Tae; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Rhyu, In-Chul

2018-04-01

The purpose of this retrospective study with 4-12 years of follow-up was to compare the marginal bone loss (MBL) between external-connection (EC) and internal-connection (IC) dental implants in posterior areas without periodontal or peri-implant disease on the adjacent teeth or implants. Additional factors influencing MBL were also evaluated. This retrospective study was performed using dental records and radiographic data obtained from patients who had undergone dental implant treatment in the posterior area from March 2006 to March 2007. All the implants that were included had follow-up periods of more than 4 years after loading and satisfied the implant success criteria, without any peri-implant or periodontal disease on the adjacent implants or teeth. They were divided into 2 groups: EC and IC. Subgroup comparisons were conducted according to splinting and the use of cement in the restorations. A statistical analysis was performed using the Mann-Whitney U test for comparisons between 2 groups and the Kruskal-Wallis test for comparisons among more than 2 groups. A total of 355 implants in 170 patients (206 EC and 149 IC) fulfilled the inclusion criteria and were analyzed in this study. The mean MBL was 0.47 mm and 0.15 mm in the EC and IC implants, respectively, which was a statistically significant difference ( P <0.001). Comparisons according to splinting (MBL of single implants: 0.34 mm, MBL of splinted implants: 0.31 mm, P =0.676) and cement use (MBL of cemented implants: 0.27 mm, MBL of non-cemented implants: 0.35 mm, P =0.178) showed no statistically significant differences in MBL, regardless of the implant connection type. IC implants showed a more favorable bone response regarding MBL in posterior areas without peri-implantitis or periodontal disease.

New orthopaedic implant management tool for computer-assisted planning, navigation, and simulation: from implant CAD files to a standardized XML-based implant database.

PubMed

Sagbo, S; Blochaou, F; Langlotz, F; Vangenot, C; Nolte, L-P; Zheng, G

2005-01-01

Computer-Assisted Orthopaedic Surgery (CAOS) has made much progress over the last 10 years. Navigation systems have been recognized as important tools that help surgeons, and various such systems have been developed. A disadvantage of these systems is that they use non-standard formalisms and techniques. As a result, there are no standard concepts for implant and tool management or data formats to store information for use in 3D planning and navigation. We addressed these limitations and developed a practical and generic solution that offers benefits for surgeons, implant manufacturers, and CAS application developers. We developed a virtual implant database containing geometrical as well as calibration information for orthopedic implants and instruments, with a focus on trauma. This database has been successfully tested for various applications in the client/server mode. The implant information is not static, however, because manufacturers periodically revise their implants, resulting in the deletion of some implants and the introduction of new ones. Tracking these continuous changes and keeping CAS systems up to date is a tedious task if done manually. This leads to additional costs for system development, and some errors are inevitably generated due to the huge amount of information that has to be processed. To ease management with respect to implant life cycle, we developed a tool to assist end-users (surgeons, hospitals, CAS system providers, and implant manufacturers) in managing their implants. Our system can be used for pre-operative planning and intra-operative navigation, and also for any surgical simulation involving orthopedic implants. Currently, this tool allows addition of new implants, modification of existing ones, deletion of obsolete implants, export of a given implant, and also creation of backups. Our implant management system has been successfully tested in the laboratory with very promising results. It makes it possible to fill the current gap that exists between the CAS system and implant manufacturers, hospitals, and surgeons.

Mandibular single-implant overdentures: preliminary results of a randomised-control trial on early loading with different implant diameters and attachment systems.

PubMed

Alsabeeha, Nabeel H M; Payne, Alan G T; De Silva, Rohana K; Thomson, W Murray

2011-03-01

To determine surgical and prosthodontic outcomes of mandibular single-implant overdentures, opposing complete maxillary dentures, using a wide diameter implant and large ball attachment system compared with different regular diameter implants with standard attachment systems. Thirty-six edentulous participants (mean age 68 years, SD 9.2) were randomly assigned into three treatment groups (n=12). A single implant was placed in the mandibular midline of participants to support an overdenture using a 6-week loading protocol. The control group received Southern regular implants and standard ball attachments. One group received Southern 8-mm-wide implants and large ball attachments. Another group received Neoss regular implants and Locator attachments. Parametric and non-parametric tests of a statistical software package (SPSS) were used to determine between groups differences in marginal bone loss, implant stability, implant, and prosthodontic success (P<0.05). Implant success after 1 year was 75% for Southern regular implant (control) group; and 100% for the Southern wide and Neoss regular implant groups (P=0.038). Mean marginal bone loss at 1 year was 0.19 mm (SD 0.39) without significant differences observed. Implant stability quotient (ISQ) at baseline was significantly lower for the Southern regular (control) group than the other two groups (P=0.001; P=0.009). At 1 year, no significant difference in implant stability was observed (mean ISQ 74.6, SD 6.1). The change in implant stability from baseline to 1 year was significant for the control group (P=0.025). Prosthodontic success was comparable between the groups but the maintenance (41 events overall, mean 1.2) was greater for the Locator and the standard ball attachments. Mandibular single-implant overdentures are a successful treatment option for older edentulous adults with early loading protocol using implants of different diameters and with different attachment systems. © 2010 John Wiley & Sons A/S.

Single-blind randomized clinical trial to evaluate clinical and radiological outcomes after one year of immediate versus delayed implant placement supporting full-arch prostheses

PubMed Central

Pellicer-Chover, Hilario; Peñarrocha-Oltra, David; Bagán, Leticia; Fichy-Fernandez, Antonio J.; Canullo, Luigi

2014-01-01

Purpose: To evaluate and compare peri-implant health, marginal bone loss and success of immediate and delayed implant placement for rehabilitation with full-arch fixed prostheses. Material and Methods: The present study was a prospective, randomized, single-blind, clinical preliminary trial. Patients were randomized into two treatment groups. In Group A implants were placed immediately post-extraction and in Group B six months after extraction. The following control time-points were established: one week, six months and twelve months after loading. Measurements were taken of peri-implant crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis. Implant success rates were evaluated for the two groups. The study sample included fifteen patients (nine women and six men) with a mean average age of 63.7 years. One hundred and forty-four implants were placed: 76 placed in healed sites and 68 placed immediately. Results: At the moment of prosthetic loading, keratinized mucosa width and probing depth were higher in immediate implants than delayed implants, with statistically significant differences. However, after six and twelve months, differences between groups had disappeared. Bone loss was 0.54 ± 0.39 mm for immediate implants and 0.66 ± 0.25 mm for delayed implants (p=0.201). No implants failed in either group. Conclusions: The present study with a short follow-up and a small sample yielded no statistically significant differences in implant success and peri-implant marginal bone loss between immediate and delayed implants with fixed full-arch prostheses. Peri-implant health showed no statistically significant differences for any of the studied parameters (crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis) at the twelve-month follow-up. Key words:Immediate implants, delayed implants, peri-implant health, success rate. PMID:24316712

Cochlear Implants.

ERIC Educational Resources Information Center

Clark, Catherine; Scott, Larry

This brochure explains what a cochlear implant is, lists the types of individuals with deafness who may be helped by a cochlear implant, describes the process of evaluating people for cochlear implants, discusses the surgical process for implanting the aid, traces the path of sound through the cochlear implant to the brain, notes the costs of…

Agile Development of Advanced Prototypes

DTIC Science & Technology

2014-11-01

prostheses: retinal implants, cochlear implants, and neuroprosthetics (EEG controlled artificial limbs); an interactive, virtual experience...demonstrations allowing users to experience, from a patient’s perspective life with three different prostheses: retinal implants, cochlear implants...three experiences were researched and developed. The applications are interactive demonstrations of retinal implants, cochlear implants, and

Diode Laser and Periodontal Regeneration-Assisted Management of Implant Complications in Anterior Maxilla.

PubMed

Salaria, Sanjeev Kumar; Sharma, Isha; Brar, Navjot Kaur; Kaur, Satwant

2018-01-01

Dental implant is being considered successful if the patient is pleased with both of its functional and esthetic outcome. As implant complications (such as peri-implantitis, inappropriate implant position, wrong angulation, and implant location too close to anatomical structures) have been frequently encountered in dental practice, therefore, thorough knowledge to manage such complications is the key prerequisite to prevent the failure of implant. The present case report discussed the etiology, diagnosis of early peri-implantitis, and periodontal abscess with their successful management through periodontal regeneration and diode laser-assisted therapy.

Linguine sign at MR imaging: does it represent the collapsed silicone implant shell?

PubMed

Gorczyca, D P; DeBruhl, N D; Mund, D F; Bassett, L W

1994-05-01

One intact and one ruptured single-lumen implant were surgically placed in a rabbit. Magnetic resonance (MR) imaging was performed before and after surgical removal, and the ruptured implant was imaged after removal of the implant shell. Multiple curvilinear hypointense lines (linguine sign) were present in the MR images of the ruptured implant and of the implant shell alone immersed in saline solution but not in the image of the free silicone. The collapsed implant shell in a ruptured silicone implant does cause the linguine sign.

Occlusion for implant-supported fixed dental prostheses in partially edentulous patients: a literature review and current concepts

PubMed Central

Sukotjo, Cortino

2013-01-01

Implant treatment has become the treatment of choice to replace missing teeth in partially edentulous areas. Dental implants present different biological and biomechanical characteristics than natural teeth. Occlusion is considered to be one of the most important factors contributing to implant success. Most literature on implant occlusal concepts is based on expert opinion, anecdotal experiences, in vitro and animal studies, and only limited clinical research. Furthermore, scientific literature regarding implant occlusion, particularly in implant-supported fixed dental prostheses remains controversial. In this study, the current status of implant occlusion was reviewed and discussed. Further randomized clinical research to investigate the correlation between implant occlusion, the implant success rate, and its risk factors is warranted to determine best clinical practices. PMID:23678387

Multiscale design and multiobjective optimization of orthopedic hip implants with functionally graded cellular material.

PubMed

Arabnejad Khanoki, Sajad; Pasini, Damiano

2012-03-01

Revision surgeries of total hip arthroplasty are often caused by a deficient structural compatibility of the implant. Two main culprits, among others, are bone-implant interface instability and bone resorption. To address these issues, in this paper we propose a novel type of implant, which, in contrast to current hip replacement implants made of either a fully solid or a foam material, consists of a lattice microstructure with nonhomogeneous distribution of material properties. A methodology based on multiscale mechanics and design optimization is introduced to synthesize a graded cellular implant that can minimize concurrently bone resorption and implant interface failure. The procedure is applied to the design of a 2D left implanted femur with optimized gradients of relative density. To assess the manufacturability of the graded cellular microstructure, a proof-of-concept is fabricated by using rapid prototyping. The results from the analysis are used to compare the optimized cellular implant with a fully dense titanium implant and a homogeneous foam implant with a relative density of 50%. The bone resorption and the maximum value of interface stress of the cellular implant are found to be over 70% and 50% less than the titanium implant while being 53% and 65% less than the foam implant.

Short-Term and Long-Term Effects of Orthopedic Biodegradable Implants

PubMed Central

Amini, Ami R.; Wallace, James S.; Nukavarapu, Syam P.

2012-01-01

Presently, orthopedic and oral/maxillofacial implants represent a combined $2.8 billion market, a figure expected to experience significant and continued growth. Although traditional permanent implants have been proved clinically efficacious, they are also associated with several drawbacks, including secondary revision and removal surgeries. Non-permanent, biodegradable implants offer a promising alternative for patients, as they provide temporary support and degrade at a rate matching tissue formation, and thus, eliminate the need for secondary surgeries. These implants have been in clinical use for nearly 25 years, competing directly with, or maybe even exceeding, the performance of permanent implants. The initial implantation of biodegradable materials, as with permanent materials, mounts an acute host inflammatory response. Over time, the implant degradation profile and possible degradation product toxicity mediate long-term biodegradable implant-induced inflammation. However, unlike permanent implants, this inflammation is likely to cease once the material disappears. Implant-mediated inflammation is a critical determinant for implant success. Thus, for the development of a proactive biodegradable implant that has the ability to promote optimal bone regeneration and minimal detrimental inflammation, a thorough understanding of short- and long-term inflammatory events is required. Here, we discuss an array of biodegradable orthopedic implants, their associated short- and long- term inflammatory effects, and methods to mediate these inflammatory events. PMID:22043969

[Researches on biomechanics of micro-implant-bone interface and optimum design of micro implant's neck].

PubMed

Deng, Feng; Zhang, Lei; Zhang, Yi; Song, Jin-lin; Fan, Yuboa

2007-07-01

To compare and analyze the stress distribution at the micro-implant-bone interface based on the different micro-implant-bone conditioned under orthodontic load, and to optimize the design of micro implant's neck. An adult skull with all tooth was scanned by spiral CT, and the data were imported into computer for three-dimensional reconstruction with software Mimics 9.0. The three dimensional finite element models of three micro-implant-bone interfaces(initial stability, full osseointegration and fibrous integration) were analyzed by finite element analysis software ABAQUS6.5. The primary stress distributions of different micro-implant-bone conditions were evaluated when 2N force was loaded. Then the diameter less than 1.5 mm of the micro implant's neck was added with 0.2 mm, to compare the stress distribution of the modified micro-implant-bone interface with traditional type. The stress mostly concentrated on the neck of micro implant and the full osseointegration interface in all models showed the lowest strain level. Compared with the traditional type, the increasing diameter neck of the micro implant obviously decreased the stress level in all the three conditions. The micro-implant-bone interface and the diameter of micro implant's neck both are the important influence factors to the stress distribution of micro implant.

Age or experience? The influence of age at implantation and social and linguistic environment on language development in children with cochlear implants.

PubMed

Szagun, Gisela; Stumper, Barbara

2012-12-01

The authors investigated the influence of social environmental variables and age at implantation on language development in children with cochlear implants. Participants were 25 children with cochlear implants and their parents. Age at implantation ranged from 6 months to 42 months ( M (age) = 20.4 months, SD = 22.0 months). Linguistic progress was assessed at 12, 18, 24, and 30 months after implantation. At each data point, language measures were based on parental questionnaire and 45-min spontaneous speech samples. Children's language and parents' child-directed language were analyzed. On all language measures, children displayed considerable vocabulary and grammatical growth over time. Although there was no overall effect of age at implantation, younger and older children had different growth patterns. Children implanted by age 24 months made the most marked progress earlier on, whereas children implanted thereafter did so later on. Higher levels of maternal education were associated with faster linguistic progress; age at implantation was not. Properties of maternal language input, mean length of utterance, and expansions were associated with children's linguistic progress independently of age at implantation. In children implanted within the sensitive period for language learning, children's home language environment contributes more crucially to their linguistic progress than does age at implantation.

Implant Insertion Torque: Its Role in Achieving Primary Stability of Restorable Dental Implants.

PubMed

Greenstein, Gary; Cavallaro, John

2017-02-01

A literature review was conducted to determine the role of insertion torque in attaining primary stability of dental implants. The review is comprised of articles that discussed the amount of torque needed to achieve primary implant stability in healed ridges and fresh extraction sockets prior to immediate implant loading. Studies were appraised that addressed the effects of minimum and maximum forces that can be used to successfully place implants. The minimum torque that can be employed to attain primary stability is undefined. Forces ≥30 Ncm are routinely used to place implants into healed ridges and fresh extraction sockets prior to immediate loading of implants. Increased insertion torque (≥50 Ncm) reduces micromotion and does not appear to damage bone. In general, the healing process after implant insertion provides a degree of biologic stability that is similar whether implants are placed with high or low initial insertion torque. Primary stability is desirable when placing implants, but the absence of micromotion is what facilitates predictable implant osseointegration. Increased insertion torque helps achieve primary stability by reducing implant micromotion. Furthermore, tactile information provided by the first surgical twist drill can aid in selecting the initial insertion torque to achieve predictable stability of inserted dental implants.

Breast Implants and the Risk of Anaplastic Large-Cell Lymphoma in the Breast.

PubMed

de Boer, Mintsje; van Leeuwen, Flora E; Hauptmann, Michael; Overbeek, Lucy I H; de Boer, Jan Paul; Hijmering, Nathalie J; Sernee, Arthur; Klazen, Caroline A H; Lobbes, Marc B I; van der Hulst, René R W J; Rakhorst, Hinne A; de Jong, Daphne

2018-03-01

Breast implants are among the most commonly used medical devices. Since 2008, the number of women with breast implants diagnosed with anaplastic large-cell lymphoma in the breast (breast-ALCL) has increased, and several reports have suggested an association between breast implants and risk of breast-ALCL. However, relative and absolute risks of breast-ALCL in women with implants are still unknown, precluding evidence-based counseling about implants. To determine relative and absolute risks of breast-ALCL in women with breast implants. Through the population-based nationwide Dutch pathology registry we identified all patients diagnosed with primary non-Hodgkin lymphoma in the breast between 1990 and 2016 and retrieved clinical data, including breast implant status, from the treating physicians. We estimated the odds ratio (OR) of ALCL associated with breast implants in a case-control design, comparing implant prevalence between women with breast-ALCL and women with other types of breast lymphoma. Cumulative risk of breast-ALCL was derived from the age-specific prevalence of breast implants in Dutch women, estimated from an examination of 3000 chest x-rays and time trends from implant sales. Relative and absolute risks of breast-ALCL in women with breast implants. Among 43 patients with breast-ALCL (median age, 59 years), 32 had ipsilateral breast implants, compared with 1 among 146 women with other primary breast lymphomas (OR, 421.8; 95% CI, 52.6-3385.2). Implants among breast-ALCL cases were more often macrotextured (23 macrotextured of 28 total implants of known type, 82%) than expected (49 193 sold macrotextured implants of total sold 109 449 between 2010 and 2015, 45%) based on sales data (P < .001). The estimated prevalence of breast implants in women aged 20 to 70 years was 3.3%. Cumulative risks of breast-ALCL in women with implants were 29 per million at 50 years and 82 per million at 70 years. The number of women with implants needed to cause 1 breast-ALCL case before age 75 years was 6920. Breast implants are associated with increased risk of breast-ALCL, but the absolute risk remains small. Our results emphasize the need for increased awareness among the public, medical professionals, and regulatory bodies, promotion of alternative cosmetic procedures, and alertness to signs and symptoms of breast-ALCL in women with implants.

In vivo osseointegration of dental implants with an antimicrobial peptide coating.

PubMed

Chen, X; Zhou, X C; Liu, S; Wu, R F; Aparicio, C; Wu, J Y

2017-05-01

This study aimed to evaluate the in vivo osseointegration of implants with hydrophobic antimicrobial GL13K-peptide coating in rabbit femoral condyles by micro-CT and histological analysis. Six male Japanese Rabbits (4 months old and weighing 2.5 kg each) were included in this study. Twelve implants (3.75 mm wide, 7 mm long) were randomly distributed in two groups, with six implants in the experimental group coated with GL13K peptide and six implants in the control group without surface coating. Each implant in the test and the control group was randomly implanted in the left or right side of femoral condyles. On one side randomly-selected of the femur, each rabbit received a drill that was left without implant as control for the natural healing of bone. After 3 weeks of healing radiographic evaluation of the implant sites was taken. After 6 weeks of healing, rabbits were sacrificed for evaluation of the short-term osseointegration of the dental implants using digital radiography, micro-CT and histology analysis. To perform evaluation of osseointegration, implant location and group was double blinded for surgeon and histology/radiology researcher. Two rabbits died of wound infection in sites with non-coated implants 2 weeks after surgery. Thus, at least four rabbits per group survived after 6 weeks of healing. The wounds healed without suppuration and inflammation. No implant was loose after 6 weeks of healing. Radiography observations showed good osseointegration after 3 and 6 weeks postoperatively, which proved that the tissues followed a natural healing process. Micro-CT reconstruction and analysis showed that there was no statistically significant difference (P > 0.05) in volume of bone around the implant between implants coated with GL13K peptide and implants without coating. Histomorphometric analysis also showed that the mineralized bone area was no statistically different (P > 0.05) between implants coated with GL13K peptide and implants without coating. This study demonstrates that titanium dental implants with an antimicrobial GL13K coating enables in vivo implant osseointegration at similar bone growth rates than gold-standard non-coated dental implants up to 6 weeks of implantation in rabbit femurs.

Prediction uncertainty of plume characteristics derived from a small number of measuring points

NASA Astrophysics Data System (ADS)

French, H. K.; van der Zee, S. E. A. T. M.; Leijnse, A.

A small number of measuring points may inflict a bias on the characterisation of flow and transport based on field experiments in the unsaturated zone. Simulation of pure advective transport of a Gaussian plume through a setup of 30 regularly placed measuring points revealed regular temporal fluctuations about the real spatial moments. An irregular setup predicted both irregular fluctuations and larger discrepancies from the real value. From these considerations, a regular setup is recommended. Spatial moments were sensitive to the plume size relative to the distance between individual measuring points. To reduce prediction errors of the variance, the distance between the measuring points should be less than twice the standard deviation of the examined plume. The total size of the setup should cover several standard deviations of the plume to avoid mass being lost from the monitored area. Numerical simulations of a dispersing plume (comparing calculations based on 9000 nodes with 30 measuring points) revealed that vertical and horizontal centres of mass were predicted well at all degrees of heterogeneity, and the same was the case for horizontal variances. Vertical variances were more susceptible to prediction errors, but estimates were of the same order of magnitude as the real values. Résumé Lorsque l'on cherche à caractériser l'écoulement et le transport à partir d'expériences de terrain dans la zone saturée, il arrive qu'un petit nombre de points introduisent un biais. La simulation d'un transport purement advectif d'un panache gaussien au travers d'un ensemble de 30 points de mesures espacés régulièrement fait apparaître des variations temporelles régulières autour des moments spatiaux réels. Un ensemble irrégulier conduit à prédire à la fois des variations irrégulières et de plus grandes divergences par rapport à la valeur réelle. A partir de ces constations, un ensemble régulier est recommandé. Les moments spatiaux sont apparus sensibles à la dimension du panache en fonction de la distance entre les différents points de mesure. Afin de réduire les erreurs de prédiction de la variance, la distance entre les points de mesure doit être inférieure au double de l'écart-type du panache examiné. La dimension totale de l'ensemble doit couvrir une étendue de plusieurs écarts-types du panache pour éviter qu'une partie de la matière échappe à la zone surveillée. Des simulations numériques du panache en dispersion (les calculs de comparaison sont basés sur 9000 nœuds avec 30 points de mesure) montrent que le centre vertical et le centre horizontal de la matière dispersée ont été bien prédits à tous les degrés d'hétérogénéité, de même que pour les variances horizontales. Les variances verticales ont été plus sensibles aux erreurs de prédiction, mais les estimations étaient du même ordre de grandeur que les valeurs réelles. Resumen Un número pequeño de puntos de medida puede producir un sesgo en la caracterización en campo del flujo y transporte de solutos en la zona no saturada. La simulación de transporte advectivo (no difusivo) de un penacho Gaussiano a travs de un conjunto de 30 puntos de medida regularmente distribuidos revelan fluctuaciones temporales regulares de los momentos espaciales del penacho. Una distribución irregular de puntos de medida predijo a su vez fluctuaciones irregulares, más alejadas de la realidad, por lo que se recomienda el uso de esquemas de muestreo regulares. Los momentos espaciales fueron sensibles a la relación entre tamaño del penacho y distancia entre puntos de medida. Para reducir los errores en la predicción de la varianza, la distancia entre puntos de observación debe ser menor que dos veces la desviación estándar del penacho. El tamaño del área muestreada debe cubrir varias desviaciones estándar del penacho para evitar perder parte de la masa. Las simulaciones numricas en un penacho dispersivo, comparando los cálculos basados en 9000 nudos con las 30 medidas, mostraron que las posiciones de los centros de masa y las varianzas en dirección horizontal se predijeron bien independientemente del grado de heterogeneidad. Las varianzas verticales, sin embargo, fueron más susceptibles a errores de predicción, pero las estimaciones eran del mismo orden de magnitud que los valores reales.

