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  1. Silicon exfoliation by hydrogen implantation: Actual nature of precursor defects

    NASA Astrophysics Data System (ADS)

    Kuisseu, Pauline Sylvia Pokam; Pingault, Timothée; Ntsoenzok, Esidor; Regula, Gabrielle; Mazen, Frédéric; Sauldubois, Audrey; Andreazza, Caroline

    2017-06-01

    MeV energy hydrogen implantation in silicon followed by a thermal annealing is a very smart way to produce high crystalline quality silicon substrates, much thinner than what can be obtained by diamond disk or wire sawing. Using this kerf-less approach, ultra-thin substrates with thicknesses between 15 μm and 100 μm, compatible with microelectronic and photovoltaic applications are reported. But, despite the benefits of this approach, there is still a lack of fundamental studies at this implantation energy range. However, if very few papers have addressed the MeV energy range, a lot of works have been carried out in the keV implantation energy range, which is the one used in the smart-cut® technology. In order to check if the nature and the growth mechanism of extended defects reported in the widely studied keV implantation energy range could be extrapolated in the MeV range, the thermal evolution of extended defects formed after MeV hydrogen implantation in (100) Si was investigated in this study. Samples were implanted at 1 MeV with different fluences ranging from 6 × 1016 H/cm2 to 2 × 1017 H/cm2 and annealed at temperatures up to 873 K. By cross-section transmission electron microscopy, we found that the nature of extended defects in the MeV range is quite different of what is observed in the keV range. In fact, in our implantation conditions, the generated extended defects are some kinds of planar clusters of gas-filled lenses, instead of platelets as commonly reported in the keV energy range. This result underlines that hydrogen behaves differently when it is introduced in silicon at high or low implantation energy. The activation energy of the growth of these extended defects is independent of the chosen fluence and is between (0.5-0.6) eV, which is very close to the activation energy reported for atomic hydrogen diffusion in a perfect silicon crystal.

  2. Photogrammetric determination of discrepancies between actual and planned position of dental implants

    NASA Astrophysics Data System (ADS)

    Forlani, G.; Rivara, F.

    2014-05-01

    The paper describes the design and testing of a photogrammetric measurement protocol set up to determine the discrepancies between the planned and actual position of computer-guided template-based dental implants. Two moulds with the implants positioned in pre- and post- intervention are produced and separately imaged with a highly redundant block of convergent images; the model with the implants is positioned on a steel frame with control points and with suitable targets attached. The theoretical accuracy of the system is better than 20 micrometers and 0.3-0.4° respectively for positions of implants and directions of implant axes. In order to compare positions and angles between the planned and actual position of an implant, coordinates and axes directions are brought to a common reference system with a Helmert transformation. A procedure for comparison of positions and directions to identify out-of-tolerance discrepancies is presented; a numerical simulation study shows the effectiveness of the procedure in identifying the implants with significant discrepancies between pre- and post- intervention.

  3. Concerns about implantable cardioverter-defibrillator shocks mediate the relationship between actual shocks and psychological distress.

    PubMed

    Thylén, Ingela; Moser, Debra K; Strömberg, Anna; Dekker, Rebecca A; Chung, Misook L

    2016-06-01

    Although most implantable cardioverter-defibrillator (ICD) patients cope well, fears about receiving ICD shocks have been identified as a major determinant of psychological distress. The relationships among ICD-related concerns, receipt of defibrillating shocks, and symptoms of anxiety and depression have not yet been investigated. Our objective was to examine whether the relationship between receipt of defibrillating shocks and psychological distress was mediated by patients' concerns related to their ICD. All Swedish ICD-recipients were invited to this cross-sectional correlational study; 3067 completing the survey (55% response rate). Their mean age was 66 ± 11 years, and 80% were male. One-third (35%) had received defibrillating shocks, and 26% had high ICD-related concerns. Regression analyses demonstrated that having received at least one shock significantly predicted symptoms of anxiety and depression [odds ratio (OR) 1.58 and OR 3.04, respectively]. The association between receipt of shocks and psychologically distress was mediated by high ICD-related concerns which explained 68% of the relationship between shocks and symptoms of anxiety, and 54% of the relationship between shocks and symptoms of depression. Implantable cardioverter-defibrillator-related concerns have a bigger impact on psychological distress than receipt of an actual shock. Assessing ICD-related concerns in clinical practice can identify patients at risk for psychological distress. Further research on assessment of, and interventions targeting, ICD-related concerns is warranted. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  4. Validation of value of actual micromotion as a direct measure of implant micromobility after healing (secondary implant stability). An in vivo histologic and biomechanical study.

    PubMed

    Trisi, Paolo; Berardini, Marco; Falco, Antonello; Podaliri Vulpiani, Michele

    2016-11-01

    The osseointegration process replaces the surgically damaged bone with newly formed bone in contact to the implant surface. This involves some loss of primary stability, which will continue until new bone is formed providing a new stability, known as "secondary stability." A direct measurement of secondary implant stability appears fundamental to determine the period and modalities for implant loading. The aim of this study was to validate the measurement of the implant micromotion to test secondary implant stability. Twenty-four 3.8 × 11.5 mm implants (Dynamix, Cortex, Shlomi, Israel) were inserted in sheep iliac crests. The animals were sacrificed after 2 months, and the freshly retrieved bone blocks were immediately fixed on a customized device to calculate the value of actual micromotion (VAM) according to a previously described technique. Implant stability quotient (ISQ) values, reverse torque value (RTV), %bone-to-implant contact (%BIC), bone volume percentage (%BV) and crestal bone loss (CBL) were also calculated for each implant. Statistical correlations between VAM and the other parameters were calculated. Data correlation analysis between the examined parameters showed that VAM significantly correlates (P < 0.05) to RTV, %BIC, ISQ and CBL. As VAM showed to be statistical correlated to the other parameters of osseointegration, it may be used to clinically check the amount of implant osseointegration, secondary stability and CBL. Future studies are needed to confirm these results moreover. An instrument to measure VAM in the oral cavity still needs to be developed. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Forward-Masked Frequency Selectivity Improvements in Simulated and Actual Cochlear Implant Users Using a Preprocessing Algorithm

    PubMed Central

    Jürgens, Tim

    2016-01-01

    Frequency selectivity can be quantified using masking paradigms, such as psychophysical tuning curves (PTCs). Normal-hearing (NH) listeners show sharp PTCs that are level- and frequency-dependent, whereas frequency selectivity is strongly reduced in cochlear implant (CI) users. This study aims at (a) assessing individual shapes of PTCs in CI users, (b) comparing these shapes to those of simulated CI listeners (NH listeners hearing through a CI simulation), and (c) increasing the sharpness of PTCs using a biologically inspired dynamic compression algorithm, BioAid, which has been shown to sharpen the PTC shape in hearing-impaired listeners. A three-alternative-forced-choice forward-masking technique was used to assess PTCs in 8 CI users (with their own speech processor) and 11 NH listeners (with and without listening through a vocoder to simulate electric hearing). CI users showed flat PTCs with large interindividual variability in shape, whereas simulated CI listeners had PTCs of the same average flatness, but more homogeneous shapes across listeners. The algorithm BioAid was used to process the stimuli before entering the CI users’ speech processor or the vocoder simulation. This algorithm was able to partially restore frequency selectivity in both groups, particularly in seven out of eight CI users, meaning significantly sharper PTCs than in the unprocessed condition. The results indicate that algorithms can improve the large-scale sharpness of frequency selectivity in some CI users. This finding may be useful for the design of sound coding strategies particularly for situations in which high frequency selectivity is desired, such as for music perception. PMID:27604785

  6. El Observatorio Gemini - Status actual

    NASA Astrophysics Data System (ADS)

    Levato, H.

    Se hace una breve descripción de la situación actual del Observatorio Gemini y de las últimas decisiones del Board para incrementar la eficiencia operativa. Se hace también una breve referencia al uso argentino del observatorio.

  7. A systematic comparison of the actual, potential, and theoretical health effects of cobalt and chromium exposures from industry and surgical implants.

    PubMed

    Keegan, Gemma M; Learmonth, Ian D; Case, C Patrick

    2008-01-01

    Humans are exposed to cobalt (Co) and chromium (Cr) from industry and surgical devices, most notably orthopedic joint replacements. This review compares the potential health effects of exposure to Co and Cr contaminants from these two different sources, both in the locally exposed tissues and at sites distant to the primary exposure. Surgical implantation results largely in exposures to ions, corrosion products, and particles of Co and Cr. Industrial exposures are predominantly to metal compounds and particles. Although there are large literatures on industrial and surgical exposures to these metals, there has yet to be a systematic comparison of the two to test whether more general lessons might be learned about the human toxicology of Co and Cr. Both industrial and surgical exposures cause inflammatory and other immune reactions in the directly exposed tissues. In the lung there is a well-established risk of cancer following long-term exposures to hexavalent Cr; however, the development of sarcoma in the connective tissues adjacent to implants in response to metal particles is rare. Both types of exposure are associated with changes in the peripheral blood, including evidence of oxidative stress, and altered numbers of circulating immune cells. There is dissemination of Co and Cr to sites distant to the orthopedic implant, but less is known about systemic dissemination of these metals away from the lung. The effects of industrial exposures in the reproductive, renal, and cardiac systems have been investigated, but this has yet to be explored after surgical exposures. The form of the metal (and associated elements) in both instances is key to the toxicological effects arising in the body and further characterization of debris released from devices is certainly recommended, as is the impact of nanotoxicology on the health and safety of workers and patients. Biomonitoring schemes currently used in industry could be translated, if required, into suitable programs for

  8. A Critical Review of Search Strategies Used in Recent Systematic Reviews Published in Selected Prosthodontic and Implant-Related Journals: Are Systematic Reviews Actually Systematic?

    PubMed

    Layton, Danielle

    The aim of this study was to outline how search strategies can be systematic, to examine how the searches in recent systematic reviews in prosthodontic and implant-related journals were structured, and to determine whether the search strategies used in those articles were systematic. A total of 103 articles published as systematic reviews and indexed in Medline between January 2013 and May 2016 were identified from eight prosthodontic and implant journals and reviewed. The search strategies were considered systematic when they met the following criteria: (1) more than one electronic database was searched, (2) more than one searcher was clearly involved, (3) both text words and indexing terms were clearly included in the search strategy, (4) a hand search of selected journals or reference lists was undertaken, (5) gray research was specifically sought, and (6) the articles were published in English and at least one other language. The data were tallied and qualitatively assessed. The majority of articles reported on implants (54%), followed by tooth-supported fixed prosthodontics (13%). A total of 23 different electronic resources were consulted, including Medline (by 100% of articles), the Cochrane Library (52%), and Embase (37%). The majority consulted more than one electronic resource (71%), clearly included more than one searcher (73%), and employed a hand search of either selected journals or reference lists (86%). Less than half used both text words and indexing terms to identify articles (42%), while 15% actively sought gray research. Articles published in languages other than English were considered in 63 reviews, but only 14 had no language restrictions. Of the 103 articles, 5 completed search strategies that met all 6 criteria, and a further 12 met 5 criteria. Two articles did not fulfill any of the criteria. More than 95% of recent prosthodontic and implant review articles published in the selected journals failed to use search strategies that were

  9. Del-1 Overexpression in Endothelial Cells Increases Vascular Density in Tissue-Engineered Implants Containing Endothelial Cells and Adipose-Derived Mesenchymal Stromal Cells

    PubMed Central

    Ciucurel, Ema C.

    2014-01-01

    We used a combination of strategies to stimulate the vascularization of tissue-engineered constructs in vivo including a modular approach to build larger tissues from individual building blocks (“modules”) mixed together. Each building block included vascular cells by design; modules were submillimeter-sized collagen gels with an outer layer of endothelial cells (ECs), and with embedded adipose-derived mesenchymal stromal cells (adMSCs) to support EC survival and blood vessel maturation in vivo. We transduced the ECs that coat the modules with a lentiviral construct to overexpress the angiogenic extracellular matrix (ECM) protein Developmental endothelial locus-1 (Del-1). Upon injection of modules in a subcutaneous SCID/Bg mouse model, there was an increase in the number of blood vessels for implants with ECs transduced to overexpress Del-1 compared with control implants (with enhanced green fluorescent protein [eGFP]–transduced ECs) over the 21-day duration of the study. The greatest difference between Del-1 and eGFP implants and the highest number of blood vessels were observed 7 days after transplantation. The day-7 Del-1 implants also had increased SMA+ staining compared with control, suggesting increased blood vessel maturation through recruitment of SMA+ smooth muscle cells or pericytes to stabilize the newly formed blood vessels. Perfusion studies (microcomputed tomography, ultrasound imaging, and systemic injection of fluorescent UEA-1 or dextran) showed that some of the newly formed blood vessels (both donor derived and host derived, in both Del-1 and eGFP implants) were perfused and connected to the host vasculature as early as 7 days after transplantation, and at later time points as well. Nevertheless, perfusion of the implants was limited in some cases, suggesting that further improvements are necessary to normalize the vasculature at the implant site. PMID:24151812

  10. Cochlear Implants

    MedlinePlus

    ... Medical Procedures Implants and Prosthetics Cochlear Implants Cochlear Implants Share Tweet Linkedin Pin it More sharing options ... normal ear, ear with hearing loss, and cochlear implant procedure Welcome to the Food and Drug Administration ( ...

  11. The Course of Actualization

    ERIC Educational Resources Information Center

    De Smet, Hendrik

    2012-01-01

    Actualization is traditionally seen as the process following syntactic reanalysis whereby an item's new syntactic status manifests itself in new syntactic behavior. The process is gradual in that some new uses of the reanalyzed item appear earlier or more readily than others. This article accounts for the order in which new uses appear during…

  12. Prevalence of DFNB1 mutations among cochlear implant users in Slovakia and its clinical implications.

    PubMed

    Varga, L; Mašindová, I; Hučková, M; Kabátová, Z; Gašperíková, D; Klimeš, I; Profant, M

    2014-06-01

    Hereditary etiology plays an important role in bilateral profound deafness as a main indication for cochlear implantation. Mutations in DFNB1 locus account for most of the inherited deafness cases in Caucasians. To provide actual data on mutation prevalence among implanted deaf subpopulation, we performed DNA analysis of GJB2 and GJB6 genes in 131 unrelated Slovak cochlear implant users. Eight previously described causal mutations and one probably pathogenic missense variant (c.127G>A) were detected in the GJB2 gene in 58 (44.28%) subjects. The most common mutation found was c.35delG with frequency 83.02% of all disease alleles, followed by c.71G>A, c.1-3201G>A, c.313_326del14, c.109G>A, 167delT, c.269T>C, and c.333_334delAA. GJB6 deletion delD13S1830 was identified in only one subject, in double heterozygosity with a GJB6 mutation. Thus, the deafness cause could be clearly attributable to DFNB1 mutations in 36.64% of the patients examined. In summary, the mutation profile found in our cohort was similar to the mutation spectrum reported for Central European deaf populations. The mutation prevalence in cochlear implant users was, however, almost by 25% higher than previously established for non-implanted hearing-impaired population in Slovakia. Finally, we also demonstrate a certain variability in deafness onset in patients with causal genotype and coincidence with other risk factors for deafness. Our results underline the importance of genetic tests in all cochlear implant candidates.

  13. 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…

  14. 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…

  15. Penile Implants

    MedlinePlus

    Penile Implants Overview By Mayo Clinic Staff Penile implants are devices placed inside the penis to allow men with erectile dysfunction (ED) to get an erection. Penile implants are typically recommended after other treatments for ED ...

  16. Dental Implants.

    PubMed

    Griggs, Jason A

    2017-10-01

    Systematic reviews of literature over the period between 2008 and 2017 are discussed regarding clinical evidence for the factors affecting survival and failure of dental implants. The factors addressed include publication bias, tooth location, insertion torque, collar design, implant-abutment connection design, implant length, implant width, bone augmentation, platform switching, surface roughness, implant coatings, and the use of ceramic materials in the implant body and abutment. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Exploring Effectiveness of Computer-Aided Planning in Implant Positioning for a Single Immediate Implant Placement.

    PubMed

    Edelmann, Alexander R; Hosseini, Bashir; Byrd, Warren C; Preisser, John S; Tyndall, Donald A; Nguyen, Tung; Bencharit, Sompop

    2016-06-01

    The value of computer-aided implant planning using cone-beam computerized tomography (CBCT) for single immediate implants was explored. Eighteen patients requiring extraction of a tooth followed by a single immediate implant were enrolled. Small volume preoperative CBCT scans were used to plan the position of the implant. A taper screwed-type implant was immediately placed into a fresh socket using only the final 1 or 2 drills for osteotomy. Postoperative CBCTs were used for the analysis of actual implant placement positioning. Measurements of the planned and the actual implant position were made with respect to their position relative to the adjacent teeth. Mesio-distal displacements and the facial-lingual deviation of the implant from the planned position were determined. Changes in the angulation of the planned and actual implant position in relation to the clinical crown were also measured. To statistically summarize the results, box plots and 95% CIs for means of paired differences were used. The analysis showed no statistical difference between the planned position and final implant placement position in any measurement. The CBCT scans coupled with the computer-aided implant planning program along with a final 1-to-2 drill protocol may improve the accuracy of single immediate implant placement for taper screwed-type implants.

  18. Dental Implants.

    PubMed

    Zohrabian, Vahe M; Sonick, Michael; Hwang, Debby; Abrahams, James J

    2015-10-01

    Dental implants restore function to near normal in partially or completely edentulous patients. A root-form implant is the most frequently used type of dental implant today. The basis for dental implants is osseointegration, in which osteoblasts grow and directly integrate with the surface of titanium posts surgically embedded into the jaw. Radiologic assessment is critical in the preoperative evaluation of the dental implant patient, as the exact height, width, and contour of the alveolar ridge must be determined. Moreover, the precise locations of the maxillary sinuses and mandibular canals, as well as their relationships to the site of implant surgery must be ascertained. As such, radiologists must be familiar with implant design and surgical placement, as well as augmentation procedures utilized in those patients with insufficient bone in the maxilla and mandible to support dental implants.

  19. Penile Implants

    MedlinePlus

    ... Three-piece inflatable implants use a fluid-filled reservoir implanted under the abdominal wall, a pump and ... an erection, you pump the fluid from the reservoir into the cylinders. Afterward, you release the valve ...

  20. La Enseñanza/Aprendizaje del Modelo Sol-Tierra Análisis de la Situación Actual y Propuesta de Mejora Para la Formación de los Futuros Profesores de Primaria

    NASA Astrophysics Data System (ADS)

    Martínez Sebastià, Bernat

    2004-12-01

    This work is an extened summary of the autor's PhD thesis. It deals with the teaching of astronomy (day/night, seasons) in primary school. At first, students teachers' undestanding of astronomical concepts related to Sun-Earth system have been analysed. Taking into account the results of the previous analysis and using a socio-constructivist approach a teaching sequence has been designed. This sequence has been tested with different groups of students teachers showing an improvement in their undestanding of elementary astronomical concepts. El trabajo que presentamos es un resumen extenso de la tesis doctoral del autor. El enfoque utilizado ha sido tratar de ligar la investigación sobre las ideas, razonamientos y obstáculos de los profesores de primaria con la planificación de la enseñanza del modelo Sol-Tierra que permite explicar el ciclo día/noche y las estaciones. En primer lugar, se ha procedido a realizar un análisis crítico de los resultados que se obtienen en el aprendizaje de los contenidos astronómicos en la enseñanza habitual. En segundo lugar se ha diseñado un curriculum potencialmente superador de esta situación desde una orientación que concibe la enseñanza y el aprendizaje como un proceso de construcción de conocimientos en una estructura problematizada. Finalmente, esta secuencia didáctica ha sido experimentada con diferentes grupos de estudiantes de magisterio, mostrando una mejora relevante en la comprensión de los conceptos astronómicos fundamentales.

  1. Norplant implants.

    PubMed

    Henley, E

    1993-06-01

    This letter to the editor is in response to 3 articles on the use of the Norplant implant contraceptive in The Indian Health Service (IHS) Provider. Norplant and the FDA-approved Depo-Provera now expand contraceptive options for women. All IHS and 638 sites might be able to offer both options. Several of the authors expressed concern regarding decreased Norplant effectiveness in heavier patients. Norplant is still more effective than any other currently available reversible contraceptive in the US at all weights. Many experts feel the current silastic capsule provides adequate hormone levels even in heavier women. The Crow Service Unit has initiated their Norplant program, although the Wyeth consent form seems unnecessarily extensive. The Albuquerque Service Unit consent form simply describes the procedure and confirms that patients have read and understand the fact sheet. The theoretical risk of thromboembolism is vastly outweighed by the potential benefit of reliable contraception in high risk alcoholic women, except perhaps in women with severe liver disease. While Norplant is expensive, programs need to consider the actual cost of a pregnancy, potential complications, and the financial and social costs of unintended pregnancy. For those in difficult straits, the manufacturer has set up a foundation for obtaining Norplant free of charge. Depo-Provera comes in a 150 mg dose vial that is given every 3 months. The mean time to ovulation is 4.5 months from the last dose. The adverse reaction spectrum is similar to Norplant as they are both progesterone-related agents. Providers and clinics should reduce barriers to family planning by giving out more pill packs at a time; letting adolescents who wish to delay their first pelvic exam have 3 months of pills without an exam; making condoms available in exam rooms rather than through pharmacy prescriptions; and increasing patient accessibility to the morning-after pill.

  2. Implantable Microimagers

    PubMed Central

    Ng, David C.; Tokuda, Takashi; Shiosaka, Sadao; Tano, Yasuo; Ohta, Jun

    2008-01-01

    Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications. PMID:27879873

  3. High Productivity Implantation ''PARTIAL IMPLANT''

    SciTech Connect

    Hino, Masayoshi; Miyamoto, Naoki; Sakai, Shigeki; Matsumoto, Takao

    2008-11-03

    The patterned ion implantation 'PARTIAL IMPLANT' has been developed as a productivity improvement tool. The Partial Implant can form several different ion dose areas on the wafer surface by controlling the speed of wafer moving and the stepwise rotation of twist axis. The Partial Implant system contains two implant methods. One method is 'DIVIDE PARTIAL IMPLANT', that is aimed at reducing the consumption of the wafer. The Divide Partial Implant evenly divides dose area on one wafer surface into two or three different dose part. Any dose can be selected in each area. So the consumption of the wafer for experimental implantation can be reduced. The second method is 'RING PARTIAL IMPLANT' that is aimed at improving yield by correcting electrical characteristic of devices. The Ring Partial Implant can form concentric ion dose areas. The dose of wafer external area can be selected to be within plus or minus 30% of dose of wafer central area. So the electrical characteristic of devices can be corrected by controlling dose at edge side on the wafer.

  4. Endodontic implants

    PubMed Central

    Yadav, Rakesh K.; Tikku, A. P.; Chandra, Anil; Wadhwani, K. K.; Ashutosh kr; Singh, Mayank

    2014-01-01

    Endodontic implants were introduced back in 1960. Endodontic implants enjoyed few successes and many failures. Various reasons for failures include improper case selection, improper use of materials and sealers and poor preparation for implants. Proper case selection had given remarkable long-term success. Two different cases are being presented here, which have been treated successfully with endodontic implants and mineral trioxide aggregate Fillapex (Andreaus, Brazil), an MTA based sealer. We suggest that carefully selected cases can give a higher success rate and this method should be considered as one of the treatment modalities. PMID:25298723

  5. About Implantable Contraception

    MedlinePlus

    ... TV, Video Games, and the Internet About Implantable Contraception KidsHealth > For Parents > About Implantable Contraception Print A ... How Much Does It Cost? What Is Implantable Contraception? Implantable contraception (often called the birth control implant) ...

  6. Linguistic Theory and Actual Language.

    ERIC Educational Resources Information Center

    Segerdahl, Par

    1995-01-01

    Examines Noam Chomsky's (1957) discussion of "grammaticalness" and the role of linguistics in the "correct" way of speaking and writing. It is argued that the concern of linguistics with the tools of grammar has resulted in confusion, with the tools becoming mixed up with the actual language, thereby becoming the central…

  7. Linguistic Theory and Actual Language.

    ERIC Educational Resources Information Center

    Segerdahl, Par

    1995-01-01

    Examines Noam Chomsky's (1957) discussion of "grammaticalness" and the role of linguistics in the "correct" way of speaking and writing. It is argued that the concern of linguistics with the tools of grammar has resulted in confusion, with the tools becoming mixed up with the actual language, thereby becoming the central…

  8. Cochlear implant

    MedlinePlus

    ... bilateral cochlear implantation: a review. Curr Opin Otolaryngol Head Neck Surg . 2007;15(5):315-318. PMID: 17823546. ... BH, Lund V, et al, eds. Cummings Otolaryngology: Head & Neck Surgery . 6th ed. Philadelphia, PA: Elsevier Saunders; 2015: ...

  9. Histrelin Implant

    MedlinePlus

    ... implant (Supprelin LA) is used to treat central precocious puberty (CPP; a condition causing children to enter puberty too soon, resulting in faster than normal bone growth and development of sexual characteristics) in girls ...

  10. Breast Implants

    MedlinePlus

    ... in the United States: saline-filled and silicone gel-filled. Both types have a silicone outer shell. ... them. Provide information on saline-filled and silicone gel-filled breast implants, including data supporting a reasonable ...

  11. Cochlear implants.

    PubMed

    Connell, Sarah S; Balkany, Thomas J

    2006-08-01

    Cochlear implants are cost-effective auditory prostheses that safely provide a high-quality sensation of hearing to adults who are severely or profoundly deaf. In the past 5 years, progress has been made in hardware and software design, candidate selection, surgical techniques, device programming, education and rehabilitation,and, most importantly, outcomes. Cochlear implantation in the elderly is well tolerated and provides marked improvement in auditory performance and psychosocial functioning.

  12. Contraceptive implants.

    PubMed

    McDonald-Mosley, Raegan; Burke, Anne E

    2010-03-01

    Implantable contraception has been extensively used worldwide. Implants are one of the most effective and reversible methods of contraception available. These devices may be particularly appropriate for certain populations of women, including women who cannot use estrogen-containing contraception. Implants are safe for use by women with many chronic medical problems. The newest implant, Implanon (Organon International, Oss, The Netherlands), is the only device currently available in the United States and was approved in 2006. It is registered for 3 years of pregnancy prevention. Contraceptive implants have failure rates similar to tubal ligation, and yet they are readily reversible with a return to fertility within days of removal. Moreover, these contraceptive devices can be safely placed in the immediate postpartum period, ensuring good contraceptive coverage for women who may be at risk for an unintended pregnancy. Irregular bleeding is a common side effect for all progestin-only contraceptive implants. Preinsertion counseling should address possible side effects, and treatment may be offered to women who experience prolonged or frequent bleeding.

  13. How People Actually Use Thermostats

    SciTech Connect

    Meier, Alan; Aragon, Cecilia; Hurwitz, Becky; Mujumdar, Dhawal; Peffer, Therese; Perry, Daniel; Pritoni, Marco

    2010-08-15

    Residential thermostats have been a key element in controlling heating and cooling systems for over sixty years. However, today's modern programmable thermostats (PTs) are complicated and difficult for users to understand, leading to errors in operation and wasted energy. Four separate tests of usability were conducted in preparation for a larger study. These tests included personal interviews, an on-line survey, photographing actual thermostat settings, and measurements of ability to accomplish four tasks related to effective use of a PT. The interviews revealed that many occupants used the PT as an on-off switch and most demonstrated little knowledge of how to operate it. The on-line survey found that 89% of the respondents rarely or never used the PT to set a weekday or weekend program. The photographic survey (in low income homes) found that only 30% of the PTs were actually programmed. In the usability test, we found that we could quantify the difference in usability of two PTs as measured in time to accomplish tasks. Users accomplished the tasks in consistently shorter times with the touchscreen unit than with buttons. None of these studies are representative of the entire population of users but, together, they illustrate the importance of improving user interfaces in PTs.

  14. Matematica Actual: Libro del Professor (Modern Mathematics: Teacher's Manual).

    ERIC Educational Resources Information Center

    Parot, Jean Jacques

    This document suggests learning activities for kindergarten children to develop skills of basic reasoning and numerical calculation that the children will be using throughout life. This teacher's guide provides a list of games and activities and discusses the relationship between the games and their themes and their intended educational…

  15. Surgeon ownership in medical device distribution: does it actually reduce healthcare costs?

    PubMed

    Steinmann, John C; Edwards, Charles; Eickmann, Thomas; Carlson, Angela; Blight, Alexis

    2015-01-01

    Surgeon ownership in medical device distribution is a new model that proposes to reduce the costs associated with surgical implants. In surgeon-owned distributorships (SDs), the surgeon becomes the purchaser through ownership and management of a distributorship. The purpose of this study is to determine whether significant cost savings can result from SDs. Five existing SDs were retrospectively reviewed, and their implant pricing was compared with non-SDs. The hospital pricing for implants supplied by the SDs was compared with 2010 pricing from the best contract/capitated rate for like implants from non-SDs. The average first-year cost savings for the SDs was 36%, with US$2,456,521 total savings in 2010. For distributorships in business for over 2 years, the average annual price from the SDs actually decreased by 1.41%. This study demonstrates that SDs are capable of providing substantial healthcare savings through lower implant costs and reduced annual price escalations.

  16. Impact of Surgical Template on the Accuracy of Implant Placement.

    PubMed

    Xu, Liang-Wei; You, Jia; Zhang, Jian-Xing; Liu, Yun-Feng; Peng, Wei

    2016-12-01

    To achieve functional and esthetic results, implants must be placed accurately; however, little information is available regarding the effect of surgical templates on the accuracy of implant placement. Thus, the aim of this study was to measure the deviation between actual and planned implant positions, and determine the deviation caused by the surgical template. Jaws from 16 patients were scanned using cone beam computed tomography (CBCT). For our study, 53 implants were planned in a virtual 3D environment, of which 35 were inserted in the mandible and 18 in the maxilla. A stereolithographic (SLA) surgical template was created. A CBCT scan of the surgical template fitted on a plaster model was performed, and the images obtained were matched to virtual implant plan images that contained the planned implant position. The actual implant position was acquired from the registration position of the surgical template. Deviation between actual and planned implant positions was analyzed. Mean central deviation at the hex and apex was 0.456 mm and 0.515 mm, respectively. Mean value of horizontal deviation at the hex was 0.193 mm, horizontal deviation at the apex was 0.277 mm, vertical deviation at the hex was 0.388 mm, vertical deviation at the apex was 0.390 mm, and angular deviation was 0.621°. Our study results revealed a significant deviation between actual and planned implant positions caused by the surgical template. © 2015 by the American College of Prosthodontists.

  17. Object choice and actual bisexuality.

    PubMed

    Limentani, A

    1976-01-01

    Actual bisexuality is to be distinguished from homosexuality in a latent state and from conscious bisexual fantasies. Contemporary social changes have caused an increased demand for help for those men and women capable of engaging in protracted heterosexual and homosexual relations. Among such people narcissistic and borderline states are common. Clinical material is presented in some detail. The author suggests that the condition is associated with a tendency to be caught up between the anaclitic and narcissistic types of object choice. The concurrent involvement with a male and female love object against a background of pseudogenitality creates the illusory appearance of two objects being involved, covering up the fact that there is splitting of the original love object together with severe preoedipal disturbance.

  18. Cochlear Implants

    MedlinePlus

    ... outside of the body, behind the ear. A second part is surgically placed under the skin. An implant does not restore normal hearing. It can help a person understand speech. Children and adults can benefit from them. National Institute on Deafness and Other Communication Disorders

  19. [Actual status of laparoscopic cholecystectomy].

    PubMed

    Chousleb Mizrahi, Elias; Chousleb Kalach, Alberto; Shuchleib Chaba, Samuel

    2004-08-01

    Since the first laparoscopic cholecystectomy in 1988, the management of gall-bladder disease has changed importantly. This technique was rapidly popularized in the U.S. as well as in Europe. Multiple studies have proved its feasibility, safeness and great advantages. Analyze usefulness and recent advances of endoscopic surgery in the management of gallbladder disease. We did a review of the recent medical literature to determine the actual status of laparoscopic cholecystectomy. Laparoscopic cholecystectomy is the most common surgical procedure performed in the digestive tract. During the year 2001, 1,100,000 cholecystectomies were done in the U.S., 85% were done laparoscopically. In Mexico cholecystectomy in government hospitals is done laparoscopically in 50% of the cases, while in private hospitals it reaches 90%. There are multiple prospective controlled studies showing superiority of laparoscopic cholecystectomy in times of recovery, costs, return to normal activity, pain, morbidity, esthetics among other advantages. Laparoscopic cholecystectomy is the gold standard for the treatment of the great majority of cases of gallbladder disease, nevertheless in developing countries open cholecystectomy is still done frequently.

  20. The actual goals of geoethics

    NASA Astrophysics Data System (ADS)

    Nemec, Vaclav

    2014-05-01

    The most actual goals of geoethics have been formulated as results of the International Conference on Geoethics (October 2013) held at the geoethics birth-place Pribram (Czech Republic): In the sphere of education and public enlightenment an appropriate needed minimum know how of Earth sciences should be intensively promoted together with cultivating ethical way of thinking and acting for the sustainable well-being of the society. The actual activities of the Intergovernmental Panel of Climate Changes are not sustainable with the existing knowledge of the Earth sciences (as presented in the results of the 33rd and 34th International Geological Congresses). This knowledge should be incorporated into any further work of the IPCC. In the sphere of legislation in a large international co-operation following steps are needed: - to re-formulate the term of a "false alarm" and its legal consequences, - to demand very consequently the needed evaluation of existing risks, - to solve problems of rights of individuals and minorities in cases of the optimum use of mineral resources and of the optimum protection of the local population against emergency dangers and disasters; common good (well-being) must be considered as the priority when solving ethical dilemmas. The precaution principle should be applied in any decision making process. Earth scientists presenting their expert opinions are not exempted from civil, administrative or even criminal liabilities. Details must be established by national law and jurisprudence. The well known case of the L'Aquila earthquake (2009) should serve as a serious warning because of the proven misuse of geoethics for protecting top Italian seismologists responsible and sentenced for their inadequate superficial behaviour causing lot of human victims. Another recent scandal with the Himalayan fossil fraud will be also documented. A support is needed for any effort to analyze and to disclose the problems of the deformation of the contemporary

  1. 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

  2. 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.

  3. Accuracy of computer-assisted implant placement with insertion templates

    PubMed Central

    Naziri, Eleni; Schramm, Alexander; Wilde, Frank

    2016-01-01

    Objectives: The purpose of this study was to assess the accuracy of computer-assisted implant insertion based on computed tomography and template-guided implant placement. Material and methods: A total of 246 implants were placed with the aid of 3D-based transfer templates in 181 consecutive partially edentulous patients. Five groups were formed on the basis of different implant systems, surgical protocols and guide sleeves. After virtual implant planning with the CoDiagnostiX Software, surgical guides were fabricated in a dental laboratory. After implant insertion, the actual implant position was registered intraoperatively and transferred to a model cast. Deviations between the preoperative plan and postoperative implant position were measured in a follow-up computed tomography of the patient’s model casts and image fusion with the preoperative computed tomography. Results: The median deviation between preoperative plan and postoperative implant position was 1.0 mm at the implant shoulder and 1.4 mm at the implant apex. The median angular deviation was 3.6º. There were significantly smaller angular deviations (P=0.000) and significantly lower deviations at the apex (P=0.008) in implants placed for a single-tooth restoration than in those placed at a free-end dental arch. The location of the implant, whether in the upper or lower jaw, did not significantly affect deviations. Increasing implant length had a significant negative influence on deviations from the planned implant position. There was only one significant difference between two out of the five implant systems used. Conclusion: The data of this clinical study demonstrate the accuracy and predictable implant placement when using laboratory-fabricated surgical guides based on computed tomography. PMID:27274440

  4. Dental Implant Surgery

    MedlinePlus

    Dental implant surgery Overview By Mayo Clinic Staff Dental implant surgery is a procedure that replaces tooth roots ... that look and function much like real ones. Dental implant surgery can offer a welcome alternative to dentures ...

  5. Hip Implant Systems

    MedlinePlus

    ... Medical Devices Products and Medical Procedures Implants and Prosthetics Metal-on-Metal Hip Implants Hip Implants Share ... femoral head) is removed and replaced with a prosthetic ball made of metal or ceramic, and the ...

  6. Complications of Poly Implant Prothèse breast implants: the current discussion.

    PubMed

    Kolios, Leila; Hirche, Christoph; Spiethoff, Alexander; Daigeler, Adrien; Lehnhardt, Marcus

    2013-03-01

    Against the background of the current discussion about Poly Implant Prothèse (PIP, Seyne-sur-mer, France) breast implants, we want to present a case demonstrating the complications such as implant rupture, silicone dissemination and level III silicone lymphadenopathy. A 29-year-old woman with cosmetic breast augmentation with PIP implants 5 years previously showed a sensitive swelling in her right axilla and neck region. All tests to detect an infectious or lymphomatous lymphadenopathy were negative. After ultrasound and MRI, rupture of the right implant was assumed and multiple pathologically enlarged lymph nodes up to supraclavicular region were shown. An excision biopsy of one axillary lymph node was performed; the histological examination detected a strong silicone lymphadenopathy. Surgical removal of both implants as well as capsulectomy was performed and 14 axillary lymph nodes up to level II were resected. Histologic evaluation confirmed the previous results. Our case underlines the actual discussion concerning increased rupture rate and massive silicone lymphadenopathy by PIP implants. The Agence Francaise de Sécurité Sanitaire des Produits de Santé (AFSSAPS) recommends clinical and ultrasound examination every 6 months for women with PIP implants. Any rupture, suspected rupture or leakage of prosthesis should lead to its explantation as well as that of the contralateral implant. In cases of unusual signs of inflammation, histological and immunohistochemical samples are to be taken.

  7. [Cochlear implants].

    PubMed

    Lehnhardt, E; Battmer, R D; Nakahodo, K; Laszig, R

    1986-07-01

    Since the middle of 1984, the HNO-Klinik der Medizinischen Hochschule Hannover has provided deaf adults with a 22-channel cochlear implant (CI) device of Clark-NUCLEUS. The digital working system consists of an implantable stimulator/receiver and an externally worn speech processor. Energy and signals are transmitted transcutaneously via a transmitter coil. During the prevailing 26 operations (April 1986) the electrode array could be inserted at least 17 mm into the cochlea. The threshold and comfort levels of all patients were adjusted very quickly; the dynamic range usually grows during the first postoperative weeks. The individual rehabilitation results vary greatly, but all patients show a significant increase of vowel and consonant comprehension while using the speech processor and an improvement of words understood per minute in speech tracking from lip-reading alone to lip-reading with speech processor. Four months after surgery seven of 17 patients (group I) are able to understand on average 42.7 words per minute by speech tracking without lip-reading. Six patients (group II) recognise 69.2% of vowels and 42.5% of consonants by speech processor alone. Four patients (group III) can correctly repeat only vowels (52.3%) without lip-reading, but using the speech processor together with lip reading they have an improvement in consonant understanding of 37.9% and under freefield conditions they are able to understand up to 17.8% numbers of the Freiburg speech test.

  8. Implant marketing: cost effective implant dentistry.

    PubMed

    Wohrle, P S; Levin, R P

    1996-01-01

    The application of the KAL-Technique to the field of implant dentistry allows both patients and dental practices to benefit. It is an exciting advance that decreases frustration and stress in providing implant procedures and lowers overall costs. Professionals using the KAL-Technique report significant predictability in achieving passive framework fit. They are also lowering overall cost of implant cases, which increases the number of patients who can accept implant treatment. It has been well established that the more individuals in a practice that receive implants, the more referrals a practice will gain. This is because implant patients find tremendous advances in the quality of life, and do not hesitate to tell others who can take advantage of this opportunity. Implant dentistry is one of the fastest growing fields in dentistry today. While some other areas of dentistry begin to decline in volume and need, implant dentistry provides the opportunity to keep practices strong and to insure long-term success.

  9. Bilayer Implants

    PubMed Central

    Schagemann, Jan C.; Rudert, Nicola; Taylor, Michelle E.; Sim, Sotcheadt; Quenneville, Eric; Garon, Martin; Klinger, Mathias; Buschmann, Michael D.; Mittelstaedt, Hagen

    2016-01-01

    Objective To compare the regenerative capacity of 2 distinct bilayer implants for the restoration of osteochondral defects in a preliminary sheep model. Methods Critical sized osteochondral defects were treated with a novel biomimetic poly-ε-caprolactone (PCL) implant (Treatment No. 2; n = 6) or a combination of Chondro-Gide and Orthoss (Treatment No. 1; n = 6). At 19 months postoperation, repair tissue (n = 5 each) was analyzed for histology and biochemistry. Electromechanical mappings (Arthro-BST) were performed ex vivo. Results Histological scores, electromechanical quantitative parameter values, dsDNA and sGAG contents measured at the repair sites were statistically lower than those obtained from the contralateral surfaces. Electromechanical mappings and higher dsDNA and sGAG/weight levels indicated better regeneration for Treatment No. 1. However, these differences were not significant. For both treatments, Arthro-BST revealed early signs of degeneration of the cartilage surrounding the repair site. The International Cartilage Repair Society II histological scores of the repair tissue were significantly higher for Treatment No. 1 (10.3 ± 0.38 SE) compared to Treatment No. 2 (8.7 ± 0.45 SE). The parameters cell morphology and vascularization scored highest whereas tidemark formation scored the lowest. Conclusion There was cell infiltration and regeneration of bone and cartilage. However, repair was incomplete and fibrocartilaginous. There were no significant differences in the quality of regeneration between the treatments except in some histological scoring categories. The results from Arthro-BST measurements were comparable to traditional invasive/destructive methods of measuring quality of cartilage repair. PMID:27688843

  10. Middle Ear Implantable Hearing Devices: An Overview

    PubMed Central

    Haynes, David S.; Young, Jadrien A.; Wanna, George B.; Glasscock, Michael E.

    2009-01-01

    Hearing loss affects approximately 30 million people in the United States. It has been estimated that only approximately 20% of people with hearing loss significant enough to warrant amplification actually seek assistance for amplification. A significant interest in middle ear implants has emerged over the years to facilitate patients who are noncompliant with conventional hearing aides, do not receive significant benefit from conventional aides, or are not candidates for cochlear implants. From the initial studies in the 1930s, the technology has greatly evolved over the years with a wide array of devices and mechanisms employed in the development of implantable middle ear hearing devices. Currently, these devices are generally available in two broad categories: partially or totally implantable using either piezoelectric or electromagnetic systems. The authors present an up-to-date overview of the major implantable middle ear devices. Although the current devices are largely in their infancy, indications for middle ear implants are ever evolving as promising studies show good results. The totally implantable devices provide the user freedom from the social and practical difficulties of using conventional amplification. PMID:19762429

  11. Racial Discrimination in Occupations; Perceived and Actual.

    ERIC Educational Resources Information Center

    Turner, Castellano B.; Turner, Barbara F.

    1981-01-01

    A study of perceived discrimination by race and by sex for each of 21 occupations was compared with actual percentages of Blacks in each field. The study suggested that: (1) perception of opportunity corresponded to actual structure of opportunity; and (2) both a change in the social structure and individual belief systems is needed to further…

  12. [Bilateral cochlear implantation].

    PubMed

    Kronenberg, Jona; Migirov, Lela; Taitelbaum-Swead, Rikey; Hildesheimer, Minka

    2010-06-01

    Cochlear implant surgery became the standard of care in hearing rehabilitation of patients with severe to profound sensorineural hearing loss. This procedure may alter the lives of children and adults enabling them to integrate with the hearing population. In the past, implantation was performed only in one ear, despite the fact that binaural hearing is superior to unilateral, especially in noisy conditions. Cochlear implantation may be performed sequentially or simultaneously. The "sensitive period" of time between hearing loss and implantation and between the two implantations, when performed sequentially, significantly influences the results. Shorter time spans between implantations improve the hearing results after implantation. Hearing success after implantation is highly dependent on the rehabilitation process which includes mapping, implant adjustments and hearing training. Bilateral cochlear implantation in children is recommended as the proposed procedure in spite of the additional financial burden.

  13. When Is Tourette Syndrome Actually Autism?

    MedlinePlus

    ... fullstory_166831.html When is Tourette Syndrome Actually Autism? Repetitive behaviors, restricted interests occur in both disorders, ... children with Tourette syndrome also tests positive for autism, a new study shows. But it's unlikely that ...

  14. Self-Actualization, Liberalism, and Humanistic Education.

    ERIC Educational Resources Information Center

    Porter, Charles Mack

    1979-01-01

    The relationship between personality factors and political orientation has long been of interest to psychologists. This study tests the hypothesis that there is no significant relationship between self-actualization and liberalism-conservatism. The hypothesis is supported. (Author)

  15. [Biomaterials in cochlear implants].

    PubMed

    Stöver, T; Lenarz, T

    2009-05-01

    Cochlear implants (CI) represent the "gold standard" for the treatment of congenitally deaf children and postlingually deafened adults. Thus, cochlear implantation is a success story of new bionic prosthesis development. Owing to routine application of cochlear implants in adults but also in very young children (below the age of one), high demands are placed on the implants. This is especially true for biocompatibility aspects of surface materials of implant parts which are in contact with the human body. In addition, there are various mechanical requirements which certain components of the implants must fulfil, such as flexibility of the electrode array and mechanical resistance of the implant housing. Due to the close contact of the implant to the middle ear mucosa and because the electrode array is positioned in the perilymphatic space via cochleostomy, there is a potential risk of bacterial transferral along the electrode array into the cochlea. Various requirements that have to be fulfilled by cochlear implants, such as biocompatibility, electrode micromechanics, and although a very high level of technical standards has been carried out there is still demand for the improvement of implants as well as of the materials used for manufacturing, ultimately leading to increased implant performance. General considerations of material aspects related to cochlear implants as well as potential future perspectives of implant development will be discussed.

  16. Peri-Implant Diseases

    MedlinePlus

    ... Alcohol Consumption and Gum Health Workshop on Regeneration Periodontal Disease More Prevalent among Ethnic Minorities Dental Implants Periodontal ... factors for developing peri-implant disease include previous periodontal disease diagnosis, poor plaque control, smoking , and diabetes . It ...

  17. Implants for lucky few

    NASA Astrophysics Data System (ADS)

    Brandon, David

    2011-08-01

    In his article "Vision of beauty" (May pp22-27), Richard Taylor points the way to fractal design for retinal implants and makes an enthusiastic case for incorporating such features into the next generation of such implants.

  18. Ridge preservation: does it actually work?

    PubMed

    Darby, Ivan

    2010-03-01

    Post-extraction the alveolus undergoes modelling which reduces height and width. This may present a problem for subsequent crown and bridge or implant therapy. Ridge preservation is the use of grafts and/or membranes to try to minimize the loss of the alveolar ridge. Extraction sockets have been filled with autogenous, allogenic and alloplastic materials. Membranes or soft tissue were used to contain the graft. More recently biodegradable sponges and materials coated in growth factors have been tested. Studies have primarily looked at either maintenance of vertical and horizontal dimensions or the healing of the socket and how much of the graft material is incorporated into the newly formed bone. Irrespective of method or materials, there seems to be some maintenance of the alveolus. Bone fill seems to occur in preserved extraction sockets, but in most cases with a high percentage of residual graft particles. In general, there is a lack of evidence to show that ridge preservation aids in correct 3-D implant placement, maintains hard and soft tissue volume over a prolonged period of time or for success and survival of implants placed into ridge preserved sockets. Still the most effective way to maintain ridge volume is to keep the natural tooth.

  19. Realizing actual feedback control of complex network

    NASA Astrophysics Data System (ADS)

    Tu, Chengyi; Cheng, Yuhua

    2014-06-01

    In this paper, we present the concept of feedbackability and how to identify the Minimum Feedbackability Set of an arbitrary complex directed network. Furthermore, we design an estimator and a feedback controller accessing one MFS to realize actual feedback control, i.e. control the system to our desired state according to the estimated system internal state from the output of estimator. Last but not least, we perform numerical simulations of a small linear time-invariant dynamics network and a real simple food network to verify the theoretical results. The framework presented here could make an arbitrary complex directed network realize actual feedback control and deepen our understanding of complex systems.

  20. Realizing actual feedback control of complex network

    NASA Astrophysics Data System (ADS)

    Tu, Chengyi; Cheng, Yuhua

    2014-06-01

    In this paper, we present the concept of feedbackability and how to identify the Minimum Feedbackability Set of an arbitrary complex directed network. Furthermore, we design an estimator and a feedback controller accessing one MFS to realize actual feedback control, i.e. control the system to our desired state according to the estimated system internal state from the output of estimator. Last but not least, we perform numerical simulations of a small linear time-invariant dynamics network and a real simple food network to verify the theoretical results. The framework presented here could make an arbitrary complex directed network realize actual feedback control and deepen our understanding of complex systems.

  1. Cochlear Implants for Children.

    ERIC Educational Resources Information Center

    Hasenstab, M. Suzanne; Laughton, Joan

    1991-01-01

    The use of cochlear implants in children with profound bilateral hearing loss is discussed, focusing on how a cochlear implant works; steps in a cochlear implant program (evaluation, surgery, programing, and training); and rehabilitation procedures involved in auditory development and speech development. (JDD)

  2. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1984-01-01

    CPI's human-implantable automatic implantable defibrillator (AID) is a heart assist system, derived from NASA's space circuitry technology, that can prevent erratic heart action known as arrhythmias. Implanted AID, consisting of microcomputer power source and two electrodes for sensing heart activity, recognizes onset of ventricular fibrillation (VF) and delivers corrective electrical countershock to restore rhythmic heartbeat.

  3. Children's Rights and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1982-01-01

    Educators need to seriously reflect upon the concept of children's rights. Though the idea of children's rights has been debated numerous times, the idea remains vague and shapeless; however, Maslow's theory of self-actualization can provide the children's rights idea with a needed theoretical framework. (Author)

  4. Group Counseling for Self-Actualization.

    ERIC Educational Resources Information Center

    Streich, William H.; Keeler, Douglas J.

    Self-concept, creativity, growth orientation, an integrated value system, and receptiveness to new experiences are considered to be crucial variables to the self-actualization process. A regular, year-long group counseling program was conducted with 85 randomly selected gifted secondary students in the Farmington, Connecticut Public Schools. A…

  5. Culture Studies and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1983-01-01

    True citizenship education is impossible unless students develop the habit of intelligently evaluating cultures. Abraham Maslow's theory of self-actualization, a theory of innate human needs and of human motivation, is a nonethnocentric tool which can be used by teachers and students to help them understand other cultures. (SR)

  6. Humanistic Education and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1984-01-01

    Stresses the need for theoretical justification for the development of humanistic education programs in today's schools. Explores Abraham Maslow's hierarchy of needs and theory of self-actualization. Argues that Maslow's theory may be the best available for educators concerned with educating the whole child. (JHZ)

  7. Developing Human Resources through Actualizing Human Potential

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    2012-01-01

    The key to human resource development is in actualizing individual and collective thinking, feeling and choosing potentials related to our minds, hearts and wills respectively. These capacities and faculties must be balanced and regulated according to the standards of truth, love and justice for individual, community and institutional development,…

  8. Racial Discrimination in Occupations: Perceived and Actual.

    ERIC Educational Resources Information Center

    Turner, Castellano B.; Turner, Barbara F.

    The relationship between the actual representation of Blacks in certain occupations and individual perceptions of the occupational opportunity structure were examined. A scale which rated the degree of perceived discrimination against Blacks in 21 occupations was administered to 75 black male, 70 black female, 1,429 white male and 1,457 white…

  9. Culture Studies and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1983-01-01

    True citizenship education is impossible unless students develop the habit of intelligently evaluating cultures. Abraham Maslow's theory of self-actualization, a theory of innate human needs and of human motivation, is a nonethnocentric tool which can be used by teachers and students to help them understand other cultures. (SR)

  10. 50 CFR 253.16 - Actual cost.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 11 2013-10-01 2013-10-01 false Actual cost. 253.16 Section 253.16 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE AID TO FISHERIES FISHERIES ASSISTANCE PROGRAMS Fisheries Finance Program §...

  11. Humanistic Education and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1984-01-01

    Stresses the need for theoretical justification for the development of humanistic education programs in today's schools. Explores Abraham Maslow's hierarchy of needs and theory of self-actualization. Argues that Maslow's theory may be the best available for educators concerned with educating the whole child. (JHZ)

  12. Introduction of implants into postdoctoral endodontic residency programs.

    PubMed

    Aminoshariae, Anita; Montagnese, Thomas A; Solanki, Poonam D; Mickel, Andre K

    2011-09-01

    The purpose of this study was to survey the directors of postdoctoral endodontic programs in the United States to ascertain their attitudes and approaches regarding incorporation of implants into the endodontic curriculum. We hypothesized that program directors would agree that implant training should be incorporated into the endodontic curriculum. We also hypothesized that they would all prefer apical surgeries and retreatment over implants when plausible. A twenty-item online survey was emailed to all fifty-two postdoctoral endodontic program directors in the United States. A 100 percent response was received. The results showed that 78.6 percent agreed that implant training should be incorporated, 85.7 percent preferred the didactic approach, and 42.9 percent preferred clinical implant training. One hundred percent preferred apical surgeries and retreatment over implants when plausible, and 53.8 percent did not prefer implants over endodontic treatment for teeth with a questionable prognosis. This survey indicates that implant training has been incorporated into postdoctoral endodontic programs and that the Commission on Dental Accreditation standards are being met. The trend may be to become more hands-on in the future if program directors believe there is a need to provide training in actual placement of implants.

  13. Whiteheadian Actual Entitities and String Theory

    NASA Astrophysics Data System (ADS)

    Bracken, Joseph A.

    2012-06-01

    In the philosophy of Alfred North Whitehead, the ultimate units of reality are actual entities, momentary self-constituting subjects of experience which are too small to be sensibly perceived. Their combination into "societies" with a "common element of form" produces the organisms and inanimate things of ordinary sense experience. According to the proponents of string theory, tiny vibrating strings are the ultimate constituents of physical reality which in harmonious combination yield perceptible entities at the macroscopic level of physical reality. Given that the number of Whiteheadian actual entities and of individual strings within string theory are beyond reckoning at any given moment, could they be two ways to describe the same non-verifiable foundational reality? For example, if one could establish that the "superject" or objective pattern of self- constitution of an actual entity vibrates at a specific frequency, its affinity with the individual strings of string theory would be striking. Likewise, if one were to claim that the size and complexity of Whiteheadian 'societies" require different space-time parameters for the dynamic interrelationship of constituent actual entities, would that at least partially account for the assumption of 10 or even 26 instead of just 3 dimensions within string theory? The overall conclusion of this article is that, if a suitably revised understanding of Whiteheadian metaphysics were seen as compatible with the philosophical implications of string theory, their combination into a single world view would strengthen the plausibility of both schemes taken separately. Key words: actual entities, subject/superjects, vibrating strings, structured fields of activity, multi-dimensional physical reality.

  14. Dancers' Perceived and Actual Knowledge of Anatomy.

    PubMed

    Kotler, Dana H; Lynch, Meaghan; Cushman, Daniel; Hu, Jason; Garner, Jocelyn

    2017-06-15

    Dancers are highly susceptible to musculoskeletal injuries and frequently require interaction with medical professionals. While many dancers have a finely tuned awareness of their bodies, their knowledge of the fundamentals of human anatomy is not uniform. There is a paucity of literature on the benefits of human anatomy education in dancers, though it seems intuitive that there should be a relationship. The purpose of this study was to assess dancers' perceived and actual knowledge of basic musculoskeletal anatomy and its relationship to function. Adult dancers at the undergraduate, pre-professional, and professional levels were surveyed through an anonymous online questionnaire. Questions included demographic information, dance techniques studied, anatomy training, and injury history. Subjects rated their perceived knowledge of anatomy and were tested with 15 multiple-choice questions on basic musculoskeletal anatomy. Four hundred seventy-five surveys were completed. Ordinal regression showed a correlation of perceived to actual knowledge of anatomy (p < 0.001). Factors that correlated with increases in both perceived and actual knowledge of anatomy included having taken an anatomy course of any type (p < 0.001) and increased age (p ≤ 0.001). Years of dance training and professional dancer status both significantly correlated with increased knowledge of anatomy (p < 0.001) but not perceived knowledge. Chi-square analysis showed that dancers with training in either modern or jazz dance had a significantly higher perceived, but not actual, knowledge when compared to those without training in those styles of dance (p < 0.001 and p = 0.011, respectively). In conclusion, dancers generally scored well on questions pertaining to basic musculoskeletal anatomy, and their perception correlated with their actual knowledge of anatomy. Factors that contribute to dancers' knowledge of anatomy include age, years of experience, professional dancer status, and anatomy training.