Performance of laser sintered Ti-6Al-4V implants with bone-inspired porosity and micro/nanoscale surface roughness in the rabbit femur

PubMed Central

Cohen, David J.; Cheng, Alice; Sahingur, Kaan; Clohessy, Ryan M.; Hopkins, Louis B.; Boyan, Barbara D.; Schwartz, Zvi

2018-01-01

Long term success of bone-interfacing implants remains a challenge in compromised patients and in areas of low bone quality. While surface roughness at the micro/nanoscale can promote osteogenesis, macro-scale porosity is important for promoting mechanical stability of the implant over time. Currently, machining techniques permit pores to be placed throughout the implant, but the pores are generally uniform in dimension. The advent of laser sintering provides a way to design and manufacture implants with specific porosity and variable dimensions at high resolution. This approach enables production of metal implants that mimic complex geometries found in biology. In this study, we used a rabbit femur model to compare osseointegration of laser sintered solid and porous implants. Ti-6Al-4V implants were laser sintered in a clinically relevant size and shape. One set of implants had a novel porosity based on human trabecular bone; both sets had grit-blasted/acid-etched surfaces. After characterization, implants were inserted transaxially into rabbit femora; mechanical testing, microCT and histomorphometry were conducted 10 weeks postoperatively. There were no differences in pull-out strength or bone-to-implant contact. However, both microCT and histomorphometry showed significantly higher new bone volume for porous compared to solid implants. Bone growth was observed into porous implant pores, especially near apical portions of the implant interfacing with cortical bone. These results show that laser sintered Ti-6Al-4V implants with micro/nanoscale surface roughness and trabecular bone-inspired porosity promote bone growth and may be used as a superior alternative to solid implants for bone-interfacing implants. PMID:28452335

Performance of laser sintered Ti-6Al-4V implants with bone-inspired porosity and micro/nanoscale surface roughness in the rabbit femur.

PubMed

Cohen, David J; Cheng, Alice; Sahingur, Kaan; Clohessy, Ryan M; Hopkins, Louis B; Boyan, Barbara D; Schwartz, Zvi

2017-04-28

Long term success of bone-interfacing implants remains a challenge in compromised patients and in areas of low bone quality. While surface roughness at the micro/nanoscale can promote osteogenesis, macro-scale porosity is important for promoting mechanical stability of the implant over time. Currently, machining techniques permit pores to be placed throughout the implant, but the pores are generally uniform in dimension. The advent of laser sintering provides a way to design and manufacture implants with specific porosity and variable dimensions at high resolution. This approach enables production of metal implants that mimic complex geometries found in biology. In this study, we used a rabbit femur model to compare osseointegration of laser sintered solid and porous implants. Ti-6Al-4V implants were laser sintered in a clinically relevant size and shape. One set of implants had a novel porosity based on human trabecular bone; both sets had grit-blasted/acid-etched surfaces. After characterization, implants were inserted transaxially into rabbit femora; mechanical testing, micro-computed tomography (microCT) and histomorphometry were conducted 10 weeks post-operatively. There were no differences in pull-out strength or bone-to-implant contact. However, both microCT and histomorphometry showed significantly higher new bone volume for porous compared to solid implants. Bone growth was observed into porous implant pores, especially near apical portions of the implant interfacing with cortical bone. These results show that laser sintered Ti-6Al-4V implants with micro/nanoscale surface roughness and trabecular bone-inspired porosity promote bone growth and may be used as a superior alternative to solid implants for bone-interfacing implants.

Sacroiliac joint stability: Finite element analysis of implant number, orientation, and superior implant length.

PubMed

Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

2018-03-18

To analyze how various implants placement variables affect sacroiliac (SI) joint range of motion. An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the SI joint using various placement configurations of triangular implants (iFuse Implant System ® ). Placement configurations were varied by changing implant orientation, superior implant length, and number of implants. The range of motion of the SI joint was calculated using a constant moment of 10 N-m with a follower load of 400 N. The changes in motion were compared between the treatment groups to assess how the different variables affected the overall motion of the SI joint. Transarticular placement of 3 implants with superior implants that end in the middle of the sacrum resulted in the greatest reduction in range of motion (flexion/extension = 73%, lateral bending = 42%, axial rotation = 72%). The range of motions of the SI joints were reduced with use of transarticular orientation (9%-18%) when compared with an inline orientation. The use of a superior implant that ended mid-sacrum resulted in median reductions of (8%-14%) when compared with a superior implant that ended in the middle of the ala. Reducing the number of implants, resulted in increased SI joint range of motions for the 1 and 2 implant models of 29%-133% and 2%-39%, respectively, when compared with the 3 implant model. Using a validated finite element model we demonstrated that placement of 3 implants across the SI joint using a transarticular orientation with superior implant reaching the sacral midline resulted in the most stable construct. Additional clinical studies may be required to confirm these results.

Sacroiliac joint stability: Finite element analysis of implant number, orientation, and superior implant length

PubMed Central

Lindsey, Derek P; Kiapour, Ali; Yerby, Scott A; Goel, Vijay K

2018-01-01

AIM To analyze how various implants placement variables affect sacroiliac (SI) joint range of motion. METHODS An experimentally validated finite element model of the lumbar spine and pelvis was used to simulate a fusion of the SI joint using various placement configurations of triangular implants (iFuse Implant System®). Placement configurations were varied by changing implant orientation, superior implant length, and number of implants. The range of motion of the SI joint was calculated using a constant moment of 10 N-m with a follower load of 400 N. The changes in motion were compared between the treatment groups to assess how the different variables affected the overall motion of the SI joint. RESULTS Transarticular placement of 3 implants with superior implants that end in the middle of the sacrum resulted in the greatest reduction in range of motion (flexion/extension = 73%, lateral bending = 42%, axial rotation = 72%). The range of motions of the SI joints were reduced with use of transarticular orientation (9%-18%) when compared with an inline orientation. The use of a superior implant that ended mid-sacrum resulted in median reductions of (8%-14%) when compared with a superior implant that ended in the middle of the ala. Reducing the number of implants, resulted in increased SI joint range of motions for the 1 and 2 implant models of 29%-133% and 2%-39%, respectively, when compared with the 3 implant model. CONCLUSION Using a validated finite element model we demonstrated that placement of 3 implants across the SI joint using a transarticular orientation with superior implant reaching the sacral midline resulted in the most stable construct. Additional clinical studies may be required to confirm these results. PMID:29564210

Implantable cardioverter defibrillator knowledge and end-of-life device deactivation: A cross-sectional survey.

PubMed

McEvedy, Samantha M; Cameron, Jan; Lugg, Eugene; Miller, Jennifer; Haedtke, Chris; Hammash, Muna; Biddle, Martha J; Lee, Kyoung Suk; Mariani, Justin A; Ski, Chantal F; Thompson, David R; Chung, Misook Lee; Moser, Debra K

2018-01-01

End-of-life implantable cardioverter defibrillator deactivation discussions should commence before device implantation and be ongoing, yet many implantable cardioverter defibrillators remain active in patients' last days. To examine associations among implantable cardioverter defibrillator knowledge, patient characteristics and attitudes to implantable cardioverter defibrillator deactivation. Cross-sectional survey using the Experiences, Attitudes and Knowledge of End-of-Life Issues in Implantable Cardioverter Defibrillator Patients Questionnaire. Participants were classified as insufficient or sufficient implantable cardioverter defibrillator knowledge and the two groups were compared. Implantable cardioverter defibrillator recipients ( n = 270, mean age 61 ± 14 years; 73% male) were recruited from cardiology and implantable cardioverter defibrillator clinics attached to two tertiary hospitals in Melbourne, Australia, and two in Kentucky, the United States. Participants with insufficient implantable cardioverter defibrillator knowledge ( n = 77, 29%) were significantly older (mean age 66 vs 60 years, p = 0.001), less likely to be Caucasian (77% vs 87%, p  = 0.047), less likely to have received implantable cardioverter defibrillator shocks (26% vs 40%, p = 0.031), and more likely to have indications of mild cognitive impairment (Montreal Cognitive Assessment score <24: 44% vs 16%, p < 0.001). Insufficient implantable cardioverter defibrillator knowledge was associated with attitudes suggesting unwillingness to discuss implantable cardioverter defibrillator deactivation, even during the last days towards end of life ( p < 0.05). Implantable cardioverter defibrillator recipients, especially those who are older or have mild cognitive impairment, often have limited knowledge about implantable cardioverter defibrillator deactivation. This study identified several potential teachable moments throughout the patients' treatment trajectory. An interdisciplinary approach is required to ensure that discussions about implantable cardioverter defibrillator deactivation issues are initiated at appropriate time points, with family members ideally also included.

MEAT SCIENCE AND MUSCLE BIOLOGY SYMPOSIUM--anabolic implants and meat quality.

PubMed

Duckett, S K; Pratt, S L

2014-01-01

Anabolic implants are routinely used in the finishing phase of beef production to improve animal performance and feed efficiency. Implanting during the feedlot phase on average increases ADG 18%, feed intake 6%, feed efficiency 8%, carcass weight 5%, and ribeye area 4% compared with nonimplanted controls. Implants reduce the cost of beef production, which is important given current high feed costs and beef prices. In a 1996 review of 37 implant trials, the use of a combination (i.e., estrogenic and trenbolone acetate) implant increased returns by US$77/head compared with nonimplanted steers. If calculated using today's prices, a combination implant would increase returns by $163/head. However, concerns about potential negative effects of implants on marbling scores, quality grades, and tenderness exist. Changes in Warner-Bratzler shear force values of steaks from implanted steers are small (<0.5 kg) and appear related to an increase in initial tenderness, possibly due to hypertrophy of muscle fiber, instead of alterations in postmortem proteolysis. The increase in ribeye size observed with implanting may also reduce marbling scores through a dilution effect. The impact of anabolic implants on gene expression has shown that implanting downregulates expression of certain lipogenic genes (e.g., stearoyl-CoA desaturase, fatty acid synthetase, fatty acid elongase-6) in steers with low quality grades (Select-) but not in implanted steers with high quality grades (Choice-). Examination of the adipocyte's transcriptome has shown that 36 genes were differentially expressed due to implant treatment. More research is needed to further determine how anabolic implants alter lipogenic gene expression to address changes in marbling deposition with implant usage. Given our current high feed costs and cattle prices, anabolic implants are one of the most cost-effective technologies that can be used in beef production systems.

Retrospective cohort study of the clinical performance of 1-stage dental implants.

PubMed

Carr, Alan B; Choi, Yong-Geun; Eckert, Steven E; Desjardins, Ronald P

2003-01-01

To evaluate long-term clinical performance of 1-stage dental implant prostheses at a single clinic, emphasizing clinical and demographic characteristics that affect implant survival. Dental records of all 308 patients (674 implants) treated with 1-stage implants at Mayo Clinic from October 1993 through May 2000 were reviewed from implant placement to last visit. Exposure and outcome variables affecting performance were collected separately to control bias in the data collection process. Additional confounding factors (age and sex) were adjusted with the stratified Cox proportional hazards model. Implant survival was determined by means of a Kaplan-Meier survival estimate. The log-rank test was used to determine the role of clinical and demographic variables in implant survival. The relative risk associated with the possible effect of clinical and demographic variables on implant survival was estimated with the Cox proportional hazards model. The implant survival rate (n = 654 implants) was 97% (mean +/- SD follow-up, 21.0 +/- 18.8 months; range, 1 to 78 months). Performance bias was limited because nearly all patients were treated by 1 prosthodontist. Two implants failed after loading (6 and 9 months). The incidence of complications was less than 4%. Among the implant failures, use of heterogeneous bone graft was associated with 4.8 times more failures than was use of autogenous bone graft (P = .04). After augmentation, delaying implant placement for 5 to 6 months resulted in 8.6 times more failures than the rate after earlier placement (P < .001). Retrospective review of the clinical performance of a 1-stage dental implant system yielded a 97% survival rate, with no failures noted after 13 months. Prosthetic complications were low, especially for fixed implant prostheses. Clinical performance of 1-stage dental implant prostheses between 1993 and 2000 demonstrated a high level of predictability.

A Retrospective Analysis of Dental Implants Replacing Failed Implants in Grafted Maxillary Sinus: A Case Series.

PubMed

Manor, Yifat; Chaushu, Gavriel; Lorean, Adi; Mijiritzky, Eithan

2015-01-01

To evaluate the survival rate of dental implants replacing failed implants in grafted maxillary sinuses using the lateral approach vs nongrafted posterior maxillae. A retrospective analysis was conducted to study the survival of secondary dental implants inserted in the posterior maxilla in previously failed implant sites between the years 2000 and 2010. The study group consisted of patients who had also undergone maxillary sinus augmentation, and the control group consisted of patients in whom implants in the posterior maxilla had failed. Clinical and demographic data were analyzed using a structured form. Seventy-five patients with a total of 75 replaced implants were included in the study. The study group comprised 40 patients and the control group, 35 patients. None of the replaced implants in the study group failed, resulting in an overall survival of 100%; three replaced implants in the control group failed (92% survival). The main reason for the primary implant removal was lack of osseointegration (35 [87.5%] of 40 study group implants and 23 [65.7%] of 35 control group implants [P = .027]). The difference between the groups with regard to the timing of primary implant failure was statistically significant. The study group had more early failures of the primary implant than did the control group (77% vs 62%; P = .038). Dental implants replaced in the posterior maxilla had a high survival rate. A higher rate of survival was found in augmented maxillary sinus sites. Within the limits of the present study, it can be concluded that previous implant failures in the grafted maxillary sinus should not discourage practitioners from a second attempt.

Group D. Initiator paper. Implants--peri-implant (hard and soft tissue) interactions in health and disease: the impact of explosion of implant manufacturers.

PubMed

Ivanovski, Saso

2015-01-01

1. The best-documented implants have a threaded solid screw-type design and are manufactured from commercially pure (grade IV) titanium. There is good evidence to support implants ≥ 6 mm in length, and ≥ 3 mm in diameter. 2. Integrity of the seal between the abutment and the implant is important for several reasons, including minimization of mechanical and biological complications and maintaining marginal bone levels. Although the ideal design features of the implant-abutment connection have not been determined, an internal connection, micro-grooves at the implant collar, and horizontal offset of the implant-abutment junction (platform switch) appear to impart favorable properties. 3. Implants with moderately rough implant surfaces provide advantages over machined surfaces in terms of the speed and extent of osseointegration. While the favorable performances of both minimally and moderately rough surfaces are supported by long-term data, moderately rough surfaces provide superior outcomes in compromised sites, such as the posterior maxilla. 4. Although plaque is critical in the progression of peri-implantitis, the disease has a multi-factorial aetiology, and may be influenced by poor integrity of the abutment/implant connection. Iatrogenic factors, such as the introduction of a foreign body. (e.g., cement) below the mucosal margin, can be important contributors. 5. Clinicians should exercise caution when using a particular implant system, ensuring that the implant design is appropriate and supported by scientific evidence. Central to this is access to and participation in quality education on the impact that implant characteristics can have on clinical outcomes. Caution should be exercised in utilizing non-genuine restorative componentry that may lead to a poor implant-abutment fit and subsequent technical and biological complications.

Systematic review of the effectiveness of polyurethane-coated compared with textured silicone implants in breast surgery.

PubMed

Duxbury, Paula J; Harvey, James R

2016-04-01

Silicone gel implants are used worldwide for breast augmentation and breast reconstruction. Textured silicone implants are the most commonly placed implant, but polyurethane-coated implants are increasingly being used in an attempt to ameliorate the long-term complications associated with implant insertion. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Electronic searches of MEDLINE, EMBASE, the Cochrane Library and www.ClinicalTrials.gov were undertaken in March 2014 using keywords. Following data extraction, 18 studies were included in the review, including four core studies of textured silicone implants and five studies reporting outcomes for polyurethane-coated silicone implants. There are no clear data reporting revision rates in patients treated with polyurethane implants. In the primary reconstructive setting, capsular contracture rates with silicone implants are 10-15% at 6 years, whilst studies of polyurethane implants report rates of 1.8-3.4%. In the primary augmentation setting, core studies show a capsular contracture rate of 2-15% at 6 years compared with 0.4-1% in polyurethane-coated implants; however, the polyurethane studies are limited by their design and poor follow-up. The use of polyurethane implants should be considered a safe alternative to textured silicone implants. It is likely that an implant surface does influence short- and long-term outcomes; however, the extent of any benefit cannot be determined from the available evidence base. Future implant studies should target the short- and long-term benefits of implant surfacing by procedure with defined outcome measures; a head-to-head comparison would help clarify outcomes. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Comparative evaluation of the effectiveness of the implantation in the lateral part of the mandible between short tissue level (TE) and bone level (BL) implant systems.

PubMed

Hadzik, Jakub; Botzenhart, Ute; Krawiec, Maciej; Gedrange, Tomasz; Heinemann, Friedhelm; Vegh, Andras; Dominiak, Marzena

2017-09-01

Short dental implants can be an alternative method of treatment to a vertical bone augmentation procedure at sites of reduced alveolar height. However, for successful treatment, an implant system that causes a minimal marginal bone loss (MBL) should be taken into consideration. The aim of the study has been to evaluate implantation effectiveness for bone level and tissue level short implants provided in lateral aspects of partially edentulous mandible and limited alveolar ridge height. The MBL and primary as well as secondary implant stability were determined in the study. Patients were randomly divided into two groups according to the method of treatment provided. Sixteen short Bone Level Implants (OsseoSpeed TX, Astra tech) and 16 short Tissue Level Implants (RN SLActive ® , Straumann) were successfully placed in the edentulous part of the mandible. The determination of the marginal bone level was based on radiographic evaluation after 12 and 36 weeks. Implant stability was measured immediately after insertion and after 12 weeks. The marginal bone level of Bone Level Implants was significantly lower compared to Tissue Level Implants. Furthermore, the Bone Level Implants had greater primary and secondary stability in comparison with Tissue Level Implants (Primary: 77.8 ISQ versus 66.5 ISQ; Secondary: 78.9 ISQ versus 73.9 ISQ, respectively). Since short Bone Level Implants showed a significantly decreased MBL 12 and 36 weeks after implantation as well as better results for the primary stability compared to Tissue Level Implants, they should preferentially be used for this mentioned indication. Copyright © 2017 Elsevier GmbH. All rights reserved.

Evaluation of primary stability of self-tapping and non-self-tapping dental implants. A 12-week clinical study.

PubMed

Marković, Aleksa; Calvo-Guirado, José Luís; Lazić, Zoran; Gómez-Moreno, Gerardo; Ćalasan, Dejan; Guardia, Javier; Čolic, Snježana; Aguilar-Salvatierra, Antonio; Gačić, Bojan; Delgado-Ruiz, Rafael; Janjić, Bojan; Mišić, Tijana

2013-06-01

The aim of this study was to investigate the relationship between surgical techniques and implant macro-design (self-tapping/non-self-tapping) for the optimization of implant stability in the low-density bone present in the posterior maxilla using resonance frequency analysis (RFA). A total of 102 implants were studied. Fifty-six self-tapping BlueSkyBredent® (Bredent GmbH&Co.Kg®, Senden, Germany) and 56 non-self-tapping Standard Plus Straumann® (Institut Straumann AG®, Waldenburg, Switzerland) were placed in the posterior segment of the maxilla. Implants of both types were placed in sites prepared with either lateral bone-condensing or with bone-drilling techniques. Implant stability measurements were performed using RFA immediately after implant placement and weekly during a 12-week follow-up period. Both types of implants placed after bone condensing achieved significantly higher stability immediately after surgery, as well as during the entire 12-week observation period compared with those placed following bone drilling. After bone condensation, there were no significant differences in primary stability or in implant stability after the first week between both implant types. From 2 to 12 postoperative weeks, significantly higher stability was shown by self-tapping implants. After bone drilling, self-tapping implants achieved significantly higher stability than non-self-tapping implants during the entire follow-up period. The outcomes of the present study indicate that bone drilling is not an effective technique for improving implant stability and, following this technique, the use of self-tapping implants is highly recommended. Implant stability optimization in the soft bone can be achieved by lateral bone-condensing technique, regardless of implant macro-design. © 2011 Wiley Periodicals, Inc.

Machined versus roughened immediately loaded and finally restored single implants inserted flapless: Preliminary 6-month data from a split- mouth randomised controlled trial.

PubMed

Cannizzaro, Gioacchino; Felice, Pietro; Loi, Ignazio; Viola, Paolo; Ferri, Vittorio; Leone, Michele; Lazzarini, Matteo; Trullenque-Eriksson, Anna; Esposito, Marco

To compare the outcome of immediately loaded single implants with a machined or a roughened surface. Fifty patients had two implant sites randomly allocated to receive flaplessplaced single Syra implants (Sweden & Martina), one with a machined and one with a roughened surface (sand-blasted with zirconia powder and acid etched), according to a split-mouth design. To be loaded immediately, implants had to be inserted with a torque superior to 50 Ncm. Implants were restored with definitive crowns in direct occlusal contact within 48 h. Patients were followed for 6 months after loading. Outcome measures were prosthetic and implant failures and complications. Two machined implants and four roughened implants were not loaded immediately. Six months after loading no dropout occurred. One implant loaded late, which had a rough implant surface, failed 20 days after loading (P (McNemar test) = 0.625; difference in proportions = -0.04; 95% CI: -0.15 to 0.07). Three crowns had to be remade on machined implants and four on roughened implants (P (McNemar test) = 1.000; difference in proportions = -0.02; 95% CI: -0.12 to 0.08). Three machined and five roughened implants experienced complications (P (McNemar test) = 0.625; difference in proportions = -0.04; 95% CI: -0.15 to 0.07). There were no statistically significant differences between groups for crown and implant losses as well as complications. Up to 6 months after loading both machined and roughened flapless-placed and immediately loaded single implants provided good and similar results, however, longer follow-ups are needed to evaluate the long-term prognosis of implants with different surfaces.

Impact of Different Surgeons on Dental Implant Failure.

PubMed

Chrcanovic, Bruno Ramos; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

To assess the influence of several factors on the prevalence of dental implant failure, with special consideration of the placement of implants by different dental surgeons. This retrospective study is based on 2,670 patients who received 10,096 implants at one specialist clinic. Only the data of patients and implants treated by surgeons who had inserted a minimum of 200 implants at the clinic were included. Kaplan-Meier curves were stratified with respect to the individual surgeon. A generalized estimating equation (GEE) method was used to account for the fact that repeated observations (several implants) were placed in a single patient. The factors bone quantity, bone quality, implant location, implant surface, and implant system were analyzed with descriptive statistics separately for each individual surgeon. A total of 10 surgeons were eligible. The differences between the survival curves of each individual were statistically significant. The multivariate GEE model showed the following variables to be statistically significant: surgeon, bruxism, intake of antidepressants, location, implant length, and implant system. The surgeon with the highest absolute number of failures was also the one who inserted the most implants in sites of poor bone and used turned implants in most cases, whereas the surgeon with the lowest absolute number of failures used mainly modern implants. Separate survival analyses of turned and modern implants stratified for the individual surgeon showed statistically significant differences in cumulative survival. Different levels of failure incidence could be observed between the surgeons, occasionally reaching significant levels. Although a direct causal relationship could not be ascertained, the results of the present study suggest that the surgeons' technique, skills, and/or judgment may negatively influence implant survival rates.

The effect of undersizing and tapping on bone to implant contact and implant primary stability: A histomorphometric study on bovine ribs.

PubMed

Di Stefano, Danilo Alessio; Perrotti, Vittoria; Greco, Gian Battista; Cappucci, Claudia; Arosio, Paolo; Piattelli, Adriano; Iezzi, Giovanna

2018-06-01

Implant site preparation may be adjusted to achieve the maximum possible primary stability. The aim of this investigation was to study the relation among bone-to-implant contact at insertion, bone density, and implant primary stability intra-operatively measured by a torque-measuring implant motor, when implant sites were undersized or tapped. Undersized (n=14), standard (n=13), and tapped (n=13) implant sites were prepared on 9 segments of bovine ribs. After measuring bone density using the implant motor, 40 implants were placed, and their primary stability assessed by measuring the integral of the torque-depth insertion curve. Bovine ribs were then processed histologically, the bone-to-implant contact measured and statistically correlated to bone density and the integral. Bone-to-implant contact and the integral of the torque-depth curve were significantly greater for undersized sites than tapped sites. Moreover, a correlation between bone to implant contact, the integral and bone density was found under all preparation conditions. The slope of the bone-to-implant/density and integral/density lines was significantly greater for undersized sites, while those corresponding to standard prepared and tapped sites did not differ significantly. The integral of the torque-depth curve provided reliable information about bone-to-implant contact and primary implant stability even in tapped or undersized sites. The linear relations found among the parameters suggests a connection between extent and modality of undersizing and the corresponding increase of the integral and, consequently, of primary stability. These results might help the physician determine the extent of undersizing needed to achieve the proper implant primary stability, according to the planned loading protocol.