  15. Advanced peri-implantitis cases with radical surgical treatment.

    PubMed

    McCrea, Shane J J

    2014-02-01

    Peri-implantitis, a clinical term describing the inflammatory process that affects the soft and hard tissues around an osseointegrated implant, may lead to peri-implant pocket formation and loss of supporting bone. However, this imprecise definition has resulted in a wide variation of the reported prevalence; ≥10% of implants and 20% of patients over a 5- to 10-year period after implantation has been reported. The individual reporting of bone loss, bleeding on probing, pocket probing depth and inconsistent recording of results has led to this variation in the prevalence. Thus, a specific definition of peri-implantitis is needed. This paper describes the vast variation existing in the definition of peri-implantitis and suggests a logical way to record the degree and prevalence of the condition. The evaluation of bone loss must be made within the concept of natural physiological bony remodelling according to the initial peri-implant hard and soft tissue damage and actual definitive load of the implant. Therefore, the reason for bone loss must be determined as either a result of the individual osseous remodelling process or a response to infection. The most current Papers and Consensus of Opinion describing peri-implantitis are presented to illustrate the dilemma that periodontologists and implant surgeons are faced with when diagnosing the degree of the disease process and the necessary treatment regime that will be required. The treatment of peri-implantitis should be determined by its severity. A case of advanced peri-implantitis is at risk of extreme implant exposure that results in a loss of soft tissue morphology and keratinized gingival tissue. Loss of bone at the implant surface may lead to loss of bone at any adjacent natural teeth or implants. Thus, if early detection of peri-implantitis has not occurred and the disease process progresses to advanced peri-implantitis, the compromised hard and soft tissues will require extensive, skill

  16. Trends in Cochlear Implants

    PubMed Central

    Zeng, Fan-Gang

    2004-01-01

    More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management. PMID:15247993

  17. SCIMITAR: subject-carried implant monitoring inductive telemetric ambulatory reader for remote data acquisition from implanted orthopaedic prostheses.

    PubMed

    Hao, Shiying; Gorjon, Jose; Taylor, Stephen

    2014-03-01

    This work describes the functions of the external, portable part of a telemetry system for powering and interrogating implantable electrical devices built within orthopaedic implants for real-time data acquisition of strain, load, temperature, humidity and other relevant data (e.g. from inertial sensors). The system contains a battery powered inductive energiser and demodulator to remotely power the implant electronics and demodulate the signals transmitted from the implanted device. Due to the housing of the internal coil, sufficient inductive coupling is obtained between the external and internal tuned circuits to enable simultaneous power and data transmission over the same inductive link. The actual performance of this system when used with one specific implant was studied, and some correspondence made to the relevant theory. Performance factors relating to both power efficiency and data reconstruction were identified.

  18. Passive and active middle ear implants

    PubMed Central

    Beutner, Dirk; Hüttenbrink, Karl-Bernd

    2011-01-01

    Besides eradication of chronic middle ear disease, the reconstruction of the sound conduction apparatus is a major goal of modern ear microsurgery. The material of choice in cases of partial ossicular replacement prosthesis is the autogenous ossicle. In the event of more extensive destruction of the ossicular chain diverse alloplastic materials, e.g. metals, ceramics, plastics or composits are used for total reconstruction. Their specialised role in conducting sound energy within a half-open implant bed sets high demands on the biocompatibility as well as the acoustic-mechanic properties of the prosthesis. Recently, sophisticated titanium middle ear implants allowing individual adaptation to anatomical variations are widely used for this procedure. However, despite modern developments, hearing restoration with passive implants often faces its limitations due to tubal-middle-ear dysfunction. Here, implantable hearing aids, successfully used in cases of sensorineural hearing loss, offer a promising alternative. This article reviews the actual state of affairs of passive and active middle ear implants. PMID:22073102

  19. Teaching implant dentistry in the predoctoral curriculum: a report from the ADEA Implant Workshop's survey of deans.

    PubMed

    Petropoulos, Vicki C; Arbree, Nancy S; Tarnow, Dennis; Rethman, Michael; Malmquist, Jay; Valachovic, Richard; Brunson, W David; Alfano, Michael C

    2006-05-01

    In 2004, a survey of the deans of U.S. and Canadian dental schools was conducted to determine the implant dentistry curriculum structure and the extent of incorporating implant dentistry clinical treatment into predoctoral programs. The questionnaire was mailed to the deans of the fifty-six dental schools in advance of the ADEA Implant Workshop conference held in Arizona in November 2004. Out of the fifty-six, thirty-nine responded, yielding a response rate of 70 percent. Thirty-eight schools (97 percent) reported that their students received didactic instruction in dental implants, while one school (3 percent) said that its students did not. Thirty schools (86 percent) reported that their students received clinical experience, while five schools (14 percent) reported that theirs did not. Four schools (10 percent) did not respond to this question. Fifty-one percent of the students actually receive the clinical experience in restoring implants, with the range of 5-100 percent. Of those schools that provide clinical experience in restoring implants, four schools (13 percent) reported that it is a requirement for them, while twenty-eight schools (88 percent) reported that it is not a requirement for them. Three schools (9 percent) did not respond. The fee for implants is 45 percent higher than a crown or a denture, with a range of 0-100 percent. Twenty-nine schools (85 percent) indicated that they did receive free components from implant companies, while five schools (15 percent) did not. The conclusions of this report are as follows: 1) most schools have advanced dental education programs; 2) single-tooth implant restorations are performed at the predoctoral level in most schools; 3) implant-retained overdenture prostheses are performed at the predoctoral level in most schools; 4) there is no predoctoral clinical competency requirement for surgical implant placement in all schools that responded to the survey; 5) there is no predoctoral clinical competency

  20. Interruption of Electrical Conductivity of Titanium Dental Implants Suggests a Path Towards Elimination Of Corrosion

    PubMed Central

    Pozhitkov, Alex E.; Daubert, Diane; Brochwicz Donimirski, Ashley; Goodgion, Douglas; Vagin, Mikhail Y.; Leroux, Brian G.; Hunter, Colby M.; Flemmig, Thomas F.; Noble, Peter A.; Bryers, James D.

    2015-01-01

    Peri-implantitis is an inflammatory disease that results in the destruction of soft tissue and bone around the implant. Titanium implant corrosion has been attributed to the implant failure and cytotoxic effects to the alveolar bone. We have documented the extent of titanium release into surrounding plaque in patients with and without peri-implantitis. An in vitro model was designed to represent the actual environment of an implant in a patient’s mouth. The model uses actual oral microbiota from a volunteer, allows monitoring electrochemical processes generated by biofilms growing on implants and permits control of biocorrosion electrical current. As determined by next generation DNA sequencing, microbial compositions in experiments with the in vitro model were comparable with the compositions found in patients with implants. It was determined that the electrical conductivity of titanium implants was the key factor responsible for the biocorrosion process. The interruption of the biocorrosion current resulted in a 4–5 fold reduction of corrosion. We propose a new design of dental implant that combines titanium in zero oxidation state for osseointegration and strength, interlaid with a nonconductive ceramic. In addition, we propose electrotherapy for manipulation of microbial biofilms and to induce bone healing in peri-implantitis patients. PMID:26461491

  1. Interruption of Electrical Conductivity of Titanium Dental Implants Suggests a Path Towards Elimination Of Corrosion.

    PubMed

    Pozhitkov, Alex E; Daubert, Diane; Brochwicz Donimirski, Ashley; Goodgion, Douglas; Vagin, Mikhail Y; Leroux, Brian G; Hunter, Colby M; Flemmig, Thomas F; Noble, Peter A; Bryers, James D

    2015-01-01

    Peri-implantitis is an inflammatory disease that results in the destruction of soft tissue and bone around the implant. Titanium implant corrosion has been attributed to the implant failure and cytotoxic effects to the alveolar bone. We have documented the extent of titanium release into surrounding plaque in patients with and without peri-implantitis. An in vitro model was designed to represent the actual environment of an implant in a patient's mouth. The model uses actual oral microbiota from a volunteer, allows monitoring electrochemical processes generated by biofilms growing on implants and permits control of biocorrosion electrical current. As determined by next generation DNA sequencing, microbial compositions in experiments with the in vitro model were comparable with the compositions found in patients with implants. It was determined that the electrical conductivity of titanium implants was the key factor responsible for the biocorrosion process. The interruption of the biocorrosion current resulted in a 4-5 fold reduction of corrosion. We propose a new design of dental implant that combines titanium in zero oxidation state for osseointegration and strength, interlaid with a nonconductive ceramic. In addition, we propose electrotherapy for manipulation of microbial biofilms and to induce bone healing in peri-implantitis patients.

  2. On the mechanical integrity of retrieved dental implants.

    PubMed

    Shemtov-Yona, K; Rittel, D

    2015-09-01

    The objective of this work is to investigate the potential state of mechanical damage in used, albeit mechanically intact, dental implants, after their retrieval from the oral cavity because of progressive bone loss (peri-implantitis). 100 retrieved dental implants were characterized with no medical record made available prior to the analysis. The implants' composition, dimensions, and surface treatments were characterized using energy dispersive X-ray analysis and scanning electron microscopy (SEM-EDX). Each implant was thoroughly examined for signs of mechanical defects and damage. The implants represent a random combination of two materials, titanium alloy (Ti-6Al-4V) and commercially pure titanium (CP-Ti), surface treatments and geometries. Two kinds of surface defects were identified: crack-like defects and full cracks that were arbitrarily divided according to their length and appearance. We found that over 60% of the implants contained both crack-like defects and full cracks. In the retrieved sample, we observed that the CP-Ti implants contained more defects and cracks than the Ti-6Al-4V ones. For the various surface roughening treatments, a general correlation with the presence of defects was observed, but without a clear differentiation between the treatments. The high incidence of embedded particles among the observed defect further strengthens the role played by the particles upon defects generation, some of which later evolve into full cracks. It was also found that the dimensions of the implant (width and length) were not correlated with the observed defects, for this specific sample. Our observations indicate that early retrieval of biologically failed implants, many of which contain early signs of mechanical failure as shown here, does actually hinder the later occurrence of implant fracture. It seems that once biological complications will be successfully overcome, such defects might grow later into full cracks as a result of cyclic mastication

  3. Remotely powered multichannel microprocessor-based telemetry systems for smart implantable devices and smart structures

    NASA Astrophysics Data System (ADS)

    Townsend, Christopher P.; Arms, Steven W.; Hamel, Michael J.

    1999-07-01

    The development of improved implantable devices and materials require knowledge of their in vivo behavior. However, little is known about the actual loads borne by implanted devices in vivo. Direct load measurement would provide extremely valuable information, for the improvement of device designs, and for the rapid rehabilitation of individuals in which devices have been implanted. Multichannel telemetry systems, combined with strain gauges, can provide this information.

  4. The Actual Apollo 13 Prime Crew

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The actual Apollo 13 lunar landing mission prime crew from left to right are: Commander, James A. Lovell Jr., Command Module pilot, John L. Swigert Jr.and Lunar Module pilot, Fred W. Haise Jr. The original Command Module pilot for this mission was Thomas 'Ken' Mattingly Jr. but due to exposure to German measles he was replaced by his backup, Command Module pilot, John L. 'Jack' Swigert Jr.

  5. A Retrospective Analysis of the Effectiveness of the Longevity Protocol for Assessing the Risk of Implant Failure.

    PubMed

    Testori, Tiziano; Clauser, Carlo; Deflorian, Matteo; Capelli, Matteo; Zuffetti, Francesco; Fabbro, Massimo Del

    2016-12-01

    A new, computerized diagnostic tool, called the Longevity Protocol, was recently developed to predict implant failure. The present retrospective analysis was undertaken to assess the prognostic validity of this protocol. A selected group of patients who had been treated with implants over the past 10 years at six dental clinics and experienced implant failure were included in the analysis. Another group of patients with similar characteristics, not experiencing implant failure, was used as control. In April of 2015, data about each of the patients was entered into the Longevity Protocol database. For each patient, the risk assessment produced by the protocol was compared to whether the implants eventually failed. The implant failure predictions and actual implant failures were compared. The Longevity Protocol analyzed the possible failure of 595 implants placed in 221 patients (323 implants placed in 138 patients classified as low risk, 180 implants placed in 55 patients classified as moderate risk, and 92 implants placed in 28 patients classified as high risk). The actual percentage of implant failure in the three groups was 10%, 15%, and 22%, respectively. The differences between the groups were statistically significant. The sensitivity and specificity of the Longevity Protocol was 84.9% and 11.90% in the high/moderate risk group and 47.17% and 32.74% in the low risk group, respectively. Statistically significant results were obtained. The Longevity Protocol reliably identified patients who risked implant failure. The protocol appears to be an important tool for prognosis assessment. © 2016 Wiley Periodicals, Inc.

  6. [Cochlear implant in adults].

    PubMed

    Bouccara, D; Mosnier, I; Bernardeschi, D; Ferrary, E; Sterkers, O

    2012-03-01

    Cochlear implant in adults is a procedure, dedicated to rehabilitate severe to profound hearing loss. Because of technological progresses and their applications for signal strategies, new devices can improve hearing, even in noise conditions. Binaural stimulation, cochlear implant and hearing aid or bilateral cochlear implants are the best opportunities to access to better level of comprehension in all conditions and space localisation. By now minimally invasive surgery is possible to preserve residual hearing and use a double stimulation modality for the same ear: electrical for high frequencies and acoustic for low frequencies. In several conditions, cochlear implant is not possible due to cochlear nerve tumour or major malformations of the inner ear. In these cases, a brainstem implantation can be considered. Clinical data demonstrate that improvement in daily communication, for both cochlear and brainstem implants, is correlated with cerebral activation of auditory cortex.

  7. Implant treatment planning considerations.

    PubMed

    Kao, Richard T

    2008-04-01

    As dental implants become a more accepted treatment modality, there is a need for all parties involved with implant dentistry to be familiar with various treatment planning issues. Though the success can be highly rewarding, failure to forecast treatment planning issues can result in an increase of surgical needs, surgical cost, and even case failure. In this issue, the focus is on implant treatment planning considerations.

  8. Osseointegrated implant prosthodontics.

    PubMed

    Rogoff, G S

    1992-06-01

    This review covers recent literature on prosthodontic aspects of osseointegrated implants. Long-term prognosis, diagnosis and treatment planning, and clinical impression techniques and fabrication technology are discussed.

  9. [Silastic implant and synovitis].

    PubMed

    Sennwald, G

    1989-07-22

    The silastic implant based on siloxane polymere induces granulomatous synovitis in certain predisposed individuals, a reaction which may continue even after removal of the implant. This is also true of a prosthesis of the trapezium in two of our patients, though to a lesser degree. This is probably the reason why the problem has not yet been widely recognized. The hypothesis is put forward that an enzymatic predisposition may allow chemical degradation of the fragmented silastic implant into a toxic component responsible for the pathologic condition. The slow progression of the lesions is a challenge for the future and puts in question the further use of silastic implants.

  10. Air resistance measurements on actual airplane parts

    NASA Technical Reports Server (NTRS)

    Weiselsberger, C

    1923-01-01

    For the calculation of the parasite resistance of an airplane, a knowledge of the resistance of the individual structural and accessory parts is necessary. The most reliable basis for this is given by tests with actual airplane parts at airspeeds which occur in practice. The data given here relate to the landing gear of a Siemanms-Schuckert DI airplane; the landing gear of a 'Luftfahrzeug-Gesellschaft' airplane (type Roland Dlla); landing gear of a 'Flugzeugbau Friedrichshafen' G airplane; a machine gun, and the exhaust manifold of a 269 HP engine.

  11. Neoadjuvant Treatment in Rectal Cancer: Actual Status

    PubMed Central

    Garajová, Ingrid; Di Girolamo, Stefania; de Rosa, Francesco; Corbelli, Jody; Agostini, Valentina; Biasco, Guido; Brandi, Giovanni

    2011-01-01

    Neoadjuvant (preoperative) concomitant chemoradiotherapy (CRT) has become a standard treatment of locally advanced rectal adenocarcinomas. The clinical stages II (cT3-4, N0, M0) and III (cT1-4, N+, M0) according to International Union Against Cancer (IUCC) are concerned. It can reduce tumor volume and subsequently lead to an increase in complete resections (R0 resections), shows less toxicity, and improves local control rate. The aim of this review is to summarize actual approaches, main problems, and discrepancies in the treatment of locally advanced rectal adenocarcinomas. PMID:22295206

  12. Explosive Percolation Transition is Actually Continuous

    NASA Astrophysics Data System (ADS)

    da Costa, R. A.; Dorogovtsev, S. N.; Goltsev, A. V.; Mendes, J. F. F.

    2010-12-01

    Recently a discontinuous percolation transition was reported in a new “explosive percolation” problem for irreversible systems [D. Achlioptas, R. M. D’Souza, and J. Spencer, Science 323, 1453 (2009)SCIEAS0036-807510.1126/science.1167782] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions.

  13. Assessment of gliosis around moveable implants in the brain

    NASA Astrophysics Data System (ADS)

    Stice, Paula; Muthuswamy, Jit

    2009-08-01

    Repositioning microelectrodes post-implantation is emerging as a promising approach to achieve long-term reliability in single neuronal recordings. The main goal of this study was to (a) assess glial reaction in response to movement of microelectrodes in the brain post-implantation and (b) determine an optimal window of time post-implantation when movement of microelectrodes within the brain would result in minimal glial reaction. Eleven Sprague-Dawley rats were implanted with two microelectrodes each that could be moved in vivo post-implantation. Three cohorts were investigated: (1) microelectrode moved at day 2 (n = 4 animals), (2) microelectrode moved at day 14 (n = 5 animals) and (3) microelectrode moved at day 28 (n = 2 animals). Histological evaluation was performed in cohorts 1-3 at four-week post-movement (30 days, 42 days and 56 days post-implantation, respectively). In addition, five control animals were implanted with microelectrodes that were not moved. Control animals were implanted for (1) 30 days (n = 1), (2) 42 days (n = 2) and (3) 56 days (n = 2) prior to histological evaluation. Quantitative assessment of glial fibrillary acidic protein (GFAP) around the tip of the microelectrodes demonstrated that GFAP levels were similar around microelectrodes moved at day 2 when compared to the 30-day controls. However, GFAP expression levels around microelectrode tips that moved at day 14 and day 28 were significantly less than those around control microelectrodes implanted for 42 and 56 days, respectively. Therefore, we conclude that moving microelectrodes after implantation is a viable strategy that does not result in any additional damage to brain tissue. Further, moving the microelectrode downwards after 14 days of implantation may actually reduce the levels of GFAP expression around the tips of the microelectrodes in the long term.

  14. Magnification rate of digital panoramic radiographs and its effectiveness for pre-operative assessment of dental implants

    PubMed Central

    Kim, Y-K; Park, J-Y; Kim, S-G; Kim, J-S; Kim, J-D

    2011-01-01

    Objectives The purpose of this study was to determine the accuracy and effectiveness of digital panoramic radiographs for pre-operative assessment of dental implants. Methods We selected 86 patients (221 implants) and calculated the length of the planned implant based on the distance between a selection of critical anatomical structures and the alveolar crest using the scaling tools provided in the digital panoramic system. We analysed the magnification rate and the difference between the actual inserted implant length and planned implant length according to the location of the implant placement and the clarity of anatomical structures seen in the panoramic radiographs. Results There was no significant difference between the planned implant length and actual inserted implant length (P > 0.05). The magnification rate of the width and length of the inserted implants, seen in the digital panoramic radiographs, was 127.28 ± 13.47% and 128.22 ± 4.17%, respectively. The magnification rate of the implant width was largest in the mandibular anterior part and there was a significant difference in the magnification rate of the length of implants between the maxilla and the mandible (P < 0.05). When the clarity of anatomical structures seen in the panoramic radiographs is low, the magnification rate of the width of the inserted implants is significantly higher (P < 0.05), but there is no significant difference between the planned implant length and actual inserted implant length according to the clarity of anatomical structures (P < 0.05). Conclusions Digital panoramic radiography can be considered a simple, readily available and considerably accurate pre-operative assessment tool in the vertical dimension for dental implant therapy. PMID:21239569

  15. Implantable ultrasound devices

    NASA Astrophysics Data System (ADS)

    Vilkomerson, David; Chilipka, Thomas; Bogan, John; Blebea, John; Choudry, Rashad; Wang, John; Salvatore, Michael; Rotella, Vittorio; Soundararajan, Krishnan

    2008-03-01

    Using medical implants to wirelessly report physiological data is a technique that is rapidly growing. Ultrasound is well-suited for implants -- it requires little power and this form of radiated energy has no ill effects on the body. We report here on techniques we have developed in our experience gained in implanting over a dozen Doppler ultrasound flow-measuring implants in dogs. The goal of our implantable device is to measure flow in an arterial graft. To accomplish this, we place a Doppler transducer in the wall of a graft and an implant unit under the skin that energizes the 20 MHz Doppler transducer system, either when started by external command or by internal timetable. The implant records the digitized Doppler real and imaginary channels and transmits the data to a nearby portable computer for storage and evaluation. After outlining the overall operation of the system, we will concentrate on three areas of implant design where special techniques are required: ensuring safety, including biocompatibility to prevent the body from reacting to its invasion; powering the device, including minimizing energy used so that a small battery can provide long-life; and transmitting the data obtained.

  16. Batteryless implanted echosonometer

    NASA Technical Reports Server (NTRS)

    Kojima, G. K.

    1977-01-01

    Miniature ultrasonic echosonometer implanted within laboratory animals obtains energy from RF power oscillator that is electronically transduced via induction loop to power receiving loop located just under animal's skin. Method of powering device offers significant advantages over those in which battery is part of implanted package.

  17. Implantable, Ingestible Electronic Thermometer

    NASA Technical Reports Server (NTRS)

    Kleinberg, Leonard

    1987-01-01

    Small quartz-crystal-controlled oscillator swallowed or surgically implanted provides continuous monitoring of patient's internal temperature. Receiver placed near patient measures oscillator frequency, and temperature inferred from previously determined variation of frequency with temperature. Frequency of crystal-controlled oscillator varies with temperature. Circuit made very small and implanted or ingested to measure internal body temperature.

  18. A no bleed implant.

    PubMed

    Ersek, R A; Navarro, J A; Nemeth, D Z; Sas, G

    1993-01-01

    Breast implants have evolved from the original saline-filled, smooth-surfaced silicone rubber bag to silicone gel-filled smooth-walled sacs to a combination of a silicone gel-filled bag within a saline-filled sac, and, most recently, a reversed, double-lumen implant with a saline bag inside of a gel-filled bag. Texture-surfaced implants were first used in 1970 when the standard silicone gel-filled implant was covered with a polyurethane foam. Because of concerns about the degradation products of this foam, they were removed from the market in 1991. In 1975 double-lumen silicone textured implants were developed, followed by silicone gel-filled textured implants. In 1990 a new radiolucent, biocompatible gel was produced that reduced the problem of radioopacity of silicone implants. Because of the gel's sufficiently low coefficient of friction, leakage caused by fold flaw fracture may also be decreased. We present a case where this new biocompatible gel implant was repositioned after four months. The resulting scar capsule in this soft breast was thin [< 0.002 cm (0.008 in.)] and evenly textured as a mirror image of the textured silicone surface. Scanning electron microscopy and x-ray defraction spectrophotometry revealed no silicone bleed.

  19. Smoking and dental implants

    PubMed Central

    Kasat, V.; Ladda, R.

    2012-01-01

    Smoking is a prevalent behaviour in the population. The aim of this review is to bring to light the effects of smoking on dental implants. These facts will assist dental professionals when implants are planned in tobacco users. A search of “PubMed” was made with the key words “dental implant,” “nicotine,” “smoking,” “tobacco,” and “osseointegration.” Also, publications on tobacco control by the Government of India were considered. For review, only those articles published from 1988 onward in English language were selected. Smoking has its influence on general as well as oral health of an individual. Tobacco negatively affects the outcome of almost all therapeutic procedures performed in the oral cavity. The failure rate of implant osseointegration is considerably higher among smokers, and maintenance of oral hygiene around the implants and the risk of peri-implantitis are adversely affected by smoking. To increase implant survival in smokers, various protocols have been recommended. Although osseointegrated dental implants have become the state of the art for tooth replacement, they are not without limitations or complications. In this litigious era, it is extremely important that the practitioner clearly understands and is able and willing to convey the spectrum of possible complications and their frequency to the patients. PMID:24478965

  20. Batteryless implanted echosonometer

    NASA Technical Reports Server (NTRS)

    Kojima, G. K.

    1977-01-01

    Miniature ultrasonic echosonometer implanted within laboratory animals obtains energy from RF power oscillator that is electronically transduced via induction loop to power receiving loop located just under animal's skin. Method of powering device offers significant advantages over those in which battery is part of implanted package.

  1. Implantable CMOS Biomedical Devices

    PubMed Central

    Ohta, Jun; Tokuda, Takashi; Sasagawa, Kiyotaka; Noda, Toshihiko

    2009-01-01

    The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented. PMID:22291554

  2. Teeth and implants.

    PubMed

    Palmer, R

    1999-08-28

    An osseointegrated implant restoration may closely resemble a natural tooth. However, the absence of a periodontal ligament and connective tissue attachment via cementum, results in fundamental differences in the adaptation of the implant to occlusal forces, and the structure of the gingival cuff.

  3. Percutaneous and skeletal biocarbon implants

    NASA Technical Reports Server (NTRS)

    Mooney, V.

    1977-01-01

    Review of carbon implants developed by NASA discussed four different types of implants and subsequent improvements. Improvements could be of specific interest to rehabilitation centers and similar organizations.

  4. Percutaneous and skeletal biocarbon implants

    NASA Technical Reports Server (NTRS)

    Mooney, V.

    1977-01-01

    Review of carbon implants developed by NASA discussed four different types of implants and subsequent improvements. Improvements could be of specific interest to rehabilitation centers and similar organizations.

  5. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  6. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  7. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  8. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  9. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The APH...

  10. Graphene for Biomedical Implants

    NASA Astrophysics Data System (ADS)

    Moore, Thomas; Podila, Ramakrishna; Alexis, Frank; Rao, Apparao; Clemson Bioengineering Team; Clemson Physics Team

    2013-03-01

    In this study, we used graphene, a one-atom thick sheet of carbon atoms, to modify the surfaces of existing implant materials to enhance both bio- and hemo-compatibility. This novel effort meets all functional criteria for a biomedical implant coating as it is chemically inert, atomically smooth and highly durable, with the potential for greatly enhancing the effectiveness of such implants. Specifically, graphene coatings on nitinol, a widely used implant and stent material, showed that graphene coated nitinol (Gr-NiTi) supports excellent smooth muscle and endothelial cell growth leading to better cell proliferation. We further determined that the serum albumin adsorption on Gr-NiTi is greater than that of fibrinogen, an important and well understood criterion for promoting a lower thrombosis rate. These hemo-and biocompatible properties and associated charge transfer mechanisms, along with high strength, chemical inertness and durability give graphene an edge over most antithrombogenic coatings for biomedical implants and devices.

  11. The actual status of Astronomy in Moldova

    NASA Astrophysics Data System (ADS)

    Gaina, A.

    The astronomical research in the Republic of Moldova after Nicolae Donitch (Donici)(1874-1956(?)) were renewed in 1957, when a satellites observations station was open in Chisinau. Fotometric observations and rotations of first Soviet artificial satellites were investigated under a program SPIN put in action by the Academy of Sciences of former Socialist Countries. The works were conducted by Assoc. prof. Dr. V. Grigorevskij, which conducted also research in variable stars. Later, at the beginning of 60-th, an astronomical Observatory at the Chisinau State University named after Lenin (actually: the State University of Moldova), placed in Lozovo-Ciuciuleni villages was open, which were coordinated by Odessa State University (Prof. V.P. Tsesevich) and the Astrosovet of the USSR. Two main groups worked in this area: first conducted by V. Grigorevskij (till 1971) and second conducted by L.I. Shakun (till 1988), both graduated from Odessa State University. Besides this research areas another astronomical observations were made: Comets observations, astroclimate and atmospheric optics in collaboration with the Institute of the Atmospheric optics of the Siberian branch of the USSR (V. Chernobai, I. Nacu, C. Usov and A.F. Poiata). Comets observations were also made since 1988 by D. I. Gorodetskij which came to Chisinau from Alma-Ata and collaborated with Ukrainean astronomers conducted by K.I. Churyumov. Another part of space research was made at the State University of Tiraspol since the beggining of 70-th by a group of teaching staff of the Tiraspol State Pedagogical University: M.D. Polanuer, V.S. Sholokhov. No a collaboration between Moldovan astronomers and Transdniestrian ones actually exist due to War in Transdniestria in 1992. An important area of research concerned the Radiophysics of the Ionosphere, which was conducted in Beltsy at the Beltsy State Pedagogical Institute by a group of teaching staff of the University since the beginning of 70-th: N. D. Filip, E

  12. What Galvanic Vestibular Stimulation Actually Activates

    PubMed Central

    Curthoys, Ian S.; MacDougall, Hamish Gavin

    2012-01-01

    In a recent paper in Frontiers Cohen et al. (2012) asked “What does galvanic vestibular stimulation actually activate?” and concluded that galvanic vestibular stimulation (GVS) causes predominantly otolithic behavioral responses. In this Perspective paper we show that such a conclusion does not follow from the evidence. The evidence from neurophysiology is very clear: galvanic stimulation activates primary otolithic neurons as well as primary semicircular canal neurons (Kim and Curthoys, 2004). Irregular neurons are activated at lower currents. The answer to what behavior is activated depends on what is measured and how it is measured, including not just technical details, such as the frame rate of video, but the exact experimental context in which the measurement took place (visual fixation vs total darkness). Both canal and otolith dependent responses are activated by GVS. PMID:22833733

  13. 3D Printed, Customized Cranial Implant for Surgical Planning

    NASA Astrophysics Data System (ADS)

    Bogu, Venkata Phanindra; Ravi Kumar, Yennam; Asit Kumar, Khanra

    2016-06-01

    The main objective of the present work is to model cranial implant and printed in FDM machine (printer model used: mojo). Actually this is peculiar case and the skull has been damaged in frontal, parietal and temporal regions and a small portion of frontal region damaged away from saggital plane, complexity is to fill this frontal region with proper curvature. The Patient CT-data (Number of slices was 381 and thickness of each slice is 0.488 mm) was processed in mimics14.1 software, mimics file was sent to 3-matic software and calculated thickness of skull at different sections where cranial implant is needed then corrected the edges of cranial implant to overcome CSF (cerebrospinal fluid) leakage and proper fitting. Finally the implant average thickness is decided as 2.5 mm and printed in FDM machine with ABS plastic.

  14. 19 CFR 162.79b - Recovery of actual loss of duties, taxes and fees or actual loss of revenue.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... is liable for the payment of actual loss of duties, taxes and fees or actual loss of revenue in any... actual loss of duties, taxes and fees or actual loss of revenue. The notice will identify the merchandise and entries involved, state the loss of duties, taxes and fees or loss of revenue and how it was...

  15. 19 CFR 162.79b - Recovery of actual loss of duties, taxes and fees or actual loss of revenue.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... is liable for the payment of actual loss of duties, taxes and fees or actual loss of revenue in any... actual loss of duties, taxes and fees or actual loss of revenue. The notice will identify the merchandise and entries involved, state the loss of duties, taxes and fees or loss of revenue and how it was...

  16. Peri-implant mucositis and peri-implantitis: bacterial infection.

    PubMed

    Khammissa, R A G; Feller, L; Meyerov, R; Lemmer, J

    2012-03-01

    Osseointegrated dental implants have a ong-term success rate of over 90%, but may be threatened by peri-implant mucostis and peri-implantitis, bacteria biofilm-induced inflammatory conditions. While peri-implant mucositis is a reversible inflammatory condition confined to the peri-implant soft-tissue unit, peri-implantitis is characterised by progressive inflammatory destruction of the crest of the alveolar bone supporting the implant, by increased peri-implant probing depths, and by bleeding and/or suppuration on probing. Effective treatment of peri-implant mucositis will prevent the development of peri-implantitis. Plaque accumulation on the implant/abutment surface juxtaposed to the junctional epithelium and to the connective tissue zone of the peri-implant soft-tissue unit induces the development of peri-implant mucositis which can subsequently progress to peri-implantitis. The aim of this paper is to review some aspects of bacterial infection of the tissue supporting dental implants, and to explore how to maintain the healthy peri-implant soft-tissue unit.

  17. [Extra-oral implants: principal areas of implantation].

    PubMed

    Badie-Modiri, B; Kaplanski, P

    2001-08-01

    The success of extra-oral implants raises a certain number of technical and medical problems. Among these, the anatomy of the implant zone and bone quality are determining factors for osteointegration of the implants. We describe the principal zones of implantation detailing the risks involved in each area.

  18. Dental Implant Systems

    PubMed Central

    Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

    2010-01-01

    Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

  19. Single implant tooth replacement.

    PubMed

    Briley, T F

    1998-01-01

    It has been shown that direct bone anchorage of dental implants will provide long-term predictability for single tooth implants and multi-unit implants. The function of implant-supported restoration is now routinely achieved. The real challenge facing the restorative dentist and laboratory technician is to achieve optimal aesthetics. The learning objective of this article is to review the prosthodontic procedures essential to maximizing natural aesthetics in implant supported restorations. It will provide a review of master impression techniques, prepable titanium abutments and designing the cement on restoration. Particular emphasis is directed to the soft tissue model from which a series of sequenced techniques can be followed to achieve optimal aesthetics. Analysis of the implant alignment with regard to the neighboring teeth will result in having to make a choice of which prepable abutment will maximize the aesthetic result. The following case outlines how to replace a single missing tooth using an externally hexed implant system and a prefabricated titanium abutment on a 26-year-old male patient.

  20. Boron implanted strontium titanate

    NASA Astrophysics Data System (ADS)

    Cooper, C. J. M.

    Single crystals of strontium titanate implanted with boron were found to have highly conductive surface layers. The effects of varying dose from 10 to the 16th power to 10 to the 17th power ions/sq cm, implantation voltage from 50 to 175 keV and annealing conditions on the room temperature surface resistance and Hall mobility are presented. Variation of the implantation voltage did not have a major effect on the sheet resistances obtained by boron implantation of strontium titanate, while dose and annealing conditions have major effects. Doses of 5 x 10 to the 16th power ions/sq cm required annealing on the order of one hour at 500 K for maximum reduction of the room temperature resistance in the implanted layer. Samples implanted with a dose of 1 x 10 to the 17th power ions/sq cm required slightly higher temperatures (approximately 575 K) to obtain a minimum resistance at room temperature. Long term (several weeks) room temperature annealing was found to occur in high dose samples. After one to two months at room temperature followed by an anneal to 575 K, the surface resistances were found to be lower than those produced by the annealing of a freshly implanted sample to 575 K.

  1. Caustic-Side Solvent Extraction: Prediction of Cesium Extraction for Actual Wastes and Actual Waste Simulants

    SciTech Connect

    Delmau, L.H.; Haverlock, T.J.; Sloop, F.V., Jr.; Moyer, B.A.

    2003-02-01

    This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. It was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios.

  2. Nanotechnology for dental implants.

    PubMed

    Tomsia, Antoni P; Lee, Janice S; Wegst, Ulrike G K; Saiz, Eduardo

    2013-01-01

    With the advent of nanotechnology, an opportunity exists for the engineering of new dental implant materials. Metallic dental implants have been successfully used for decades, but they have shortcomings related to osseointegration and mechanical properties that do not match those of bone. Absent the development of an entirely new class of materials, faster osseointegration of currently available dental implants can be accomplished by various surface modifications. To date, there is no consensus regarding the preferred method(s) of implant surface modification, and further development will be required before the ideal implant surface can be created, let alone become available for clinical use. Current approaches can generally be categorized into three areas: ceramic coatings, surface functionalization, and patterning on the micro- to nanoscale. The distinctions among these are imprecise, as some or all of these approaches can be combined to improve in vivo implant performance. These surface improvements have resulted in durable implants with a high percentage of success and long-term function. Nanotechnology has provided another set of opportunities for the manipulation of implant surfaces in its capacity to mimic the surface topography formed by extracellular matrix components of natural tissue. The possibilities introduced by nanotechnology now permit the tailoring of implant chemistry and structure with an unprecedented degree of control. For the first time, tools are available that can be used to manipulate the physicochemical environment and monitor key cellular events at the molecular level. These new tools and capabilities will result in faster bone formation, reduced healing time, and rapid recovery to function.

  3. Optimization of dental implantation

    NASA Astrophysics Data System (ADS)

    Dol, Aleksandr V.; Ivanov, Dmitriy V.

    2017-02-01

    Modern dentistry can not exist without dental implantation. This work is devoted to study of the "bone-implant" system and to optimization of dental prostheses installation. Modern non-invasive methods such as MRI an 3D-scanning as well as numerical calculations and 3D-prototyping allow to optimize all of stages of dental prosthetics. An integrated approach to the planning of implant surgery can significantly reduce the risk of complications in the first few days after treatment, and throughout the period of operation of the prosthesis.

  4. Oxygen implanter for simox

    NASA Astrophysics Data System (ADS)

    Guerra, M.; Benveniste, V.; Ryding, G.; Douglas-Hamilton, D. H.; Reed, M.; Gagne, G.; Armstrong, A.; Mack, M.

    1985-01-01

    Interest in silicon or) insulator (SOI) technology has led to the development of several alternatives to silicon on sapphire. One of the most promising techniques makes use of an ion implanter to form a buried oxide layer directly in the silicon substrate. To have useful single crystalline silicon on top of the oxide layer, it is necessary to do the implant at high wafer temperatures and rely on solid phase epitaxy to maintain surface structure. A high current, 160 keV, Nova ion implanter has been adapted to provide the ability to perform oxygen implants at elevated temperatures. The operator is free to choose any temperature in the range between 400°C and 600°C. The system then preheats the wafers to the selected temperature before the implant begins. A novel technique for providing both heating and cooling capability to the end station is employed. An infrared signal from the wafers is monitored by a room temperature lead salt detector. This signal is then used by a servo-loop to control the heating of the end station and to maintain the wafer temperature to within ± 20°C during the implant. High doses of the type necessary to form a silicon dioxide buried layer require long lived, high current oxygen sources. An oxygen source has been specially developed, which provides as much as 10 mA of ion current. At a 6 mA output, source lifetimes in excess of 40 hours have been achieved. The implanter uses a specifically designed high temperature disk, which holds ten wafers, each of four inch diameter. A variety of implant angles lying between 0° and 15° is available. The beam is scanned mechanically and an electron flood gun can be used to prevent wafer charging. Special thermal barriers have been employed to protect the apparatus from extreme temperatures and to make the heating sequence more efficient and more rapid. Every effort has been made to avoid contamination of the implant. The implant disk, for example, is overcoated with silicon monoxide. Silicon

  5. Biomedical implantable microelectronics.

    PubMed

    Meindl, J D

    1980-10-17

    Innovative applications of microelectronics in new biomedical implantable instruments offer a singular opportunity for advances in medical research and practice because of two salient factors: (i) beyond all other types of biomedical instruments, implants exploit fully the inherent technical advantages--complex functional capability, high reliability, lower power drain, small size and weight-of microelectronics, and (ii) implants bring microelectronics into intimate association with biological systems. The combination of these two factors enables otherwise impossible new experiments to be conducted and new paostheses developed that will improve the quality of human life.

  6. Transcatheter aortic valve implantation.

    PubMed

    Oliemy, Ahmed; Al-Attar, Nawwar

    2014-01-01

    Transcatheter aortic valve implantation was developed to offer a therapeutic solution to patients with severe symptomatic aortic stenosis who are not candidates for conventional aortic valve replacement. The improvement in transcatheter aortic valve implantation outcomes is still of concern in the areas of stroke, vascular injury, heart block, paravalvular regurgitation and valve durability. Concomitantly, the progress, both technical and in terms of material advances of transcatheter valve systems, as well as in patient selection, renders transcatheter aortic valve implantation an increasingly viable treatment for more and more patients with structural heart disease.

  7. Can we predict the insertion torque using the bone density around the implant?

    PubMed

    Wada, M; Suganami, T; Sogo, M; Maeda, Y

    2016-02-01

    The purpose of this study was to examine the correlation between initial stability and bone density in patients undergoing implant treatment. Twenty-five screw-type dental implants were inserted in 12 patients. All patients underwent multi-detector computed tomography (CT) examination prior to implant insertion. The implant sockets were prepared according to the drilling protocol, and peak insertion torque values were measured. CT values around the implants were measured using preoperatively scanned CT data, which were combined with actual implant positions. Spearman's rank correlation coefficient was used to investigate the correlation between insertion torque values and CT values (in Hounsfield units, HU). Twenty-three implants (8 or 10 mm in length) were inserted in the mandibular molar region and two (10mm length) in the maxillary molar region. The mean CT value of the 8-mm implants was 508.6 ± 187.0 HU and mean insertion torque was 27.2 ± 12.1 N·cm; for the 10-mm implants, these values were 579.6 ± 224.3 HU and 28.1 ± 14.6 N·cm, respectively. Statistical analysis revealed a strong positive correlation between the insertion torque and mean CT values (r=0.699, 8 mm; r=0.771, 10 mm). The results revealed that bone density around the implant is a useful index. This study indicates that preoperative CT may enable the prediction of initial implant stability.

  8. 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

  9. Dealing with dental implant failures.

    PubMed

    Levin, L

    2010-01-01

    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.

  10. Dealing with dental implant failures.

    PubMed

    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.

  11. Dealing with dental implant failures.

    PubMed

    Levin, L

    2010-07-01

    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.

  12. Breast Reconstruction with Implants

    MedlinePlus

    ... removes your breast to treat or prevent breast cancer. One type of breast reconstruction uses breast implants — silicone devices filled with silicone gel or salt water (saline) — to reshape your breasts. Breast reconstruction ...

  13. Biocompatibility of surgical implants

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.

    1979-01-01

    Method of selecting biocompatible materials for surgical implants uses fracture mechanic relationships and surface energies of candidate materials in presence of blood plasma. Technique has been used to characterize 190 materials by parameters that reflect their biocompatibility.

  14. Biocompatibility of surgical implants

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.

    1979-01-01

    Method of selecting biocompatible materials for surgical implants uses fracture mechanic relationships and surface energies of candidate materials in presence of blood plasma. Technique has been used to characterize 190 materials by parameters that reflect their biocompatibility.

  15. Implantable Medical Devices

    MedlinePlus

    ... a Heart Attack Treatment of a Heart Attack Life After a Heart Attack Heart Failure About Heart Failure ... Attack Introduction Medications Surgical Procedures Implantable Medical Devices • Life After a Heart Attack • Heart Attack Tools & Resources • Support ...

  16. Urinary incontinence - injectable implant

    MedlinePlus

    Intrinsic sphincter deficiency repair; ISD repair; Injectable bulking agents for stress urinary incontinence ... Urine leakage that gets worse Pain where the injection was done Allergic reaction to the material Implant ...

  17. Superelastic Orthopedic Implant Coatings

    NASA Astrophysics Data System (ADS)

    Fournier, Eric; Devaney, Robert; Palmer, Matthew; Kramer, Joshua; El Khaja, Ragheb; Fonte, Matthew

    2014-07-01

    The demand for hip and knee replacement surgery is substantial and growing. Unfortunately, most joint replacement surgeries will fail within 10-25 years, thereby requiring an arduous, painful, and expensive revision surgery. To address this issue, a novel orthopedic implant coating material ("eXalt") has been developed. eXalt is comprised of super elastic nitinol wire that is knit into a three-dimensional spacer fabric structure. eXalt expands in vivo to conform to the implantation site and is porous to allow for bone ingrowth. The safety and efficacy of eXalt were evaluated through structural analysis, mechanical testing, and a rabbit implantation model. The results demonstrate that eXalt meets or exceeds the performance of current coating technologies with reduced micromotion, improved osseointegration, and stronger implant fixation in vivo.

  18. Breast reconstruction - implants

    MedlinePlus

    ... cosmetic surgery after breast cancer can improve your sense of well-being and your quality of life. Alternative Names Breast implants surgery References Roehl KR, Wilhelmi BJ, Phillips LG. Breast reconstruction. ...

  19. Consequences of Predicted or Actual Asteroid Impacts

    NASA Astrophysics Data System (ADS)

    Chapman, C. R.

    2003-12-01

    Earth impact by an asteroid could have enormous physical and environmental consequences. Impactors larger than 2 km diameter could be so destructive as to threaten civilization. Since such events greatly exceed any other natural or man-made catastrophe, much extrapolation is necessary just to understand environmental implications (e.g. sudden global cooling, tsunami magnitude, toxic effects). Responses of vital elements of the ecosystem (e.g. agriculture) and of human society to such an impact are conjectural. For instance, response to the Blackout of 2003 was restrained, but response to 9/11 terrorism was arguably exaggerated and dysfunctional; would society be fragile or robust in the face of global catastrophe? Even small impacts, or predictions of impacts (accurate or faulty), could generate disproportionate responses, especially if news media reports are hyped or inaccurate or if responsible entities (e.g. military organizations in regions of conflict) are inadequately aware of the phenomenology of small impacts. Asteroid impact is the one geophysical hazard of high potential consequence with which we, fortunately, have essentially no historical experience. It is thus important that decision makers familiarize themselves with the hazard and that society (perhaps using a formal procedure, like a National Academy of Sciences study) evaluate the priority of addressing the hazard by (a) further telescopic searches for dangerous but still-undiscovered asteroids and (b) development of mitigation strategies (including deflection of an oncoming asteroid and on- Earth civil defense). I exemplify these issues by discussing several representative cases that span the range of parameters. Many of the specific physical consequences of impact involve effects like those of other geophysical disasters (flood, fire, earthquake, etc.), but the psychological and sociological aspects of predicted and actual impacts are distinctive. Standard economic cost/benefit analyses may not

  20. A Method of Producing Surface Conduction on Ceramic Accelerator Components Using Metal Ion Implantation

    SciTech Connect

    Liu, F.; Brown, I.; Phillips, H.; Biallas, George; Siggins, Timothy

    1997-05-01

    An important technique used for the suppression of surface flashover on high voltage DC ceramic insulators as well as for RF windows is that of providing some surface conduction to bleed off accumulated surface charge. We have used metal ion implantation to modify the surface of high voltage ceramic vacuum insulators to provide a niform surface resistivity of approximately 5 x 1010 W/square. A vacuum arc ion source based implanter was used to implant Pt at an energy of about 135 keV to doses of up to more than 5 x 1016 ions/cm2 into small ceramic test coupons and also into the inside surface of several ceramic accelerator columns 25 cm I. D. by 28 cm long. Here we describe the experimental set-up used to do the ion implantation and summarize the results of our exploratory work on implantation into test coupons as well as the implantations of the actual ceramic columns.

  1. Plasma source ion-implantation technique for surface modification of materials

    NASA Astrophysics Data System (ADS)

    Conrad, J. R.; Radtke, J. L.; Dodd, R. A.; Worzala, Frank J.; Tran, Ngoc C.

    1987-12-01

    Plasma source ion-implantation (PSII) is a new ion-implantation technique which has been optimized for surface modification of materials such as metals, plastics, and ceramics. PSII departs radically from conventional implantation technology by circumventing the line-of-sight restriction inherent in conventional ion implantation. In PSII, targets to be implanted are placed directly in a plasma source and then pulse biased to a high negative potential. A plasma sheath forms around the target and ions bombard the entire target simultaneously. Preliminary experiments have demonstrated that PSII: (1) efficiently implants ions to concentrations and depths required for surface modification, (2) produces material with improved microhardness and wear properties, and (3) dramatically improves the life of manufacturing tools in actual industrial applications. For example, the tool life of M-2 pierce punches used to produce holes in mild steel plate has been increased by a factor of 80.

  2. [Larynx: implants and stents].

    PubMed

    Sittel, C

    2009-05-01

    There is a wide variety of devices and materials to be implanted into the human larynx. Some are intended to remain only for a period of time, like laryngeal stents. If removal is not intended the device meets the definition for a medical implant. The majority of implants is used for the treatment of unilateral vocal fold immobility. There a 2 types of implants serving this purpose: Implants in a stricter sense are devices of solid material, which are brought into the paraglottic space through a window in the laryngeal framework (medialization thyroplasty). Several different products are presented in this review. In contrast, there are different substances available for endoscopic injection into the paralyzed vocal fold (injection laryngoplasty). Since some of these substances show a corpuscular consistency and a high viscosity they need to be deposited into the lateral paraglottic space. Therefore, the term "injectable implants" has been coined for these materials. The different substances available are discussed in detail in this review. Laryngeal stents are primarily used in the early postoperative phase after open reconstruction of the larynx. The different devices available on the market are described with their specific characteristics and intended use.

  3. Anodized dental implant surface.

    PubMed

    Mishra, Sunil Kumar; Kumar, Muktadar Anand; Chowdhary, Ramesh

    2017-01-01

    Anodized implants with moderately rough surface were introduced around 2000. Whether these implants enhanced biologic effect to improve the environment for better osseointegration was unclear. The purpose of this article was to review the literature available on anodized surface in terms of their clinical success rate and bone response in patients till now. A broad electronic search of MEDLINE and PubMed databases was performed. A focus was made on peer-reviewed dental journals. Only articles related to anodized implants were included. Both animal and human studies were included. The initial search of articles resulted in 581 articles on anodized implants. The initial screening of titles and abstracts resulted in 112 full-text papers; 40 animal studies, 16 studies on cell adhesion and bacterial adhesion onto anodized surfaced implants, and 47 human studies were included. Nine studies, which do not fulfill the inclusion criteria, were excluded. The long-term studies on anodized surface implants do favor the surface, but in most of the studies, anodized surface is compared with that of machined surface, but not with other surfaces commercially available. Anodized surface in terms of clinical success rate in cases of compromised bone and immediately extracted sockets has shown favorable success.

  4. Biocompatible implant surface treatments.

    PubMed

    Pattanaik, Bikash; Pawar, Sudhir; Pattanaik, Seema

    2012-01-01

    Surface plays a crucial role in biological interactions. Surface treatments have been applied to metallic biomaterials in order to improve their wear properties, corrosion resistance, and biocompatibility. A systematic review was performed on studies investigating the effects of implant surface treatments on biocompatibility. We searched the literature using PubMed, electronic databases from 1990 to 2009. Key words such as implant surface topography, surface roughness, surface treatment, surface characteristics, and surface coatings were used. The search was restricted to English language articles published from 1990 to December 2009. Additionally, a manual search in the major dental implant journals was performed. When considering studies, clinical studies were preferred followed by histological human studies, animal studies, and in vitro studies. A total of 115 articles were selected after elimination: clinical studies, 24; human histomorphometric studies, 11; animal histomorphometric studies, 46; in vitro studies, 34. The following observations were made in this review: · The focus has shifted from surface roughness to surface chemistry and a combination of chemical manipulations on the porous structure. More investigations are done regarding surface coatings. · Bone response to almost all the surface treatments was favorable. · Future trend is focused on the development of osteogenic implant surfaces. Limitation of this study is that we tried to give a broader overview related to implant surface treatments. It does not give any conclusion regarding the best biocompatible implant surface treatment investigated till date. Unfortunately, the eventually selected studies were too heterogeneous for inference of data.

  5. Biomaterials in cochlear implants

    PubMed Central

    Stöver, Timo; Lenarz, Thomas

    2011-01-01

    The cochlear implant (CI) represents, for almost 25 years now, the gold standard in the treatment of children born deaf and for postlingually deafened adults. These devices thus constitute the greatest success story in the field of ‘neurobionic’ prostheses. Their (now routine) fitting in adults, and especially in young children and even babies, places exacting demands on these implants, particularly with regard to the biocompatibility of a CI’s surface components. Furthermore, certain parts of the implant face considerable mechanical challenges, such as the need for the electrode array to be flexible and resistant to breakage, and for the implant casing to be able to withstand external forces. As these implants are in the immediate vicinity of the middle-ear mucosa and of the junction to the perilymph of the cochlea, the risk exists – at least in principle – that bacteria may spread along the electrode array into the cochlea. The wide-ranging requirements made of the CI in terms of biocompatibility and the electrode mechanism mean that there is still further scope – despite the fact that CIs are already technically highly sophisticated – for ongoing improvements to the properties of these implants and their constituent materials, thus enhancing the effectiveness of these devices. This paper will therefore discuss fundamental material aspects of CIs as well as the potential for their future development. PMID:22073103

  6. Contraceptive implants and lactation.

    PubMed

    Díaz, Soledad

    2002-01-01

    The safety and efficacy of four contraceptive implants, plant, Implanon, Nestorone and Elcometrine, have been evaluated during use in the postpartum period by lactating women. These implants provide highly effective contraceptive protection with no negative effect on breastfeeding or infant growth and development. Breastfeeding women initiating Norplant use in the second postpartum month experience significantly longer periods of amenorrhea than do untreated women or intrauterine device users. After weaning, the bleeding pattern is similar to that observed in non-nursing women. Norplant use does not affect bone turnover and density during lactation. Norplant and Implanon release orally active progestins while Nestorone and Elcometrine implants release an orally inactive progestin, which represents an advantage since the infant should be free of steroidal effects. The infant's daily intake of steroids (estimated from concentrations in maternal milk during the first month of use) range from 90 to 100 ng of levonorgestrel (Norplant), 75-120 ng of etonogestrel (Implanon), and 50 ng and 110 ng of Nestorone (Nestorone and Elcometrine implants, respectively). Nursing women needing contraception may use progestin-only implants when nonhormonal methods are not available or acceptable. Implants that deliver orally active steroids should only be used after 6 weeks postpartum to avoid transferring of steroids to the newborn.

  7. Simple Implant Augmentation Rhinoplasty

    PubMed Central

    Nguyen, Anh H.; Bartlett, Erica L.; Kania, Katarzyna; Bae, Sang Mo

    2015-01-01

    Augmentation rhinoplasty among Asian patients is often performed to improve the height of the nasal dorsum. As the use of autogenous tissues poses certain limitations, alloplastic materials are a viable alternative with a long history of use in Asia. The superiority of one implant prosthesis over another for augmentation rhinoplasty is a matter of debate, with each material representing varying strengths and weaknesses, indications for use, and precautions to consider in nasal implant placement. An implant prosthesis should be used on a case-by-case basis. Augmentation rhinoplasty requires the consideration of specific anatomical preoperative factors, including the external nose, nasal length, nasofrontal angle, humps, and facial proportions. It is equally important to consider several operative guidelines to appropriately shape implants to minimize the occurrence of adverse effects and postoperative complications. The most common postoperative complications include infection, nasal height change, movement of implant prosthesis, and silicone implant protrusion. In addition, the surgeon should consider the current standards of Asian beauty aesthetics to better understand the patient's desired outcome. PMID:26648804

  8. 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.

  9. Engineering of implantable liver tissues.

    PubMed

    Sakai, Yasuyuki; Nishikawa, M; Evenou, F; Hamon, M; Huang, H; Montagne, K P; Kojima, N; Fujii, T; Niino, T

    2012-01-01

    In this chapter, from the engineering point of view, we introduce the results from our group and related research on three typical configurations of engineered liver tissues; cell sheet-based tissues, sheet-like macroporous scaffold-based tissues, and tissues based on special scaffolds that comprise a flow channel network. The former two do not necessitate in vitro prevascularization and are thus promising in actual human clinical trials for liver diseases that can be recovered by relatively smaller tissue mass. The third approach can implant a much larger mass but is still not yet feasible. In all cases, oxygen supply is the key engineering factor. For the first configuration, direct oxygen supply using an oxygen-permeable polydimethylsiloxane membrane enables various liver cells to exhibit distinct behaviors, complete double layers of mature hepatocytes and fibroblasts, spontaneous thick tissue formation of hepatocarcinoma cells and fetal hepatocytes. Actual oxygen concentration at the cell level can be strictly controlled in this culture system. Using this property, we found that initially low then subsequently high oxygen concentrations were favorable to growth and maturation of fetal cells. For the second configuration, combination of poly-L: -lactic acid 3D scaffolds and appropriate growth factor cocktails provides a suitable microenvironment for the maturation of cells in vitro but the cell growth is limited to a certain distance from the inner surfaces of the macropores. However, implantation to the mesentery leaves of animals allows the cells again to proliferate and pack the remaining spaces of the macroporous structure, suggesting the high feasibility of 3D culture of hepatocyte progenitors for liver tissue-based therapies. For the third configuration, we proposed a design criterion concerning the dimensions of flow channels based on oxygen diffusion and consumption around the channel. Due to the current limitation in the resolution of 3D

  10. Actualization and the Fear of Death: Retesting an Existential Hypothesis.

    ERIC Educational Resources Information Center

    Wood, Keith; Robinson, Paul J.

    1982-01-01

    Demonstrates that within a group of highly actualized individuals, the degree to which "own death" is integrated into constructs of self is a far more powerful predictor of fear of death than actualization. Findings suggest that actualization and integration are independent in their overall effect on fear of death. (Author)

  11. [Dental implant-related infections].

    PubMed

    López-Cerero, Lorena

    2008-11-01

    Dental implant-associated infections are expected to be increasingly more common as the number of patients with implants for more than 10 years rises. There are 2 stages of peri-implant infection: early mucositis, consisting of inflammation of the peri-implant soft tissues without loss of supporting bone, and a more advanced form involving a loss of osseointegration, known as peri-implantitis. The estimated prevalence of this latter infection is 10% of 5-year implants and the main risk factor is previous periodontal disease. The etiopathogenesis of peri-implantitis is related with reservoirs of periodontal pathogens; however factors that lead to colonization of the implant surface or increased susceptibility to infection may also have an influence. Treatment should include removal of the bacterial biofilm, debridement of the exposed surface, and surgical regeneration of the peri-implant pocket.