A prospective clinical study to evaluate the performance of zirconium dioxide dental implants in single-tooth gaps.

PubMed

Gahlert, Michael; Kniha, Heinz; Weingart, Dieter; Schild, Sabine; Gellrich, Nils-Claudius; Bormann, Kai-Hendrik

2016-12-01

Dental implants have traditionally been made from titanium or its alloys, but recently full-ceramic implants have been developed with comparable osseointegration properties and functional strength properties to titanium. These ceramic implants may have advantages in certain patients and situations, for example, where esthetic outcomes are particularly important. The objective of this investigation was to evaluate the performance of a newly developed full-ceramic ZrO 2 monotype implant design (PURE Ceramic Implant; Institut Straumann AG, Basel, Switzerland) in single-tooth gaps in the maxilla and mandible. This was a prospective, open-label, single-arm study in patients requiring implant rehabilitation in single-tooth gaps. Full-ceramic implants were placed, with provisional and final prostheses inserted after 3 and 6 months, respectively. Crestal bone level was measured at implant placement and after 6 and 12 months. Implant survival and success were evaluated after 6 and 12 months. Further evaluations are planned after 24 and 36 months. Forty-six patients were screened for potential study participation, of whom 44 (17 men and 27 women, mean age 48 ± 14 years) were recruited into the study. The majority of implants (90.9%) were placed in the maxilla. The implant survival and implant success rate after 12 months were 97.6%. A minor change of the mean bone level occurred between implant loading (final prosthesis insertion after 6 months) and 12 months (-0.14 mm) after initial bone remodeling was observed between implant placement and loading (-0.88 mm). The results indicated that monotype ceramic implants can achieve clinical outcomes comparable to published outcomes of equivalent titanium implants. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Short Dental Implants Retaining Two-Implant Mandibular Overdentures in Very Old, Dependent Patients: Radiologic and Clinical Observation Up to 5 Years.

PubMed

Maniewicz, Sabrina; Buser, Ramona; Duvernay, Elena; Vazquez, Lydia; Loup, Angelica; Perneger, Thomas V; Schimmel, Martin; Müller, Frauke

To describe the survival rate and peri-implant bone loss in very old patients dependent for their activities of daily living (ADL), treated with mandibular two-implant overdentures (IODs) in the context of a previously reported randomized controlled trial. A total of 19 patients received two interforaminal Straumann implants (Regular Neck, 4.1 mm diameter, 8 mm length) that were subsequently loaded with Locator attachments, transforming their preexisting inferior conventional denture into an IOD. The primary outcome measures were implant survival rate and radiographically assessed peri-implant bone loss. Secondary outcome measures included peri-implant probing depth and Plaque Index scores, as well as implant mobility. Nutritional state (body mass index and blood markers) and cognitive state (Mini-Mental State Examination) were also analyzed. The patient cohort comprised eight men and 11 women with a mean age of 85.7 ± 6.6 years. The implant survival rate up to 5 years was 94.7%, with one early and one late implant failure. The mean loss of peri-implant bone height was 0.17 mm per year (95% confidence interval: 0.09 to 0.24; P < .001). Peri-implant probing depth and Plaque Index scores were low and stable during the first 2 years, and thereafter increased continuously. Correlation analysis suggests that a reduced cognitive function and nutritional state are not a particular risk factor for accelerated peri-implant bone loss. The high implant survival and acceptable peri-implant health suggest that neither age nor dependency for the ADLs is a contraindication for the placement of implants. Nevertheless, close monitoring of the patients concerning a potential further functional decline precluding denture management and performing oral hygiene measures is advised.

Bone healing at implants with a fluoride-modified surface: an experimental study in dogs.

PubMed

Berglundh, T; Abrahamsson, I; Albouy, J-P; Lindhe, J

2007-04-01

The aim of the present experiment was to study early stages of osseointegration to implants with a fluoride-modified surface. Six mongrel dogs, about 1-year old, were used. All mandibular premolars and the first mandibular molars were extracted. Three months later, mucoperiosteal flaps were elevated in one side of the mandible and six sites were identified for implant placement. The control implants (MicroThread) had a TiOblast surface, while the test implants (OsseoSpeed) had a fluoride-modified TiOblast surface. Both types of implants had a similar geometry, a diameter of 3.5 mm and were 8 mm long. Following installation, cover screws were placed and the flaps were adjusted and sutured to cover all implants. Four weeks after the first implant surgery, the installation procedure was repeated in the opposite side of the mandible. Two weeks later, biopsies were obtained and prepared for histological analysis. The void that occurred between the cut bone wall of the recipient site and the macro-threads of the implant immediately following implant installation was used to study early bone formation. It was demonstrated that the amount of new bone that formed in the voids within the first 2 weeks of healing was larger at fluoride-modified implants (test) than at TiOblast (control) implants. It was further observed that the amount of bone-to-implant contact that had been established after 2 weeks in the macro-threaded portion of the implant was significantly larger at the test implants than at the controls. It is suggested that the fluoride-modified implant surface promotes osseointegration in the early phase of healing following implant installation.

Enhanced antitumor efficacy of poly(D,L-lactide-co-glycolide)-based methotrexate-loaded implants on sarcoma 180 tumor-bearing mice

PubMed Central

Gao, Li; Xia, Lunyang; Zhang, Ruhui; Duan, Dandan; Liu, Xiuxiu; Xu, Jianjian; Luo, Lan

2017-01-01

Purpose Methotrexate is widely used in chemotherapy for a variety of malignancies. However, severe toxicity, poor pharmacokinetics, and narrow safety margin of methotrexate limit its clinical application. The aim of this study was to develop sustained-release methotrexate-loaded implants and evaluate antitumor activity of the implants after intratumoral implantation. Materials and methods We prepared the implants containing methotrexate, poly(D,L-lactide-co-glycolide), and polyethylene glycol 4000 with the melt-molding technique. The implants were characterized with regards to drug content, morphology, in vitro, and in vivo release profiles. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were carried out to investigate the physicochemical properties of the implants. Furthermore, the antitumor activity of the implants was tested in a sarcoma 180 mouse model. Results The implants were prepared as solid rods. Scanning electron microscopy images showed a smooth surface of the implant, suggesting that methotrexate was homogeneously dispersed in the polymeric matrix. The results of DSC and FTIR indicated that no significant interaction between methotrexate and the polymer was observed in the implants. Both in vitro and in vivo release profiles of the implants were characterized by burst release followed by sustained release of methotrexate. Intratumoral implantation of methotrexate-loaded implants could efficiently delay tumor growth. Moreover, an increase in the dose of implants led to a higher tumor suppression rate without additional systemic toxicity. Conclusion These results demonstrate that methotrexate-loaded implants had significant antitumor efficacy in a sarcoma 180 mouse model without dose-limiting side effects, and suggest that the implants could be potentially applied as an intratumoral delivery system to treat cancer. PMID:29118572

Analysis of risk factors for cluster behavior of dental implant failures.

PubMed

Chrcanovic, Bruno Ramos; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

2017-08-01

Some studies indicated that implant failures are commonly concentrated in few patients. To identify and analyze cluster behavior of dental implant failures among subjects of a retrospective study. This retrospective study included patients receiving at least three implants only. Patients presenting at least three implant failures were classified as presenting a cluster behavior. Univariate and multivariate logistic regression models and generalized estimating equations analysis evaluated the effect of explanatory variables on the cluster behavior. There were 1406 patients with three or more implants (8337 implants, 592 failures). Sixty-seven (4.77%) patients presented cluster behavior, with 56.8% of all implant failures. The intake of antidepressants and bruxism were identified as potential negative factors exerting a statistically significant influence on a cluster behavior at the patient-level. The negative factors at the implant-level were turned implants, short implants, poor bone quality, age of the patient, the intake of medicaments to reduce the acid gastric production, smoking, and bruxism. A cluster pattern among patients with implant failure is highly probable. Factors of interest as predictors for implant failures could be a number of systemic and local factors, although a direct causal relationship cannot be ascertained. © 2017 Wiley Periodicals, Inc.

Implant-Abutment Contact Surfaces and Microgap Measurements of Different Implant Connections Under 3-Dimensional X-Ray Microtomography.

PubMed

Scarano, Antonio; Valbonetti, Luca; Degidi, Marco; Pecci, Raffaella; Piattelli, Adriano; de Oliveira, P S; Perrotti, Vittoria

2016-10-01

The presence of a microgap between implant and abutment could produce a bacterial reservoir which could interfere with the long-term health of the periimplant tissues. The aim of this article was to evaluate, by x-ray 3-dimensional microtomography, implant-abutment contact surfaces and microgaps at the implant-abutment interface in different types of implant-abutment connections. A total of 40 implants were used in this in vitro study. Ten implants presented a screw-retained internal hexagon abutment (group I), 10 had a Morse Cone taper internal connection (group II), 10 another type of Morse Cone taper internal connection (group III), and 10 had a screwed trilobed connection (group IV). In both types of Morse Cone internal connections, there was no detectable separation at the implant-abutment in the area of the conical connection, and there was an absolute congruity without any microgaps between abutment and implant. No line was visible separating the implant and the abutment. On the contrary, in the screwed abutment implants, numerous gaps and voids were present. The results of this study support the hypothesis that different types of implant-abutment joints are responsible for the observed differences in bacterial penetration.

A review of nanostructured surfaces and materials for dental implants: surface coating, patterning and functionalization for improved performance.

PubMed

Rasouli, Rahimeh; Barhoum, Ahmed; Uludag, Hasan

2018-05-10

The emerging field of nanostructured implants has enormous scope in the areas of medical science and dental implants. Surface nanofeatures provide significant potential solutions to medical problems by the introduction of better biomaterials, improved implant design, and surface engineering techniques such as coating, patterning, functionalization and molecular grafting at the nanoscale. This review is of an interdisciplinary nature, addressing the history and development of dental implants and the emerging area of nanotechnology in dental implants. After a brief introduction to nanotechnology in dental implants and the main classes of dental implants, an overview of different types of nanomaterials (i.e. metals, metal oxides, ceramics, polymers and hydrides) used in dental implant together with their unique properties, the influence of elemental compositions, and surface morphologies and possible applications are presented from a chemical point of view. In the core of this review, the dental implant materials, physical and chemical fabrication techniques and the role of nanotechnology in achieving ideal dental implants have been discussed. Finally, the critical parameters in dental implant design and available data on the current dental implant surfaces that use nanotopography in clinical dentistry have been discussed.

Effect of Induced Periimplantitis on Dental Implants With and Without Ultrathin Hydroxyapatite Coating.

PubMed

Madi, Marwa; Zakaria, Osama; Ichinose, Shizuko; Kasugai, Shohei

2016-02-01

The aim of this study was to compare the effect of ligature-induced periimplantitis on dental implants with and without hydroxyapatite (HA) coat. Thirty-two dental implants (3.3 mm wide, 13 mm long) with 4 surface treatments (8 implant/group) (M: machined, SA: sandblasted acid etched, S: sputter HA coat and P: plasma-sprayed HA coat) were inserted into canine mandibles. After 12 weeks, oral hygiene procedures were stopped and silk ligatures were placed around the implant abutments to allow plaque accumulation for the following 16 weeks. Implants with the surrounding tissues were retrieved and prepared for histological examination. Bone-to-implant contact (BIC) and implant surfaces were examined using scanning electron microscopy and energy dispersive x-ray spectroscopy. Histological observation revealed marginal bone loss and large inflammatory cell infiltrates in the periimplant soft tissue. Sputter HA implants showed the largest BIC (98.1%) and machined implant showed the smallest values (70.4%). After 28 weeks, thin sputter HA coat was almost completely dissolved, whereas plasma-sprayed HA coat showed complete thickness preservation. Thin sputter HA-coated implants showed more bone implant contact and less marginal bone loss than thick HA-coated implants under periimplantitis condition.

Evaluation of single-tooth implants in the second molar region: a 5-year life-table analysis of a retrospective study.

PubMed

Koo, Ki-Tae; Wikesjö, Ulf M E; Park, Jang-Yeol; Kim, Tae-Il; Seol, Yang-Jo; Ku, Young; Rhyu, In-Chul; Chung, Chong-Pyoung; Lee, Yong-Moo

2010-09-01

To our knowledge, no study has evaluated the success or survival rate of single-tooth implants that replaced missing maxillary and mandibular second molars. The purpose of the present study was to evaluate the 1- to 5-year cumulative survival rate (CSR) for single-tooth implants placed in the second molar region and the effects of associated factors. Four hundred eighty-nine patients (298 males and 191 females; age range: 23 to 91 years; mean age: 47 years) who were admitted to the Seoul National University Dental Hospital between March 2003 and July 2008 and treated with single-tooth implants in the second molar region (227 maxillary implants and 294 mandibular implants; total: 521 implants) were included in the study. Thirty-two subjects received two implants each. A 1- to 5-year CSR was calculated using a life-table analysis. A comparison of CSRs between maxillary versus mandibular implants, one-stage versus two-stage implants, short (10 mm) implants, and standard-diameter (or=5.0 mm) implants was performed using Wilcoxon (Gehan) statistics. P <0.05 was considered significant. Fifteen of the 521 implants were lost between insertion and the follow-up examinations. The 1- to 5-year CSR was 95.1%. There were no statistically significant differences in CSRs between implants placed in maxillas and mandibles (96.3% versus 94.9%, respectively; P = 0.084), one- and two-stage implants (95.6% versus 94.7%, respectively; P = 0.267), short and long implants (100% versus 95.1%, respectively; P = 0.582), and standard- and wide-diameter implants (93.8% versus 96.8%, respectively; P = 0.065). Within the limitations of the study, the placement of single-tooth implants in the second molar region was an effective and reliable treatment modality. Also, associated factors such as implant diameter, length, and location (the maxilla versus the mandible) may not have an impact on the long-term success of implants.

Comparative Clinical Study of Conventional Dental Implants and Mini Dental Implants for Mandibular Overdentures: A Randomized Clinical Trial.

PubMed

Aunmeungtong, Weerapan; Kumchai, Thongnard; Strietzel, Frank P; Reichart, Peter A; Khongkhunthian, Pathawee

2017-04-01

Dental implant-retained overdentures have been chosen as the treatment of choice for complete mandibular removable dentures. Dental implants, such as mini dental implants, and components for retaining overdentures, are commercially available. However, comparative clinical studies comparing mini dental implants and conventional dental implants using different attachment for implant-retained overdentures have not been well documented. To compare the clinical outcomes of using two mini dental implants with Equator ® attachments, four mini dental implants with Equator attachments, or two conventional dental implants with ball attachments, by means of a randomized clinical trial. Sixty patients received implant-retained mandibular overdentures in the interforaminal region. The patients were divided into three groups. In Groups 1 and 2, two and four mini dental implants, respectively, were placed and immediately loaded by overdentures, using Equator ® attachments. In Group 3, conventional implants were placed. After osseointegration, the implants were loaded by overdentures, using ball attachments. The study distribution was randomized and double-blinded. Outcome measures included changes in radiological peri-implant bone level from surgery to 12 months postinsertion, prosthodontic complications and patient satisfaction. The cumulative survival rate in the three clinical groups after one year was 100%. There was no significant difference (p < 0.05) in clinical results regarding the number (two or four) of mini dental implants with Equator attachments. However, there was a significant difference in marginal bone loss and patient satisfaction between those receiving mini dental implants with Equator attachments and conventional dental implants with ball attachments. The marginal bone resorption in Group 3 was significantly higher than in Groups 1 and 2 (p < 0.05); there were no significant differences between Groups 1 and 2. There was no significant difference in patient satisfaction between Groups 1 and 2 but it was significantly higher than that in Group3 (p < 0.05). Two and four mini dental implants can be immediately used successfully for retaining lower complete dentures, as shown after a 1-year follow up. © 2016 Wiley Periodicals, Inc.

Titanium versus zirconia implants supporting maxillary overdentures: three-dimensional finite element analysis.

PubMed

Osman, Reham B; Elkhadem, Amr H; Ma, Sunyoung; Swain, Michael V

2013-01-01

The purpose of this study was to compare the stress and strain occurring in peri-implant bone and implants used to support maxillary overdentures. Three-dimensional finite element analysis (3D FEA) was used to compare one-piece zirconia and titanium implants. Two types of implants were simulated using a 3D FEA model: one-piece zirconia and titanium implants (diameter, 3.8 × 11.5 mm) with 2.25-mm diameter ball abutments. In each simulation four implants were placed bilaterally in the canine/premolar region of an edentulous maxillary model. Static loads were applied axially and 20 degrees buccolingually on the buccal slope of the lingual cusps of posterior teeth of the first quadrant. Von Mises stresses and equivalent strains generated in peri-implant bone and first principal stresses in the implants were calculated. Comparable stress and strain values were shown in the peri-implant bone for both types of implants. The maximum equivalent strain produced in the peri-implant region was mostly within the range for bone augmentation. Under oblique loading, maximum von Mises stresses and equivalent strain were more evident at the neck of the most distal implant on the loaded side. Under axial load, the stress and strain were transferred to the peri-implant bone around the apex of the implant. Maximum tensile stresses that developed for either material were well below their fracture strength. The highest stresses were mainly located at the distobuccal region of the neck for the two implant materials under both loading conditions. From a biomechanical point of view, ceramic implants made from yttrium-stabilized tetragonal polycrystalline zirconia may be a potential alternative to conventional titanium implants for the support of overdentures. This is particularly relevant for a select group of patients with a proven allergy to titanium. Prospective clinical studies are still required to confirm these in vitro results. Different simulations presenting various cortical bone thicknesses and implant designs are required to provide a better understanding of the biomechanics of zirconia implants.

2D FEA of evaluation of micromovements and stresses at bone-implant interface in immediately loaded tapered implants in the posterior maxilla

PubMed Central

Desai, Shrikar R.; Singh, Rika; Karthikeyan, I.

2013-01-01

Aim: The aim of the study is to evaluate the influence implant length on stress distribution at bone implant interface in single immediately loaded implants when placed in D4 bone quality. Materials and Methods: A 2-dimensional finite element models were developed to simulate two types of implant designs, standard 3.75 mm–diameter tapered body implants of 6 and 10 mm lengths. The implants were placed in D4 bone quality with a cortical bone thickness of 0.5 mm. The implant design incorporated microthreads at the crestal part and the rest of the implant body incorporated Acme threads. The Acme thread form has a 29° thread angle with a thread height half of the pitch; the apex and valley are flat. A 100 N of force was applied vertically and in the oblique direction (at an angle of 45°) to the long axis of the implants. The respective material properties were assigned. Micro-movements and stresses at the bone implant interface were evaluated. Results: The results of total deformation (micro-movement) and Von mises stress were found to be lower for tapered long implant (10 mm) than short implant (6 mm) while using both vertical as well as oblique loading. Conclusion: Short implants can be successfully placed in poor bone quality under immediate loading protocol. The novel approach of the combination of microthreads at the crestal portion and acme threads for body portion of implant fixture gave promising results. PMID:24174759

Effect of Macrogeometry on the Surface Topography of Dental Implants.

PubMed

Naves, Marina Melo; Menezes, Helder Henrique Machado; Magalhães, Denildo; Ferreira, Jessica Afonso; Ribeiro, Sara Ferreira; de Mello, José Daniel Biasoli; Costa, Henara Lillian

2015-01-01

Because the microtopography of titanium implants influences the biomaterial-tissue interaction, surface microtexturing treatments are frequently used for dental implants. However, surface treatment alone may not determine the final microtopography of a dental implant, which can also be influenced by the implant macrogeometry. This work analyzed the effects on surface roughness parameters of the same treatment applied by the same manufacturer to implants with differing macro-designs. Three groups of titanium implants with different macro-designs were investigated using laser interferometry and scanning electron microscopy. Relevant surface roughness parameters were calculated for different regions of each implant. Two flat disks (treated and untreated) were also investigated for comparison. The tops of the threads and the nonthreaded regions of all implants had very similar roughness parameters, independent of the geometry of the implant, which were also very similar to those of flat disks treated with the same process. In contrast, the flanks and valleys of the threads presented larger irregularities (Sa) with higher slopes (Sdq) and larger developed surface areas (Sdr) on all implants, particularly for implants with threads with smaller heights. The flanks and valleys displayed stronger textures (Str), particularly on the implants with threads with larger internal angles. Parameters associated with the height of the irregularities (Sa), the slope of the asperities (Sdq), the presence of a surface texture (Str), and the developed surface area of the irregularities (Sdr) were significantly affected by the macrogeometry of the implants. Flat disks subjected to the same surface treatment as dental implants reproduced only the surface topography of the flat regions of the implants.

Maxillary "All-On-Four" treatment using zygomatic implants. A mechanical analysis.

PubMed

de Moraes, P H; Olate, S; Nóbilo, M de Arruda; Asprino, L; de Moraes, M; Barbosa, J de Albergaría

2016-04-01

Zygomatic implants may be used for dental rehabilitation in atrophic maxillae. The aim of this study was to establish experimentally the areas of stress distribution using 2 kinds of "All-On-Four" maxillary procedures. The best position to insert the implants was selected using polyurethane craniomaxillary models and surgical guides were made. Group 1 was designed with two posterior zygomatic implants and two conventional anterior implants, and group 2 with two posterior zygomatic implants and two anterior zygomatic implants. A titanium bar was built to link the 4 implants in both groups. Photoelastic replicas of these models were made and the implants were inserted using the surgical guides. An Instrom 4411 testing machine was used to perform a unilateral compressive loading at the level of the right first molar until 2mm of displacement was obtained. Group 1 showed a high strain concentration in the right lateral orbital region at the level of the apex of the zygomatic implant. Less strain was noticed at the apical levels of the conventional implants in the anterior sector and of the contralateral zygomatic implant. Group 2 showed high strains in the lateral inferior orbital area. The load was low in the alveolar bone sector. Zygomatic bone and paranasal structures are loaded at high levels when zygomatic implants are used to stabilize a full maxillary prosthodontic rehabilitation on 4 implants. The use of 4 zygomatic implants loads the alveolar bone to a lower extent and seems better suited from a mechanical point of view than the use of 2 zygomatic implants. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Traditional Postextractive Implant Site Preparation Compared with Pre-extractive Interradicular Implant Bed Preparation in the Mandibular Molar Region, Using an Ultrasonic Device: A Randomized Pilot Study.

PubMed

Scarano, Antonio

The immediate placement of single postextractive implants is increasing in the everyday clinical practice. Due to insufficient bone tissue volume, proper primary stability, essential for subsequent osseointegration, is sometimes not reached. The aim of this work was to compare two different approaches: implant bed preparation before and after root extraction. Twenty-two patients of both sexes were selected who needed an implant-prosthetic rehabilitation of the fractured first mandibular molar or presented an untreatable endodontic pathology. The sites were randomly assigned to the test group (treated with implant bed preparation before molar extractions) or control group (treated with implant bed preparation after molar extractions) by a computer-generated table. All implants were placed by the same operator, who was experienced in both traditional and ultrasonic techniques. The implant stability quotient (ISQ) and the position of the implant were evaluated. Statistical analysis was carried out. In the control group, three implants were placed in the central portion of the bone septum, while eight implants were placed with a tilted axis in relation to the septum; in the test group, all implants were placed in ideal positions within the root extraction sockets. The different position of the implants between the two procedures was statistically significant. This work presented an innovative approach for implant placement at the time of mandibular molar extraction. Preparing the implant bed with an ultrasonic device before root extraction is a simple technique and also allows greater stability to be reached in a selective case.

Influence of metals on cytokines production in connection with successful implantation therapy in dentistry.

PubMed

Podzimek, Stepan; Tomka, Milan; Nemeth, Tibor; Himmlova, Lucie; Matucha, Petr; Prochazkova, Jarmila

2010-01-01

In most of patients in need of implantation treatment in the oral cavity, implants heal well, nevertheless, there are some individuals, in whom titanium implants fail for reasons, which remain unclear. The aim of our study was to determine if there is a difference between metal influenced IL-1β, IL-4, IL-6, TNF-α and IFN-γ cytokines production in patients with successfully healed implants compared to those, whose implant therapy was unsuccessful. The two study groups included 12 patients with failed dental titanium implants and 9 patients with successfully healed implants. In the subjects, cytokine production was established after lymphocyte cultivation with mercury, nickel and titanium antigens. IL-1β levels were significantly increased in all patients after stimulation with titanium and in patients with accepted implants compared to patients with failed implants after the stimulation with mercury and titanium. Titanium caused significantly increased IL-6 production in all patients. TNF-α and IFN-γ levels were also significantly increased after the stimulation with titanium. Significantly increased TNF-α levels were found in patients with accepted implants as compared to patients with failed implants. Increased production of IL-1β a IL-6 cytokines in reaction to titanium and increased production of TNF-α and IFN-γ cytokines in reaction to mercury, which is very often present in the form of amalgam in the oral cavity of persons in need of implant therapy, can play an important role in immune reactions during implant healing process. In patients with failed titanium implants, decreased production of these cytokines may participate in implant failure.

A Different Approach for Usage of the Implant Materials: The Composite Graft Prefabrication.

PubMed

Deniz, Lutfi Murat; Ataman, Murat Görkem; Borman, Huseyin; Erinanç, Hilal

2016-10-01

With all implanted materials, a certain sequence of biological events occurs following the implantation. This process is destructive to the implant and peri-implant tissues. The aforementioned sequence of biological events may be responsible for the complications. In this study, the natural biologic process following implantation was completed in an area other than the final implantation area. The aim was to keep the peri-implant tissues in the final implantation area away from the process. In the control group, the porous polyethylene discs were implanted to subcutaneous area on the frontal bone of the rats. A month after the implantation, macroscopic and microscopic examinations were performed. In the study group, the discs were implanted primarily above the rectus abdominis muscle of the rats. It was named as "the composite graft prefabrication." Twenty-one days after the first implantation, the discs were removed from the rectus muscle and implanted to subcutaneous area on the frontal bone of the rats. A month after the final implantation, macroscopic and microscopic examinations were performed. In macroscopic examination, all possible complications were evaluated. In microscopic examination, apoptosis, fibrosis, inflammation, and fibrovascular in-growing were evaluated. In the control group, implant exposure was observed in 3 of the rats. In the study group, no complications were observed. Although there was no statistical difference between 2 groups in the microscopic findings, at first glance, the inflammation seemed to be the factor responsible for the complication in the control group. According to the macroscopic results, the composite graft prefabrication seemed to be effective in preventing complications.

Primary prevention of peri-implantitis: managing peri-implant mucositis.

PubMed

Jepsen, Søren; Berglundh, Tord; Genco, Robert; Aass, Anne Merete; Demirel, Korkud; Derks, Jan; Figuero, Elena; Giovannoli, Jean Louis; Goldstein, Moshe; Lambert, France; Ortiz-Vigon, Alberto; Polyzois, Ioannis; Salvi, Giovanni E; Schwarz, Frank; Serino, Giovanni; Tomasi, Cristiano; Zitzmann, Nicola U

2015-04-01

Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considered as a preventive measure for the onset of peri-implantitis. Therefore, the remit of this working group was to assess the prevalence of peri-implant diseases, as well as risks for peri-implant mucositis and to evaluate measures for the management of peri-implant mucositis. Discussions were informed by four systematic reviews on the current epidemiology of peri-implant diseases, on potential risks contributing to the development of peri-implant mucositis, and on the effect of patient and of professionally administered measures to manage peri-implant mucositis. This consensus report is based on the outcomes of these systematic reviews and on the expert opinion of the participants. Key findings included: (i) meta-analysis estimated a weighted mean prevalence for peri-implant mucositis of 43% (CI: 32-54%) and for peri-implantitis of 22% (CI: 14-30%); (ii) bleeding on probing is considered as key clinical measure to distinguish between peri-implant health and disease; (iii) lack of regular supportive therapy in patients with peri-implant mucositis was associated with increased risk for onset of peri-implantitis; (iv) whereas plaque accumulation has been established as aetiological factor, smoking was identified as modifiable patient-related and excess cement as local risk indicator for the development of peri-implant mucositis; (v) patient-administered mechanical plaque control (with manual or powered toothbrushes) has been shown to be an effective preventive measure; (vi) professional intervention comprising oral hygiene instructions and mechanical debridement revealed a reduction in clinical signs of inflammation; (vii) adjunctive measures (antiseptics, local and systemic antibiotics, air-abrasive devices) were not found to improve the efficacy of professionally administered plaque removal in reducing clinical signs of inflammation. Consensus was reached on recommendations for patients with dental implants and oral health care professionals with regard to the efficacy of measures to manage peri-implant mucositis. It was particularly emphasized that implant placement and prosthetic reconstructions need to allow proper personal cleaning, diagnosis by probing and professional plaque removal. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Silicone Gel-Filled Breast Implants

MedlinePlus

... and Medical Procedures Implants and Prosthetics Breast Implants Silicone Gel-Filled Breast Implants Share Tweet Linkedin Pin ... sharing options Linkedin Pin it Email Print Description: Silicone gel-filled breast implants have a silicone outer ...

Effectiveness of disinfection therapies and promotion of osteoblast growth on osseotite and nanotite implant surfaces.

PubMed

Lubin, Judith; Hernandez, Maria A; Drukteinis, Saulius E; Parker, William B; Murray, Peter E

2014-08-01

To evaluate the effectiveness of 4 procedures to disinfect implant surfaces intentionally inoculated with bacteria and afterward to evaluate osteoblast viability to the disinfected implant surfaces. Eighty-eight commercially pure Osseotite and Nanotite titanium implant discs were inoculated with Porphyromonas gingivalis. The implant surfaces were disinfected with EDTA, tetracycline, citric acid, or neodymium-doped yttrium aluminum garnet (Nd:YAG) laser. The implant discs were then placed in cultures of osteoblast cells. Osseotite implant discs were easier to disinfect compared with the Nanotite implant discs. Citric acid and tetracycline were the most effective solutions for the disinfection of P. gingivalis from the Osseotite implant discs. The Nanotite implant discs were the most difficult to disinfect, likely because of their chemical and physical properties. Citric acid and tetracycline were most effective for disinfecting the Osseotite implant discs, and further clinical research is needed to verify these effects in vivo. The Nd:YAG laser was the weakest disinfection method, and it is not recommended for disinfecting implant surfaces until its effectiveness is improved.

Implantable Myoelectric Sensors (IMESs) for Intramuscular Electromyogram Recording

PubMed Central

Weir, Richard F. ff.; Troyk, Phil R.; DeMichele, Glen A.; Kerns, Douglas A.; Schorsch, Jack F.; Maas, Huub

2011-01-01

We have developed a multichannel electrogmyography sensor system capable of receiving and processing signals from up to 32 implanted myoelectric sensors (IMES). The appeal of implanted sensors for myoelectric control is that electromyography (EMG) signals can be measured at their source providing relatively cross-talk-free signals that can be treated as independent control sites. An external telemetry controller receives telemetry sent over a transcutaneous magnetic link by the implanted electrodes. The same link provides power and commands to the implanted electrodes. Wireless telemetry of EMG signals from sensors implanted in the residual musculature eliminates the problems associated with percutaneous wires, such as infection, breakage, and marsupialization. Each implantable sensor consists of a custom-designed application-specified integrated circuit that is packaged into a bio-compatible RF BION capsule from the Alfred E. Mann Foundation. Implants are designed for permanent long-term implantation with no servicing requirements. We have a fully operational system. The system has been tested in animals. Implants have been chronically implanted in the legs of three cats and are still completely operational four months after implantation. PMID:19224729

Method for implantation of high dopant concentrations in wide band gap materials

DOEpatents

Usov, Igor [Los Alamos, NM; Arendt, Paul N [Los Alamos, NM

2009-09-15

A method that combines alternate low/medium ion dose implantation with rapid thermal annealing at relatively low temperatures. At least one dopant is implanted in one of a single crystal and an epitaxial film of the wide band gap compound by a plurality of implantation cycles. The number of implantation cycles is sufficient to implant a predetermined concentration of the dopant in one of the single crystal and the epitaxial film. Each of the implantation cycles includes the steps of: implanting a portion of the predetermined concentration of the one dopant in one of the single crystal and the epitaxial film; annealing one of the single crystal and the epitaxial film and implanted portion at a predetermined temperature for a predetermined time to repair damage to one of the single crystal and the epitaxial film caused by implantation and activates the implanted dopant; and cooling the annealed single crystal and implanted portion to a temperature of less than about 100.degree. C. This combination produces high concentrations of dopants, while minimizing the defect concentration.

Evaluation of early bone response to fluoride-modified and anodically oxidized titanium implants through continuous removal torque analysis.

PubMed

Kwon, Taek-Ka; Lee, Hyo-Jung; Min, Seung-Ki; Yeo, In-Sung

2012-10-01

To compare between a bioactive and a bioinert implant with different geometries by continuous measurement of the removal torque and calculation of the angular momentum of each surfaced implant. Six New Zealand white rabbits were used in the study. Each rabbit received 2 implants. A bioactive fluoride-modified implant with a conical connection and microthread design was inserted into one tibia, and a bioinert anodically oxidized implant with an external connection design was inserted into the other. After 2 weeks of implant insertion, the removal torque values were continuously measured according to time. Using the time-torque curve resulting from the measurements, the maximum values were determined, and the angular momenta were calculated. The anodically oxidized implant had significantly higher peak removal torque and angular momentum values than the fluoride-modified implant (P < 0.05). The impact of the fluoride-modified bioactive implant on early bone response remains unclear. Considering the angular momentum of dental implants may assist in the elucidation of the effect of implant geometry on bone response.

Cellular Responses Evoked by Different Surface Characteristics of Intraosseous Titanium Implants

PubMed Central

Feller, Liviu; Jadwat, Yusuf; Khammissa, Razia A. G.; Meyerov, Robin; Lemmer, Johan

2015-01-01

The properties of biomaterials, including their surface microstructural topography and their surface chemistry or surface energy/wettability, affect cellular responses such as cell adhesion, proliferation, and migration. The nanotopography of moderately rough implant surfaces enhances the production of biological mediators in the peri-implant microenvironment with consequent recruitment of differentiating osteogenic cells to the implant surface and stimulates osteogenic maturation. Implant surfaces with moderately rough topography and with high surface energy promote osteogenesis, increase the ratio of bone-to-implant contact, and increase the bonding strength of the bone to the implant at the interface. Certain features of implant surface chemistry are also important in enhancing peri-implant bone wound healing. It is the purpose of this paper to review some of the more important features of titanium implant surfaces which have an impact on osseointegration. PMID:25767803

Survival of Dental Implants Placed in Grafted and Nongrafted Bone: A Retrospective Study in a University Setting.

PubMed

Tran, Duong T; Gay, Isabel C; Diaz-Rodriguez, Janice; Parthasarathy, Kavitha; Weltman, Robin; Friedman, Lawrence

2016-01-01

To compare dental implant survival rates when placed in native bone and grafted sites. Additionally, risk factors associated with dental implant loss were identified. This study was based on the hypothesis that bone grafting has no effect on implant survival rates. A retrospective chart review was conducted for patients receiving dental implants at the University of Texas, School of Dentistry from 1985 to 2012. Exclusion criteria included patients with genetic diseases, radiation and chemotherapy, or an age less than 18 years. To avoid misclassification bias, implants were excluded if bone grafts were only done at the same time of placement. Data on age, sex, tobacco use, diabetes, osteoporosis, anatomical location of the implant, implant length and width, bone graft, and professional maintenance were collected for analysis. A total of 1,222 patients with 2,729 implants were included. The cumulative survival rates at 5 and 10 years were 92% and 87% for implants placed in native bone and 90% and 79% for implants placed in grafted bone, respectively. The results from multivariate analysis (Cox regression) indicated no significant difference in survival between the two groups; having maintenance therapy after implant placement reduced the failure rate by 80% (P < .001), and using tobacco increased the failure rate by 2.6-fold (P = .001). There was no difference in the dental implant survival rate when implants were placed in native bone or bone-grafted sites. Smoking and lack of professional maintenance were significantly related to increased implant loss.

Effects of Thread Depth in the Neck Area on Peri-Implant Hard and Soft Tissues: An Animal Study.

PubMed

Sun, Shan-Pao; Lee, Dong-Won; Yun, Jeong-Ho; Park, Kwang-Ho; Park, Kwang-Bum; Moon, Ik-Sang

2016-11-01

Implants with deep thread depth have been developed for the purpose of increasing total implant surface area. However, effects of implant thread depth remain controversial. The aim of this study is to examine effects of thread depth on peri-implant tissues in terms of bone-implant contact (BIC), bone-implant volume (BIV), and hard and soft tissue dimensions using comprehensive analyses, including microcomputed tomography (micro-CT). Five beagle dogs received experimental intramandibular implants 3 months after removal of their premolars and first molars (P 2 , P 3 , P 4 , and M 1 ). Two different types of implants were installed in each animal: deep threaded (DT) and shallow threaded (ST). Resonance frequency testing was performed on the day of implantation as well as 4 and 8 weeks after implantation. Intraoral radiography, micro-CT, and histomorphometry were used to evaluate peri-implant tissues 4 and 8 weeks after implantation. There were no significant differences in resonance frequency test results between the two groups. Although radiographic analysis showed no group differences, micro-CT (P = 0.01) and histomorphometry (P = 0.003) revealed the DT group had significantly lower BIC values than the ST group at 4 weeks. However, by 8 weeks, BIC values of the two groups did not differ significantly. No significant differences in BIV or soft tissue height were observed between the two groups at either time point. DT implants showed no benefits over ST implants when inserted in dog mandibles.

Correlation between MRI results and intraoperative findings in patients with silicone breast implants.

PubMed

Lindenblatt, Nicole; El-Rabadi, Karem; Helbich, Thomas H; Czembirek, Heinrich; Deutinger, Maria; Benditte-Klepetko, Heike

2014-01-01

Silicone gel breast implants may silently rupture without detection. This has been the main reason for magnetic resonance imaging (MRI) of the augmented or reconstructed breast. The aim of the present study was to investigate the accuracy of MRI for implant rupture. Fifty consecutive patients with 85 silicone gel implants were included in the study. The mean age of the patients was 51 (range 21-72) years, with a mean duration of implantation of 3.8 (range 1-28) years. All patients underwent clinical examination and breast MRI. Intraoperative implant rupture was diagnosed by the operating surgeon. Nineteen of the 50 patients suffered from clinical symptoms. An implant rupture was diagnosed by MRI in 22 of 85 implants (26%). In seven of 17 removed implants (41%), the intraoperative diagnosis corresponded with the positive MRI result. However, only 57% of these patients were symptomatic. Ultrasound imaging of the harvested implants showed signs of interrupted inner layers of the implant despite integrity of the outer shell. By microsurgical separation of the different layers of the implant shell, we were able to reproduce this phenomenon and to produce signs of implant rupture on MRI. Our results show that rupture of only the inner layers of the implant shell with integrity of the outer shell leads to a misdiagnosis on MRI. Correlation with clinical symptoms and the specific wishes of the patient should guide the indication for implant removal.

Correlation between MRI results and intraoperative findings in patients with silicone breast implants

PubMed Central

Lindenblatt, Nicole; El-Rabadi, Karem; Helbich, Thomas H; Czembirek, Heinrich; Deutinger, Maria; Benditte-Klepetko, Heike

2014-01-01

Background Silicone gel breast implants may silently rupture without detection. This has been the main reason for magnetic resonance imaging (MRI) of the augmented or reconstructed breast. The aim of the present study was to investigate the accuracy of MRI for implant rupture. Methods Fifty consecutive patients with 85 silicone gel implants were included in the study. The mean age of the patients was 51 (range 21–72) years, with a mean duration of implantation of 3.8 (range 1–28) years. All patients underwent clinical examination and breast MRI. Intraoperative implant rupture was diagnosed by the operating surgeon. Results Nineteen of the 50 patients suffered from clinical symptoms. An implant rupture was diagnosed by MRI in 22 of 85 implants (26%). In seven of 17 removed implants (41%), the intraoperative diagnosis corresponded with the positive MRI result. However, only 57% of these patients were symptomatic. Ultrasound imaging of the harvested implants showed signs of interrupted inner layers of the implant despite integrity of the outer shell. By microsurgical separation of the different layers of the implant shell, we were able to reproduce this phenomenon and to produce signs of implant rupture on MRI. Conclusion Our results show that rupture of only the inner layers of the implant shell with integrity of the outer shell leads to a misdiagnosis on MRI. Correlation with clinical symptoms and the specific wishes of the patient should guide the indication for implant removal. PMID:25114595

Assessment of a polyelectrolyte multilayer film coating loaded with BMP-2 on titanium and PEEK implants in the rabbit femoral condyle

PubMed Central

Guillot, R.; Pignot-Paintrand, I.; Lavaud, J.; Decambron, A.; Bourgeois, E.; Josserand, V.; Logeart-Avramoglou, D.; Viguier, E.; Picart, C.

2016-01-01

The aim of this study was to evaluate the osseointegration of titanium implants (Ti-6Al-4V, noted here TA6V) and poly(etheretherketone) PEEK implants induced by a BMP-2-delivering surface coating made of polyelectrolyte multilayer films. The in vitro bioactivity of the polyelectrolyte film-coated implants was assessed using the alkaline phosphatase assay. BMP-2-coated TA6V and PEEK implants with a total dose of 9.3 µg of BMP-2 were inserted into the femoral condyles of New Zealand white rabbits and compared to uncoated implants. Rabbits were sacrificed 4 and 8 weeks after implantation. Histomorphometric analyses on TA6V and PEEK implants and microcomputed tomography on PEEK implants revealed that the bone-to-implant contact and bone area around the implants were significantly lower for the BMP-2-coated implants than for the bare implants. This was confirmed by scanning electron microscopy imaging. This difference was more pronounced at 4 weeks in comparison to the 8-week time point. However, bone growth inside the hexagonal upper hollow cavity of the screws was higher in the case of the BMP-2 coated implants. Overall, this study shows that a high dose of BMP-2 leads to localized and temporary bone impairment, and that the dose of BMP-2 delivered at the surface of an implant needs to be carefully optimized. PMID:26965394

Stress analysis of mandibular implant overdenture with locator and bar/clip attachment: Comparative study with differences in the denture base length.

PubMed

Yoo, Jin Suk; Kwon, Kung-Rock; Noh, Kwantae; Lee, Hyeonjong; Paek, Janghyun

2017-06-01

The design of the attachment must provide an optimum stress distribution around the implant. In this study, for implant overdentures with a bar/clip attachment or a locator attachment, the stress transmitted to the implant in accordance with the change in the denture base length and the vertical pressure was measured and analyzed. Test model was created with epoxy resin. The strain gauges made a tight contact with implant surfaces. A universal testing machine was used to exert a vertical pressure on the mandibular implant overdenture and the strain rate of the implants was measured. Means and standard deviations of the maximum micro-deformation rates were determined. 1) Locator attachment: The implants on the working side generally showed higher strain than those on the non-working side. Tensile force was observed on the mesial surface of the implant on the working side, and the compressive force was applied to the buccal surface and on the surfaces of the implant on the non-working side. 2) Bar/clip attachment: The implants on the both non-working and working sides showed high strain; all surfaces except the mesial surface of the implant on the non-working side showed a compressive force. To minimize the strain on implants in mandibular implant overdentures, the attachment of the implant should be carefully selected and the denture base should be extended as much as possible.

A Comparative Analysis on Two Types of Oral Implants, Bone-Level and Tissue-Level, with Different Cantilever Lengths of Fixed Prosthesis.

PubMed

Mosavar, Alireza; Nili, Monireh; Hashemi, Sayed Raouf; Kadkhodaei, Mahmoud

2017-06-01

Depending on esthetic, anatomical, and functional aspects, in implant-prosthetic restoration of a completely edentulous jaw, the selection of implant type is highly important; however, bone- and tissue-level implants and their stress distribution in bone have not yet been comparatively investigated. Hence, finite element analysis was used to study the influence of cantilever length in a fixed prosthesis on stress distribution in peri-implant bone around these two types of oral implants. A 3D edentulous mandible was modeled. In simulations, a framework with four posterior cantilever lengths and two types of implants, bone-level and tissue-level, was considered. A compressive load was applied to the distal regions of the cantilevers, and the von-Mises stress of peri-implant bone was investigated. The independent t-test and the Pearson correlation coefficient analyzed the results (α = 0.05). Stresses in the cortical bone around the bone-level implants were greater than those in the tissue-level implants with the same cantilever length. In addition, by extending the cantilever length, the stress values in peri-implant bone increased. Therefore, when the cantilever was at its maximum length, the maximum stress was in cortical bone and around the bone-level distal implants. The results of the present study indicate that treatment with tissue-level implants is potentially more advantageous than with bone-level implants for implant-supported fixed prostheses. © 2015 by the American College of Prosthodontists.

Synergistic effects of bisphosphonate and calcium phosphate nanoparticles on peri-implant bone responses in osteoporotic rats.

PubMed

Alghamdi, Hamdan S; Bosco, Ruggero; Both, Sanne K; Iafisco, Michele; Leeuwenburgh, Sander C G; Jansen, John A; van den Beucken, Jeroen J J P

2014-07-01

The prevalence of osteoporosis will increase within the next decades due to the aging world population, which can affect the bone healing response to dental and orthopedic implants. Consequently, local drug targeting of peri-implant bone has been proposed as a strategy for the enhancement of bone-implant integration in osteoporotic conditions. In the present study, an established in-vivo femoral condyle implantation model in osteoporotic and healthy bone is used to analyze the osteogenic capacity of titanium implants coated with bisphosphonate (BP)-loaded calcium phosphate nanoparticles (nCaP) under compromised medical conditions. After 4 weeks of implantation, peri-implant bone volume (%BV; by μCT) and bone area (%BA; by histomorphometry) were significantly increased within a distance of 500 μm from implant surfaces functionalized with BP compared to control implants in osteoporotic and healthy conditions. Interestingly, the deposition of nCaP/BP coatings onto implant surfaces increased both peri-implant bone contact (%BIC) and volume (%BV) compared to the deposition of nCaP or BP coatings individually, in osteoporotic and healthy conditions. The results of real-time PCR revealed similar osteogenic gene expression levels to all implant surfaces at 4-weeks post-implantation. In conclusion, simultaneous targeting of bone formation (by nCaP) and bone resorption (by BP) using nCaP/BP surface coatings represents an effective strategy for synergistically improvement of bone-implant integration, especially in osteoporotic conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of bone loss in antibacterial coated dental implants: An experimental study in dogs.

PubMed

Godoy-Gallardo, Maria; Manzanares-Céspedes, Maria Cristina; Sevilla, Pablo; Nart, José; Manzanares, Norberto; Manero, José M; Gil, Francisco Javier; Boyd, Steven K; Rodríguez, Daniel

2016-12-01

The aim of this study was to evaluate the in vivo effect of antibacterial modified dental implants in the first stages of peri-implantitis. Thirty dental implants were inserted in the mandibular premolar sites of 5 beagle dogs. Sites were randomly assigned to Ti (untreated implants, 10units), Ti_Ag (silver electrodeposition treatment, 10units), and Ti_TSP (silanization treatment, 10units). Coated implants were characterized by scanning electron microscopy, interferometry and X-ray photoelectron spectroscopy. Two months after implant insertion, experimental peri-implantitis was initiated by ligature placement. Ligatures were removed 2months later, and plaque formation was allowed for 2 additional months. Clinical and radiographic analyses were performed during the study. Implant-tissue samples were prepared for micro computed tomography, backscattered scanning electron microscopy, histomorphometric and histological analyses and ion release measurements. X-ray, SEM and histology images showed that vertical bone resorption in treated implants was lower than in the control group (P<0.05). This effect is likely due to the capacity of the treatments to reduce bacteria colonization on the implant surface. Histological analysis suggested an increase of peri-implant bone formation on silanized implants. However, the short post-ligature period was not enough to detect differences in clinical parameters among implant groups. Within the limits of this study, antibacterial surface treatments have a positive effect against bone resorption induced by peri-implantitis. Copyright © 2016 Elsevier B.V. All rights reserved.

Low-energy BF2, BCl2, and BBr2 implants for ultrashallow P+-N junctions

NASA Astrophysics Data System (ADS)

Nandan, S. R.; Agarwal, Vikas; Banerjee, Sanjay K.