  12. External Validity of Contingent Valuation: Comparing Hypothetical and Actual Payments.

    PubMed

    Ryan, Mandy; Mentzakis, Emmanouil; Jareinpituk, Suthi; Cairns, John

    2016-10-09

    Whilst contingent valuation is increasingly used in economics to value benefits, questions remain concerning its external validity that is do hypothetical responses match actual responses? We present results from the first within sample field test. Whilst Hypothetical No is always an Actual No, Hypothetical Yes exceed Actual Yes responses. A constant rate of response reversals across bids/prices could suggest theoretically consistent option value responses. Certainty calibrations (verbal and numerical response scales) minimise hypothetical-actual discrepancies offering a useful solution. Helping respondents resolve uncertainty may reduce the discrepancy between hypothetical and actual payments and thus lead to more accurate policy recommendations. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Assessment of maxillary position. Implant vs cephalometric methods.

    PubMed

    Verayannont, Panisha; Hägg, Urban; Wong, Ricky W K; McGrath, Colman; Yeung, Shadow

    2010-09-01

    To compare changes in maxillary position assessed from a maxillary implant and three cephalometric methods based on linear measurements. Series of tracings of the maxilla obtained around puberty from an implant study were analyzed. The displacement of the implant was used to determine the direction and amount of "actual" maxillary growth. Displacement of point A was measured according to three cephalometric methods. The values obtained from absolute, horizontal, and vertical displacement of point A by three cephalometric methods and by the implant method were compared. Results showed that estimation of displacement of the maxilla by three cephalometric methods (point A) was significantly larger than that of the implant method in all directions. The average difference in the horizontal plane was 0.7 mm, 1.2 mm, and 1.6 mm, respectively; the average difference in the vertical plane was 2.2 mm, 2.5 mm, and 3.6 mm, respectively. Estimations of changes in maxillary position by the implant method and by cephalometric methods were not proportional. All three cephalometric methods overestimated changes in the position of the maxilla.

  14. Frequency-place compression and expansion in cochlear implant listeners

    NASA Astrophysics Data System (ADS)

    Başkent, Deniz; Shannon, Robert V.

    2004-11-01

    In multichannel cochlear implants, low frequency information is delivered to apical cochlear locations while high frequency information is delivered to more basal locations, mimicking the normal acoustic tonotopic organization of the auditory nerves. In clinical practice, little attention has been paid to the distribution of acoustic input across the electrodes of an individual patient that might vary in terms of spacing and absolute tonotopic location. In normal-hearing listeners, Başkent and Shannon (J. Acoust. Soc. Am. 113, 2003) simulated implant signal processing conditions in which the frequency range assigned to the array was systematically made wider or narrower than the simulated stimulation range in the cochlea, resulting in frequency-place compression or expansion, respectively. In general, the best speech recognition was obtained when the input acoustic information was delivered to the matching tonotopic place in the cochlea with least frequency-place distortion. The present study measured phoneme and sentence recognition scores with similar frequency-place manipulations in six Med-El Combi 40+ implant subjects. Stimulation locations were estimated using the Greenwood mapping function based on the estimated electrode insertion depth. Results from frequency-place compression and expansion with implants were similar to simulation results, especially for postlingually deafened subjects, despite the uncertainty in the actual stimulation sites of the auditory nerves. The present study shows that frequency-place mapping is an important factor in implant performance and an individual implant patient's map could be optimized with functional tests using frequency-place manipulations. .

  15. Positron implantation in solids

    SciTech Connect

    Ghosh, V.J.; Lynn, K.G.; Welch, D.O.

    1993-12-31

    The Monte Carlo technique for modeling positron prior to annihilation and electron implantation in semi-infinite metals is described. Particle implantation is modelled as a multistep process, a series of collisions with the atoms of the host material. In elastic collisions with neutral atoms there is no transfer of energy. The particle loses energy by several different channels, excitation of the electron gas, ionization of the ion cores, or, at low energies, by phonon excitation. These competing scattering mechanisms have been incorporated into the Monte Carlo framework and several different models are being used. Brief descriptions of these Monte Carlo schemes, as well as an analytic model for positron implantation are included. Results of the Monte Carlo simulations are presented and compared with expermental data. Problems associated with modeling positron implantation are discuss and the need for more expermental data on energy-loss in different materials is stressed. Positron implantation in multilayers of different metals is briefly described and extensions of this work to include a study of multilayers and heterostructures is suggested.

  16. Extraoral prostheses using extraoral implants.

    PubMed

    Pekkan, G; Tuna, S H; Oghan, F

    2011-04-01

    The aim of this study was to evaluate extraoral prostheses and the use of extraoral implants in patients with facial defects. 10 cases were treated utilizing maxillofacial prostheses employing extraoral implants in five cases. 16 extraoral implants were installed. Seven implants were placed in irradiated sites in the orbital regions. Six implants were placed in mastoid regions and three in a zygoma region that was irradiated. Two implants failed before initial integration was achieved in irradiated areas. Using 14 extraoral implants as anchors, five extraoral prostheses were set. The other five cases were treated with extraoral prostheses without using extraoral implants due to cost and patient-related factors. The data included age, sex, primary disease, implant length, implant failure, prosthetic attachment, radiation therapy, and peri-implant skin reactions. The use of extraoral implants for the retention of extraoral prostheses has simplified the placement, removal, and cleaning of the prosthesis by the patient. The stability of the prostheses was improved by anchors. Clinical and technical problems are presented with the techniques used for their resolution. Using extraoral implants resulted in a high rate of success in retaining facial prostheses and gave good stability and aesthetic satisfaction.

  17. Management of peri-implantitis

    PubMed Central

    Prathapachandran, Jayachandran; Suresh, Neethu

    2012-01-01

    Peri-implantitis is a site-specific infectious disease that causes an inflammatory process in soft tissues, and bone loss around an osseointegrated implant in function. The etiology of the implant infection is conditioned by the status of the tissue surrounding the implant, implant design, degree of roughness, external morphology, and excessive mechanical load. The microorganisms most commonly associated with implant failure are spirochetes and mobile forms of Gram-negative anaerobes, unless the origin is the result of simple mechanical overload. Diagnosis is based on changes of color in the gingiva, bleeding and probing depth of peri-implant pockets, suppuration, X-ray, and gradual loss of bone height around the tooth. Treatment will differ depending upon whether it is a case of peri-implant mucositis or peri-implantitis. The management of implant infection should be focused on the control of infection, the detoxification of the implant surface, and regeneration of the alveolar bone. This review article deals with the various treatment options in the management of peri-implantitis. The article also gives a brief description of the etiopathogenesis, clinical features, and diagnosis of peri-implantitis. PMID:23559913

  18. Dental implants: A review.

    PubMed

    Guillaume, B

    2016-12-01

    A high number of patients have one or more missing tooth and it is estimated that one in four American subjects over the age of 74 have lost all their natural teeth. Many options exist to replace missing teeth but dental implants have become one of the most used biomaterial to replace one (or more) missing tooth over the last decades. Contemporary dental implants made with titanium have been proven safe and effective in large series of patients. This review considers the main historical facts concerned with dental implants and present the different critical factors that will ensure a good osseo-integration that will ensure a stable prosthesis anchorage. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Towards biodegradable wireless implants.

    PubMed

    Boutry, Clémentine M; Chandrahalim, Hengky; Streit, Patrick; Schinhammer, Michael; Hänzi, Anja C; Hierold, Christofer

    2012-05-28

    A new generation of partially or even fully biodegradable implants is emerging. The idea of using temporary devices is to avoid a second surgery to remove the implant after its period of use, thereby improving considerably the patient's comfort and safety. This paper provides a state-of-the-art overview and an experimental section that describes the key technological challenges for making biodegradable devices. The general considerations for the design and synthesis of biodegradable components are illustrated with radiofrequency-driven resistor-inductor-capacitor (RLC) resonators made of biodegradable metals (Mg, Mg alloy, Fe, Fe alloys) and biodegradable conductive polymer composites (polycaprolactone-polypyrrole, polylactide-polypyrrole). Two concepts for partially/fully biodegradable wireless implants are discussed, the ultimate goal being to obtain a fully biodegradable sensor for in vivo sensing.

  20. Complications in implant dentistry

    PubMed Central

    Hanif, Ayesha; Qureshi, Saima; Sheikh, Zeeshan; Rashid, Haroon

    2017-01-01

    After tooth loss, an individual may seek tooth replacement so that his/her function and esthetics could be restored. Clinical prosthodontics, during the past decade, has significantly improved and developed according to the advancements in the science and patient's demands and needs. Conventional options in prosthodontics for substituting a missing single tooth include the removable partial denture, partial and full coverage bridgework, and resin-bonded bridgework. Dental implants have gained increasing popularity over the years as they are capable of restoring the function to near normal in both partial and completely edentulous arches. With substantial evidence available, fixed implant-supported prosthesis are fully acknowledged as a reliable treatment option for the replacement of single or multiple missing teeth nowadays. While dental implants are increasingly becoming the choice of replacement for missing teeth, the impediments associated with them are progressively emerging too. PMID:28435381

  1. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Medrad utilized NASA's Apollo technology to develop a new device called the AID implantable automatic pulse generator which monitors the heart continuously, recognizes the onset of ventricular fibrillation and delivers a corrective electrical shock. AID pulse generator is, in effect, a miniaturized version of the defibrillator used by emergency squads and hospitals to restore rhythmic heartbeat after fibrillation, but has the unique advantage of being permanently available to the patient at risk. Once implanted, it needs no specially trained personnel or additional equipment. AID system consists of a microcomputer, a power source and two electrodes which sense heart activity.

  2. Hydroxylapatite Otologic Implants

    SciTech Connect

    McMillan, A.D.; Lauf, R.J.; Beale, B.; Johnson, R.

    2000-01-01

    A Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corporation (LMER) and Smith and Nephew Richards Inc. of Bartlett, TN, was initiated in March 1997. The original completion date for the Agreement was March 25, 1998. The purpose of this work is to develop and commercialize net shape forming methods for directly creating dense hydroxylapatite (HA) ceramic otologic implants. The project includes three tasks: (1) modification of existing gelcasting formulations to accommodate HA slurries; (2) demonstration of gelcasting to fabricate green HA ceramic components of a size and shape appropriate to otologic implants: and (3) sintering and evaluation of the HA components.

  3. Current trends in dental implants

    PubMed Central

    Gaviria, Laura; Salcido, John Paul; Guda, Teja

    2014-01-01

    Tooth loss is very a very common problem; therefore, the use of dental implants is also a common practice. Although research on dental implant designs, materials and techniques has increased in the past few years and is expected to expand in the future, there is still a lot of work involved in the use of better biomaterials, implant design, surface modification and functionalization of surfaces to improve the long-term outcomes of the treatment. This paper provides a brief history and evolution of dental implants. It also describes the types of implants that have been developed, and the parameters that are presently used in the design of dental implants. Finally, it describes the trends that are employed to improve dental implant surfaces, and current technologies used for the analysis and design of the implants. PMID:24868501

  4. In Vivo Ultrasonic Detection of Polyurea Crosslinked Silica Aerogel Implants

    PubMed Central

    Sabri, Firouzeh; Sebelik, Merry E.; Meacham, Ryan; Boughter, John D.; Challis, Mitchell J.; Leventis, Nicholas

    2013-01-01

    Background Polyurea crosslinked silica aerogels are highly porous, lightweight, and mechanically strong materials with great potential for in vivo applications. Recent in vivo and in vitro studies have demonstrated the biocompatibility of this type of aerogel. The highly porous nature of aerogels allows for exceptional thermal, electric, and acoustic insulating capabilities that can be taken advantage of for non-invasive external imaging techniques. Sound-based detection of implants is a low cost, non-invasive, portable, and rapid technique that is routinely used and readily available in major clinics and hospitals. Methodology In this study the first in vivo ultrasound response of polyurea crosslinked silica aerogel implants was investigated by means of a GE Medical Systems LogiQe diagnostic ultrasound machine with a linear array probe. Aerogel samples were inserted subcutaneously and sub-muscularly in a) fresh animal model and b) cadaveric human model for analysis. For comparison, samples of polydimethylsiloxane (PDMS) were also imaged under similar conditions as the aerogel samples. Conclusion/significance Polyurea crosslinked silica aerogel (X-Si aerogel) implants were easily identified when inserted in either of the regions in both fresh animal model and cadaveric model. The implant dimensions inferred from the images matched the actual size of the implants and no apparent damage was sustained by the X-Si aerogel implants as a result of the ultrasonic imaging process. The aerogel implants demonstrated hyperechoic behavior and significant posterior shadowing. Results obtained were compared with images acquired from the PDMS implants inserted at the same location. PMID:23799093

  5. Biofilm related to dental implants.

    PubMed

    Lee, Angie; Wang, Hom-Lay

    2010-10-01

    Oral biofilm-related diseases such as periodontal and peri-implant diseases are unique infections in that they develop from the resident indigenous microflora. As more implants are nowadays being placed, clinicians may encounter more complications. Therefore, understanding the etiology is warranted to establish adequate diagnosis and provide proper treatment. This article focuses on understanding peri-implant microbiology and its roles in peri-implant diseases.

  6. Biomimetic approach to dental implants.

    PubMed

    Kim, Tae-Il; Jang, Jun-Hyeog; Kim, Hae-Won; Knowles, Jonathan C; Ku, Young

    2008-01-01

    Titanium, as an implant material, is regarded to be durable and biocompatible, which allows functional replacement of missing teeth. Successful dental implantation depends on an osseointegration phenomenon, a direct structural and functional binding reaction between bone and implant. It is well known that physicochemical characteristics of the dental implant surface, such as roughness, topography, chemistry, and electrical charge affect the biological reactions occurring at the interface of tissue and implant. Therefore, considerable efforts have been made to modify the surface of titanium implants which are based on mechanical, physical and chemical treatments. Recently, biological molecules were introduced onto the surface of implants to stimulate osteogenic cells in the early stage of implantation and consequently accelerate bone formation around implant and subsequent rapid implant stabilization. A range of extracellular matrix components, designed peptides, and growth factors have been proposed as the biological moiety. In this review, we address several issues related to the biology of dental implants and discuss biomimetic modification of the implant surface as a novel approach to obtain successful osseointegration.

  7. The silicone breast implant controversy.

    PubMed

    Guerette, P H

    1995-02-01

    Feminists call it objectification. Consumer advocates call it victimization. Medical personnel call it augmentation. Women, implantation. Whatever the term, media hype and the increasing number of lawsuits against U.S. manufacturers of silicone breast implants has caused widespread concern among women and raised serious questions about the long term health risks and safety of breast implant devices.

  8. Sterilisation of bioresorbable polymer implants.

    PubMed

    Bernkopf, M

    2007-01-01

    Bioresorbable polymer implants are rapidly growing alternatives to traditional implants in many applications. Because of their resorption in the body, it is necessary to sterilise the complete product before application. The suitability of different sterilisation methods for bioresorbable polymers is discussed using polylactic acid implants as an example.

  9. Treatment of peri-implantitis and the failing implant.

    PubMed

    Robertson, Kevin; Shahbazian, Timothy; MacLeod, Stephen

    2015-04-01

    Appropriate treatment of implants is becoming increasingly important for the general dentist as the number of implants placed per year continues to increase. Early diagnosis of peri-implantitis is imperative; initiating the correct treatment protocol depends on a proper diagnosis. Several risk factors exist for the development of peri-implantitis, which can guide patient selection and treatment planning. Treatment of peri-implantitis should be tailored to the severity of the lesion (as outlined by the cumulative interceptive supportive treatment protocol), ranging from mechanical debridement to explantation. Several surgical and nonsurgical treatment alternatives exist. There is little consensus on superior treatment methods. Published by Elsevier Inc.

  10. A Review of Stress-Corrosion Cracking and Corrosion Fatigue of Magnesium Alloys for Biodegradable Implant Applications

    NASA Astrophysics Data System (ADS)

    Jafari, Sajjad; Harandi, Shervin Eslami; Singh Raman, R. K.

    2015-05-01

    Magnesium (Mg) alloys have recently attracted great attention as potential biodegradable materials for temporary implant applications. It is essential for any implant material to have adequate resistance to cracking or fracture in actual body environments. The most important mechanisms by which implants may fail are stress corrosion cracking (SCC) and corrosion fatigue (CF). This article presents an overview of the current knowledge of SCC and CF of Mg alloys in chloride-containing corrosive environments including simulated body fluid (SBF) and the associated fracture mechanisms, as well as critical relevance to biodegradable implant applications.

  11. The optimal design of an implant to improve bone quality of implant surroundings based on stress analysis

    NASA Astrophysics Data System (ADS)

    Noyama, Yoshihiro; Nagayama, Noriyuki; Kuramoto, Koichi; Nakano, Takayoshi

    2009-05-01

    Research on how implant surface shape contributes to long-term stability after implantation is important in the field of orthopaedics. In particular, technology that controls various bone quality parameters and voluntary bone inducement in implant surroundings should be developed for the next generation of implants and this will improve the patient's quality of life (QOL). For this research, we focused on the inducement of the appropriate alignment for biological apatite (BAp) crystallites and related collagen (Col.) fibres as a bone quality parameter. In this study, we predicted that when stress is applied to bone, the BAp/Col. preferential alignment can be formed if osteocytes are in an environment that is aligned with the principle stress vector. We tested this idea by introducing grooves in the principal stress direction on the surface of an implant. This work thus analyzes the effect of stress transmission by a load at the proximal femur on the bone inside and near the grooves by using mechanical simulation in which groove angles can be changed on the implant surface. Coordinate data from the mechanical simulation of the combined bone/implant environment was verified against the coordinate data obtained by CT scans of actual canine bone. Results suggest that the tendency of stress transmission differs depending on the position and angle of the grooves and based on a vector diagram of the maximum and minimum principal stresses. The simulation was able to predict bone dynamics in vivo and enabled a best design of an implant to control the BAp/Col. alignment as an index of bone quality.

  12. 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

  13. Implant contamination during spine surgery.

    PubMed

    Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

    2013-06-01

    Postoperative spine infections have been reported to occur in 1% to 15% of patients and subsequently lead to significant morbidity and cost, with an elevated risk for instrumented cases. Every effort should be made to minimize the risk of intraoperative wound contamination. Consequently, certain practices are followed in the operating room to prevent contamination, many of which are not evidence based. Conversely, certain objects believed to be sterile are frequently overlooked as potential sources of contamination. To assess to what degree contamination of spinal implants occurs during spine surgery and evaluate whether coverage of implants alters the rate of contamination. Prospective study. This study included 105 consecutive noninfection surgical cases performed by a single spine surgeon that required the use of instrumentation. Spinal implant contamination. Cases were randomized to have all implant trays either remain uncovered (n=54) or covered (n=51) with sterile surgical towels on opening until implants were required for the case. After the last implant was placed, a sterile culture swab was used to obtain a sample from all open implants that had been present at the start of the case. The paper outer wraps of the implant trays were sampled in each case as a positive control, and an additional 105 swabs were capped immediately after they were opened to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates. Of note, only departmental funding was used and no applicable financial relationships exist with any author. No growth was observed on any of the 105 negative controls, whereas 99.1% of positive controls demonstrated obvious contamination. Cultures from implant samples demonstrated a 9.5% overall rate of contamination with 2.0% (n=1) of covered implants versus 16.7% (n=9) of uncovered implants demonstrating contamination. Length of time implant trays were open before sample collection; implant type

  14. Remote actuated valve implant

    DOEpatents

    McKnight, Timothy E; Johnson, Anthony; Moise, Jr., Kenneth J; Ericson, Milton Nance; Baba, Justin S; Wilgen, John B; Evans, III, Boyd McCutchen

    2014-02-25

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  15. Remote actuated valve implant

    DOEpatents

    McKnight, Timothy E.; Johnson, Anthony; Moise, Kenneth J.; Ericson, Milton Nance; Baba, Justin S.; Wilgen, John B.; Evans, Boyd Mccutchen

    2016-05-10

    Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

  16. Implantable electrical device

    NASA Technical Reports Server (NTRS)

    Jhabvala, M. D. (Inventor)

    1982-01-01

    A fully implantable and self contained device is disclosed composed of a flexible electrode array for surrounding damaged nerves and a signal generator for driving the electrode array with periodic electrical impulses of nanoampere magnitude to induce regeneration of the damaged nerves.

  17. Semiconductor Ion Implanters

    SciTech Connect

    MacKinnon, Barry A.; Ruffell, John P.

    2011-06-01

    In 1953 the Raytheon CK722 transistor was priced at $7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at $6.2 billion. Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing 'only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around $2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  18. Implantable continuous glucose sensors.

    PubMed

    Renard, Eric

    2008-08-01

    Because of the limits of wearable needle-type or microdialysis-based enzymatic sensors in clinical use, fully implantable glucose monitoring systems (IGMS) represent a promising alternative. Long-term use reducing impact of invasiveness due to implantation, less frequent calibration needs because of a more stable tissue environment around the sensor and potential easier inclusion in a closed-loop insulin delivery system are the expected benefits of IGMS. First experiences with subcutaneous and intravenous IGMS have been recently collected in pilot studies. While no severe adverse events have been reported, biointerface issues have been responsible for the failures of IGMS. Tissue reactions around implanted subcutaneous devices and damages of intravenous sensors due to shearing forces of blood flow impaired IGMS function and longevity. In functioning systems, accuracy of glucose measurement reached satisfactory levels for average durations of about 120 days with subcutaneous IGMS and 259 days with intravenous sensors. Moreover, sensor information could help to improve time spent in normal glucose range when provided to patients wearing subcutaneous IGMS and allowed safe and effective closed-loop glucose control when intravenous sensors were connected to implanted pumps using intra-peritoneal insulin delivery. These data could open a favourable perspective for IGMS after improvement of biointerface conditions and if compatible with an affordable cost.

  19. Cochlear Implantation in Neurobrucellosis

    PubMed Central

    Bajin, Münir Demir; Savaş, Özden; Aslan, Filiz; Sennaroğlu, Levent

    2016-01-01

    Background: Neurobrucellosis is a disease consisting of a wide spectrum of complications such as peripheral neuropathy, cranial nerve involvement, ataxia, meningeal irritation, paraplegia, seizures, coma, and even death. The vestibulocochlear nerve seems to be the most commonly affected cranial nerve (10%). We present a patient with neurobrucellosis whose auditory perception and speech intelligibility skill performances improved after cochlear implantation. Case Report: A 35 year-old woman was admitted to another hospital 2 years ago with the symptoms of headache, nausea, and altered consciousness, who was finally diagnosed with neurobrucellosis. She developed bilateral profound sensorineural hearing loss during the following 6 months. There was no benefit of using hearing aids. After successful treatment of her illness, she was found to be suitable for cochlear implantation. After the operation, her auditory perception skills improved significantly with a Categories of Auditory Performance (CAP) score of 5. According to clinical observations and her family members’ statements, her Speech Intelligibility Rating (SIR) score was 3. Her speech intelligibility skills are still improving. Conclusion: Our case report represents the second case of hearing rehabilitation with cochlear implantation after neurobrucellosis. Cochlear implantation is a cost-effective and time-proven successful intervention in post-lingual adult patients with sensorineural hearing loss. Early timing of the surgery after appropriate treatment of meningitis helps the patient to achieve better postoperative results. PMID:26966626

  20. Practicing implant dentistry profitably.

    PubMed

    Stump, G; Adams, M; Alwan, M

    1997-03-01

    The success of dental implants has opened up countless treatment possibilities for restorative dentists to offer to their patients. Just as our clinical paradigms have had to change because of this new technology, so too must our paradigms concerning the way we communicate with our patients change if we are to get them to say "yes" to treatment that we know that they need. Success in clinical treatment using implants requires a systematic approach. A systematic approach to communicating with your patients will allow you to have the same high degree of success with treatment acceptance that is possible with dental implants. The key to the systems we have discussed is Relationship Centered Care. A relationship is fostered and enhanced through a Comprehensive Examination Process, a structured Consultation Process utilizing the influencing process and Financial Arrangements that allow the patient to receive what they want while the office maintains the profitability that it needs. A system for calculating rational fees can be utilized that allows the practice to have control over an area that traditionally was controlled by anecdotal factors. The Pride Institute has developed this material and is presenting it to the profession so that restorative dentists can truly practice implant dentistry profitably.

  1. Implantable Drug Dispenser

    NASA Technical Reports Server (NTRS)

    Collins, E. R. J.

    1983-01-01

    Drugs such as insulin are injected as needed directly into bloodstream by compact implantable dispensing unit. Two vapor cavities produce opposing forces on drug-chamber diaphragm. Heaters in cavities allow control of direction and rate of motion of bellows. Dispensing capsule fitted with coil so batteries can be recharged by induction.

  2. Implantable Drug Dispenser

    NASA Technical Reports Server (NTRS)

    Collins, E. R. J.

    1983-01-01

    Drugs such as insulin are injected as needed directly into bloodstream by compact implantable dispensing unit. Two vapor cavities produce opposing forces on drug-chamber diaphragm. Heaters in cavities allow control of direction and rate of motion of bellows. Dispensing capsule fitted with coil so batteries can be recharged by induction.

  3. Implantable Impedance Plethysmography

    PubMed Central

    Theodor, Michael; Ruh, Dominic; Ocker, Martin; Spether, Dominik; Förster, Katharina; Heilmann, Claudia; Beyersdorf, Friedhelm; Manoli, Yiannos; Zappe, Hans; Seifert, Andreas

    2014-01-01

    We demonstrate by theory, as well as by ex vivo and in vivo measurements that impedance plethysmography, applied extravascularly directly on large arteries, is a viable method for monitoring various cardiovascular parameters, such as blood pressure, with high accuracy. The sensor is designed as an implant to monitor cardiac events and arteriosclerotic progression over the long term. PMID:25123467

  4. Semiconductor Ion Implanters

    NASA Astrophysics Data System (ADS)

    MacKinnon, Barry A.; Ruffell, John P.

    2011-06-01

    In 1953 the Raytheon CK722 transistor was priced at 7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at 6.2 billion! Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing `only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around 2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  5. Effect of implant design on initial stability of tapered implants.

    PubMed

    Chong, Linus; Khocht, Ahmed; Suzuki, Jon B; Gaughan, John

    2009-01-01

    Implant design is one of the parameters for achieving successful primary stability. This study aims to examine the effect of a self-tapping blades implant design on initial stability in tapered implants. Polyurethane blocks of different densities were used to simulate different bone densities. The two different implant designs included one with self-tapping blades and one without self-tapping blades. Implants were placed at 3 different depths: apical third, middle third, and fully inserted at 3 different densities of polyurethane blocks. A resonance frequency (RF) analyzer was then used to measure stability of the implants. Repeated-measures analysis of variance was used to examine the effect of implant design, insertion depth, and block density on RF. Analysis of covariance was used to examine the strength of association between RF and the aforementioned factors. In both medium-density (P = .017) and high-density (P = .002) blocks, fully inserted non-self-tapping implants showed higher initial stability than self-tapping implants. No differences were noted between the 2 implant designs that were not fully inserted. The highest strength of association was with insertion depth (standardized beta [std beta] = -0.60, P = .0001), followed by block density (std beta = -0.15, P = .0002). Implant design showed a weak association (std beta = -0.07, P = .09). In conclusion, fully inserted implants without self-tapping blades have higher initial stability than implants with self-tapping blades. However, the association strength between implant design and initial stability is less relevant than other factors, such as insertion depth and block density. Thus, if bone quality and quantity are optimal, they may compensate for design inadequacy.

  6. Prosthodontic management of implant therapy.

    PubMed

    Thalji, Ghadeer; Bryington, Matthew; De Kok, Ingeborg J; Cooper, Lyndon F

    2014-01-01

    Implant-supported dental restorations can be screw-retained, cement-retained, or a combination of both, whereby a metal superstructure is screwed to the implants and crowns are individually cemented to the metal frame. Each treatment modality has advantages and disadvantages. The use of computer-aided design/computer-assisted manufacture technologies for the manufacture of implant superstructures has proved to be advantageous in the quality of materials, precision of the milled superstructures, and passive fit. Maintenance and recall evaluations are an essential component of implant therapy. The longevity of implant restorations is limited by their biological and prosthetic maintenance requirements.

  7. [Allergic reactions to implant materials].

    PubMed

    Thomas, P

    2003-01-01

    The extent of the immune response upon implantation of metallic devices depends on the individual reactivity and on material characteristics. If specific T-cellular sensitization occurs or an allergy to metal preexists, hypersensitive reactions to implant components may develop. They include eczema, impaired wound healing, and sterile osteomyelitis. The existence of allergy-induced implant loosening is still an open question. Further improvement of clinical allergological diagnostics, better understanding of peri-implantar immune reactions, and interdisciplinary collection of epidemiological data concerning allergy to implants will contribute to a better knowledge about tolerance of implant material in humans.

  8. Patient perceived burden of implant placement compared to surgical tooth removal and apicectomy.

    PubMed

    Reissmann, Daniel R; Poulopoulos, Georgios; Durham, Justin

    2015-12-01

    To assess how patients actually perceive implant placement, to evaluate whether patients' perceived burdens are related to specific stages during implant placement, and to compare patients' perceptions during implant placement with other surgical procedures. A sample of 287 patients was consecutively recruited. Only patients with implantations (n=45), surgical tooth removal (n=147), or apicectomies (n=95) were included. Patients' perceptions during oral surgery and implantation were assessed using the Burdens in Oral Surgery Questionnaire (BiOS-Q). Effects of treatment on BiOS-Q total and domain scores were assessed using multivariate linear regression analyses, and effect sizes (Cohen's d) were computed. Overall, patients' perceived burdens during oral surgery were low indicated by a mean BiOS-Q total score of 28.5 points, with lowest scores for Side effects (19.4) and highest scores for Anesthesia (34.1). Among treatment groups, implantation was perceived least unpleasant. This was related to lower burdens during Bone and soft tissue manipulation during implantation than during surgical tooth removal (difference: 14.8 points; d=0.8) or apicectomy (difference: 13.1 points; d=0.7). Implantation has a low overall perceived burden and is significantly less burdensome during bone and soft tissue manipulation than surgical tooth removal or apicectomy. Patients can be informed that implant placement is less unpleasing than other commonly performed oral surgery procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. The status of undergraduate implant education in dental schools outside the United States.

    PubMed

    Seckinger, R J; Weintraub, A M; Berthold, P; Weintraub, G S

    1995-01-01

    Over the past 20 years the incorporation of implant dentistry into academia has been documented in some detail for North American dental schools but has not been pursued on an international level. In June of 1993, we surveyed 51 dental schools outside of the United States affiliated with the University of Pennsylvania School of Dental Medicine's Office of International Relations concerning their teaching involvement with implant dentistry. Results from the 44 (86 percent) responding schools suggest that implant dentistry is being incorporated into predoctoral curriculums. Industrialized countries were more inclined to provide implant education. Insufficient time and the thought that the predoctoral level was not the place for implant dentistry were cited as some of the reasons for not incorporating implant dentistry into the curriculum. Oral surgery, prosthodontics, and periodontics departments developed and administered the implant curriculum. Formats varied among schools with respect to allotted time, curricular placement, laboratory experience, and clinical participation. Didactic material most frequently presented included a historical overview, diagnosis and treatment planning, classification of dental implants, and surgical and prosthetic concepts. Clinical involvement varied from actual implant placement to observation of prosthodontic procedures. Results were categorized based on the TOEFL (Test of English as a Foreign Language) classification of countries in six regions.

  10. Degenerative Calcification of Pericardial Bioprostheses: Comparison of Five Implantation Methods in a Rabbit Model.

    PubMed

    Kim, Dai-Hyun; Park, Han Ki; Park, Young Hwan; Lee, Seung Hyun; Joo, Hyun-Chel; Lee, Sak; Youn, Young-Nam; Shin, Hong Ju

    2015-09-01

    The degenerative calcification of bioprosthetic heart valves remains a clinical challenge, especially among young adults and children. Animal models that are based on subcutaneous and intramuscular implantation and are typically used to assess interventions to prevent bioprosthetic heart valve calcification do not reflect actual hemodynamic stress and lack direct blood contact. Thus, the study aim was to investigate bioprosthesis calcification at different implantation sites. The calcification degrees of five valve implantation methods, namely subcutaneous, intramuscular and intravenous implantation, and arterial and venous patch angioplasty, were simultaneously investigated in 10 New Zealand White rabbits. Ultrasonography and computed tomography images showed vascular patency to be well maintained in all implanted vessels. Histologically, cellular infiltrates around the implant and within the collagen fibers were only found in the intravenous implantation group, which also had the highest calcium level among the methods. The present study was the first to compare the degree of calcification after applying five implantation methods simultaneously in one animal species. The rabbit intravenous implantation model, which involved direct contact with blood factors, is expected to serve as a useful animal model for research into the prevention of bioprosthetic heart valve degeneration.

  11. Bilateral cochlear implantation: current concepts.

    PubMed

    Eapen, Rose J; Buchman, Craig A

    2009-10-01

    The goal of this review is to examine the most recent literature exploring the indications, outcomes, and long-term benefit of bilateral cochlear implantation in children and adults. The indications for cochlear implantation have expanded, as many unilaterally implanted individuals are able to achieve open-set word recognition. Despite the benefits seen in unilateral implantation, many individuals have difficulty perceiving speech in noisy environments. Bilateral cochlear implantation has made great strides in providing individuals access to sound information from both ears, allowing improved speech perception in quiet and in noise, as well as sound localization. Recently, the House Cochlear Implant study group released a position statement in which the group strongly endorsed bilateral cochlear implantation. Improved speech perception in quiet has also been demonstrated by many groups with bilateral implantation. Improved sound localization abilities have been shown to be dependent on interaural level differences. The binaural benefits of head shadow and summation have been long shown in bilaterally implanted individuals. Recently, a growth in squelch has been seen in these individuals likely as a result of increased experience with both implants. This may indicate neural integration of the inputs over time. The literature supports the binaural benefit of bilateral cochlear implantation with demonstrated improved speech perception outcomes in quiet and in noise, sound localization data, and subjective benefits.

  12. Engineered porous metals for implants

    NASA Astrophysics Data System (ADS)

    Vamsi Krishna, B.; Xue, Weichang; Bose, Susmita; Bandyopadhyay, Amit

    2008-05-01

    Interest is significant in patient-specific implants with the possibility of guided tissue regeneration, particularly for load-bearing implants. For such implants to succeed, novel design approaches and fabrication technologies that can achieve balanced mechanical and functional performance in the implants are necessary. This article is focused on porous load-bearing implants with tailored micro-as well as macrostructures using laser-engineered net shaping (LENS™), a solid freeform fabrication or rapid prototyping technique that can be used to manufacture patient-specific implants. This review provides an insight into LENS, some properties of porous metals, and the potential applications of this process to fabricate unitized structures which can eliminate longstanding challenges in load-bearing implants to increase their in-vivo lifetime, such as in a total hip prosthesis.

  13. Impression techniques for implant dentistry.

    PubMed

    Chee, W; Jivraj, S

    2006-10-07

    The object of making an impression in implant dentistry is to accurately relate an analogue of the implant or implant abutment to the other structures in the dental arch. This is affected by use of an impression coping which is attached to the implant or implant abutment. This impression coping is incorporated in an impression - much as a metal framework is 'picked up' in a remount impression for fixed prosthodontics. With implant copings the coping is usually attached to the implant or abutment with screws. The impression material used is usually an elastomeric impression material; the two types most widely used and shown to be the most appropriate are polyether and polyvinyl siloxane impression materials.

  14. School Guidance Counselors' Perceptions of Actual and Preferred Job Duties

    ERIC Educational Resources Information Center

    Edwards, John Dexter

    2010-01-01

    The purpose of this study was to provide process data for school counselors, administrators, and the public, regarding school counselors' actual roles within the guidance counselor preferred job duties and actual job duties. In addition, factors including National Certification or no National Certification, years of counseling experience, and…

  15. 26 CFR 1.953-2 - Actual United States risks.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Actual United States risks. 1.953-2 Section 1... (CONTINUED) INCOME TAXES Controlled Foreign Corporations § 1.953-2 Actual United States risks. (a) In general. For purposes of paragraph (a) of § 1.953-1, the term “United States risks” means risks described...

  16. 26 CFR 1.953-2 - Actual United States risks.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 10 2011-04-01 2011-04-01 false Actual United States risks. 1.953-2 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Controlled Foreign Corporations § 1.953-2 Actual United States risks. (a) In general. For purposes of paragraph (a) of § 1.953-1, the term “United States risks” means...

  17. 26 CFR 1.953-2 - Actual United States risks.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 10 2014-04-01 2013-04-01 true Actual United States risks. 1.953-2 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Controlled Foreign Corporations § 1.953-2 Actual United States risks. (a) In general. For purposes of paragraph (a) of § 1.953-1, the term “United States risks” means...

  18. 26 CFR 1.953-2 - Actual United States risks.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 10 2013-04-01 2013-04-01 false Actual United States risks. 1.953-2 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Controlled Foreign Corporations § 1.953-2 Actual United States risks. (a) In general. For purposes of paragraph (a) of § 1.953-1, the term “United States risks” means...

  19. 26 CFR 1.953-2 - Actual United States risks.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 10 2012-04-01 2012-04-01 false Actual United States risks. 1.953-2 Section 1... (CONTINUED) INCOME TAXES (CONTINUED) Controlled Foreign Corporations § 1.953-2 Actual United States risks. (a) In general. For purposes of paragraph (a) of § 1.953-1, the term “United States risks” means...

  20. Self-Actualization Effects Of A Marathon Growth Group

    ERIC Educational Resources Information Center

    Jones, Dorothy S.; Medvene, Arnold M.

    1975-01-01

    This study examined the effects of a marathon group experience on university student's level of self-actualization two days and six weeks after the experience. Gains in self-actualization as a result of marathon group participation depended upon an individual's level of ego strength upon entering the group. (Author)

  1. Facebook as a Library Tool: Perceived vs. Actual Use

    ERIC Educational Resources Information Center

    Jacobson, Terra B.

    2011-01-01

    As Facebook has come to dominate the social networking site arena, more libraries have created their own library pages on Facebook to create library awareness and to function as a marketing tool. This paper examines reported versus actual use of Facebook in libraries to identify discrepancies between intended goals and actual use. The results of a…

  2. Self-Actualization and the Effective Social Studies Teacher.

    ERIC Educational Resources Information Center

    Farmer, Rodney B.

    1980-01-01

    Discusses a study undertaken to investigate the relationship between social studies teachers' degrees of self-actualization and their teacher effectiveness. Investigates validity of using Maslow's theory of self-actualization as a way of identifying the effective social studies teacher personality. (Author/DB)

  3. Facebook as a Library Tool: Perceived vs. Actual Use

    ERIC Educational Resources Information Center

    Jacobson, Terra B.

    2011-01-01

    As Facebook has come to dominate the social networking site arena, more libraries have created their own library pages on Facebook to create library awareness and to function as a marketing tool. This paper examines reported versus actual use of Facebook in libraries to identify discrepancies between intended goals and actual use. The results of a…

  4. School Guidance Counselors' Perceptions of Actual and Preferred Job Duties

    ERIC Educational Resources Information Center

    Edwards, John Dexter

    2010-01-01

    The purpose of this study was to provide process data for school counselors, administrators, and the public, regarding school counselors' actual roles within the guidance counselor preferred job duties and actual job duties. In addition, factors including National Certification or no National Certification, years of counseling experience, and…

  5. Self-actualization: Its Use and Misuse in Teacher Education.

    ERIC Educational Resources Information Center

    Ivie, Stanley D.

    1982-01-01

    The writings of Abraham Maslow are analyzed to determine the meaning of the psychological term "self-actualization." After pointing out that self-actualization is a rare quality and that it has little to do with formal education, the author concludes that the concept has little practical relevance for teacher education. (PP)

  6. The Self-Actualization of Polk Community College Students.

    ERIC Educational Resources Information Center

    Pearsall, Howard E.; Thompson, Paul V., Jr.

    This article investigates the concept of self-actualization introduced by Abraham Maslow (1954). A summary of Maslow's Needs Hierarchy, along with a description of the characteristics of the self-actualized person, is presented. An analysis of humanistic education reveals it has much to offer as a means of promoting the principles of…

  7. Self-Actualization Effects Of A Marathon Growth Group

    ERIC Educational Resources Information Center

    Jones, Dorothy S.; Medvene, Arnold M.

    1975-01-01

    This study examined the effects of a marathon group experience on university student's level of self-actualization two days and six weeks after the experience. Gains in self-actualization as a result of marathon group participation depended upon an individual's level of ego strength upon entering the group. (Author)

  8. A Study of Self-Actualization and Facilitative Communication.

    ERIC Educational Resources Information Center

    Omizo, Michael M.

    1981-01-01

    Examined the relationship between self-actualization measures and ability in facilitative communication of trainees from counseling, social work, and psychology programs to determine if differences existed between the three groups. Self-actualization indexes were significantly correlated with ability in facilitative communication. (RC)

  9. Self-actualization: Its Use and Misuse in Teacher Education.

    ERIC Educational Resources Information Center

    Ivie, Stanley D.

    1982-01-01

    The writings of Abraham Maslow are analyzed to determine the meaning of the psychological term "self-actualization." After pointing out that self-actualization is a rare quality and that it has little to do with formal education, the author concludes that the concept has little practical relevance for teacher education. (PP)

  10. SELF-ACTUALIZATION AND THE UTILIZATION OF TALENT.

    ERIC Educational Resources Information Center

    FRENCH, JOHN R.P.; MILLER, DANIEL R.

    THIS STUDY ATTEMPTED (1) TO DEVELOP A THEORY OF THE CAUSES AND CONSEQUENCES OF SELF-ACTUALIZATION AS RELATED TO THE UTILIZATION OF TALENT, (2) TO FIT THE THEORY TO EXISTING DATA, AND (3) TO PLAN ONE OR MORE RESEARCH PROJECTS TO TEST THE THEORY. TWO ARTICLES ON IDENTITY AND MOTIVATION AND SELF-ACTUALIZATION AND SELF-IDENTITY THEORY REPORTED THE…

  11. Clinical Evaluation of Shaped Gel Breast Implant Rotation Using High-Resolution Ultrasound.

    PubMed

    Sieber, David A; Stark, Ran Y; Chase, Serena; Schafer, Mark; Adams, William P

    2017-03-01

    Clinical trials have demonstrated through core and independent studies that anatomical devices are safe and effective with low complication rates. The rotation rate of shaped breast implants in the literature is 0 to 8.2%. Currently there are no studies evaluating the efficacy of in office ultrasound or clinical rotation vs actual rotation rates seen on high-resolution ultrasound (HRUS). The purpose of the study is to demonstrate the ease and reliability of HRUS for evaluating the rotation rate of 2 different brands of anatomic implants and to correlate this with the presumed clinical rate, as well as independent evaluators assessments. A total of 69 patients were followed up at routine intervals and were evaluated for rotation. Any implant rotated past >30° off of midline (outside 5-7 o’clock) was considered to be rotated. To determine if radiographic rotation was clinically evident, 20 composite patient photos were blindly evaluated. A random total of 69 patients underwent bilateral augmentation mammoplasty with form stable anatimic gel implants using 138 implants. Twenty-nine of the 69 (42%) patients and 37 of the 138 (27%) implants were found to be rotated-using HRUS. Eight of the 69 (12%) patients had bilateral rotations. Independent evaluators were able to identify two of 12 (17%) possible rotations, or 2 rotations in 40 (5%) total implants. Anatomic form stable gel implants are actually rotated up to 25 times more frequently than previously thought, but these rotations do not translate into clinically significant sequela. High-resolution ultrasound is a simple alternative for breast implant surveillance and is better accepted by patients than magnetic resonance imaging (MRI). The clinical value of HRUS is also discussed and recommendations for FDA implant labeling changes are provided in this article. 4

  12. Cochlear implants in children implanted in Jordan: A parental overview.

    PubMed

    Alkhamra, Rana A

    2015-07-01

    Exploring the perspective of parents on the cochlear implant process in Jordan. Sixty parents of deaf children were surveyed on the information gathering process prior to cochlear implant surgery, and their implant outcome expectations post-surgery. Whether child or parent characteristics may impact parents' post-surgical expectations was explored. Although parents used a variety of information sources when considering a cochlear implant, the ear, nose and throat doctor comprised their major source of information (60%). Parents received a range of information prior to cochlear implant but agreed (93.3%) on the need for a multidisciplinary team approach. Post-surgically, parents' expected major developments in the areas of spoken language (97%), and auditory skills (100%). Receiving education in mainstream schools (92%) was expected too. Parents perceived the cochlear implant decision as the best decision they can make for their child (98.3%). A significant correlation was found between parents contentment with the cochlear implant decision and expecting developments in the area of reading and writing (r=0.7). Child's age at implantation and age at hearing loss diagnosis significantly affected parents' post-implant outcome expectations (p<0.05). Despite the general satisfaction from the information quantity and quality prior to cochlear implant, parents agree on the need for a comprehensive multidisciplinary team approach during the different stages of the cochlear implant process. Parents' education about cochlear implants prior to the surgery can affect their post-surgical outcome expectations. The parental perspective presented in this study can help professionals develop better understanding of parents' needs and expectations and henceforth improve their services and support during the different stages of the cochlear implant process. Copyright © 2015. Published by Elsevier Ireland Ltd.

  13. Management of peri-implant mucositis and peri-implantitis.

    PubMed

    Figuero, Elena; Graziani, Filippo; Sanz, Ignacio; Herrera, David; Sanz, Mariano

    2014-10-01

    Peri-implant diseases are defined as inflammatory lesions of the surrounding peri-implant tissues and include peri-implant mucositis (an inflammatory lesion limited to the surrounding mucosa of an implant) and peri-implantitis (an inflammatory lesion of the mucosa that affects the supporting bone with resulting loss of osseointegration). This review aims to describe the different approaches to manage both entities and to provide a critical evaluation of the evidence available on their efficacy. Therapy of peri-implant mucositis and nonsurgical therapy of peri-implantitis usually involve mechanical debridement of the implant surface using curettes, ultrasonic devices, air-abrasive devices or lasers, with or without the adjunctive use of local antibiotics or antiseptics. The efficacy of these therapies has been demonstrated for mucositis: controlled clinical trials show an improvement in clinical parameters, especially in bleeding on probing. For peri-implantitis, the results are limited, especially in terms of probing pocket-depth reduction. Surgical therapy of peri-implantitis is indicated when nonsurgical therapy fails to control the inflammatory changes. Selection of the surgical technique should be based on the characteristics of the peri-implant lesion. In the presence of deep circumferential and intrabony defects, surgical interventions should aim to provide thorough debridement, implant-surface decontamination and defect reconstruction. In the presence of defects without clear bony walls or with a predominant suprabony component, the aim of the surgical intervention should be the thorough debridement and the repositioning of the marginal mucosa to enable the patient to perform effective oral-hygiene practices, although this aim may compromise the esthetic result of the implant-supported restoration. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Detection of bacteria in healthy middle ears during cochlear implantation.

    PubMed

    Tonnaer, Edith L; Mylanus, Emmanuel A; Mulder, Jef J; Curfs, Jo H

    2009-03-01

    To assess whether free-living and/or biofilm bacteria are present in the putative sterile middle ear cavity before insertion of the electrode array during cochlear implantation. Prospective study. Tertiary academic hospital. The study included 45 healthy children (with or without a history of otitis media) undergoing cochlear implantation. Transmission electron microscopy or scanning electron microscopy was used to detect the presence of bacteria. Presence of both free-living bacteria and biofilm bacteria on the epithelial surface of biopsy specimens of middle ear mucosa. A majority of all mucosal specimens from clinically healthy tympanic cavities displayed inflammatory areas as well as dispersed, nonmatrix-enclosed bacteria. Also, rarely, fragments of biofilms were found. The presence of bacteria in the tympanic cavity, which is generally assumed to be sterile in healthy individuals, may provide an explanation for infectious complications after cochlear implantation. However, the possibility that the electrode array of a cochlear implant will actually become contaminated during insertion is unlikely because of the small amounts and dispersed presence of bacteria, which may account for the relatively low incidence of infectious complications after cochlear implantation.

  15. Rupture of poly implant prothèse silicone breast implants: an implant retrieval study.

    PubMed

    Swarts, Eric; Kop, Alan M; Nilasaroya, Anastasia; Keogh, Catherine V; Cooper, Timothy

    2013-04-01

    Poly Implant Prothèse implants were recalled in Australia in April of 2010 following concerns of higher than expected rupture rates and the use of unauthorized industrial grade silicone as a filler material. Although subsequent investigations found that the gel filler material does not pose a threat to human health, the important question of what caused a relatively modern breast implant to have such a poor outcome compared with contemporary silicone breast implants is yet to be addressed. From a cohort of 27 patients, 19 ruptured Poly Implant Prothèse breast implants were subjected to a range of mechanical tests and microscopic/macroscopic investigations to evaluate possible changes in properties as a result of implantation. New Poly Implant Prothèse implants were used as controls. All samples, explanted and controls, complied with the requirements for shell integrity as specified in the International Organization for Standardization 14607. Compression testing revealed rupture rates similar to those reported in the literature. Shell thickness was highly variable, with most shells having regions below the minimum thickness of 0.57 mm that was specified by the manufacturer. Potential regions of stress concentration were observed on the smooth inner surfaces and outer textured surfaces. The high incidence of Poly Implant Prothèse shell rupture is most likely a result of inadequate quality control, with contributory factors being shell thickness variation and manufacturing defects on both inner and outer surfaces of the shell. No evidence of shell degradation with implantation time was determined.

  16. Quality of Life for Children with Cochlear Implants: Perceived Benefits and Problems and the Perception of Single Words and Emotional Sounds

    ERIC Educational Resources Information Center

    Schorr, Efrat A.; Roth, Froma P.; Fox, Nathan A.

    2009-01-01

    Purpose: This study examined children's self-reported quality of life with a cochlear implant as related to children's actual perceptions of speech and the emotional information conveyed by sound. Effects of age at amplification with hearing aids and fitting of cochlear implants on perceived quality of life were also investigated. Method: A…

  17. Quality of Life for Children with Cochlear Implants: Perceived Benefits and Problems and the Perception of Single Words and Emotional Sounds

    ERIC Educational Resources Information Center

    Schorr, Efrat A.; Roth, Froma P.; Fox, Nathan A.

    2009-01-01

    Purpose: This study examined children's self-reported quality of life with a cochlear implant as related to children's actual perceptions of speech and the emotional information conveyed by sound. Effects of age at amplification with hearing aids and fitting of cochlear implants on perceived quality of life were also investigated. Method: A…

  18. Piezosurgery in implant dentistry

    PubMed Central

    Stübinger, Stefan; Stricker, Andres; Berg, Britt-Isabelle

    2015-01-01

    Piezosurgery, or the use of piezoelectric devices, is being applied increasingly in oral and maxillofacial surgery. The main advantages of this technique are precise and selective cuttings, the avoidance of thermal damage, and the preservation of soft-tissue structures. Through the application of piezoelectric surgery, implant-site preparation, bone grafting, sinus-floor elevation, edentulous ridge splitting or the lateralization of the inferior alveolar nerve are very technically feasible. This clinical overview gives a short summary of the current literature and outlines the advantages and disadvantages of piezoelectric bone surgery in implant dentistry. Overall, piezoelectric surgery is superior to other methods that utilize mechanical instruments. Handling of delicate or compromised hard- and soft-tissue conditions can be performed with less risk for the patient. With respect to current and future innovative surgical concepts, piezoelectric surgery offers a wide range of new possibilities to perform customized and minimally invasive osteotomies. PMID:26635486

  19. [Fully implantable hearing systems].

    PubMed

    Maurer, J

    2009-03-01

    As yet comparatively little experience has been gained with fully implantable hearing systems, as the two systems available at present have only recently received CE permission for Europe and the FDA permissions are still pending in the USA. Additionally the technology is expensive and usually not covered by insurance companies. However, it could be shown that by careful patient selection and very careful surgical techniques, good results can be achieved with this highly sensitive technology, often with better patient satisfaction and hearing quality than with conventional hearing aids. To spread the technology further, the systems must also show reliable results on a broad application. Further surgery to change the batteries should not be necessary more frequently than with cardiac pacemakers. Not all technical problems are finally solved. However, it is to be foreseen that fully implantable hearing systems will be a good long-term alternative to conventional hearing aids for some patients.

  20. Piezosurgery in implant dentistry.

    PubMed

    Stübinger, Stefan; Stricker, Andres; Berg, Britt-Isabelle

    2015-01-01

    Piezosurgery, or the use of piezoelectric devices, is being applied increasingly in oral and maxillofacial surgery. The main advantages of this technique are precise and selective cuttings, the avoidance of thermal damage, and the preservation of soft-tissue structures. Through the application of piezoelectric surgery, implant-site preparation, bone grafting, sinus-floor elevation, edentulous ridge splitting or the lateralization of the inferior alveolar nerve are very technically feasible. This clinical overview gives a short summary of the current literature and outlines the advantages and disadvantages of piezoelectric bone surgery in implant dentistry. Overall, piezoelectric surgery is superior to other methods that utilize mechanical instruments. Handling of delicate or compromised hard- and soft-tissue conditions can be performed with less risk for the patient. With respect to current and future innovative surgical concepts, piezoelectric surgery offers a wide range of new possibilities to perform customized and minimally invasive osteotomies.

  1. Implantable visual prostheses.

    PubMed

    Thanos, S; Heiduschka, P; Stupp, T

    2007-01-01

    Visual impairment and blindness is primarily caused by optic neuropathies like injuries and glaucomas, as well as retinopathies like agerelated macular degeneration (MD), systemic diseases like diabetes, hypertonia and hereditary retinitis pigmentosa (RP). These pathological conditions may affect retinal photoreceptors, or retinal pigment epithelium, or particular subsets of retinal neurons, and in particular retinal ganglion cells (RGCs). The RGCs which connect the retina with the brain are unique cells with extremely long axons bridging the distance from the retina to visual relays within the thalamus and midbrain, being therefore vulnerable to heterogeneous pathological conditions along this pathway. When becoming mature, RGCs loose the ability to divide and to regenerate their accidentally or experimentally injured axons. Consequently, any loss of RGCs is irreversible and results to loss of visual function. The advent of micro- and nanotechnology, and the construction of artificial implants prompted to create visual prostheses which aimed at compensating for the loss of visual function in particular cases. The purpose of the present contribution is to review the considerable engineering expertise that is essential to fabricate current visual prostheses in connection with their functional features and applicability to the animal and human eye. In this chapter, 1) Retinal and cortical implants are introduced, with particular emphasis given to the requirements they have to fulfil in order to replace very complex functions like vision. 2) Advanced work on material research is presented both from the technological and from the biocompatibility aspect as prerequisites of any perspectives for implantation. 3) Ultimately, experimental studies are presented showing the shaping of implants, the procedures of testing their biocompatibility and essential modifications to improve the interfaces between technical devices and the biological environment. The review ends by

  2. 19 CFR 162.79b - Recovery of actual loss of duties, taxes and fees or actual loss of revenue.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Recovery of actual loss of duties, taxes and fees or actual loss of revenue. 162.79b Section 162.79b Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) INSPECTION, SEARCH, AND SEIZURE...

  3. Bone Substitutes for Peri-Implant Defects of Postextraction Implants

    PubMed Central

    Santos, Pâmela Letícia; Gulinelli, Jéssica Lemos; Telles, Cristino da Silva; Betoni Júnior, Walter; Chiacchio Buchignani, Vivian; Queiroz, Thallita Pereira

    2013-01-01

    Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immediately after tooth extraction, this study aimed to present a literature review about biomaterials surrounding immediate dental implants. The search included 56 articles published from 1969 to 2012. The results were based on data analysis and discussion. It was observed that implant fixation immediately after extraction is a reliable alternative to reduce the treatment length of prosthetic restoration. In general, the biomaterial should be used to increase bone/implant contact and enhance osseointegration. PMID:24454377

  4. Zirconia in fixed implant prosthodontics.

    PubMed

    Guess, Petra Christine; Att, Wael; Strub, Joerg Rudolf

    2012-10-01

    CAD/CAM technology in combination with zirconia ceramic has increasingly gained popularity in implant dentistry. This narrative review presents the current knowledge on zirconia utilized as framework material for implant-borne restorations and implant abutments, laboratory tests and developments, clinical performance, and possible future trends for implant dentistry are addressed. A review of available literature from 1990 through 2010 was conducted with search terms zirconia,"implants,"abutment,"crown," and "fixed dental prosthesis" using electronic databases (PubMed) and manual searching. Latest applications of zirconia in implant dentistry include implant abutments, multiple unit and full-arch frameworks as well as custom-made bars to support fixed and removable prostheses. High biocompatibility, low bacterial surface adhesion as well as favorable chemical properties of zirconia ceramics are reported. Zirconia stabilized with yttrium oxide exhibits high flexural strength and fracture toughness due to a transformation toughening mechanism. Preliminary clinical data confirmed the high stability of zirconia for abutments and as a framework material for implant borne crowns and fixed dental prostheses. Zirconia abutment or framework damage has rarely been encountered. However, veneering porcelain fractures are the most common technical complication in implant-supported zirconia restorations. These porcelain veneer failures have led to concerns regarding differences in coefficient of thermal expansions between core and veneering porcelain and their respective processing techniques. As presently evidence of clinical long-term data is missing, caution with regard to especially extensive implant-borne zirconia frameworks is recommended. © 2010 Wiley Periodicals, Inc.