1997-08-01

We have examined low energy BCl2 and BBr2 implants as a means of fabricating ultra-shallow P+-N junctions. Five keV and 9 keV BCl2 implants and 18 keV BBr2 implants have been compared to 5 keV BF2 implants to study the benefits of using these species. BCl2 and BBr2, being heavier species, have a lower projected range and produce more damage. The greater damage restricts channeling, resulting in shallower as-implanted profiles. The increased damage amorphizes the substrate at low implant doses which results in reduced transient enhanced diffusion (TED) during the post-implant anneal. Post-anneal SIMS profiles indicate a junction depth reduction of over 10 nm (at 5 X 1017 cm-3 background doping) for 5 keV BCl2 implants as compared to 5 keV BF2 implants. Annealed junctions as shallow as 10 nm have been obtained from the 18 keV BBr2 implants. The increased damage degrades the electrical properties of these junctions by enhancing the leakage current densities. BCl2 implanted junctions have leakage current densities of approximately 1 (mu) A/cm2 as compared to 10 nA/cm2 for the BF2 implants. BBr2 implants have a lower leakage density of approximately 50 nA/cm2. Low energy BBr2 implants offer an exciting alternative for fabricating low leakage, ultra-shallow P+-N junctions.

Biomechanical 3-Dimensional Finite Element Analysis of Obturator Protheses Retained with Zygomatic and Dental Implants in Maxillary Defects

PubMed Central

Akay, Canan; Yaluğ, Suat

2015-01-01

Background The objective of this study was to investigate the stress distribution in the bone around zygomatic and dental implants for 3 different implant-retained obturator prostheses designs in a Aramany class IV maxillary defect using 3-dimensional finite element analysis (FEA). Material\\Methods A 3-dimensional finite element model of an Aramany class IV defect was created. Three different implant-retained obturator prostheses were modeled: model 1 with 1 zygomatic implant and 1 dental implant, model 2 with 1 zygomatic implant and 2 dental implants, and model 3 with 2 zygomatic implants. Locator attachments were used as a superstructure. A 150-N load was applied 3 different ways. Qualitative analysis was based on the scale of maximum principal stress; values obtained through quantitative analysis are expressed in MPa. Results In all loading conditions, model 3 (when compared models 1 and 2) showed the lowest maximum principal stress value. Model 3 is the most appropirate reconstruction in Aramany class IV maxillary defects. Two zygomatic implants can reduce the stresses in model 3. The distribution of stresses on prostheses were more rational with the help of zygoma implants, which can distribute the stresses on each part of the maxilla. Conclusions Aramany class IV obturator prosthesis placement of 2 zygomatic implants in each side of the maxilla is more advantageous than placement of dental implants. In the non-defective side, increasing the number of dental implants is not as suitable as zygomatic implants. PMID:25714086

Long-term success of dental implants in patients with head and neck cancer after radiation therapy.

PubMed

Curi, M M; Condezo, A F B; Ribeiro, K D C B; Cardoso, C L

2018-06-01

The purpose of this study was to analyze the long-term success and factors potentially influencing the success of dental implants placed in patients with head and neck cancer who underwent radiation therapy with a minimum total dose of 50Gy during the years 1995-2010. Thirty-five patients (169 dental implants) were included in this study. Data on demographic characteristics, tumour type, radiation therapy, implant sites, implant dimensions, and hyperbaric oxygen therapy (HBOT) were obtained from the medical records and analyzed. Implant survival was estimated using Kaplan-Meier survival curves. Seventy-nine dental implants were placed in the maxilla and 90 in the mandible. The mean follow-up after implant installation was 7.4 years (range 0.3-14.7 years). The overall 5-year survival rate for all implants was 92.9%. Sex (P<0.001) and the mode of radiation therapy delivery (P=0.005) had a statistically significant influence on implant survival. Age, time of implantation after irradiation, implant brand and dimensions, and HBOT had no statistically significant influence on implant survival. Osseointegrated dental implants can be used successfully in the oral rehabilitation of patients with head and neck cancer with a history of radiation therapy. Risk factors such as sex and the mode of radiation therapy delivery can affect implant survival. Copyright © 2018 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Evaluation of mandibular posterior single implants with two different surfaces: a 5-year comparative study.

PubMed

Jung, Ui-Won; Choi, Jung-Yoo; Kim, Chang-Sung; Cho, Kyoo-Sung; Chai, Jung-Kiu; Kim, Chong-Kwan; Choi, Seong-Ho

2008-10-01

Anatomic and biomechanical limitations can jeopardize successful single implantation in the mandibular posterior area. To overcome the limitations, the design and the surface of the fixtures were modified. This study evaluated the cumulative survival rate (CSR) of mandibular molars replaced with a sand-blasted, large-grit, acid-etched (SLA) single implant or an anodized (ANO) single implant and examined associated factors, such as the surface treatment, position, and length and diameter of the implants. One hundred ninety-three single implants restored with an SLA implant and 112 single implants restored with an ANO implant in the mandibular molar area were selected from subjects who had visited the Department of Periodontology, Dental Hospital of Yonsei University, from March 2001 through June 2006. In the SLA group, 123 and 70 implants were placed in the first and second molar area, respectively. In the ANO group, 55 and 57 implants were placed in the first and second molar area, respectively. The 1- to 6-year CSR of the SLA and ANO groups was calculated using the life-table analysis. In addition, associated factors, such as the surface treatment, position, and length and diameter of the implants, were compared and analyzed using the chi(2) test (P <0.05). Two of 193 implants in the SLA group failed, giving a CSR of 98.96%; four of 112 ANO implants failed, giving a CSR of 96.43%. There were no significant differences with regard to the surface treatment, position, and length and diameter of the implants. Despite the anatomic and biomechanical limitation in the mandibular posterior area, mandibular posterior single implants showed a high CSR during the observation period. Mandibular posterior single implants can be an effective and reliable treatment modality that is not affected by the surface treatment, position, or length and diameter of the implant.

Biomechanical validation of finite element models for two silicone metacarpophalangeal joint implants.

PubMed

Hussein, A I; Stranart, J C; Meguid, S A; Bogoch, E R

2011-02-01

Silicone implants are used for prosthetic arthroplasty of metacarpophalangeal (MCP) joints severely damaged by rheumatoid arthritis. Different silicone elastomer MCP implant designs have been developed, including the Swanson and the NeuFlex implants. The goal of this study was to compare the in vitro mechanical behavior of Swanson and NeuFlex MCP joint implants. Three-dimensional (3D) finite element (FE) models of the silicone implants were modeled using the commercial software ANSYS and subjected to angular displacement from 0 deg to 90 deg. FE models were validated using mechanical tests of implants incrementally bent from 0 deg to 90 deg in a joint simulator. Swanson size 2 and 4 implants were compared with NeuFlex size 10 and 30 implants, respectively. Good agreement was observed throughout the range of motion for the flexion bending moment derived from 3D FE models and mechanical tests. From 30 deg to 90 deg, the Swanson 2 demonstrated a greater resistance to deformation than the NeuFlex 10 and required a greater bending moment for joint flexion. For larger implant sizes, the NeuFlex 30 had a steeper moment-displacement curve, but required a lower moment than the Swanson 4, due to implant preflexion. On average, the stress generated at the implant hinge from 30 deg to 90 deg was lower in the NeuFlex than in the Swanson. On average, starting from the neutral position of 30 deg for the preflexed NeuFlex implant, higher moments were required to extend the NeuFlex implants to 0 deg compared with the Swanson implants, which returned spontaneously to resting position. Implant toggling within the medullary canals was less in the NeuFlex than in the Swanson. The differential performance of these implants may be useful in implant selection based on the preoperative condition(s) of the joint and specific patient functional needs.

Lateral forces exerted through ball or bar attachments in relation to the inclination of mini-implant underneath overdentures: in vitro study.

PubMed

Takagaki, Kyozo; Gonda, Tomoya; Maeda, Yoshinobu

2015-09-01

Lateral force to mini-implants should be avoided because mini-implants are weak mechanically because of its small diameter. Overdentures retained by mini-implants are usually formed using ball attachments. However, bar attachments can offer the advantage of splinting the mini-implants. This study examined the effect of attachments in withstanding these lateral forces in tilted mini-implants of overdentures. Strain gauges were attached to the mini-implants (2.5 × 18 mm) embedded in an acrylic resin block. Two mini-implants were inserted vertically (Control) or with one mini-implant inclined at 10° or 20° (10-inclined and 20-inclined, respectively). The female portions of the attachments were secured to the denture base. A prefabricated ball attachment and CAD/CAM-fabricated bar attachment were compared. A vertical load of 49 N was applied to the occlusal surface at a distance 10 mm away from the center of two mini-implants. The lateral force borne by the mini-implants was measured via the attached strain gauge. Mann-Whitney U-test and an analysis of Bonferroni correction were used to compare differences between the two attachments and among the three models (P < 0.05). The lateral force exerted to the inclined mini-implant was significantly greater than that borne by a vertical mini-implant for both attachment types. The lateral force on the 20° inclined mini-implants with bar attachments was smaller than that on mini-implants with ball attachments. Inclined mini-implants are subjected to greater stresses than vertical ones, and a bar attachment can reduce the lateral forces borne by the mini-implant when one mini-implant inclined at 20°. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Implant-supported maxillary overdentures retained with milled bars: maxillary anterior versus maxillary posterior concept--a retrospective study.

PubMed

Krennmair, Gerald; Krainhöfner, Martin; Piehslinger, Eva

2008-01-01

The aim of the present retrospective investigation was to evaluate implant-supported maxillary overdentures using either anterior (group 1) or posterior (group 2) maxillary implant placement. Maxillary overdentures were planned with support by either 4 implants placed in the maxillary anterior region (group 1) or 6 to 8 implants placed in augmented maxillary posterior regions (group 2, bilateral sinus augmentation) and anchored either on an anterior or on 2 bilaterally placed milled bars. Cumulative implant survival rate, peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, and Calculus Index) and the incidence and type of prosthodontic maintenance were assessed and compared for the 2 groups. In addition, the cumulative survival rate for implants placed in grafted regions was compared with that of implants placed in nongrafted regions. Thirty-four patients (16 for group 1 and 18 for group 2) with 179 implants were available for follow-up examination after a mean period of 42.1 +/- 20.1 months. Four initially placed implants failed to osseointegrate and were replaced, but no further losses were seen during the loading period, for a 5-year cumulative implant survival rate of 978%. No differences in implant survival rates were seen between either the group-1 (98.4%) and group-2 (97.4%) concepts or nongrafted (98.0%) and grafted (97.5%) implants. The peri-implant parameters showed a healthy soft tissue, good oral hygiene, and an acceptable degree of peri-implant marginal bone loss. The rigid fixation of all overdentures was associated with a low incidence of prosthodontic maintenance, without any significant differences between the 2 groups. In well-planned overdenture treatment programs, a high survival rate and excellent peri-implant conditions can be achieved for implants placed in the anterior or posterior maxilla. Rigid anchorage of maxillary overdentures either on an extended anterior milled bar or on 2 bilateral posterior milled bars provides for a low incidence of prosthodontic maintenance.

Effect of insertion torque on titanium implant osseointegration: an animal experimental study.

PubMed

Duyck, Joke; Roesems, Rutger; Cardoso, Marcio V; Ogawa, Toru; De Villa Camargos, Germana; Vandamme, Katleen

2015-02-01

To evaluate the effect of implant insertion torque on the peri-implant bone healing and implant osseointegration. Bilaterally in the tibia of five adult New Zealand white rabbits, 20 implants were installed, subdivided into four groups, corresponding to two insertion torque conditions (low, < 10 Ncm vs. high > 50 Ncm) and 2 experimental periods (2 weeks vs. 4 weeks of healing). The implant insertion torque was determined by the surgical drill diameter relative to the implant diameter. Implant osseointegration was evaluated by quantitative histology (bone-to-implant contact with host bone [BIC-host], with neoformed bone [BIC-de novo], with both bone types [BIC-total], and peri-implant bone [BA/TA]). Every response was modelled over time using GEE (general estimation equation) with an unstructured variance-covariance matrix to correct for dependency between the measurements from one animal. The statistical significance level of α = 0.05 was applied. Significantly, more BIC-host and BIC-total were recorded for H implants compared with L implants after 2 week of healing (P = 0.010 and P = 0.0001, respectively). However, this result was no longer found for the extended healing period. Furthermore, BIC-total significantly increased over time for L implants (P < 0.00001). In contrast, the significant increase in BA/TA over time was found for H implants (P < 0.01). Finally, H insertion torque led to an increased BA/TA after 4 week of healing (P < 0.02) compared with the L insertion protocol. L insertion torque implants installed in the rabbit tibial bone osseointegrate with considerable de novo bone formation. This bone neoformation enables L implants to catch up, already during the early osseointegration stage, the initial inferior amount BIC contact compared with that of H implants. A negative impact of the created strain environment accompanying H insertion torque implant installation on the biological process of osseointegration could not be observed, at least not at tissue level. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Study on the neotype zirconia's implant coated nanometer hydroxyapatite ceramics

NASA Astrophysics Data System (ADS)

Zhu, J. W.; Yang, D. W.

2007-07-01

In recent years, biologic ceramics is a popular material of implants and bioactive surface modification of dental implant became a research emphasis, which aims to improve bioactivity of implants materials and acquire firmer implants-bone interface. The zirconia ceramic has excellent mechanical properties and nanometer HA ceramics is a bioceramic well known for its bioactivity, therefore, nanometer HA ceramics coating on zirconia, allows combining the excellent mechanical properties of zirconia substrates with its bioactivity. This paper shows a new method for implant shape design and bioactive modification of dental implants surface. Zirconia's implant substrate was prepared by sintered method, central and lateral tunnels were drilled in the zirconia hollow porous cylindrical implants by laser processing. The HA powders and needle-like HA crystals were made by a wet precipitation and calcining method. Its surface was coated with nanometer HA ceramics which was used brush HA slurry and vacuum sintering. Mechanical testing results revealed that the attachment strength of nanometer HA ceramics coated zirconia samples is high. SEM and interface observation after inserted experiment indicated that calcium and phosphor content increased and symmetrically around coated implant-bone tissue interface. A significantly higher affinity index was demonstrated in vivo by histomorphometric evaluation in coated versus uncoated implants. SEM analysis demonstrated better bone adhesion to the material in coated implant at any situation. In addition, the hollow porous cylindrical implant coated with nanometer HA ceramics increase the interaction of bone and implant, the new bone induced into the surface of hollow porous cylindrical implant and through the most tunnels filled into central hole. The branch-like structure makes the implant and bone a body, which increased the contact area and decreased elastic ratio. Therefore, the macroscopical and microcosmic nested structure of implant coated nanometer HA ceramics had increased biocompatibility and improved the osteointegration. It endows the implants with new vital activity.

Salivary Concentration of Oxidative Stress Biomarkers in a Group of Patients with Peri-Implantitis: A Transversal Study.

PubMed

Sánchez-Siles, Mariano; Lucas-Azorin, Javier; Salazar-Sánchez, Noemi; Carbonell-Meseguer, Luis; Camacho-Alonso, Fabio

2016-10-01

The purpose of this study was to know if peri-implantitis causes an increase in the total salivary concentration of oxidative stress markers. Seventy patients, 28 men and 42 women, 60 of them with dental implants, 30 of which had peri-implantitis and 30 were healthy. The remaining 10 were the control group: healthy subjects without implants. The average number of implants per patient was 4.70 ± 2.29 in the peri-implantitis group and 2 70 ± 2.11 in the control group. Periodontal/peri-implant variables were assessed, including bleeding index, gingival index, clinical attachment level, probing depth, presence of pockets larger than 4 and 6 mm, pain to percussion, suppuration, gingival hyperplasia or granuloma, crestal bone loss (both mesially and distally), evaluated through periapical radiography. Saliva samples from the 70 subjects were collected for measurement of malondialdehyde high performance liquid chromatography (HPLC) and myeloperoxidase (enzyme-linked immunosorbent assay analysis) concentrations. Implants affected with peri-implantitis had an average follow-up of 26.40 ± 7.97 months. 4.12% of implants with peri-implantitis had a painful response to percussion. 2.06% showed suppuration; 25.77% had granuloma. The mean crestal bone loss in implants wtih peri-implantitis was 3.78 ± 1.17 mm. Total salivary malondialdehyde concentration in the peri-implantitis group (0.52 ± 0.37 μM/l) was slightly higher than that in the group with healthy implants (0.40 ± 0.16 μM/l) and also slightly higher than that in the group of healthy patients without implants (0.41 ± 0.79 μM/l), although the difference was not statistically significant, p value = .442. Myeloperoxidase concentration was slightly higher in the peri-implantitis group (12.32 ± 2.17 ng/ml) than in the group with healthy implants (11.54 ± 2.80 ng/ml) and the group of healthy patients without implants (11.86 ± 2.67 ng/ml), without statistically significant differences, p value = .584. The salivary concentration of oxidative stress markers in patients with peri-implantitis and without periodontitis is not higher than that found in healthy patients. © 2015 Wiley Periodicals, Inc.

R&D on dental implants breakage

NASA Astrophysics Data System (ADS)

Croitoru, Sorin Mihai; Popovici, Ion Alexandru

2017-09-01

Most used dental implants for human dental prostheses are of two steps type: first step means implantation and, after several months healing and osseointegration, second step is prosthesis fixture. For sure, dental implants and prostheses are meant to last for a lifetime. Still, there are unfortunate cases when dental implants break. This paper studies two steps dental implants breakage and proposes a set of instruments for replacement and restoration of the broken implant. First part of the paper sets the input data of the study: structure of the studied two steps dental implants based on two Romanian patents and values of the loading forces found in practice and specialty papers. In the second part of the paper, using DEFORM 2D™ FEM simulation software, worst case scenarios of loading dental implants are studied in order to determine which zones and components of the dental implant set are affected (broken). Last part of the paper is dedicated to design and presentation of a set for extracting and cutting tools used to restore the broken implant set.

Peri-implant bone formation and implant integration strength of peptide-modified p(AAM-co-EG/AAC) interpenetrating polymer network-coated titanium implants.

PubMed

Barber, Thomas A; Ho, James E; De Ranieri, Aladino; Virdi, Amarjit S; Sumner, Dale R; Healy, Kevin E

2007-02-01

Interpenetrating polymer networks (IPNs) of poly (acrylamide-co-ethylene glycol/acrylic acid) functionalized with an -Arg-Gly-Asp- (RGD) containing 15 amino acid peptides, derived from rat bone sialoprotein (bsp-RGD(15), were grafted to titanium implants in an effort to modulate bone formation in the peri-implant region in the rat femoral ablation model. Bone-implant contact (BIC) and bone formation within the medullary canal were determined using microcomputed tomography at 2 and 4 weeks postimplantation. BIC for bsp-RGD(15)-IPN implants was enhanced relative to hydroxyapatite tricalcium phosphate (HA-TCP) coated implants, but was similar to all other groups. Aggregate bone formation neither indicated a dose-dependent effect of bsp-RGD(15) nor a meaningful trend. Mechanical testing of implant fixation revealed that only the HA-TCP coated implants supported significant (>1 MPa) interfacial shear strength, despite exhibiting lower overall BIC, an indication that bone ingrowth into the rougher coating was the primary mode of implant fixation. While no evidence was found to support the hypothesis that bsp-RGD(15)-modified IPN coated implants significantly impacted bone-implant bonding, these results point to the lack of correlation between in vitro studies employing primary osteoblasts and in vivo wound healing in the peri-implant region. Copyright 2006 Wiley Periodicals, Inc.

The effect of thread pattern upon implant osseointegration.

PubMed

Abuhussein, Heba; Pagni, Giorgio; Rebaudi, Alberto; Wang, Hom-Lay

2010-02-01

Implant design features such as macro- and micro-design may influence overall implant success. Limited information is currently available. Therefore, it is the purpose of this paper to examine these factors such as thread pitch, thread geometry, helix angle, thread depth and width as well as implant crestal module may affect implant stability. A literature search was conducted using MEDLINE to identify studies, from simulated laboratory models, animal, to human, related to this topic using the keywords of implant thread, implant macrodesign, thread pitch, thread geometry, helix angle, thread depth, thread width and implant crestal module. The results showed how thread geometry affects the distribution of stress forces around the implant. A decreased thread pitch may positively influence implant stability. Excess helix angles in spite of a faster insertion may jeopardize the ability of implants to sustain axial load. Deeper threads seem to have an important effect on the stabilization in poorer bone quality situations. The addition of threads or microthreads up to the crestal module of an implant might provide a potential positive contribution on bone-to to-implant contact as well as on the preservation of marginal bone; nonetheless this remains to be determined. Appraising the current literature on this subject and combining existing data to verify the presence of any association between the selected characteristics may be critical in the achievement of overall implant success.

Comparison of Implant Stability Using Resonance Frequency Analysis: Osteotome Versus Conventional Drilling

PubMed Central

Sadeghi, Rokhsareh; Miremadi, Asghar

2015-01-01

Objectives: Implant primary stability is one of the important factors in achieving implant success. The osteotome technique may improve primary stability in patients with poor bone quality. The aim of this study was to compare implant stability using two different techniques namely osteotome versus conventional drilling in the posterior maxilla. Materials and Methods: In this controlled randomized clinical trial, 54 dental implants were placed in 32 patients; 29 implants were placed in the osteotome group and 25 in the conventional drilling group. Implant stability was assessed at four time intervals namely at baseline, one, two and three months after implant placement using resonance frequency analysis (RFA). Results: Primary stability based on implant stability quotient (ISQ) units was 71.4±7 for the osteotome group and 67.4±10 for the control group. There was no statistically significant difference between the two groups in implant stability at any of the measurement times. In each group, changes in implant stability from baseline to one month and also from two months to three months post-operatively were not significant but from one month to two months after implant placement, implant stability showed a significant increase in both groups. Conclusion: The results of this study revealed that in both techniques, good implant stability was achieved and osteotome technique did not have any advantage compared to conventional drilling in this regard. PMID:27148375

Influence of controlled immediate loading and implant design on peri-implant bone formation.

PubMed

Vandamme, Katleen; Naert, Ignace; Geris, Liesbet; Vander Sloten, Jozef; Puers, Robert; Duyck, Joke

2007-02-01

Tissue formation at the implant interface is known to be sensitive to mechanical stimuli. The aim of the study was to compare the bone formation around immediately loaded versus unloaded implants in two different implant macro-designs. A repeated sampling bone chamber with a central implant was installed in the tibia of 10 rabbits. Highly controlled loading experiments were designed for a cylindrical (CL) and screw-shaped (SL) implant, while the unloaded screw-shaped (SU) implant served as a control. An F-statistic model with alpha=5% determined statistical significance. A significantly higher bone area fraction was observed for SL compared with SU (p<0.0001). The mineralized bone fraction was the highest for SL and significantly different from SU (p<0.0001). The chance that osteoid- and bone-to-implant contact occurred was the highest for SL and significantly different from SU (p<0.0001), but not from CL. When bone-to-implant contact was observed, a loading (SL versus SU: p=0.0049) as well as an implant geometry effect (SL versus CL: p=0.01) was found, in favour of the SL condition. Well-controlled immediate implant loading accelerates tissue mineralization at the interface. Adequate bone stimulation via mechanical coupling may account for the larger bone response around the screw-type implant compared with the cylindrical implant.

Influence of custom-made implant designs on the biomechanical performance for the case of immediate post-extraction placement in the maxillary esthetic zone: a finite element analysis.

PubMed

Chen, Jianyu; Zhang, Zhiguang; Chen, Xianshuai; Zhang, Xiao

2017-05-01

Due to the increasing adoption of immediate implantation strategies and the rapid development of the computer aided design/computer aided manufacturing technology, a therapeutic concept based on patient-specific implant dentistry has recently been reintroduced by many researchers. However, little information is available on the designs of custom-made dental implant systems, especially their biomechanical behavior. The influence of the custom-made implant designs on the biomechanical performance for both an immediate and a delayed loading protocol in the maxillary esthetic zone was evaluated by means of the finite element (FE) method. FE models of three dental implants were considered: a state of the art cylindrical implant and two custom-made implants designed by reverse engineering technology, namely a root-analogue implant and a root-analogue threaded implant. The von Mises stress distributions and micro-motions around the bone-implant interfaces were calculated using ANSYS software. In a comparison of the three implant designs for both loading protocols, a favorable biomechanical performance was observed for the use of root-analogue threaded implant which approximated the geometry of natural anterior tooth and maintained the original long-axis. The results indicated that bone-implant interfacial micro-motion was reduced and a favorable stress distribution after osseointegration was achieved.

Effect of healing time on bone-implant contact of orthodontic micro-implants: a histologic study.

PubMed

Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

2014-01-01

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability.

Biomechanical aspects of initial intraosseous stability and implant design: a quantitative micro-morphometric analysis.

PubMed

Akça, Kivanç; Chang, Ting-Ling; Tekdemir, Ibrahim; Fanuscu, Mete I

2006-08-01

The objective of this biomechanical study was to explore the effect of bone micro-morphology on initial intraosseous stability of implants with different designs. Straumann and Astra Tech dental implants were placed into anterior and posterior regions of completely edentulous maxilla and mandible of a human cadaver. Experiments were undertaken to quantify initial implant stability and bone micro-morphology. Installation torque values (ITVs) and implant stability quotients (ISQs) were measured to determine initial intraosseous implant stability. For quantification of relative bone volume and micro-architecture, sectioned implant-bone and bone core specimens of each implant placement site were consecutively scanned and trabecular bone was analyzed in a micro-computed tomography (micro-CT) unit. Experimental outcomes were evaluated for correlations among implant designs, initial intraosseous implant stability and bone micro-structural parameters. ITVs correlated higher with bone volume fraction (BV/TV) than ISQs, at 88.1% and 68.9% levels, respectively. Correlations between ITVs and micro-morphometric parameters were significant at the 95% confidence level (P<0.05) while ISQs were not. Differences in ITVs, ISQs and BV/TV data in regards to implant designs used were not significant at the 95% confidence level (P>0.05). Bone micro-morphology has a prevailing effect over implant design on intraosseus initial implant stability, and ITV is more sensitive in terms of revealing biomechanical properties at the bone-implant interface in comparison with ISQ.

The quantitative assessment of peri-implant bone responses using histomorphometry and micro-computed tomography.

PubMed

Schouten, Corinne; Meijer, Gert J; van den Beucken, Jeroen J J P; Spauwen, Paul H M; Jansen, John A

2009-09-01

In the present study, the effects of implant design and surface properties on peri-implant bone response were evaluated with both conventional histomorphometry and micro-computed tomography (micro-CT), using two geometrically different dental implants (Screw type, St; Push-in, Pi) either or not surface-modified (non-coated, CaP-coated, or CaP-coated+TGF-beta1). After 12 weeks of implantation in a goat femoral condyle model, peri-implant bone response was evaluated in three different zones (inner: 0-500 microm; middle: 500-1000 microm; and outer: 1000-1500 microm) around the implant. Results indicated superiority of conventional histomorphometry over micro-CT, as the latter is hampered by deficits in the discrimination at the implant/tissue interface. Beyond this interface, both analysis techniques can be regarded as complementary. Histomorphometrical analysis showed an overall higher bone volume around St compared to Pi implants, but no effects of surface modification were observed. St implants showed lowest bone volumes in the outer zone, whereas inner zones were lowest for Pi implants. These results implicate that for Pi implants bone formation started from two different directions (contact- and distance osteogenesis). For St implants it was concluded that undersized implantation technique and loosening of bone fragments compress the zones for contact and distant osteogenesis, thereby improving bone volume at the interface significantly.

Finite Element Analysis of Bone Stress around Micro-Implants of Different Diameters and Lengths with Application of a Single or Composite Torque Force.

PubMed

Lu, Ying-juan; Chang, Shao-hai; Ye, Jian-tao; Ye, Yu-shan; Yu, Yan-song

2015-01-01

Stress on the bone surrounding dental micro-implants affects implant success. To compare the stress on the bone surrounding a micro-implant after application of a single force (SF) of 200 g or a composite force (CF) of 200 g and 6 N.mm torque. Finite element models were developed for micro-implant diameters of 1.2, 1.6, and 2.0 mm, and lengths of 6, 8, 10, and 12 mm and either a SF or CF was applied. The maximum equivalent stress (Max EQS) of the bone surrounding the micro-implant was determined, and the relationships among type of force, diameter, and length were evaluated. The Max EQS of the CF exceeded that of the SF (P< 0.05). The effect of force on stress was related to implant diameter, but not to implant length. The larger CF led to greater instability of the micro-implant and the effect was most pronounced at an implant diameter of 1.2 mm. The use of implant diameters of 1.6 mm and 2.0 mm produced no significant difference in implant stability when either a CF or SF was applied. When considering the use of an implant to perform three-dimensional control on the teeth, the implant diameter chosen should be > 1.2 mm.

Finite Element Analysis of Bone Stress around Micro-Implants of Different Diameters and Lengths with Application of a Single or Composite Torque Force

PubMed Central

Lu, Ying-juan; Chang, Shao-hai; Ye, Jian-tao; Ye, Yu-shan; Yu, Yan-song

2015-01-01

Background Stress on the bone surrounding dental micro-implants affects implant success. Purpose To compare the stress on the bone surrounding a micro-implant after application of a single force (SF) of 200 g or a composite force (CF) of 200 g and 6 N.mm torque. Materials and Methods Finite element models were developed for micro-implant diameters of 1.2, 1.6, and 2.0 mm, and lengths of 6, 8, 10, and 12 mm and either a SF or CF was applied. The maximum equivalent stress (Max EQS) of the bone surrounding the micro-implant was determined, and the relationships among type of force, diameter, and length were evaluated. Results The Max EQS of the CF exceeded that of the SF (P< 0.05). The effect of force on stress was related to implant diameter, but not to implant length. The larger CF led to greater instability of the micro-implant and the effect was most pronounced at an implant diameter of 1.2 mm. The use of implant diameters of 1.6 mm and 2.0 mm produced no significant difference in implant stability when either a CF or SF was applied. Conclusion When considering the use of an implant to perform three-dimensional control on the teeth, the implant diameter chosen should be > 1.2 mm. PMID:26659581

Influence of abutment design on the success of immediately loaded dental implants: experimental and numerical studies.

PubMed

Hasan, I; Röger, B; Heinemann, F; Keilig, L; Bourauel, C

2012-09-01

The aim of the present study was to investigate experimentally and numerically the influence of a fine threaded- against a roughened-cervical region of immediately loaded dental implants in combination with straight and 20°-angled abutments on the implant primary stability. A total of 30 implants were inserted in bovine rib-segments, 14 cervically roughened implants and 16 implants with fine cervical threads. Each implant system received two abutments, straight and 20°-angled. Implant displacements and rotations were measured using a biomechanical measurement system. Subsequently, eight samples were selected for geometrical reconstruction and numerical investigation of stress and strain distributions in the bone by means of the finite element method. Experimentally, both implant systems showed similar behaviour with the straight abutments concerning displacements and rotations. However, fine threaded implants showed much less displacement and rotation against roughened implants when angled abutments were considered. Numerically, stresses were within 35-45 MPa in the cortical bone for both implant systems. The strains showed highest values within the spongious bone with the roughened implants connected to angled abutments. The results indicate that implants with fine cervical threads could be recommended in particular with angled abutments. The outcomes of this study are currently confirmed by long-term clinical investigations. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

Esthetic evaluation of single-tooth implants in the anterior maxilla following autologous bone augmentation.

PubMed

Hof, M; Pommer, B; Strbac, G D; Sütö, D; Watzek, G; Zechner, W

2013-08-01

Autologous bone augmentation to rebuild compromised alveolar ridge contour prior to implant placement allows for favorable three-dimensional implant positioning to achieve optimum implant esthetics. The aim of the present study was to evaluate peri-implant soft tissue conditions around single-tooth implants following bone grafts in the esthetic zone of the maxilla. Sixty patients underwent autologous bone augmentation of deficient maxillary sites prior to placement of 85 implants in the esthetic zone. In case of multiple implants per patient, one implant was randomly selected. Objective evaluation of 60 single-tooth implants was performed using the Pink-Esthetic-Score (PES) and Papilla Index (PI) and supplemented by subjective patient evaluation, as well as clinical and radiologic examination. Objective ratings of implant esthetics were satisfactory (median PES: 11, median PI: 2) and significantly correlated with high patient satisfaction (mean VAS score: 80%). Both esthetic indices demonstrated respectable levels of inter- as well as intra-observer agreement. Poor implant esthetics (low PES and PI ratings) were significantly associated with increased anatomic crown height, while no influence of horizontal implant-tooth distance could be found. The present investigation indicates that favorable esthetic results may be achieved in the augmented anterior maxilla. However, bony reconstruction of compromised alveolar ridges does not guarantee optimum implant esthetics. © 2011 John Wiley & Sons A/S.

Esthetics of Flapless Single-Tooth Implants in the Anterior Maxilla Using Guided Surgery: Association of Three-Dimensional Accuracy and Pink Esthetic Score.

PubMed

Fürhauser, Rudolf; Mailath-Pokorny, Georg; Haas, Robert; Busenlechner, Dieter; Watzek, Georg; Pommer, Bernhard

2015-10-01

Flapless implant placement using surgical templates may guarantee predictable and esthetic results provided that preplanned implant positions are transfered precisely into surgical reality. The study aims to investigate the effect of three-dimensional accuracy in guided implant surgery on the esthetic outcome of single-tooth implants in the anterior maxilla. Single-tooth implants for delayed replacement of upper incisors were inserted in 27 patients using stereolithographic templates. Superimposition of postoperative cone beam computed tomography (CBCT) scans allowed assessment of positional inaccuracy at the implant shoulder and apex, as well as angular deviation. Objective evaluation of implant esthetics was performed after a mean follow-up of 2.3 years using the Pink Esthetic Score (PES). Mean deviation between planned and actual implant position was 0.84 mm at the implant shoulder and significantly correlated to average PES of 12 (p = .031). Inaccuracy toward the buccal side was most frequent (70%). Deviations  ≥  0.8  mm resulted in significantly worse implant esthetics (median PES: 9.5, interquartile range [IQR]: 8-11) compared with more accurate implant positions (median PES: 13, IQR: 12-13, p = .039). Positional inaccuracy is low in guided implant surgery, but may however significantly compromise implant esthetics in the anterior maxilla. © 2014 Wiley Periodicals, Inc.

Effect of Healing Time on Bone-Implant Contact of Orthodontic Micro-Implants: A Histologic Study

PubMed Central

Ramazanzadeh, Barat Ali; Fatemi, Kazem; Dehghani, Mahboobe; Mohtasham, Nooshin; Jahanbin, Arezoo; Sadeghian, Hamed

2014-01-01

Objectives. This study aimed to evaluate the effect of immediate and delayed loading of orthodontic micro-implants on bone-implant contact. Materials and Methods. Sixty four micro-implants were implanted in dog's jaw bone. The micro-implants were divided into loaded and unloaded (control) groups. The control group had two subgroups: four and eight weeks being implanted. The loaded group had two subgroups of immediate loading and delayed (after four weeks healing) loading. Loaded samples were subjected to 200g load for four weeks. After sacrificing the animals micro-implants and surrounding tissues were observed histologically. Bone-implant contact ratios (BIC) were calculated and different groups' results were compared by three-way ANOVA. Results. Mean survival rate was 96.7% in general. Survival rates were 96.7%, 94.4% and 100% for control, immediate and delayed loaded groups, respectively. BIC values were not significantly different in loaded and control groups, immediate and delayed loading groups, and pressure and tension sides. Mandibular micro-implants had significantly higher BIC than maxillary ones in immediate loading, 4-weeks control, and 8-weeks control groups (P = 0.021, P = 0.009, P = 0.003, resp.). Conclusion Immediate or delayed loading of micro-implants in dog did not cause significant difference in Bone-implant contact which could be concluded that healing time had not significant effect on micro-implant stability. PMID:25006463

Surface microstructure of dental implants before and after insertion: an in vitro study by means of scanning probe microscopy.

PubMed

Salerno, Marco; Itri, Angelo; Frezzato, Marco; Rebaudi, Alberto

2015-06-01

The surface microstructure of dental implants affects osseointegration, which makes their accurate topographic characterization important. We defined a procedure for evaluation of implant topography before (pre-) and after (post-) in vitro implantation test in bovine bone. The apical morphology of ten implants was analyzed in pre- and post-conditions using atomic force microscopy or 3D profilometry. We extracted four topographical parameters (two amplitude, 1 spatial, and 1 hybrid) and assessed the differences by analysis of variance. The implant with coating (Spline Twist MP-1 HA) was damaged. The two implants with highest pre-amplitude parameters (Pitt Easy VTPS, TLR3815) maintained their character on testing. Pitt Easy PURETEX and OT-F1 were the only nondamaged implants whose amplitude parameters increased. The surface area underwent minor changes even when the texture changed (Tri-Vent, Pitt Easy PURETEX, Exp #1). The implants that ranked the lowest in all parameters before implantation were DT4013TI, Tri-Vent, OT-F1, and Exp #2. On testing, DT4013TI showed the highest decrease in values, whereas Tri-Vent showed the highest increase in surface area. All the experimental implants showed similar topographic properties both pre- and post-test. For most implants, no major changes occurred in surface topography on implantation. The procedure applied seems promising to evaluate the degradation of implant surface on insertion.

Association Between Peri-implant Bone Morphology and Marginal Bone Loss: A Retrospective Study on Implant-Supported Mandibular Overdentures.

PubMed

Ding, Qian; Zhang, Lei; Geraets, Wil; Wu, Wuqing; Zhou, Yongsheng; Wismeijer, Daniel; Xie, Qiufei

The present study aimed to explore the association between marginal bone loss and type of peri-implant bony defect determined using a new peri-implant bony defect classification system. A total of 110 patients with implant-supported mandibular overdentures were involved. Clinical information was collected, including gender, age, smoking habit, and the overdenture attachment system used. Peri-implant bony defect types and marginal distances (ie, distance between the marginal bone level and the top of the implant shoulder) of all sites were identified on panoramic radiographs by a single experienced observer. The associations between marginal distance and peri-implant bony defect type, gender, age, smoking habit, attachment system, and time after implantation were investigated using marginal generalized linear models and regression analysis. A total of 83 participants were included in the final sample with a total of 224 implants involving 3,124 implant sites. The mean observation time was 10.7 years. All peri-implant bony defect types except Type 5 (slit-like) were significantly related to marginal distance in all models (P < .01). Smoking and time after implantation were significantly related to marginal distance while gender, age, and the overdenture attachment system used were not. The peri-implant bony defect type, determined using the new classification system, is associated with the extent of marginal bone loss.

Evaluation of the peri-implant bone around parallel-walled dental implants with a condensing thread macrodesign and a self-tapping apex: a 10-year retrospective histological analysis.

PubMed

Degidi, Marco; Perrotti, Vittoria; Shibli, Jamil A; Mortellaro, Carmen; Piattelli, Adriano; Iezzi, Giovanna

2014-05-01

The long-term high percentages of survival and success of dental implants reported in the literature are related mainly to new, innovative implant and thread designs, and new implant surfaces that allow to obtain very good primary and secondary stability in most anatomical and clinical situations, even in low quality and quantity of bone, promoting a more rapid osseointegration. The aim of this retrospective study was a histological and histomorphometrical evaluation of the bone response around implants with a parallel-wall configuration, condensing thread macrodesign, and self-tapping apex, retrieved from man for different causes. A total of 10 implants were reported in the present study, and these implants had been retrieved after a loading period comprised between a few weeks to about 8 years. Mineralized newly formed bone was found at the interface of all the implants, in direct contact with the implant surface, with no gaps or connective fibrous tissue. This bone adapted very well to the microirregularities of the implant surface. Areas of bone remodeling were present in some regions of the interface, with many reversal lines. High bone-implant contact percentages were found. In conclusion, both the macrostructure and the microstructure of this specific type of implant could be very helpful in the long-term high survival and success implant percentages.

Sound-direction identification with bilateral cochlear implants.

PubMed

Neuman, Arlene C; Haravon, Anita; Sislian, Nicole; Waltzman, Susan B

2007-02-01

The purpose of this study was to compare the accuracy of sound-direction identification in the horizontal plane by bilateral cochlear implant users when localization was measured with pink noise and with speech stimuli. Eight adults who were bilateral users of Nucleus 24 Contour devices participated in the study. All had received implants in both ears in a single surgery. Sound-direction identification was measured in a large classroom by using a nine-loudspeaker array. Localization was tested in three listening conditions (bilateral cochlear implants, left cochlear implant, and right cochlear implant), using two different stimuli (a speech stimulus and pink noise bursts) in a repeated-measures design. Sound-direction identification accuracy was significantly better when using two implants than when using a single implant. The mean root-mean-square error was 29 degrees for the bilateral condition, 54 degrees for the left cochlear implant, and 46.5 degrees for the right cochlear implant condition. Unilateral accuracy was similar for right cochlear implant and left cochlear implant performance. Sound-direction identification performance was similar for speech and pink noise stimuli. The data obtained in this study add to the growing body of evidence that sound-direction identification with bilateral cochlear implants is better than with a single implant. The similarity in localization performance obtained with the speech and pink noise supports the use of either stimulus for measuring sound-direction identification.

Sequías Hidrológicas en la República Argentina y su relación con Variables Macroclimáticas

NASA Astrophysics Data System (ADS)

Díaz, Erica Betiana

2016-07-01

Una adecuada planificación y gestión requiere un conocimiento de la distribución temporal y espacial de los recursos hídricos. Una amenaza que afecta al desarrollo y aprovechamiento de los recursos hídricos, y para las cuales la ingeniería debe dar soluciones, son las situaciones de extremos hidrológicos como inundaciones o sequías. Siendo estas últimas un fenómeno hidrológico extremo de gran complejidad del cual aún se conoce poco. Con el objetivo de identificar y caracterizar temporal y espacialmente las sequías hidrológicas en Argentina, esta tesis abordó en primera instancia, la identificación y caracterización de sequías desde el punto de vista hidrológico, abarcando el mayor período de tiempo y espacio, en función de los datos de caudales disponibles. Con el fin de predecir eventos plurianuales de sequías hidrológicas en el mediano y largo plazo se generaron, a través del análisis espectral y armónico de las series históricas de caudales observados, series sintéticas que reproducen las componentes periódicas plurianuales más significativas de las series observadas. Además, para lograr un avance en el conocimiento de los fenómenos climáticos que conducen a las sequías hidrológicas, se identificaron las variables macroclimáticas que tienen una mayor correlación con los caudales escurridos en las distintas cuencas. Esta tesis comprende el estudio de 14 cuencas hidrográficas argentinas, pertenecientes a los ríos Colorado, Mendoza, San Juan, Atuel, Ctalamochita, Anizacate, Xanaes, Suquía, Dulce, Juramento, Salado, Paraná, Bermejo y Pilcomayo. Los resultados a los que se abordaron en esta tesis son de relevancia para la gestión de los recursos hídricos ya que usos tales como el abastecimiento humano, el riego y la producción energética, entre otros, pueden ser seriamente afectados por la ocurrencia de manera simultánea de sequías severas en cuencas que aportan a una región y zonas vecinas.

Histologic analysis of resorbable blasting media surface implants retrieved from humans: a report of two cases

PubMed Central

2016-01-01

The purpose of this study is to evaluate the degree of osseointegration of resorbable blasting media (RBM) surface implants retrieved from humans. Three implants in the mandibular molar region that were surface-treated with RBM were retrieved from two patients. The implants were used to manufacture specimens in order to measure the bone-implant contact (BIC) ratio. The BIC ratios of the three implants were found to be an average of 69.0%±9.1%. In conclusion, that RBM surface implants are integrated into the host environment with histological significance and the BIC ratio of the RBM surface-treated implant was not significantly different from that of other surface-treated implants. PMID:26904493

Modification of Fixture Mount to be Used as an Impression Coping in Closely Placed Implants

PubMed Central

Jain, Anoop; K, Cauvery; Kumar, Pawan; Havale, Raghavendra

2014-01-01

An implant-level impression is often desired for designing and fabricating an implant-supported fixed restoration. This clinical report describes the use of modified press-fit metal implant fixture mount as an impression coping for making an impression of closely placed implants. The fixture mount is easier to manipulate, time saving and more comfortable for both the clinician and patient because the implant fixture mount is connected to the implant by pressing on instead of screwing. As compared to plastic press fit impression coping, metal fixture mount will not distort when modification of fixture mount are required in convergently or closely placed implants. It has the advantage of both the open-tray and closed-tray implant impression techniques. PMID:24959520

Modification of Fixture Mount to be Used as an Impression Coping in Closely Placed Implants.

PubMed

Mahoorkar, Sudhindra; Jain, Anoop; K, Cauvery; Kumar, Pawan; Havale, Raghavendra

2014-04-01

An implant-level impression is often desired for designing and fabricating an implant-supported fixed restoration. This clinical report describes the use of modified press-fit metal implant fixture mount as an impression coping for making an impression of closely placed implants. The fixture mount is easier to manipulate, time saving and more comfortable for both the clinician and patient because the implant fixture mount is connected to the implant by pressing on instead of screwing. As compared to plastic press fit impression coping, metal fixture mount will not distort when modification of fixture mount are required in convergently or closely placed implants. It has the advantage of both the open-tray and closed-tray implant impression techniques.

A participatory approach to integrated aquifer management: The case of Guanajuato State, Mexico

NASA Astrophysics Data System (ADS)

Sandoval, Ricardo

Guanajuato State, located in central Mexico, with less than 2% of the country's area, has almost 17,000 deep water wells, from which nearly 4,000 cubic hectometers (hm3) per year are being extracted, more than 1,000 hm3 over the estimated renewable yield. Since, in Mexico, water is administered under federal jurisdiction by the National Water Commission (CNA, for its Spanish acronym), the state government faces the challenge of ensuring its population's economic development without formal means of intervention. Being thus limited to apply mandatory policies and measures, the state water program has focused on the implementation of a two-sided strategy. First, basic hydrogeological studies and mathematical groundwater hydrodynamic models were developed upon a comprehensive survey of existing wells and a general revision of the state's geological framework. Second, a structure for water user's participation in water management actions was promoted (from the dissemination of information to the implementation of pilot efficient water use projects) with financial, technical and political support from the state. Simultaneously, a coordinated effort towards the completion of the water user's registry was performed with the federal authority along with other supporting measures such as training and monitoring programs. In this paper, a general overview of the project's achievements and challenges is presented. L'État de Guanajuato, situé dans la partie centrale du Mexique, avec moins de 2% de la surface du pays, a près de 17 000 puits profonds, d'où sont extraits près de 4 000 hm3 par an, soit plus de 1 000 hm3 de plus que le débit renouvelable estimé. Comme au Mexique l'eau est administrée dans le cadre d'une juridiction fédérale, le gouvernement de l'État fait tout son possible pour assurer le développement de sa population sans moyens formels d'intervention. Étant ainsi limité à appliquer des politiques et des mesures de recommandations, le programme Eau de l'État s'est appliqué à développer une stratégie sur deux plans. Tout d'abord, des études hydrogéologiques de base et des modèles mathématiques d'écoulement et de transport de nappe ont été réalisés à partir d'un suivi d'ensemble des puits existants et d'une révision générale du contexte géologique de l'État. Ensuite, on a soutenu une structure de participation des usagers de l'eau aux actions de gestion de l'eau, à partir de la dissémination de l'information pour la mise en place de projets pilotes efficaces d'utilisation de l'eau, avec des aides financières, techniques et politiques de l'État. Simultanément, un effort coordonné en vue de l'achèvement de l'enregistrement des usagers de l'eau a été fait avec l'autorité fédérale, en même temps que d'autres mesures de soutien, telles que des programmes de formation et des campagnes de surveillance. Cet article présente une vue d'ensemble des réalisations de projets et des défis. Resumen El Estado de Guanajuato, situado en el centro de México, ocupa menos del 2% de la superficie del país. Tiene casi 17.000 pozos profundos, de los cuales se extrae cerca de 4.000 hm3/a, lo que supone un exceso de 1.000 hm3/a respecto a la recarga anual. Puesto que el agua es administrada a nivel federal en México, el gobierno del Estado afronta el reto de asegurar el desarrollo de la población sin disponer de medios formales de intervención. Dadas las limitaciones para aplicar políticas y medidas reguladoras, el programa del agua en el Estado tiene como objetivo principal la implantación de una doble estrategia. Por un lado, desarrollar estudios hidrogeológicos básicos y modelos matemáticos de flujo y transporte de los acuíferos, basándose en una campaña exhaustiva de pozos existentes y en una revisión del marco geológico del Estado. Por otro lado, promover-con soporte financiero, técnico y político-una estructura de participación de los usuarios en las acciones de gestión, incluyendo desde la difusión de la información hasta la implantación de proyectos piloto para un uso eficiente del agua. Simultáneamente, se ha llevado a cabo un esfuerzo coordinado con la autoridad federal para completar el registro de usuarios del agua, además de promover otras medidas de ayuda, como programas de capacitación y campañas de muestreo. En este artículo, se ofrece una visión general de los logros y retos del proyecto.