  5. [Implantable middle ear hearing aids].

    PubMed

    à Wengen, D F

    2004-01-01

    Conventional acoustic hearing aids are limited in their performance. Due to physical laws their amplification of sound is limited to within 5 kHz. However, the frequencies between 5 and 10 kHz are essential for understanding consonants. Words can only be understood correctly if their consonants can be understood. Furthermore noise amplification remains a problem with hearing aids. Other problems consist of recurrent infections of the external auditory canal, intolerance for occlusion of the ear canal, feedback noise, and resonances in speech or singing. Implantable middle ear hearing aids like the Soundbridge of Symphonix-Siemens and the MET of Otologics offer improved amplification and a more natural sound. Since the first implantation of a Soundbridge in Switzerland in 1996 almost one thousand patients have been implanted worldwide. The currents systems are semi-implantable. The external audio processor containing the microphone, computer chip, battery and radio system is worn in the hair bearing area behind the ear. Implantation is only considered after unsuccessful fitting of conventional hearing aids. In Switzerland the cost for these implantable hearing aids is covered by social insurances. Initially the cost for an implant is higher than for hearing aids. However, hearing aids need replacement every 5 or 6 years whereas implants will last 20 to 30 years. Due to the superior sound quality and the improved understanding of speech in noise, the number of patients with implantable hearing aids will certainly increase in the next years. Other middle ear implants are in clinical testing.

  6. Electronic retinal implant surgery.

    PubMed

    MacLaren, R E

    2017-02-01

    Blindness due to outer retinal degeneration still remains largely untreatable. Photoreceptor loss removes light sensitivity, but the remaining inner retinal layers, the optic nerve, and indeed the physical structure of the eye itself may be unaffected by the degenerative processes. This provides the opportunity to restore some degree of vision with an electronic device in the subretinal space. In this lecture I will provide an overview of our experiences with the first-generation retinal implant Alpha IMS, developed by Retina Implant AG and based on the technology developed by Eberhart Zrenner as part of a multicentre clinical trial (NCT01024803). We are currently in the process of running a second NIHR-funded clinical trial to assess the next-generation device. The positive results from both studies to date indicate that the retinal implant should be included as a potential treatment for patients who are completely blind from retinitis pigmentosa. Evolution of the technology in future may provide further opportunities for earlier intervention or for other diseases.

  7. [Neurotology and cochlear implants].

    PubMed

    Merchán, Miguel A

    2015-05-01

    In this review we analyse cochlear implantation in terms of the fundamental aspects of the functioning of the auditory system. Concepts concerning neuronal plasticity applied to electrical stimulation in perinatal and adult deep hypoacusis are reviewed, and the latest scientific bases that justify early implantation following screening for congenital deafness are discussed. Finally, this review aims to serve as an example of the importance of fostering the sub-specialty of neurotology in our milieu, with the aim of bridging some of the gaps between specialties and thus improving both the knowledge in the field of research on auditory pathologies and in the screening of patients. The objectives of this review, targeted above all towards specialists in the field of otorhinolaryngology, are to analyse some significant neurological foundations in order to reach a better understanding of the clinical events that condition the indications and the rehabilitation of patients with cochlear implants, as well as to use this means to foster the growth of the sub-specialty of neurotology.

  8. The breast implant controversy.

    PubMed

    Cook, R R; Harrison, M C; LeVier, R R

    1994-02-01

    The breast implant issue is a "bad news/good news" story. For many women with implants, the controversy has caused a fair degree of anxiety which may or may not be resolved as further information becomes available. It has also taken its toll on Dow Corning. Whole lines of medical products have been eliminated or are being phase out. The development of new medical applications has been terminated. As a consequence, employees have lost their jobs. What the effect will be on the biomedical industry as a whole remains to be seen (11). While silicones have been an important component in various medical devices, it is likely that other materials can be used as replacements. However, suppliers of non-silicone materials are also reevaluating their role in this market. For example, Du Pont, the nation's largest chemical company, has determined that the unpredictable and excessive costs of doing business with manufacturers of implantable medical devices no longer justifies the unrestricted sale of standard raw materials into this industry. Other companies are quietly following suit. On the up side, it is possible that the research being driven by this controversy will result in a greater understanding of the immunologic implications of xenobiotics, of the importance of nonbiased observations, of the need for ready access to valid data sets, and of the opportunity for valid scientific information to guide legal decisions. Only time will tell.

  9. Tubo-uterine implantation.

    PubMed

    Green-armytage, V G

    1957-02-01

    After characterizing 2 types of patients presenting with tubal infertility (1 that is "as a rule overweight (the uterus is fixed (and there is easily palpable tubo-uterine pathology," and 1 that is "slim, young, intelligent and often beautiful", 12 1-sentence suggestions are made to increase the success of tubo-uterine implantations in the second type of presenting patient (because the first group has, in the author's mind, disappointing prognosis). Figures are the bulk of the document, with 3 figures demonstrating the type of operation, 3 showing the scheme of the operation, 1 figure showing a posterior view of the implanted tube in utero with a polyethylene prosthesis in situ down to the cervix, and 1 figure showing the instruments used in the operation. A few points of experience the author shares are: 1) operate immediately after a menstrual period; 2) give antibiotics prophylactically and after the procedure; 3) use a Bonney Myomectomy Clamp to elevate the uterus; 4) never use a knife or bistoury at the cornua; 5) use polyethylene rods, when available; and 6) caesarean section is the indicated delivery route after tubo-uterine implantation. Out of 38 patients with the requisite history and findings who have been operated on by this author, 14 have gone to full-term, i.e., 36.1%; 2 have aborted, giving a pregnancy rate of 42.2%, and there was 1 ectopic pregnancy.

  10. Spatial channel interactions in cochlear implants

    NASA Astrophysics Data System (ADS)

    Tang, Qing; Benítez, Raul; Zeng, Fan-Gang

    2011-08-01

    side. In contrast, the evoked compound action potential and perceptual channel interaction data showed much greater individual variability. It is likely that actual reduction in neural and higher level interactions, instead of simple sharpening of the electric current field, would be the key to predicting and hopefully improving the variable cochlear implant performance. The present results are obtained with auditory prostheses but can be applied to other neural prostheses, in which independent spatial channels, rather than a high stimulation rate, are critical to their performance.

  11. Spatial channel interactions in cochlear implants.

    PubMed

    Tang, Qing; Benítez, Raul; Zeng, Fan-Gang

    2011-08-01

    side. In contrast, the evoked compound action potential and perceptual channel interaction data showed much greater individual variability. It is likely that actual reduction in neural and higher level interactions, instead of simple sharpening of the electric current field, would be the key to predicting and hopefully improving the variable cochlear implant performance. The present results are obtained with auditory prostheses but can be applied to other neural prostheses, in which independent spatial channels, rather than a high stimulation rate, are critical to their performance.

  12. Actual 10-year survivors following resection of adrenocortical carcinoma.

    PubMed

    Tran, Thuy B; Postlewait, Lauren M; Maithel, Shishir K; Prescott, Jason D; Wang, Tracy S; Glenn, Jason; Phay, John E; Keplinger, Kara; Fields, Ryan C; Jin, Linda X; Weber, Sharon M; Salem, Ahmed; Sicklick, Jason K; Gad, Shady; Yopp, Adam C; Mansour, John C; Duh, Quan-Yang; Seiser, Natalie; Solorzano, Carmen C; Kiernan, Colleen M; Votanopoulos, Konstantinos I; Levine, Edward A; Hatzaras, Ioannis; Shenoy, Rivfka; Pawlik, Timothy M; Norton, Jeffrey A; Poultsides, George A

    2016-12-01

    Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with limited therapeutic options beyond surgical resection. The characteristics of actual long-term survivors following surgical resection for ACC have not been previously reported. Patients who underwent resection for ACC at one of 13 academic institutions participating in the US Adrenocortical Carcinoma Group from 1993 to 2014 were analyzed. Patients were stratified into four groups: early mortality (died within 2 years), late mortality (died within 2-5 years), actual 5-year survivor (survived at least 5 years), and actual 10-year survivor (survived at least 10 years). Patients with less than 5 years of follow-up were excluded. Among the 180 patients available for analysis, there were 49 actual 5-year survivors (27%) and 12 actual 10-year survivors (7%). Patients who experienced early mortality had higher rates of cortisol-secreting tumors, nodal metastasis, synchronous distant metastasis, and R1 or R2 resections (all P < 0.05). The need for multi-visceral resection, perioperative blood transfusion, and adjuvant therapy correlated with early mortality. However, nodal involvement, distant metastasis, and R1 resection did not preclude patients from becoming actual 10-year survivors. Ten of twelve actual 10-year survivors were women, and of the seven 10-year survivors who experienced disease recurrence, five had undergone repeat surgery to resect the recurrence. Surgery for ACC can offer a 1 in 4 chance of actual 5-year survival and a 1 in 15 chance of actual 10-year survival. Long-term survival was often achieved with repeat resection for local or distant recurrence, further underscoring the important role of surgery in managing patients with ACC. J. Surg. Oncol. 2016;114:971-976. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Actual 10-Year Survivors Following Resection of Adrenocortical Carcinoma

    PubMed Central

    Tran, Thuy B.; Postlewait, Lauren M.; Maithel, Shishir K.; Prescott, Jason D.; Wang, Tracy S.; Glenn, Jason; Phay, John E.; Keplinger, Kara; Fields, Ryan C.; Jin, Linda X.; Weber, Sharon M.; Salem, Ahmed; Sicklick, Jason K.; Gad, Shady; Yopp, Adam C.; Mansour, John C.; Duh, Quan-Yang; Seiser, Natalie; Solorzano, Carmen C.; Kiernan, Colleen M.; Votanopoulos, Konstantinos I.; Levine, Edward A.; Hatzaras, Ioannis; Shenoy, Rivfka; Pawlik, Timothy M.; Norton, Jeffrey A.; Poultsides, George A.

    2017-01-01

    Background Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with limited therapeutic options beyond surgical resection. The characteristics of actual long-term survivors following surgical resection for ACC have not been previously reported. Method Patients who underwent resection for ACC at one of 13 academic institutions participating in the US Adrenocortical Carcinoma Group from 1993 to 2014 were analyzed. Patients were stratified into four groups: early mortality (died within 2 years), late mortality (died within 2–5 years), actual 5-year survivor (survived at least 5 years), and actual 10-year survivor (survived at least 10 years). Patients with less than 5 years of follow-up were excluded. Results Among the 180 patients available for analysis, there were 49 actual 5-year survivors (27%) and 12 actual 10-year survivors (7%). Patients who experienced early mortality had higher rates of cortisol-secreting tumors, nodal metastasis, synchronous distant metastasis, and R1 or R2 resections (all P < 0.05). The need for multi-visceral resection, perioperative blood transfusion, and adjuvant therapy correlated with early mortality. However, nodal involvement, distant metastasis, and R1 resection did not preclude patients from becoming actual 10-year survivors. Ten of twelve actual 10-year survivors were women, and of the seven 10-year survivors who experienced disease recurrence, five had undergone repeat surgery to resect the recurrence. Conclusion Surgery for ACC can offer a 1 in 4 chance of actual 5-year survival and a 1 in 15 chance of actual 10-year survival. Long-term survival was often achieved with repeat resection for local or distant recurrence, further underscoring the important role of surgery in managing patients with ACC. PMID:27633419

  14. Implantation of the Subcutaneous Implantable Cardioverter-Defibrillator: An Evaluation of 4 Implantation Techniques.

    PubMed

    Brouwer, Tom F; Miller, Marc A; Quast, Anne-Floor B E; Palaniswamy, Chandrasekar; Dukkipati, Srinivas R; Reddy, Vivek; Wilde, Arthur A; Willner, Jonathan M; Knops, Reinoud E

    2017-01-01

    Alternative techniques to the traditional 3-incision subcutaneous implantation of the subcutaneous implantable cardioverter-defibrillator may offer procedural and cosmetic advantages. We evaluate 4 different implant techniques of the subcutaneous implantable cardioverter-defibrillator. Patients implanted with subcutaneous implantable cardioverter-defibrillators from 2 hospitals between 2009 and 2016 were included. Four implantation techniques were used depending on physician preference and patient characteristics. The 2- and 3-incision techniques both place the pulse generator subcutaneously, but the 2-incision technique omits the superior parasternal incision for lead positioning. Submuscular implantation places the pulse generator underneath the serratus anterior muscle and subfascial implantation underneath the fascial layer on the anterior side of the serratus anterior muscle. Reported outcomes include perioperative parameters, defibrillation testing, and clinical follow-up. A total of 246 patients were included with a median age of 47 years and 37% female. Fifty-four patients were implanted with the 3-incision technique, 118 with the 2-incision technique, 38 with submuscular, and 37 with subfascial. Defibrillation test efficacy and shock lead impedance during testing did not differ among the groups; respectively, P=0.46 and P=0.18. The 2-incision technique resulted in the shortest procedure duration and time-to-hospital discharge compared with the other techniques (P<0.001). A total of 18 complications occurred, but there were no significant differences between the groups (P=0.21). All infections occurred in subcutaneous implants (3-incision, n=3; 2-incision, n=4). In the 2-incision group, there were no lead displacements. The presented implantation techniques are feasible alternatives to the standard 3-incision subcutaneous implantation, and the 2-incision technique resulted in shortest procedure duration. © 2017 American Heart Association, Inc.

  15. Biocompatible gradient ceramic coatings for metal implants

    NASA Astrophysics Data System (ADS)

    Sharkany, Josif P.; Sichka, Mikhail J.; Potapchuk, Anatolij M.; Lemko, Ivan S.; Pintye, Josif L.

    2001-08-01

    For the acceleration of the osteointegration processes of the metals implants we deposit on their surface the biokompotible ceramic coatings on the basis of hydroxyapatite. However such coatings have a certain deficiency connected with the absence of the necessary strength characteristics for a such kind of the implant. That's why it actual to create the coatings having beside biological compatibility the necessary strength and springy- elastic properties. We have developed the method of the receiving of the new biocompatible coatings with gradient structure over width on the titanium substrate. The essence of the developed method is in plasma coatings deposition within beforehand given supply of the powder consisting of two components (oxyde aluminum and hydroxyapatite) in the process of the deposition. It's showed that the received gradient coatings are the mixture of the crystals Al2O3 and HA, the concentrations of which change over the width. The topological investigation of the surface and the coating cross-sections was performed from which the chemical composition distribution over width was studied and found the absense of the chemical interaktion between Al2O3 and HA. By regulation of the distribution of the initial components over the coating widths it is possible to set the phase comsposition and crystal sizes in the biocompatible coatings. In the process of etching in the solutions imitating the physiological ones it is found the formation of the pores having dendritic structure. The performed investigations show the possibility of the usage of the developed coatings in medicine particularly in stomatolgoy.

  16. Exploring the benefits of bilateral cochlear implants.

    PubMed

    van Hoesel, Richard J M

    2004-01-01

    Several recent reports indicate that both localization and speech intelligibility in spatially separated noise are substantially improved by using cochlear implants (CIs) in both ears rather than in just one. Benefits appear to be largely derived from the effects of level variations at the two ears due to the head shadow whereas contributions from interaural time differences (ITDs) seem smaller than in normal hearing listeners. The effect of binaural unmasking estimated from speech studies to date varies from study to study and is possibly confounded by issues such as listening experience, bias or loudness effects when comparing the performance for the better ear with that using both ears. To improve the contribution from timing information at the two ears, it may be necessary to change present clinical sound-processing schemes that currently preserve only envelope cues so that they also preserve fine-timing information. However, recently published data show that basic psychophysical sensitivity to fine-timing ITDs in CI patients is very poor for rates beyond a few hundred hertz, suggesting that subjects do not actually hear ITD cues at those rates anyway. Data from a number of new studies are presented to discuss these and other issues related to the potential to benefit from bilateral implantation. Copyright 2004 S. Karger AG, Basel

  17. Electrodermal responses to implied versus actual violence on television.

    PubMed

    Kalamas, A D; Gruber, M L

    1998-01-01

    The electrodermal response (EDR) of children watching a violent show was measured. Particular attention was paid to the type of violence (actual or implied) that prompted an EDR. In addition, the impact of the auditory component (sounds associated with violence) of the show was evaluated. Implied violent stimuli, such as the villain's face, elicited the strongest EDR. The elements that elicited the weakest responses were the actual violent stimuli, such as stabbing. The background noise and voices of the sound track enhanced the total number of EDRs. The results suggest that implied violence may elicit more fear (as measured by EDRs) than actual violence does and that sounds alone contribute significantly to the emotional response to television violence. One should not, therefore, categorically assume that a show with mostly actual violence evokes less fear than one with mostly implied violence.

  18. 40. Photocopy of plan of the Castillo c. 1779 (Actual ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Photocopy of plan of the Castillo c. 1779 (Actual Negative 4'x5') STAR PLAN, COURTYARD FACADE PROFILE AND DEFENSIVE LINKS - Castillo de San Marcos, 1 Castillo Drive, Saint Augustine, St. Johns County, FL

  19. Accuracy of Dynamic Navigation for Dental Implant Placement-Model-Based Evaluation.

    PubMed

    Emery, Robert W; Merritt, Scott A; Lank, Kathryn; Gibbs, Jason D

    2016-10-01

    The purpose of this model-based study was to determine the accuracy of placing dental implants using a new dynamic navigation system. This investigation focuses on measurements of overall accuracy for implant placement relative to the virtual plan in both dentate and edentulous models, and provides a comparison with a meta-analysis of values reported in the literature for comparable static guidance, dynamic guidance, and freehand placement studies. This study involves 1 surgeon experienced with dynamic navigation placing implants in models under clinical simulation using a dynamic navigation system (X-Guide, X-Nav Technologies, LLC, Lansdale, Pa) based on optical triangulation tracking. Virtual implants were placed into planned sites using the navigation system computer. Post-implant placement cone-beam scans were taken. These scans were mesh overlaid with the virtual plan and used to determine deviations from the virtual plan. The primary outcome variables were platform and angular deviations comparing the actual placement to the virtual plan. The angular accuracy of implants delivered using the tested device was 0.89° ± 0.35° for dentate case types and 1.26° ± 0.66° for edentulous case types, measured relative to the preoperative implant plan. Three-dimensional positional accuracy was 0.38 ± 0.21 mm for dentate and 0.56 ± 0.17 mm for edentulous, measured from the implant apex.

  20. Convex optimization of MRI exposure for mitigation of RF-heating from active medical implants.

    PubMed

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2015-09-21

    Local RF-heating of elongated medical implants during magnetic resonance imaging (MRI) may pose a significant health risk to patients. The actual patient risk depends on various parameters including RF magnetic field strength and frequency, MR coil design, patient's anatomy, posture, and imaging position, implant location, RF coupling efficiency of the implant, and the bio-physiological responses associated with the induced local heating. We present three constrained convex optimization strategies that incorporate the implant's RF-heating characteristics, for the reduction of local heating of medical implants during MRI. The study emphasizes the complementary performances of the different formulations. The analysis demonstrates that RF-induced heating of elongated metallic medical implants can be carefully controlled and balanced against MRI quality. A reduction of heating of up to 25 dB can be achieved at the cost of reduced uniformity in the magnitude of the B(1)(+) field of less than 5%. The current formulations incorporate a priori knowledge of clinically-specific parameters, which is assumed to be available. Before these techniques can be applied practically in the broader clinical context, further investigations are needed to determine whether reduced access to a priori knowledge regarding, e.g. the patient's anatomy, implant routing, RF-transmitter, and RF-implant coupling, can be accepted within reasonable levels of uncertainty.

  1. Peri-implant complications for posterior endosteal implants

    PubMed Central

    Esquivel-Upshaw, Josephine; Mehler, Alex; Clark, Arthur; Neal, Dan; Gonzaga, Luiz; Anusavice, Kenneth

    2014-01-01

    Objectives (1) To assess whether there is evidence of an association between the number of peri-implant tissue complications and patient characteristics such as gender, diabetes status, smoking status, and bite force; (2) To assess whether there is evidence of an association between the number of peri-implant tissue complications and location of the implant, surgical technique used, bone graft status and sinus lift status. Materials and Methods This randomized controlled clinical trial included a total of 176 implants (Osseospeed, Dentsply) in 67 participants with 88 fixed dental prostheses. Information was obtained from health histories, a baseline exam, surgical notes, and postoperative exams. The data were analyzed using Fisher's exact and Mann-Whitney tests, and generalized estimating equations logistic regression with a significance level set at 0.05. Results All 176 implants survived within a recall period of three years but 11 implants demonstrated peri-implant tissue complications. Ten sites showed dehiscence and one case exhibited vertical bone loss. There was a statistically significant association between surgical technique used (1-stage or 2-stage) and the presence of soft tissue complications (p = 0.005), where 2-stage surgery was associated with a higher frequency of peri-implant soft tissue complications. A correlation, although not statistically significant (p=0.077) was noted, between peri-implant tissue complications and bone grafting, suggesting a possible role for this factor as well. Conclusions Participants who did not require any second stage surgery at the implant sites experienced fewer complications. Therefore, additional surgical procedures should be performed judiciously considering their possible effects on peri-implant tissue health. PMID:25263400

  2. Transfer characteristics of subretinal visual implants: corneally recorded implant responses.

    PubMed

    Stingl, K; Bartz-Schmidt, K U; Braun, A; Gekeler, F; Greppmaier, U; Schatz, A; Stett, A; Strasser, T; Kitiratschky, V; Zrenner, E

    2016-10-01

    The subretinal Alpha IMS visual implant is a CE-approved medical device for restoration of visual functions in blind patients with end-stage outer retina degeneration. We present a method to test the function of the implant objectively in vivo using standard electroretinographic equipment and to assess the devices' parameter range for an optimal perception. Subretinal implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) consists of 1500 photodiode-amplifier-electrode units and is implanted surgically into the subretinal space in blind retinitis pigmentosa patients. The voltages that regulate the amplifiers' sensitivity (V gl) and gain (V bias), related to the perception of contrast and brightness, respectively, are adjusted manually on a handheld power supply device. Corneally recorded implant responses (CRIR) to full-field illumination with long duration flashes in various implant settings for brightness gain (V bias) and amplifiers' sensitivity (V gl) are measured using electroretinographic setup with a Ganzfeld bowl in a protocol of increasing stimulus luminances up to 1000 cd/m(2). CRIRs are a meaningful tool for assessing the transfer characteristic curves of the electronic implant in vivo monitoring the implants' voltage output as a function of log luminance in a sigmoidal shape. Changing the amplifiers' sensitivity (V gl) shifts the curve left or right along the log luminance axis. Adjustment of the gain (V bias) changes the maximal output. Contrast perception is only possible within the luminance range of the increasing slope of the function. The technical function of subretinal visual implants can be measured objectively using a standard electroretinographic setup. CRIRs help the patient to optimise the perception by adjusting the gain and luminance range of the device and are a useful tool for clinicians to objectively assess the function of subretinal visual implants in vivo.

  3. Graphene synthesis by ion implantation

    PubMed Central

    Garaj, Slaven; Hubbard, William; Golovchenko, J. A.

    2010-01-01

    We demonstrate an ion implantation method for large-scale synthesis of high quality graphene films with controllable thickness. Thermally annealing polycrystalline nickel substrates that have been ion implanted with carbon atoms results in the surface growth of graphene films whose average thickness is controlled by implantation dose. The graphene film quality, as probed with Raman and electrical measurements, is comparable to previously reported synthesis methods. The implantation synthesis method can be generalized to a variety of metallic substrates and growth temperatures, since it does not require a decomposition of chemical precursors or a solvation of carbon into the substrate. PMID:21124725

  4. Short implants: A systematic review

    PubMed Central

    Karthikeyan, I.; Desai, Shrikar R.; Singh, Rika

    2012-01-01

    Background: Short implants are manufactured for use in atrophic regions of the jaws. Although many studies report on short implants as ≤10 mm length with considerable success, the literature regarding survival rate of ≤7 mm is sparse. Purpose: The purpose of this study was to systematically evaluate the publications concerning short dental implants defined as an implant with a length of ≤7 mm placed in the maxilla or in the mandible. Materials and Methods: A Medline and manual search was conducted to identify studies concerning short dental implants of length ≤7 mm published between 1991 and 2011. The articles included in this study report data on implant length ≤7 mm, such as demographic variables, implant type, location in jaws, observation time, prostheses and complications. Results: The 28 included studies represent one randomized controlled trial, 12 prospective studies and 10 retrospective studies. The survival rate of short implant was found to be increased from 80% to 90% gradually, with recent articles showing 100%. Conclusion: When severe atrophy of jaws was encountered, short and wide implants can be placed successfully. PMID:23162320

  5. Implant biomaterials: A comprehensive review

    PubMed Central

    Saini, Monika; Singh, Yashpal; Arora, Pooja; Arora, Vipin; Jain, Krati

    2015-01-01

    Appropriate selection of the implant biomaterial is a key factor for long term success of implants. The biologic environment does not accept completely any material so to optimize biologic performance, implants should be selected to reduce the negative biologic response while maintaining adequate function. Every clinician should always gain a thorough knowledge about the different biomaterials used for the dental implants. This article makes an effort to summarize various dental bio-materials which were used in the past and as well as the latest material used now. PMID:25610850

  6. Actuarial and actual analysis of surgical results: empirical validation.

    PubMed

    Grunkemeier, G L; Anderson, R P; Starr, A

    2001-06-01

    This report validates the use of the Kaplan-Meier (actuarial) method of computing survival curves by comparing 12-year estimates published in 1978 with current assessments. It also contrasts cumulative incidence curves, referred to as "actual" analysis in the cardiac-related literature with Kaplan-Meier curves for thromboembolism and demonstrates that with the former estimate the percentage of events that will actually occur.

  7. Predictability in orbital reconstruction. A human cadaver study, part III: Implant-oriented navigation for optimized reconstruction.

    PubMed

    Dubois, Leander; Essig, Harald; Schreurs, Ruud; Jansen, Jesper; Maal, Thomas J J; Gooris, Peter J J; Becking, Alfred G

    2015-12-01

    Navigation-assisted orbital reconstruction remains a challenge, because the surgeon focuses on a two-dimensional multiplanar view in relation to the preoperative planning. This study explored the addition of navigation markers in the implant design for three-dimensional (3D) orientation of the actual implant position relative to the preoperative planning for more fail-safe and consistent results. Pre-injury computed tomography (CT) was performed for 10 orbits in human cadavers, and complex orbital fractures (Class III/IV) were created. The orbits were reconstructed using preformed orbital mesh through a transconjunctival approach under image-guided navigation and navigation by referencing orientating markers in the implant design. Ideal implant positions were planned using preoperative CT scans. Implant placement accuracy was evaluated by comparing the planned and realized implant positions. Significantly better translation (3.53 mm vs. 1.44 mm, p = 0.001) and rotation (pitch: -1.7° vs. -2.2°, P = 0.52; yaw: 10.9° vs. 5.9°, P = 0.02; roll: -2.2° vs. -0.5°, P = 0.16) of the placed implant relative to the planned position were obtained by implant-oriented navigation. Navigation-assisted surgery can be improved by using navigational markers on the orbital implant for orientation, resulting in fail-safe reconstruction of complex orbital defects and consistent implant positioning.

  8. Nevado del Huila, Columbia

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Nevado del Huila Volcano in Colombia is actually a volcanic chain running north to south, capped by a glacier. With peaks ranging in height from 2,600 to 5,780 meters (8,530 to 18,960 feet), Nevado del Huila is a stratovolcano composed of alternating layers of hardened lava, solidified ash, and volcanic rocks. Its first recorded eruption occurred in the mid-sixteenth century. The long-dormant volcano erupted again in mid-April 2007. A few months before the eruption, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Nevado del Huila, on February 23, 2007. In this image, the bright white area just east of the central summit is ice. Immediately west of the summit are bare rocks, appearing as blue-gray. West of those rocks, white reappears, but this patch of white results from clouds hovering in the nearby valley. In the east, the colors turn to brown (indicating bare rock) and bright green (indicating vegetation). ASTER photographed Nevado del Huila near the end of a long phase of quietude. On April 17, 2007, local authorities recorded seismic activity associated with rock fracturing on the volcano's central summit, according to the ReliefWeb Website. Activity intensified the following day with an eruption and mudflows, forcing thousands of nearby residents to evacuate. As the Associated Press reported, the eruption caused avalanches and floods that wiped away both houses and bridges. It marked the volcano's first recorded eruption since the Spanish colonized the area five centuries earlier. NASA image created by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  9. Subdermal progestin implant contraception.