Hydrogeologic uncertainties and policy implications: The Water Consumer Protection Act of Tucson, Arizona, USA

NASA Astrophysics Data System (ADS)

Wilson, L. G.; Matlock, W. G.; Jacobs, K. L.

The 1995 Water Consumer Protection Act of Tucson, Arizona, USA (hereafter known as the Act) was passed following complaints from Tucson Water customers receiving treated Central Arizona Project (CAP) water. Consequences of the Act demonstrate the uncertainties and difficulties that arise when the public is asked to vote on a highly technical issue. The recharge requirements of the Act neglect hydrogeological uncertainties because of confusion between "infiltration" and "recharge." Thus, the Act implies that infiltration in stream channels along the Central Wellfield will promote recharge in the Central Wellfield. In fact, permeability differences between channel alluvium and underlying basin-fill deposits may lead to subjacent outflow. Additionally, even if recharge of Colorado River water occurs in the Central Wellfield, groundwater will become gradually salinized. The Act's restrictions on the use of CAP water affect the four regulatory mechanisms in Arizona's 1980 Groundwater Code as they relate to the Tucson Active Management Area: (a) supply augmentation; (b) requirements for groundwater withdrawals and permitting; (c) Management Plan requirements, particularly mandatory conservation and water-quality issues; and (d) the requirement that all new subdivisions use renewable water supplies in lieu of groundwater. Political fallout includes disruption of normal governmental activities because of the demands in implementing the Act. Résumé La loi de 1995 sur la protection des consommateurs d'eau de Tucson (Arizona, États-Unis) a été promulguée à la suite des réclamations des consommateurs d'eau de Tucson alimentés en eau traitée à partir à la station centrale d'Arizona (CAP). Les conséquences de cette loi montrent les incertitudes et les difficultés qui apparaissent lorsque le public est appeléà voter sur un problème très technique. Les exigences de la loi en matière de recharge négligent les incertitudes hydrogéologiques du fait de la confusion entre "infiltration" et "recharge". C'est ainsi que la loi laisse entendre que l'infiltration à partir des lits de rivières le long du champ captant central favorise la recharge de cette zone. En réalité, les différences de perméabilité entre les alluvions du lit et les dépôts sous-jacents remplissant le bassin peuvent provoquer un écoulement sous-jacent. En outre, même si une recharge par l'eau de la rivière Colorado se produit dans cette zone, la nappe sera progressivement salifiée. Les restrictions imposées par la loi quant à l'utilisation de l'eau de la station centrale d'Arizona affectent les quatre outils réglementaires du Code des eaux souterraines de l'Arizona de 1980, en ce qu'ils concernent la zone de gestion active de Tucson: (a) l'augmentation de l'approvisionnement (b) les conditions requises pour les prélèvements d'eau souterraine et les autorisations; (c) les conditions requises pour le plan de gestion, en particulier la pérennité du concessionnaire et les résultats en matière de qualité de l'eau et (d) la condition que tous les nouveaux districts aient recours à des ressources en eau renouvelables à la place de l'eau souterraine. Les demandes concernant la mise en oeuvre de la loi ont conduit jusqu'à l'arrêt des activités normales des instances politiques. Resumen El Acta de Protección de los Usuarios de Agua de Tucson, Arizona (EE.UU.) de 1995 (el Acta) se aprobó a raíz de las quejas de los usuarios de agua de Tucson que recibían agua tratada por el Proyecto de Arizona Central (CAP). Las consecuencias del Acta demuestran las incertidumbres y dificultades que se producen cuando se le pide al público que vote sobre temas muy técnicos. Los requerimientos de recarga del Acta desprecian incertidumbres hidrogeológicas al confundir entre "infiltración" y "recarga". Así, el Acta dice que la infiltración en los canales de los arroyos a lo largo del Campo de Producción Central aumentará la recarga a dicho campo. De hecho, la diferencia de permeabilidad entre el canal aluvial y los depósitos de relleno subyacentes puede provocar descarga subyacente. Además, incluso si el Río Colorado recargase este Campo Central, el agua subterránea se salinizaría progresivamente. Las restricciones del Acta sobre el uso del agua del CAP afectan los cuatro mecanismos legales del Código de Aguas Subterráneas de Arizona de 1980 relacionados con el Área de Gestión Activa de Tucson: (a) aumento del suministro; (b) requisitos y permisos para la extracción de aguas subterráneas (c) necesidades del Plan de Gestión, particularmente la conservación obligatoria y temas de calidad de aguas; y (d) la obligación de que todas las nuevas subdivisiones usen agua con suministro renovable en lugar de subterránea. Como problemas adicionales se incluye la perturbación de las actividades políticas normales como consecuencia de las demandas para aprobar y poner en marcha el Acta.

Predictors and moderators of outcomes of HIV/STD sex risk reduction interventions in substance abuse treatment programs: a pooled analysis of two randomized controlled trials.

PubMed

Crits-Christoph, Paul; Gallop, Robert; Sadicario, Jaclyn S; Markell, Hannah M; Calsyn, Donald A; Tang, Wan; He, Hua; Tu, Xin; Woody, George

2014-01-16

The objective of the current study was to examine predictors and moderators of response to two HIV sexual risk interventions of different content and duration for individuals in substance abuse treatment programs. Participants were recruited from community drug treatment programs participating in the National Institute on Drug Abuse Clinical Trials Network (CTN). Data were pooled from two parallel randomized controlled CTN studies (one with men and one with women) each examining the impact of a multi-session motivational and skills training program, in comparison to a single-session HIV education intervention, on the degree of reduction in unprotected sex from baseline to 3- and 6- month follow-ups. The findings were analyzed using a zero-inflated negative binomial (ZINB) model. Severity of drug use (p < .01), gender (p < .001), and age (p < .001) were significant main effect predictors of number of unprotected sexual occasions (USOs) at follow-up in the non-zero portion of the ZINB model (men, younger participants, and those with greater severity of drug/alcohol abuse have more USOs). Monogamous relationship status (p < .001) and race/ethnicity (p < .001) were significant predictors of having at least one USO vs. none (monogamous individuals and African Americans were more likely to have at least one USO). Significant moderators of intervention effectiveness included recent sex under the influence of drugs/alcohol (p < .01 in non-zero portion of model), duration of abuse of primary drug (p < .05 in non-zero portion of model), and Hispanic ethnicity (p < .01 in the zero portion, p < .05 in the non-zero portion of model). These predictor and moderator findings point to ways in which patients may be selected for the different HIV sexual risk reduction interventions and suggest potential avenues for further development of the interventions for increasing their effectiveness within certain subgroups.

Minimum Map of Social Institutional Network: a multidimensional strategy for research in Nursing.

PubMed

Carlos, Diene Monique; Pádua, Elisabete Matallo Marchesini de; Nakano, Ana Márcia Spanó; Ferriani, Maria das Graças Carvalho

2016-06-01

To analyze the use of methodological strategies in qualitative research - Minimum Maps of Social Institutional Network, as proposed to understand the phenomena in the multidimensional perspective. Methodological theoretical essay in which we aimed to reflect on the use of innovative methodological strategies in nursing research, supported in Complex Paradigm fundamentals. The minimum map of Social Institutional External Network aims to identify institutional linkages and gaps for the intervention work of the surveyed institutions. The use of these maps provided important advances in know-how qualitative research in Health and Nursing. In this perspective, the use of minimum Social Intitutional Network maps can be stimulated and enhanced to meet the current demands of the contemporary world, particularly for its flexibility in adapting to various research subjects; breadth and depth of discussion; and possibilities with health services. Analisar o uso de estratégias metodológicas em pesquisas qualitativas - Mapa mínimo da Rede Social Institucional, como proposta para compreender os fenômenos na perspectiva multidimensional. Ensaio teórico metodológico em que buscou-se refletir sobre o uso de estratégias metodológicas inovadoras de pesquisa na enfermagem, sustentada nos fundamentos do Pensamento Complexo. O mapa mínimo da Rede Social Institucional Externa tem o objetivo de identificar os vínculos institucionais e lacunas para o trabalho de intervenção das instituições pesquisadas. O uso destes mapas proporcionou avanços importantes no saber-fazer pesquisa qualitativa em Saúde e Enfermagem. Nessa perspectiva, o uso de mapas mínimos da Rede Social Institucional pode ser estimulado e potencializado para responder às atuais demandas da contemporaneidade, em especial pela sua flexibilidade na adequação a diversos objetos de pesquisa; amplitude e profundidade de discussão; e possibilidades de articulação com a prática dos serviços.

International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Operation, Recovery, and Lessons Learned

NASA Technical Reports Server (NTRS)

Balistreri, Steven F.; Steele, John W.; Caron, Mark E.; Laliberte, Yvon J.; Shaw, Laura A.

2013-01-01

The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX in the ISS segments, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the ISS cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings as well as remediation and recovery of the full heat exchanger will be discussed.

International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Failures and Lessons Learned

NASA Technical Reports Server (NTRS)

Balistreri, Steven F.; Shaw, Laura A.; Laliberte, Yvon

2010-01-01

The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within in the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings and potential remediation techniques will also be discussed.

Influence of implant rod curvature on sagittal correction of scoliosis deformity.

PubMed

Salmingo, Remel Alingalan; Tadano, Shigeru; Abe, Yuichiro; Ito, Manabu

2014-08-01

Deformation of in vivo-implanted rods could alter the scoliosis sagittal correction. To our knowledge, no previous authors have investigated the influence of implanted-rod deformation on the sagittal deformity correction during scoliosis surgery. To analyze the changes of the implant rod's angle of curvature during surgery and establish its influence on sagittal correction of scoliosis deformity. A retrospective analysis of the preoperative and postoperative implant rod geometry and angle of curvature was conducted. Twenty adolescent idiopathic scoliosis patients underwent surgery. Average age at the time of operation was 14 years. The preoperative and postoperative implant rod angle of curvature expressed in degrees was obtained for each patient. Two implant rods were attached to the concave and convex side of the spinal deformity. The preoperative implant rod geometry was measured before surgical implantation. The postoperative implant rod geometry after surgery was measured by computed tomography. The implant rod angle of curvature at the sagittal plane was obtained from the implant rod geometry. The angle of curvature between the implant rod extreme ends was measured before implantation and after surgery. The sagittal curvature between the corresponding spinal levels of healthy adolescents obtained by previous studies was compared with the implant rod angle of curvature to evaluate the sagittal curve correction. The difference between the postoperative implant rod angle of curvature and normal spine sagittal curvature of the corresponding instrumented level was used to evaluate over or under correction of the sagittal deformity. The implant rods at the concave side of deformity of all patients were significantly deformed after surgery. The average degree of rod deformation Δθ at the concave and convex sides was 15.8° and 1.6°, respectively. The average preoperative and postoperative implant rod angle of curvature at the concave side was 33.6° and 17.8°, respectively. The average preoperative and postoperative implant rod angle of curvature at the convex side was 25.5° and 23.9°, respectively. A significant relationship was found between the degree of rod deformation and preoperative implant rod angle of curvature (r=0.60, p<.005). The implant rods at the convex side of all patients did not have significant deformation. The results indicate that the postoperative sagittal outcome could be predicted from the initial rod shape. Changes in implant rod angle of curvature may lead to over- or undercorrection of the sagittal curve. Rod deformation at the concave side suggests that corrective forces acting on that side are greater than the convex side. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of anabolic implants on adrenal cortisol synthesis in feedlot beef cattle implanted early or late in the finishing phase.

PubMed

Gifford, C A; Branham, K A; Ellison, J O; Gómez, B I; Lemley, C O; Hart, C G; Krehbiel, C R; Bernhard, B C; Maxwell, C L; Goad, C L; Hallford, D M; Hernandez Gifford, J A

2015-01-01

Implantation of anabolic steroids to increase growth rate in beef cattle impacts adrenal glucocorticoid production. The mechanism by which combination androgen and estrogen implants reduce cortisol biosynthesis in heifers is not clear. The objective of this study was to identify whether pituitary or adrenal gene expression and liver enzyme activity may contribute to altered serum cortisol concentrations in heifers receiving a combination implant. On d 0 of a 122-d finishing phase, 187 predominantly Angus heifers (361 kg) approximately 14 months old were randomly assigned to one of three implant groups: (1) non-implanted control, (2) implanted at the beginning of the finishing phase (d 0; early implant) with a combination implant (200mg TBA+20mg E2; Revalor 200®), and (3) implanted during the late stage of the finishing phase (d 56; late implant) with Revalor 200®. At d 56, body weight (BW) was greater (P<0.0001) for the early implanted heifers (456 ± 1.9 kg) compared to 437 and 435 (± 1.8) kg for control and late implanted heifers, respectively. Final BW (d 122) was similar between both implanted groups and heavier than non-implanted controls (P<0.0001). Serum cortisol was similar among groups at d 0 (P=0.86) however, by d 28 heifers receiving the combination implant had reduced (P<0.05) serum cortisol concentrations (31.2 ng/mL) compared to controls (49.4 ng/mL) and late (48.2 ng/mL) groups. On d 84 cortisol was similar (P=0.75) among implanted heifers and was less (P<0.01) than non-implanted heifers. Expression of pituitary and adrenal genes involved in glucocorticoid synthesis was evaluated at d 28/29 or 84/85; however, despite decreased serum cortisol in implanted heifers, no change in mRNA expression was demonstrated. Liver CYP3A enzyme activity at d 28/29 was decreased 59% in early implanted heifers compared to control heifers (P=0.01). Additionally, at d 84/85 AKR1C activity was greatest (P=0.01) in control heifers compared to both implanted groups. Data suggest that components of hypothalamic-pituitary-adrenal axis are influenced by exposure to exogenous hormones and this should be recognized when considering cortisol levels as a marker for stress response. Copyright © 2014 Elsevier Inc. All rights reserved.

Subgingival Microbiome Colonization and Cytokine Production during Early Dental Implant Healing.

PubMed

Payne, Jeffrey B; Johnson, Paul G; Kok, Car Reen; Gomes-Neto, João C; Ramer-Tait, Amanda E; Schmid, Marian J; Hutkins, Robert W

2017-01-01

Little is known about longitudinal development of the peri-implant subgingival microbiome and cytokine production as a new sulcus forms after dental implant placement. Therefore, the purpose of this observational study was to evaluate simultaneous longitudinal changes in the oral microbiome and cytokine production in the developing peri-implant sulcus compared to control natural teeth. Four and 12 weeks after implant placement and abutment connection, a dental implant and a natural tooth were sampled in 25 patients for subgingival plaque and gingival crevicular fluid (GCF [around teeth] and peri-implant crevicular fluid [PICF] around implants). DNA from plaque samples was extracted and sequenced using Illumina-based 16S rRNA sequencing. GCF and PICF samples were analyzed using a customized Milliplex human cytokine and chemokine magnetic bead panel. Beta diversity analysis revealed that natural teeth and implants had similar subgingival microbiomes, while teeth had greater alpha diversity than implants. At the genus level, however, few differences were noted between teeth and dental implants over 12 weeks. Specifically, Actinomyces and Selenomonas were significantly elevated around teeth versus dental implants at both 4 weeks and 12 weeks, while Corynebacterium and Campylobacter were significantly elevated only at 4 weeks around teeth. The only difference between PICF and GCF biomarkers was significantly elevated granulocyte-macrophage colony-stimulating factor levels around teeth versus dental implants at the 4-week visit. The subgingival microbiome and cytokine production were similar between teeth and implants during early healing, suggesting that these profiles are driven by the patient following dental implant placement and are not determined by anatomical niche. IMPORTANCE Dental implants are a common treatment option offered to patients for tooth replacement. However, little is known regarding initial colonization of the subgingival microbiome and simultaneous longitudinal cytokine production in humans during the early healing phase following implant placement. We report findings from an in vivo study that assessed initial colonization of the subgingival microbiome and concomitant early cytokine production in a newly formed anatomical space, namely, an implant sulcus. This approach may be useful in future interventional studies to influence dental implant success. Our data showed that the subgingival microbiome and cytokine profile were similar for control natural teeth and dental implants at both 4 and 12 weeks after implant placement. These data suggest that these profiles are driven by the patient and not by anatomical location (i.e., tooth versus dental implant).

Survival and tissue maintenance of an implant with a sloped configurated shoulder in the posterior mandible-a prospective multicenter study.

PubMed

Schiegnitz, E; Noelken, R; Moergel, M; Berres, M; Wagner, W

2017-06-01

Clinical studies evaluating the influence of the implant design on the preservation of peri-implant keratinized mucosa are rare. The aim of this prospective multicenter study was to investigate the survival, and soft and hard tissue maintenance of an implant with a sloped shoulder configuration, when placed in the posterior mandible. In this study, 24 centers participated and 184 patients receiving 238 implants (OsseoSpeed ™ Profile TX implants) were included. Clinical assessments of soft tissue parameters were performed before implant placement, immediately after implant placement, at prosthetic delivery and at 6, 12 and 24 months after implant placement and marginal bone adaptation was examined. After an average time in situ of 28.7 ± 4.7 months (2.4 ± 0.4 years), the survival rate was 99.2%. Analysis of the peri-implant soft tissues during follow-up showed a slight but significant increase in peri-implant keratinized mucosa width after 2 years (P < 0.001). All patients with reduced peri-implant keratinized mucosa width of ≤ 2 mm at postoperative examination (n = 95) showed a pronounced and statistically significant increase in the peri-implant keratinized mucosa width over time (P < 0.001). After a mean follow-up of 20.7 ± 8 months (1.7 ± 0.7 years), mean inter-proximal marginal bone loss was 0.30 ± 0.6 mm, indicating high bone stability around the sloped implant neck. These results indicate that sloped configurated implants have a high survival rate after 2 years in function. The sloped implant shoulder configuration helps to support the hard and soft tissue around the implant neck and supports the regain of a physiological peri-implant keratinized mucosa in patients with compromised peri-implant soft tissue conditions (Clinicaltrials.gov: NCT01400321). © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Implant stability and marginal bone level of microgrooved zirconia dental implants: A 3-month experimental study on dogs.

PubMed

Delgado-Ruiz, Rafael Arcesio; Marković, Aleksa; Calvo-Guirado, José Luís; Lazić, Zoran; Piattelli, Adriano; Boticelli, Daniele; Maté-Sánchez, José Eduardo; Negri, Bruno; Ramírez-Fernández, María Piedad; Mišić, Tijana

2014-05-01

The modification of implant surfaces could affect mechanical implant stability as well as dynamics and quality of peri-implant bone healing. The aim of this 3-month experimental study in dogs was to investigate implant stability, marginal bone levels and bone tissue response to zirconia dental implants with two laser-micro-grooved intraosseous surfaces in comparison with nongrooved sandblasted zirconia and sandblasted, high-temperature etched titanium implants. Implant surface characterization was performed using optical interferometric profilometty and energy dispersive X-ray spectroscopy. A total of 96 implants (4 mm in diameter and 10 mm in length) were inserted randomly in both sides of the lower jaw of 12 Fox Hound dogs divided into groups of 24 each: the control (titanium), the group A (sandblasted zirconia), the group B (sandolasted zirconia plus microgrooved neck) and the group C (sandblasted zirconia plus all microgrooved). All the implants were immediately loaded. Insertion torque, periotest values, radiographic crestal bone level and removal torque were recorded during the 3-month follow-up. Qualitative scanning electon microscope (SEM) analysis of the bone-implant interfaces of each group was performed. Insertion torque values were higher in the group C and control implants (p < 0.05). Periotest values increased in all the periods in proportion to the extent of microgrooving as follows: the group C > the control > the group B > the group A (p < 0.05). Radiographic measurements showed minimal crestal bone loss at 3 months for microgrooved zirconia implants (groups C and B) and control implants compared with the group A implants (p < 0.05). The removal torque values increased with time for all the groups as follows: the group C > the control > the group B > the group A (p < 0.05). SEM showed that implant surfaces of the groups B and C had an extra bone growth inside the microgrooves that corresponded to the shape and direction of the microgrooves. The addition of microgrooves to the entire intraosseous surface of zirconia dental implants enhances primary and secondary implant stability, promotes bone tissue ingrowth and preserves crestal bone levels.

The Effect of Insertion Torque on the Clinical Outcome of Single Implants: A Randomized Clinical Trial.

PubMed

Barone, Antonio; Alfonsi, Fortunato; Derchi, Giacomo; Tonelli, Paolo; Toti, Paolo; Marchionni, Saverio; Covani, Ugo

2016-06-01

The insertion torque value has been extensively used as an indicator for implant primary stability, which is considered a determining parameter for the implants success. The primary goal of the present randomized clinical trial was to evaluate and compare the clinical outcome for implants placed with high insertion torque (between 50 Ncm and 100 Ncm) and regular insertion torque (within 50 Ncm) in healed ridges. Partially edentulous patients, missing one or more mandibular or maxillary teeth, having an adequate amount of bone, requiring implant placement, were randomized to receive Blossom CT implants with regular insertion torque (<50 Ncm) or CT implants with high insertion torque (≥50 Ncm). Implants were left to heal submerged for 3 months. Implants were restored with individualized abutments and cemented metal-ceramic crowns. Acquired measurements were: insertion torque values (IT), thickness of buccal bone plate after implant osteotomy preparation (BBT), marginal bone level (MBL), and facial soft tissue level (FST). All patients were followed 12 months after implant placement. One hundred sixteen implants were placed in one hundred sixteen patients and enrolled for the study. Fifty-eight implants were randomly allocated in regular-IT and high-IT groups with a mean insertion torque ranging from 20 Ncm to 50 Ncm and from 50 Ncm to 100 Ncm, respectively. Three implants failed, and another five implants showed at the 12-month evaluation a marginal bone loss (ΔMBL) greater than 1.5 mm, being considered unsuccessful. The findings suggested that implants inserted with high-IT (≥50 Ncm) in healed bone ridges showed more peri-implant bone remodeling and buccal soft tissue recession than implants inserted with a regular-IT (<50 Ncm). Moreover, sites with a thick buccal bone wall (≥1 mm) - after implant osteotomy site preparation - seemed to be less prone to buccal soft tissue recession after 12 months than sites with a thin buccal bone wall (<1 mm). © 2015 Wiley Periodicals, Inc.

Periapical implant lesion: A systematic review

PubMed Central

Blaya-Tárraga, Juan-Antonio; Cervera-Ballester, Juan; Peñarrocha-Oltra, David; Peñarrocha-Diago, Miguel

2017-01-01

Background The aim of this study was to systematically review the evidence for periapical implant lesion, which makes a patient more susceptible to the periapical lesion, frequency, symptoms, signs (including radiological findings) and possible treatment options. Material and Methods A systematic literature review and analysis of publications included in PubMed, Embase and Cochrane; articles published until March 2016; with a populations, exposures and outcomes (PEO) search strategy was performed, focused on the issue: “In patients with periapical lesion to the implant during the osseointegration, what symptoms, signs, and changes in complementary examination manifested, for according to that stage, be intervened with the appropriate approach?”. The set criteria for inclusion were peer-reviewed articles. Results From a total of 212 papers identified, 36 studies were included in this systematic review, with 15461 implants evaluated and 183 periapical implant lesions. Which 8 papers included more than 5 cases and 28 included equal or less than 5 cases. Analysis of the papers revealed that periapical implant lesion is classified according to evolution stages into acute (non-suppurated and suppurated) and subacute (or suppurated-fistulized). In the acute stage and in the subacute if there is no loss of implant stability, the correct treatment approach is implant periapical surgery. In the subacute stage associated with implant mobility the implant must be removed. Conclusions Evidence on the subject is very limited, there are few studies with small sample, without homogeneity of criteria for diagnosing the disease and without design of scientific evidence. Currently etiology lacks consensus. The early diagnosis of periapical implant periapical lesions during the osseointegration phase and early treatment, will lead to a higher survival rate of implants treated, hence preventing the need for implant extraction. Key words:Apical peri-implantitis, retrograde peri-implantitis, inflammatory peri-implantitis lesion. PMID:29053646

Biomechanical investigation of thread designs and interface conditions of zirconia and titanium dental implants with bone: three-dimensional numeric analysis.

PubMed

Fuh, Lih-Jyh; Hsu, Jui-Ting; Huang, Heng-Li; Chen, Michael Y C; Shen, Yen-Wen

2013-01-01

Bone stress and interfacial sliding at the bone-implant interface (BII) were analyzed in zirconia and titanium implants with various thread designs and interface conditions (bonded BII and contact BIIs with different frictional coefficients) for both conventional and immediately loaded treatments. A total of 18 finite element models comprising two implant materials (zirconia and titanium), three thread designs (different shapes and pitches), and three interface conditions (bonded and contact BIIs) were analyzed to assess the effects on bone stresses and on sliding at the BII. The material properties of the bone model were anisotropic, and a lateral force of 130 N was applied as the loading condition. In the immediately loaded implant, the stress was highly concentrated at one site of the peri-implant bone. The peak bone stress was more than 20% lower in zirconia implants than in titanium implants for a bonded BII and 14% to 20% lower for a contact BII. The bone stresses did not differ significantly between implants with V-shaped threads and square threads. However, sliding at the BII was more than 25% lower with square-thread implants than with V-shaped-thread implants for titanium implants and 36% lower for zirconia implants. Reducing the thread size and pitch in cortical bone (via two V-shaped threads with different pitches) decreased the bone stress by 13%. Increasing the frictional coefficient reduced sliding at the BII in both zirconia and titanium implants. As an implant material, zirconia can reduce the bone stress in the crestal cortical region. Bone stress and sliding at the BII are heavily dependent on the thread design and the frictional coefficient at the BII of immediately loaded implants.

Effects of implant system, impression technique, and impression material on accuracy of the working cast.

PubMed

Wegner, Kerstin; Weskott, Katharina; Zenginel, Martha; Rehmann, Peter; Wöstmann, Bernd

2013-01-01

This in vitro study aimed to identify the effects of the implant system, impression technique, and impression material on the transfer accuracy of implant impressions. The null hypothesis tested was that, in vitro and within the parameters of the experiment, the spatial relationship of a working cast to the placement of implants is not related to (1) the implant system, (2) the impression technique, or (3) the impression material. A steel maxilla was used as a reference model. Six implants of two different implant systems (Standard Plus, Straumann; Semados, Bego) were fixed in the reference model. The target variables were: three-dimensional (3D) shift in all directions, implant axis direction, and rotation. The target variables were assessed using a 3D coordinate measuring machine, and the respective deviations of the plaster models from the nominal values of the reference model were calculated. Two different impression techniques (reposition/pickup) and four impression materials (Aquasil Ultra, Flexitime, Impregum Penta, P2 Magnum 360) were investigated. In all, 80 implant impressions for each implant system were taken. Statistical analysis was performed using multivariate analysis of variance. The implant system significantly influenced the transfer accuracy for most spatial dimensions, including the overall 3D shift and implant axis direction. There was no significant difference between the two implant systems with regard to rotation. Multivariate analysis of variance showed a significant effect on transfer accuracy only for the implant system. Within the limits of the present study, it can be concluded that the transfer accuracy of the intraoral implant position on the working cast is far more dependent on the implant system than on the selection of a specific impression technique or material.

Bruxism and dental implant failures: a multilevel mixed effects parametric survival analysis approach.

PubMed

Chrcanovic, B R; Kisch, J; Albrektsson, T; Wennerberg, A

2016-11-01

Recent studies have suggested that the insertion of dental implants in patients being diagnosed with bruxism negatively affected the implant failure rates. The aim of the present study was to investigate the association between the bruxism and the risk of dental implant failure. This retrospective study is based on 2670 patients who received 10 096 implants at one specialist clinic. Implant- and patient-related data were collected. Descriptive statistics were used to describe the patients and implants. Multilevel mixed effects parametric survival analysis was used to test the association between bruxism and risk of implant failure adjusting for several potential confounders. Criteria from a recent international consensus (Lobbezoo et al., J Oral Rehabil, 40, 2013, 2) and from the International Classification of Sleep Disorders (International classification of sleep disorders, revised: diagnostic and coding manual, American Academy of Sleep Medicine, Chicago, 2014) were used to define and diagnose the condition. The number of implants with information available for all variables totalled 3549, placed in 994 patients, with 179 implants reported as failures. The implant failure rates were 13·0% (24/185) for bruxers and 4·6% (155/3364) for non-bruxers (P < 0·001). The statistical model showed that bruxism was a statistically significantly risk factor to implant failure (HR 3·396; 95% CI 1·314, 8·777; P = 0·012), as well as implant length, implant diameter, implant surface, bone quantity D in relation to quantity A, bone quality 4 in relation to quality 1 (Lekholm and Zarb classification), smoking and the intake of proton pump inhibitors. It is suggested that the bruxism may be associated with an increased risk of dental implant failure. © 2016 John Wiley & Sons Ltd.

Bone integration capability of nanopolymorphic crystalline hydroxyapatite coated on titanium implants

PubMed Central

Yamada, Masahiro; Ueno, Takeshi; Tsukimura, Naoki; Ikeda, Takayuki; Nakagawa, Kaori; Hori, Norio; Suzuki, Takeo; Ogawa, Takahiro

2012-01-01

The mechanism by which hydroxyapatite (HA)-coated titanium promotes bone–implant integration is largely unknown. Furthermore, refining the fabrication of nano-structured HA to the level applicable to the mass production process for titanium implants is challenging. This study reports successful creation of nanopolymorphic crystalline HA on microroughened titanium surfaces using a combination of flame spray and low-temperature calcination and tests its biological capability to enhance bone–implant integration. Sandblasted microroughened titanium implants and sandblasted + HA-coated titanium implants were subjected to biomechanical and histomorphometric analyses in a rat model. The HA was 55% crystallized and consisted of nanoscale needle-like architectures developed in various diameters, lengths, and orientations, which resulted in a 70% increase in surface area compared to noncoated microroughened surfaces. The HA was free from impurity contaminants, with a calcium/phosphorus ratio of 1.66 being equivalent to that of stoichiometric HA. As compared to microroughened implants, HA-coated implants increased the strength of bone–implant integration consistently at both early and late stages of healing. HA-coated implants showed an increased percentage of bone–implant contact and bone volume within 50 μm proximity of the implant surface, as well as a remarkably reduced percentage of soft tissue intervention between bone and the implant surface. In contrast, bone volume outside the 50 μm border was lower around HA-coated implants. Thus, this study demonstrated that the addition of pure nanopolymorphic crystalline HA to microroughened titanium not only accelerates but also enhances the level of bone–implant integration and identified the specific tissue morphogenesis parameters modulated by HA coating. In particular, the nanocrystalline HA was proven to be drastic in increasing osteoconductivity and inhibiting soft tissue infiltration, but the effect was limited to the immediate microenvironment surrounding the implant. PMID:22359461

Effect of roughened micro-threaded implant neck 
and platform switching on marginal bone loss: 
a multicenter retrospective study with 6-year follow-up.

PubMed

Di Stefano, Danilo Alessio; Giacometti, Edoardo; Greco, Gian Battista; Gastaldi, Giorgio; Gherlone, Enrico

2016-01-01

The aim of this retrospective study was to evaluate medium-term marginal peri-implant bone loss following placement of root-form implants featuring a micro-threaded rough-surfaced neck and a platform-switched implant-abutment connection. Records were identified of patients treated with such implants over a 3-year period at three Italian dental centers. Patient radiographs were digitized and subjected to computerized analysis of peri-implant bone resorption. Records of 112 patients who received 257 implants were analyzed. Although implant diameters and lengths varied, all had a 0.3-mm platform-switching width and a 2.5-mm high micro-threaded neck. All patients healed uneventfully, and no peri-implant infection, implant mobility, or radiolucency around the implant were detected at any follow-up control. At the 72-month control (average 71 ± 5 months) all implants were successful according to Albrektsson and Zarb's criteria. At implant level, average peri-implant bone resorption was 0.18 ± 0.12 mm at 6 months, 0.22 ± 0.15 mm at 12 months, 0.23 ± 0.16 mm at 24 months, 0.25 ± 0.17 mm at 36 months, 0.26 ± 0.15 mm at 48 months, and stable at subsequent controls, regardless of the implant diameter and length. At patient level, a similar trend was observed, with crestal bone loss stabilizing from 48 months onward. The surface, geometry, and platform-switching features of the implant under investigation allowed effective bone preservation on a medium-term basis.

Evaluation of the Alteration of Occlusal Distribution in Unilateral Free-End and Intermediate Missing Cases.

PubMed

Kon, Kazuhiro; Shiota, Makoto; Sakuyama, Aoi; Ozeki, Maho; Kozuma, Wataru; Kawakami, Sawako; Kasugai, Shohei

2017-02-01

The present study aimed to evaluate the effect of implant prostheses on the occlusal force and area as well as the distribution of occlusal loading in unilateral free-end and intermediate missing cases. Fourteen healthy subjects (7 free-end missing cases in the first and second molars and 7 intermediate missing cases in the first molar region) were included. Six months after the implant prosthesis was placed, an occlusal evaluation was performed with or without the implant superstructure by using Dental Prescale film and an occluder device. In free-end missing cases, the total occlusal force and area, implant-side occlusal force and area, and implant-side occlusal force and area of the residual natural teeth were significantly affected by the implant prostheses. In intermediate missing cases, the implant-side occlusal force of the residual natural teeth was significantly affected by the implant prostheses. In free-end missing cases, the proportions of implant-side occlusal force, non-implant-side occlusal force, and implant-side occlusal force of the residual natural teeth relative to the total occlusal force were significantly affected by the implant prostheses. In the intermediate missing cases, the proportion of the implant-side occlusal force of the residual natural teeth relative to the total occlusal force was significantly affected by the implant prostheses. The proportion of the occlusal area was also significantly affected. In free-end missing cases, implant prostheses significantly increased the occlusal force and area, which resulted in the proper occlusal distribution. In intermediate missing cases, an implant prosthesis may only improve the same-side occlusal loading of the natural teeth.

Evaluation of bone response to titanium-coated polymethyl methacrylate resin (PMMA) implants by X-ray tomography.

PubMed

Shalabi, Manal M; Wolke, Johannes G C; Cuijpers, Vincent M J I; Jansen, John A

2007-10-01

High-resolution three-dimensional data about the bone response to oral implants can be obtained by using microfocus computer tomography. However, a disadvantage is that metallic implants cause streaking artifacts due to scattering of X-rays, which prevents an accurate evaluation of the interfacial bone-to-implant contact. It has been suggested that the use of thin titanium coatings deposited on polymeric implants can offer an alternative option for analyzing bone contact using micro-CT imaging. Consequently, the aim of the current study was to investigate bone behavior to titanium-coated polymethylmethacrylate (PMMA) implants by micro-CT and histological evaluation. For the experiment titanium-coated PMMA implants were used. The implants had a machined threaded appearance and were provided with a 400-500 nm thick titanium coating. The implants were inserted in the right or left tibia of 10 goats. After an implantation period of 12 weeks the implants were retrieved and prepared for micro-computer tomography (microCT), light microscopy, and X-ray microanalysis. The micro-CT showed that the screw-threads and typical implant configuration were well maintained through the installation procedure. Overall, histological responses showed that the titanium-coated implants were well tolerated and caused no atypical tissue response. In addition, the bone was seen in direct contact with the titanium-coated layer. The X-ray microanalysis results confirmed the light microscopical data. In conclusion, the obtained results proof the final use of titanium-coated PMMA implants for evaluation of the bone-implant response using microCT. However, this study also confirms that for a proper analysis of the bone-implant interface the additional use of microscopical techniques is still required.

Effect of Implant Diameter and Ridge Dimension on Stress Distribution in Mandibular First Molar Sites-A Photoelastic Study.

PubMed

Termeie, Deborah; Klokkevold, Perry R; Caputo, Angelo A

2015-10-01

The long-term clinical success of a dental implant is dependent upon maintaining sufficient osseointegration to resist forces of occlusion. The purpose of this study was to investigate the effect of implant diameter on stress distribution around screw-type dental implants in mandibular first molar sites using photoelastic models. The design included models with different buccal-lingual dimension. Twelve composite photoelastic models were assembled using 2 different resins to simulate trabecular and cortical bone. Half of the models were fabricated with average dimensions for ridge width and the other half with narrower buccal-lingual dimensions. One internal connection implant (13 mm length) with either a standard (4 mm), wide (5 mm), or narrow (3.3 mm) diameter was embedded in the first molar position of each photoelastic model. Half the implants were tapered and the other half were straight. Full gold crowns in the shape of a mandibular first molar were fabricated and attached to the implants. Vertical and angled loads of 15 and 30 pounds were applied to specific points on the crown. Wide-diameter implants produced the least stress in all ridges while narrow-diameter implants generated the highest stress, especially in narrow ridges. It may be that the volume and quality of bone surrounding implants influences stress distribution with a greater ratio of cortical to trabecular bone, thus providing better support. Models with wide-diameter implants loaded axially had a more symmetrical stress distribution compared to standard and narrow diameter implants. A more asymmetrical stress pattern developed along the entire implant length with angled loads. Implant diameter and ridge width had considerable influence on stress distribution. Narrow-diameter implants produced more stress than wide diameter implants in all conditions tested.

Sino-implant (II) - a levonorgestrel-releasing two-rod implant: systematic review of the randomized controlled trials

PubMed Central

Steiner, Markus J.; Lopez, Laureen M.; Grimes, David A.; Cheng, Linan; Shelton, Jim; Trussell, James; Farley, Timothy M.M.; Dorflinger, Laneta

2013-01-01

Background Sino-implant (II) is a subdermal contraceptive implant manufactured in China. This two-rod levonorgestrel-releasing implant has the same amount of active ingredient (150 mg levonorgestrel) and mechanism of action as the widely available contraceptive implant Jadelle. We examined randomized controlled trials of Sino-implant (II) for effectiveness and side effects. Study design We searched electronic databases for studies of Sino-implant (II), and then restricted our review to randomized controlled trials. The primary outcome of this review was pregnancy. Results Four randomized trials with a total of 15,943 women assigned to Sino-implant (II) had first-year probabilities of pregnancy ranging from 0.0% to 0.1%. Cumulative probabilities of pregnancy during the four years of the product's approved duration of use were 0.9% and 1.06% in the two trials that presented date for four-year use. Five-year cumulative probabilities of pregnancy ranged from 0.7% to 2.1%. In one trial, the cumulative probability of pregnancy more than doubled during the fifth year (from 0.9% to 2.1%), which may be why the implant is approved for four years of use in China. Five-year cumulative probabilities of discontinuation due to menstrual problems ranged from 12.5% to 15.5% for Sino-implant (II). Conclusions Sino-implant (II) is one of the most effective contraceptives available today. These available clinical data, combined with independent laboratory testing, and the knowledge that 7 million women have used this method since 1994, support the safety and effectiveness of Sino-implant (II). The lower cost of Sino-implant (II) compared with other subdermal implants could improve access to implants in resource-constrained settings. PMID:20159174

Effect of radial head implant shape on joint contact area and location during static loading.

PubMed

Shannon, Hannah L; Deluce, Simon R; Lalone, Emily A; Willing, Ryan; King, Graham J W; Johnson, James A

2015-04-01

To examine the effect of implant shape on radiocapitellar joint contact area and location in vitro. We used 8 fresh-frozen cadaveric upper extremities. An elbow loading simulator examined joint contact in pronation, neutral rotation, and supination with the elbow at 90° flexion. Muscle tendons were attached to pneumatic actuators to allow for computer-controlled loading to achieve the desired forearm rotation. We performed testing with the native radial head, an axisymmetric implant, a reverse-engineered patient-specific implant, and a population-based quasi-anatomic implant. Implants were inserted using computer navigation. Contact area and location were quantified using a casting technique. We found no significant difference between contact locations for the native radial head and the 3 implants. All of the implants had a contact area lower than the native radial head; however, only the axisymmetric implant was significantly different. There was no significant difference in contact area between implant shapes. The similar contact areas and locations of the 3 implant designs suggest that the shape of the implant may not be important with respect to radiocapitellar joint contact mechanics when placed optimally using computer navigation. Further work is needed to explore the sensitivity of radial head implant malpositioning on articular contact. The lower contact area of the radial head implants relative to the native radial head is similar to previous benchtop studies and is likely the result of the greater stiffness of the implant. Radial head implant shape does not appear to have a pronounced influence on articular contact, and both axisymmetric and anatomic metal designs result in elevated cartilage stress relative to the intact state. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Current use of implantable electrical devices in Sweden: data from the Swedish pacemaker and implantable cardioverter-defibrillator registry.

PubMed

Gadler, Fredrik; Valzania, Cinzia; Linde, Cecilia

2015-01-01

The National Swedish Pacemaker and Implantable Cardioverter-Defibrillator (ICD) Registry collects prospective data on all pacemaker and ICD implants in Sweden. We aimed to report the 2012 findings of the Registry concerning electrical devices implantation rates and changes over time, 1 year complications, long-term device longevity and patient survival. Forty-four Swedish implanting centres continuously contribute implantation of pacemakers and ICDs to the Registry by direct data entry on a specific website. Clinical and technical information on 2012 first implants and postoperative complications were analysed and compared with previous years. Patient survival data were obtained from the Swedish population register database. In 2012, the mean pacemaker and ICD first implantation rates were 697 and 136 per million inhabitants, respectively. The number of cardiac resynchronization therapy (CRT) first implantations/million capita was 41 (CRT pacemakers) and 55 (CRT defibrillators), with only a slight increase in CRT-ICD rate compared with 2011. Most device implantations were performed in men. Complication rates for pacemaker and ICD procedures were 5.3 and 10.1% at 1 year, respectively. Device and lead longevity differed among manufacturers. Pacemaker patients were older at the time of first implant and had generally worse survival rate than ICD patients (63 vs. 82% after 5 years). Pacemaker and ICD implantation rates seem to have reached a level phase in Sweden. Implantable cardioverter-defibrillator and CRT implantation rates are very low and do not reflect guideline indications. Gender differences in CRT and ICD implantations are pronounced. Device and patient survival rates are variable, and should be considered when deciding device type. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Long-term evaluation of Astra Tech and Brånemark implants in patients treated with full-arch bridges. Results after 12-15 years.

PubMed

Ravald, Nils; Dahlgren, Simon; Teiwik, Anders; Gröndahl, Kerstin

2013-10-01

To study the long-term outcome of implant survival rate, soft and hard tissue conditions and prosthetic status in a group of individuals treated with either Astra Tech TiOblast or Brånemark turned implants supporting a full-arch bridge. Edentulous patients treated with either Astra Tech TiOblast surface or Brånemark turned implants were recalled for examination after 12-15 years. Out of initially 66 patients 46 were available for examination. Intra-oral radiographs were taken for bone level assessments. Clinical prosthetic conditions, number of surviving implants, implant stability, plaque scores, probing pocket depths, bleeding and pus after probing were recorded. Analyses of bone level changes during the total observation period were performed. Three patients in the Astra Tech group lost totally eight implants and five patients in the Brånemark group lost 10 implants during the total observation period. No statistically significant difference in implant loss or bone level change was found. Sixteen per cent of Astra Tech and 29% of Brånemark patients showed at least one implant with ≥2 mm bone loss after the first year in function. The corresponding prevalence on implant level was 6% and 5% respectively. No significant differences were found between the other examined variables. Two patients showed prosthetic complications of the supra construction in need of repair. Seven bridges had minor ceramic chippings. Treatment with Astra Tech TiOblast implants and Brånemark turned implants supporting full-arch bridges showed generally good clinical results with low numbers of implants with marginal bone loss indicative of peri-implantitis. No significant differences were found between the implant systems after 12-15 years in function. © 2012 John Wiley & Sons A/S.

Comparison of retention and stability of implant-retained overdentures based upon implant number and distribution.

PubMed

Scherer, Michael D; McGlumphy, Edwin A; Seghi, Robert R; Campagni, Wayne V

2013-01-01

The purpose of this investigation was to evaluate the effects of number and distribution of implants upon in vitro dislodging forces to a simulated implant-supported overdenture and to examine differences between several different attachment systems. An experiment was undertaken utilizing a model simulating a mandibular edentulous ridge with dental implants in positions on the model approximating tooth positions in the natural dentition. A cobalt-chromium-cast testing framework was used to measure the peak load required to disconnect an attachment. Four different types of commercially available attachments were used in various positions on the model in sequence to evaluate the effects of retention and stability of overdentures based on implant number and distribution: (1) ERA, (2) O-Ring, (3) Locator, and (4) Ball. For each group, 10 measurements were made of peak dislodging forces. Means were calculated and differences among the systems, directions, and groups were identified using a repeated measured analysis of variance (α = .05). The interactions between the attachment system, direction of force, and implant number and distribution were statistically significant. Vertical dislodging forces of the simulated overdenture prosthesis increased with additional widely spaced implants. Oblique dislodging forces of the simulated prosthesis increased with additional widely spaced implants except in the two-implant model with all attachments, and in the four-implant groups with Locator attachments. Anteroposterior dislodging forces of a simulated overdenture prosthesis increased with additional widely spaced implants except in the four-implant groups with Ball and Locator attachments. Ball attachments reported the highest levels of retention and stability followed by Locator, O-Ring, and ERA. Within the limitations of this study, retention and stability of an implant overdenture prosthesis are significantly affected by implant number, implant distribution, and abutment type.

How to treat two adjacent missing teeth with dental implants. A systematic review on single implant-supported two-unit cantilever FDP's and results of a 5-year prospective comparative study in the aesthetic zone.

PubMed

Van Nimwegen, W G; Raghoebar, G M; Tymstra, N; Vissink, A; Meijer, H J A

2017-06-01

To conduct a systematic review on the clinical outcome of single implant-supported two-unit cantilever FDP's and to conduct a 5-year prospective comparative pilot study of patients with a missing central and lateral upper incisor treated with either a single implant-supported two-unit cantilever FDP or two implants with solitary implant crowns in the aesthetic zone. Medline, Embase and the Cochrane Central Register of Controlled Trials were searched (last search 1 August 2016) for eligible studies. In the comparative pilot study, an implant-cantilever group of five patients with a single implant-supported two-unit cantilever FDP (NobelReplace Groovy Regular Platform) was compared with an implant-implant group of five patients with two adjacent single implant-supported crowns (NobelReplace Groovy Regular Platform) in the aesthetic zone. Implant survival, marginal bone level (MBL) changes, pocket probing depth, papilla index and patient satisfaction were assessed during a 5-year follow-up period. Five of 276 articles were considered eligible for data extraction. Implant survival ranged from 96·6% to 100%. Marginal bone level changes were higher in the anterior region than in the posterior region. Technical complications occurred more often in the posterior than anterior region. In the 5-year comparative pilot study, no clinically significant differences in hard and soft peri-implant tissue levels occurred between both groups. Single implant-supported two-unit cantilever FDP's can be a viable alternative to the placement of two adjacent single implant crowns in the aesthetic zone. Due to technical complications, placement of two-unit cantilever crowns in the posterior region can be considered unwise. © 2017 John Wiley & Sons Ltd.

Prevalence of Dental Implants and Evaluation of Peri-implant Bone Levels in Patients Presenting to a Dental School: A Radiographic Cross-Sectional 2-Year Study.

PubMed

Alkan, Eylem Ayhan; Mau, Lian Ping; Schoolfield, John; Guest, Gary F; Cochran, David L

To evaluate the number of patients with dental implants who present to a dental school clinic for screening and to report the prevalence of peri-implant bone level change detected on digital panoramic radiographs of those subjects. Patient screening files for 9,422 patients over a 2-year period were examined to see how many patients presented with dental implants. Those patients with at least one implant were further evaluated by measuring the bone level on the mesial and distal sides of the implant using the screening radiograph. A total of 187 patients (2%) had at least one implant. In regard to implants, 423 were examined and 146 (33%) had no detectable bone loss defined as bone level below the top of the implant. When thresholds of bone loss were evaluated, 109 implants (25%) had ≥ 2 mm of bone loss on either the mesial or distal sides or both. The median bone loss was 1.74 mm for the 277 implants with detectable bone loss and 2.97 mm for the 109 implants that had ≥ 2 mm bone loss. Interestingly, patients who were ≥ 70 years of age had significantly (P = .03) more bone loss in the mandible compared with the maxilla, while patients who were 60 to 69 years of age had significantly greater loss in the maxilla. These data reveal that for patients presenting to the dental school for a screening over a 2-year period, 1.98% had one or more dental implants. Furthermore, those patients with implants had a minimum amount of bone loss as measured from the top of the implant.