    PubMed

    Darney, P D

    1991-08-01

    Sustained-release progestin contraceptives are a new approach to meeting a worldwide need for more effective and acceptable birth control. These contraceptive systems provide low, stable levels of synthetic progestins for periods of months to several years. Unlike earlier injectable and oral contraceptives, they do not cause peaks in progestin levels beyond those required for effective contraception, nor do they employ estrogens. For these reasons, sustained-release progestin systems are without some of the health risks attributed to birth control pills, and they are more effective, as well as easy to use, and completely reversible. They share common side effects, the most frequent of which is irregular menstrual bleeding caused by the erratic shedding of hypotrophic endometrium. Despite this and other minor side effects, most users find the sustained-release systems acceptable alternatives to other methods of contraception. Permanent or biodegradable subdermal implants, injections, intrauterine and intracervical devices, and vaginal rings are all employed as delivery systems for contraceptive progestins. The Norplant (Wyeth Ayerst, Radnor, PA) system, consisting of six silastic tubes filled with levonorgestrel and implanted under the skin, was recently approved by the US Food and Drug Administration and is already used by more than a half million women worldwide. The other sustained-release systems are in various stages of development, at least several years away from general use. When these new methods complete clinical trials, women will be able to choose from among implants, injections, or pellets with various durations of action, all providing convenient, highly effective contraception with low risk to health.

  10. Age at implantation and auditory memory in cochlear implanted children.

    PubMed

    Mikic, B; Miric, D; Nikolic-Mikic, M; Ostojic, S; Asanovic, M

    2014-05-01

    Early cochlear implantation, before the age of 3 years, provides the best outcome regarding listening, speech, cognition an memory due to maximal central nervous system plasticity. Intensive postoperative training improves not only auditory performance and language, but affects auditory memory as well. The aim of this study was to discover if the age at implantation affects auditory memory function in cochlear implanted children. A total of 50 cochlear implanted children aged 4 to 8 years were enrolled in this study: early implanted (1-3y) n = 27 and late implanted (4-6y) n = 23. Two types of memory tests were used: Immediate Verbal Memory Test and Forward and Backward Digit Span Test. Early implanted children performed better on both verbal and numeric tasks of auditory memory. The difference was statistically significant, especially on the complex tasks. Early cochlear implantation, before the age of 3 years, significantly improve auditory memory and contribute to better cognitive and education outcomes.

  11. Broad beam ion implanter

    DOEpatents

    Leung, K.N.

    1996-10-08

    An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes. 6 figs.

  12. Broad beam ion implanter

    DOEpatents

    Leung, Ka-Ngo

    1996-01-01

    An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.

  13. Implantable medical sensor system

    DOEpatents

    Darrow, Christopher B.; Satcher, Jr., Joe H.; Lane, Stephen M.; Lee, Abraham P.; Wang, Amy W.

    2001-01-01

    An implantable chemical sensor system for medical applications is described which permits selective recognition of an analyte using an expandable biocompatible sensor, such as a polymer, that undergoes a dimensional change in the presence of the analyte. The expandable polymer is incorporated into an electronic circuit component that changes its properties (e.g., frequency) when the polymer changes dimension. As the circuit changes its characteristics, an external interrogator transmits a signal transdermally to the transducer, and the concentration of the analyte is determined from the measured changes in the circuit. This invention may be used for minimally invasive monitoring of blood glucose levels in diabetic patients.

  14. Gluteal lift with subfascial implants.

    PubMed

    de la Peña-Salcedo, Jose Abel; Soto-Miranda, Miguel Angel; Vaquera-Guevara, Marcelo Osvaldo; Lopez-Salguero, Jose Fernando; Lavareda-Santana, Marco Antonio; Ledezma-Rodriguez, Jocelyn Celeste

    2013-06-01

    Gluteal enhancement surgery includes buttock implants, gluteal flaps, lipografting, and gluteal lifts. However, no information is available on the outcomes achievable using the gluteal lift combined with subfascial gluteal implants. A retrospective study was performed to analyze the outcomes of gluteal lift combined with subfascial gluteal implants performed during a 7-year period by a single surgeon at a single institution. During the study period, 114 patients (228 implants) ages 27-68 years (mean 47 years) were found. The follow-up period was 1-7 years (mean 4.5 years). The findings showed seroma in 11.4 % of the patients, hematoma in 5.26 %, minor wound dehiscence in 19.29 %, major wound dehiscence in 1.75 %, minor infection in 1.75 %, implant exposure in 0 %, capsular contracture Becker 3 and 4 in 3.5 %, implant rupture in 0 %, implant malposition in 5.25 %, long-term numbness of the buttock in 0 %, palpability of the implant in 0 %, implant rippling in 0 %, implant rupture in 0 %, wide scars in 41.2 %, need for secondary surgery in 26.31 %, and dissatisfaction with the final volume in 10.52 %. A patient satisfaction rate of 9.6 in 10 was found. The study showed that the gluteal lift combined with gluteal implants placed in the subfascial pocket provided good long-lasting results with an acceptable rate of complications, very high patient satisfaction, and easily concealed scars. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  15. [Implant rehabilitation of distal mandibular atrophy using a blade implant].

    PubMed

    Veron, C; Chanavaz, M

    1997-11-01

    After a brief revision of the anatomy of the posterior mandible and its natural resorption pattern, the ramus plate-form implant would be the implant of choice for the rehabilitation of this region. This "site specific" implant is inserted on the top of the crest and superficially impacted within the residual alveolar bone at the distal segment of the horizontal branch and guided to climb parallel to the anterior aspect of the ascending ramus. Its form and specific dimensions are perfectly compatible with the frequently limited quantity of available bone above the nerve canal in patients with advanced atrophy of the posterior mandible. It provides a predictable abutment for the implant-supported or dento-implant-supported prostheses of the posterior mandible.

  16. Wireless microsensor network solutions for neurological implantable devices

    NASA Astrophysics Data System (ADS)

    Abraham, Jose K.; Whitchurch, Ashwin; Varadan, Vijay K.

    2005-05-01

    The design and development of wireless mocrosensor network systems for the treatment of many degenerative as well as traumatic neurological disorders is presented in this paper. Due to the advances in micro and nano sensors and wireless systems, the biomedical sensors have the potential to revolutionize many areas in healthcare systems. The integration of nanodevices with neurons that are in communication with smart microsensor systems has great potential in the treatment of many neurodegenerative brain disorders. It is well established that patients suffering from either Parkinson"s disease (PD) or Epilepsy have benefited from the advantages of implantable devices in the neural pathways of the brain to alter the undesired signals thus restoring proper function. In addition, implantable devices have successfully blocked pain signals and controlled various pelvic muscles in patients with urinary and fecal incontinence. Even though the existing technology has made a tremendous impact on controlling the deleterious effects of disease, it is still in its infancy. This paper presents solutions of many problems of today's implantable and neural-electronic interface devices by combining nanowires and microelectronics with BioMEMS and applying them at cellular level for the development of a total wireless feedback control system. The only device that will actually be implanted in this research is the electrodes. All necessary controllers will be housed in accessories that are outside the body that communicate with the implanted electrodes through tiny inductively-coupled antennas. A Parkinson disease patient can just wear a hat-system close to the implantable neural probe so that the patient is free to move around, while the sensors continually monitor, record, transmit all vital information to health care specialist. In the event of a problem, the system provides an early warning to the patient while they are still mobile thus providing them the opportunity to react and

  17. An Unusual Bone Loss Around Implants

    PubMed Central

    Rokn, Amir Reza; Sajedinejad, Neda; Yousefyfakhr, Hosnieh; Badri, Samare

    2013-01-01

    Pre-implant disease is an inflammatory process that affects the surrounding tissues of a functional osseointegrated implant. It is usually the result of a disequilibrium between the micro-flora and the defense system. This case reports a 57-year-old man with unusual bone loss around dental implants. This was an unusual case of peri-implantitis that occurred only in the implants on one side of the mouth although they were all unloaded implants. PMID:24396359

  18. Implanted Dosimeters Identify Radiation Overdoses During IMRT for Prostate Cancer

    SciTech Connect

    Den, Robert B.; Nowak, Kamila; Buzurovic, Ivan; Cao Junsheng; Harrison, Amy S.; Lawrence, Yaacov R.; Dicker, Adam P.; Showalter, Timothy N.

    2012-07-01

    Purpose: Image-guided dose-escalated radiotherapy is the standard of care for the treatment of prostate cancer. Although many published methods are available that account for prostate motion during delivery, evidence demonstrating that the planned dose is actually delivered on a daily basis is lacking. We report our initial clinical experience using implantable dosimeters to quantify and adjust the dose received during intensity-modulated radiotherapy (IMRT). Methods and Materials: A total of 20 patients undergoing IMRT with cone-beam computed tomography (CT) image guidance for prostate cancer had the dose verification system with radiopaque metal-oxide-semiconductor field effect transistor dosimeters implanted before treatment planning. All patients underwent planning with CT simulation in the supine position with custom immobilization, and the implanted dosimeters were located in the IMRT plans. The predicted dose for each dosimeter was defined and compared with the wireless readings before and after each treatment session. Investigations by physicians and medical physicists were initiated for two or more discrepancies >6% for any five consecutive fractions or for any discrepancy {>=}10%. Results: Using implanted in vivo dosimeters, dose measurements consistently >6% greater than the predicted values were observed during treatment for 3 of 20 prostate cancer patients who received IMRT with daily image guidance. A review of the daily cone-beam CT images revealed acceptable alignment of the prostate target volumes and implanted dosimeters but identified significant anatomic changes within the treated region. Repeat CT simulation and RT planning was performed, with resolution of the dose discrepancies in all 3 cases with the adoption of a new IMRT plan. Conclusions: Our report illustrates the potential effect of implanted in vivo dosimetry for prostate IMRT and emphasizes the importance of careful planning and delivery with attention to systematic shifts or anatomic

  19. Cochlear implant programs: balancing clinical and financial sustainability.

    PubMed

    McKinnon, Brian J

    2013-01-01

    In 2006, a tertiary academic medical center's adult and pediatric cochlear implant program was closed due to financial losses. Using business practices known as supply chain and revenue management, the objective was to establish a new cochlear implant program that was financially viable. Retrospective cohort study using a nonequivalent historical comparison group design. Using available financial data from the period of 1999 to 2006, cost and revenue figures were estimated, and a business plan developed using supply chain and revenue management principles to re-establish the cochlear implant program in 2007. Actual cost and revenue data from 2007 to 2011, the current program, were assessed for current financial performance and compared to the historical data. In comparing the period of 1999 to 2006 to the period of 2007 to 2011, the net loss per implanted patient went from $22,365 to $976. Profitable gross and net margins were achieved for all payers except Medicaid, for which the loss per case remained unchanged. This per case loss may change with receipt of pending Medicaid Upper Payment Limit supplemental payments. Use of supply chain and revenue management principles markedly improved the financial performance of the re-established cochlear implant program. With improved cost and revenue outcomes, the overall negative net margin was reduced. Physicians who learn and use supply chain and revenue management methods can work to ensure that their patients will have continued access to cochlear implant surgery, and are applicable to any clinical services or procedures that must meet the challenge of achieving financial sustainability. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  20. Dental implant changes following incineration.

    PubMed

    Berketa, J; James, H; Marino, V

    2011-04-15

    Non-visual identification of victims utilizes DNA, fingerprint and dental comparison as primary scientific identifiers. In incidents where a victim has been incinerated, there may be loss of fingerprint detail and denaturing of DNA. Although extremely durable, tooth loss will also occur with extreme temperatures and the characteristics of recovered dental implants, if any, may be the only physical identifying data available. Currently, there are no experimental investigations to determine what changes occur to dental implants following high temperature exposure. A selection of dental implants was radiographed, utilizing purpose built apparatus to allow standard methodology. They were then heated in an INFI-TROL™ kiln to a maximum temperature of 1125°C and the radiographic procedure repeated. Image subtraction evaluation of the radiographs was recorded using Adobe(®) Photoshop(®). Both commercially pure titanium and titanium alloy dental implants survived the incineration and there was oxidation of the surface leading to minor alteration of the image. There was, however, no detectable sagging of the implants. The results of this research suggest that dental implants are still recognizable following incineration. In scenarios commonly seen by forensic odontologists, heat will destroy both teeth and conventional dental restorative materials. Implants, however, will resist these conditions and will also retain the features necessary to identify the type of implant. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Implant Maintenance: A Clinical Update

    PubMed Central

    Gulati, Minkle; Govila, Vivek; Anand, Vishal; Anand, Bhargavi

    2014-01-01

    Introduction. The differences in the supporting structure of the implant make them more susceptible to inflammation and bone loss when plaque accumulates as compared to the teeth. Therefore, a comprehensive maintenance protocol should be followed to ensure the longevity of the implant. Material and Method. A research to provide scientific evidence supporting the feasibility of various implant care methods was carried out using various online resources to retrieve relevant studies published since 1985. Results. The electronic search yielded 708 titles, out of which a total of 42 articles were considered appropriate and finally included for the preparation of this review article. Discussion. A typical maintenance visit for patients with dental implants should last 1 hour and should be scheduled every 3 months to evaluate any changes in their oral and general history. It is essential to have a proper instrument selection to prevent damage to the implant surface and trauma to the peri-implant tissues. Conclusion. As the number of patients opting for dental implants is increasing, it becomes increasingly essential to know the differences between natural teeth and implant care and accept the challenges of maintaining these restorations. PMID:27437506

  2. Regenerative Surgical Treatment of Peri-implantitis

    ClinicalTrials.gov

    2016-08-31

    Failure of Dental Implant Due to Infection; Infection; Inflammation; Peri-implantitis; Bacterial Infections; Bleeding of Subgingival Space; Molecular Sequence Variation; Periodontal Diseases; Mouth Diseases

  3. Peri-implant complications for posterior endosteal implants.

    PubMed

    Esquivel-Upshaw, Josephine; Mehler, Alex; Clark, Arthur; Neal, Dan; Gonzaga, Luiz; Anusavice, Kenneth

    2015-12-01

    (1) To assess whether there is evidence of an association between the number of peri-implant tissue complications and patient characteristics such as gender, diabetes status, smoking status, and bite force; (2) To assess whether there is evidence of an association between the number of peri-implant tissue complications and location of the implant, surgical technique used, bone graft status and sinus lift status. This randomized, controlled clinical trial included a total of 176 implants (OsseoSpeed, DENTSPLY) in 67 participants with 88 fixed dental prostheses. Information was obtained from health histories, a baseline exam, surgical notes, and post-operative exams. The data were analyzed using Fisher's exact and Mann-Whitney tests and generalized estimating equations using logistic regression with a significance level set at 0.05. All 176 implants survived within a recall period of 3 years, but 11 implants demonstrated peri-implant tissue complications. Ten sites showed dehiscence and one case exhibited vertical bone loss. There was a statistically significant association between surgical technique used (1-stage or 2-stage) and the presence of soft tissue complications (P = 0.005), where 2-stage surgery was associated with a higher frequency of peri-implant soft tissue complications. A correlation, although not statistically significant (P = 0.077), was noted, between peri-implant tissue complications and bone grafting, suggesting a possible role for this factor as well. Participants who did not require any second-stage surgery at the implant sites experienced fewer complications. Therefore, additional surgical procedures should be performed judiciously considering their possible effects on peri-implant tissue health. The clinical implication of this research study is that secondary surgery should be considered with caution during implant placement and it should be performed only when other options have been exhausted, as it has been shown to have a direct

  4. Cochlear implantation following cerebellar surgery.

    PubMed

    Saeed, Shahad; Mawman, Deborah; Green, Kevin

    2011-08-01

    Cochlear implantation in patients with known central nervous system conditions can result in wide-ranging outcomes. The aim of this study is to report two cases of cochlear implantation outcomes in patients with acquired cerebellar ataxia following cerebellar surgery. The first is a female implanted with the Nucleus 24 implant in September 2000 and the second is a male implanted with a MED-EL Sonata Flexsoft electro-acoustic stimulation in July 2009. Programming these patients resulted in significant non-auditory stimulation which resulted in less than optimum map fittings. The patients did not gain any open set speech perception benefit although both of them gained an awareness of sound with the device. However, patient 2 elected to become a non-user because of the limited benefit.

  5. Implant fixation by bone ingrowth.

    PubMed

    Kienapfel, H; Sprey, C; Wilke, A; Griss, P

    1999-04-01

    The term osseointegration referred originally to an intimate contact of bone tissue with the surface of a titanium implant; the term bone ingrowth refers to bone formation within an irregular (beads, wire mesh, casting voids, cut grooves) surface of an implant. The section dealing with the historical background describes the development of macroporous, microporous, and textured surfaces with an emphasis on the evolution of porous and textured metal surfaces. The principal requirements for osseointegration and bone ingrowth are systematically reviewed as follows: i) the physiology of osseointegration and bone ingrowth, including biomaterial biocompatibility with respect to cellular and matrix response at the interface; ii) the implant surface geometry characteristics; iii) implant micromotion and fixation modes; and iv) the implant-bone interface distances. Based on current methods of bone ingrowth assessment, this article comparatively reviews and discusses the results of experimental studies with the objective of determining local and systemic factors that enhance bone ingrowth fixation.

  6. Bimodal fitting or bilateral implantation?

    PubMed

    Ching, Teresa Y C; Massie, Robyn; Van Wanrooy, Emma; Rushbrooke, Emma; Psarros, Colleen

    2009-01-01

    This paper summarises findings from studies that evaluated the benefits of bimodal fitting (combining a hearing aid and a cochlear implant in opposite ears) or bilateral cochlear implantation, relative to unilateral implantation, for children (Ching et al., 2007). On average, the size of binaural speech intelligibility advantages due to redundancy and head shadow was similar for the two bilateral conditions. An added advantage of bimodal fitting was that the low-frequency cues provided by acoustic hearing complemented the high-frequency cues conveyed by electric hearing in perception of voice and music. Some children with bilateral cochlear implants were able to use spatial separation between speech and noise to improve speech perception in noise. This is possibly a combined effect of the directional microphones in their implant systems and their ability to use spatial cues. The evidence to date supports the provision of hearing in two ears as the standard of care.

  7. Progestin implants for female contraception.

    PubMed

    Croxatt, Horacio B

    2002-01-01

    Four different implants, in the form of capsules or covered rods, that release one of the synthetic progestins levonorgestrel, etonogestrel, Nestorone, or Elcometrine and nomegestrol acetate were reviewed. Biocompatible polymers or copolymers of polydimethyl/polymethylvinyl-siloxanes or ethylvinylacetate are used to hold the steroid crystals and to control the rate of release. Once inserted under the skin, these implants release the corresponding steroid continuously over prolonged periods, a process that can be readily interrupted by implant removal. During long-term use of the implant, the released steroid circulates in blood at a fairly stable level. The physical characteristics of the implants, including drug contents and rate of release, serum levels of the progestin during use, and the duration of their effective life are described. Total steroid loads vary in the range of 50 mg to 216 mg; average release rates are in the range of 30-100 ug/day, and effective lives from 6 months to 7 years.

  8. Titanium diffusion in shinbone of rats with osseointegrated implants.

    PubMed

    Grenón, Miriam S; Robledo, José; Ibáñez, Juan Carlos; Sánchez, Héctor J

    2016-11-01

    Dental implants are composed of commercially pure Ti (which is actually an alloy of titanium, and minor or trace components such as aluminium and vanadium). When the implant is inserted, its surface undergoes a number of chemical and mechanical processes, releasing particles of titanium to the medium. The metabolism of free ions of titanium is uncertain; the uptaking processes in the body are not well known, nor their toxic dose. In addition, physical properties of newly formed bone, such as diffusivity and activation energy, are scarce and rarely studied. In this study, we analysed the diffusion of titanium in the titanium-implanted shinbones of six adult male Wistar rats by spatially resolved micro x-ray fluorescence. The measurements were carried out at the microfluorescence station of the x-ray fluorescence (XRF) beamline of the Brazilian synchrotron facility LNLS (from Portuguese 'Laboratorio Nacional de Luz Sincrotron'). For each sample, XRF spectra were taken by linear scanning in area near the new bone formed around the Ti implant. The scanning line shows a clear effect of titanium diffusion whereas calcium intensity presents a different behaviour. Moreover, a clear correlation among the different structures of bones is observed in the Ti and Ca intensities. The results obtained in these measurements may allow determining quantitatively the parameters of diffusion rates and other physical properties of new bone like diffusion coefficients. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  9. Hydrogen Implants for Layer Exfoliation

    NASA Astrophysics Data System (ADS)

    Cherekdjian, S.; Couillard, J. G.; Wilcox, C.

    2011-01-01

    Researchers at Corning Incorporated have developed a process whereby single crystal silicon thin films are transferred onto a flat panel display glass substrate using hydrogen ion implantation. The energy of the implant controls the effective exfoliation thickness, agreeing well with SRIM calculations, while the hydrogen ion dose controls the size of the platelets formed. The ion dose was found to influence the final void defect count in exfoliated films. Finally, the ion beam and ion implant end-station cooling characteristics were investigated. These parameters control the effective implant heat load generated during ion beam processing. The temperature at which exfoliation occurs during an exfoliation heat cycle was found to be inversely proportional to the hydrogen ion dose when the temperature during ion implantation is <100 °C. The most sensitive exfoliation temperature to ion dose dependence was observed for cooler implants, i.e. <35 °C. Data indicates that at the minimum exfoliation dose the exfoliation temperature is reduced significantly by increasing the implant heat generated during ion beam processing. Higher hydrogen doses than the minimum required for exfoliation exhibit only a small exfoliation temperature variation with ion dose. By optimizing the implant heat load generated during ion beam processing it is observed that the efficiency of the exfoliation process is also enhanced. Implant temperatures of 150 to 160 °C were found to further reduce the minimum implant dose required for exfoliation by an additional 5%, as verified by calorimetric measurements. These results enable us to further conclude that hydrogen out-diffusion is not significant in this process.

  10. Tribological properties of nitrogen implanted and boron implanted steels

    SciTech Connect

    Kern, K.T.; Walter, K.C.; Griffin, A.J. Jr.; Kung, H.; Lu, Y.; Nastasi, M.; Tesmer, J.R.; Fayeulle, S.

    1996-06-01

    Samples of a steel with high chrome content was implanted separately with 75 keV nitrogen ions and with 75 keV boron ions. Implanted doses of each ion species were 2-, 4-, and 8 {times} 10{sup 17}/cm{sup 2}. Retained doses were measured using resonant non-Rutherford Backscattering Spectrometry. Tribological properties were determined using a pin-on-disk test with a 6-mm diameter ruby pin with a velocity of 0.94 m/min. Testing was done at 10% humidity with a load of 377 g. Wear rate and coefficient of friction were determined from these tests. While reduction in the wear rate for nitrogen implanted materials was observed, greater reduction (more than an order of magnitude) was observed for boron implanted materials. In addition, reduction in the coefficient of friction for high-dose boron implanted materials was observed. Nano-indentation revealed a hardened layer near the surface of the material. Results from grazing incidence x-ray diffraction suggest the formation of Fe{sub 2}N and Fe{sub 3}N in the nitrogen implanted materials and Fe{sub 3}B in the boron implanted materials. Results from transmission electron microscopy will be presented.

  11. Perceived and actual noise levels in critical care units.

    PubMed

    White, Brittany Lynn; Zomorodi, Meg

    2017-02-01

    To compare the noise levels perceived by critical care nurses in the Intensive Care Unit (ICU) to actual noise levels in the ICU. Following a pilot study (n=18) and revision of the survey tool, a random sample of nurses were surveyed twice in a 3-day period (n=108). Nurses perception of noise was compared to the actual sound pressure level using descriptive statistics. Nurses perceived the ICUs to be noisier than the actual values. The ICU was louder than the recommended noise level for resotrative sleep. This finding raises the question of how we can assist nurses to reduce what they perceive to be a loud environment. Future work is needed to develop interventions specifically for nurses to raise awareness of noise in the ICU and to provide them with skills to assist in noise reduction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Double valve Implantation

    PubMed Central

    Stassano, Paolo; Mannacio, Vito; Musumeci, Antonino; Golino, Alessandro; Maida, Piero; Ferrigno, Vincenzo; Buonocore, Gaetano; Spampinato, Nicola

    1991-01-01

    From January 1976 through December 1987, 194 patients with a mean age of 43.3 ± 13.7 years (range, 11 to 74 years) underwent double (mitral and aortic) replacement of native valves with 8 types of bioprostheses: Carpentier-Edwards, 127 valves; Hancock, 76 valves; Liotta-Bioimplant, 57 valves; Ionescu-Shiley, 53 valves; Vascor, 27 valves; Carpentier-Edwards Pericardial, 22 valves; Angell-Shiley, 20 valves; and Implamedic, 6 valves. Concomitant cardiac procedures were performed in 25 patients (12.8%). There were 18 operative deaths (9.27%). Our retrospective analysis was restricted to 352 bioprostheses implanted in the 176 patients who survived surgery and were considered at risk for valve tissue failure. The overall cumulative duration of follow-up was 1,174.1 patient-years (range, 1 to 13 years). The durations of follow-up for specific valves were: Carpentier-Edwards, 920.2 valve-years; Hancock, 383.8 valve-years; Liotta-Bioimplant, 310.2 valve-years; Ionescu-Shiley, 357.7 valve-years; Vascor, 131.2 valve-years; Carpentier-Edwards Pericardial, 52.0 valve-years; Angell-Shiley, 167.0 valve-years; and Implamedic, 31.0 valve-years. Thirty patients had thromboembolic accidents, for a linearized incidence of 2.5% per patient-year. At 13 years, the actuarial freedom from thromboembolic accidents was 85.8% ± 10.7%. Nine patients had endocarditis, for a linearized incidence of 0.7% per patient-year. At 13 years, the actuarial freedom from endocarditis was 92.0% ± 1.5%. Twenty-four patients had valve tissue failure, for a cumulative linearized incidence of 1.87% per valve-year. The cumulative actuarial probability of freedom from valve tissue failure was 78.6% ± 3.7% at 10 years and 51.2% ± 10.7% at 13 years. The 24 patients with valve tissue failure all underwent reoperation: 20 of these had double valve replacement, 3 had aortic valve replacement alone, and 1 had mitral valve replacement alone. The mean interval between initial valve implantation and reoperation was

  13. Hearing preservation in cochlear implantation and drug treatment.

    PubMed

    Barriat, Sebastien; Poirrier, Annelise; Malgrange, Brigitte; Lefebvre, Philippe

    2010-01-01

    Insertion of an electrode array into the cochlea produces immediate damage to the inner ear, which is responsible for a hearing loss. In addition, a delayed hearing loss can be observed. In order to maximize hearing preservation after insertion of an electrode and to enhance the performance of the cochlear implant, it has been proposed to deliver pharmacological agents to the inner ear. Molecules can be administered locally to the inner ear through a direct perilymphatic perfusion or through the round window membrane. These modalities of treatment have already been successfully applied to some patients with inner ear diseases. In this paper, we will review some basic aspects of drug delivery to the inner ear to prevent the degeneration of the neurosensory hair cells and auditory neurons, and the actual applicability to humans in order to maintain hearing function after the insertion of electrodes of a cochlear implant.

  14. Comparison of simulated and actual wind shear radar data products

    NASA Technical Reports Server (NTRS)

    Britt, Charles L.; Crittenden, Lucille H.

    1992-01-01

    Prior to the development of the NASA experimental wind shear radar system, extensive computer simulations were conducted to determine the performance of the radar in combined weather and ground clutter environments. The simulation of the radar used analytical microburst models to determine weather returns and synthetic aperture radar (SAR) maps to determine ground clutter returns. These simulations were used to guide the development of hazard detection algorithms and to predict their performance. The structure of the radar simulation is reviewed. Actual flight data results from the Orlando and Denver tests are compared with simulated results. Areas of agreement and disagreement of actual and simulated results are shown.

  15. Management of fluocinolone implant dissociation during implant exchange.

    PubMed

    Yeh, Steven; Cebulla, Colleen M; Witherspoon, S Robert; Emerson, Geoffrey G; Emerson, M Vaughn; Suhler, Eric B; Albini, Thomas A; Flaxel, Christina J

    2009-09-01

    Three patients with chronic, noninfectious uveitis requiring immunosuppressive therapy underwent fluocinolone acetonide (FA) implant exchange complicated by dissociation of the medication reservoir from its anchoring strut. In 2 patients, the medication reservoir descended into the vitreous cavity and required pars plana vitrectomy with intraocular foreign body removal techniques for its retrieval. The use of viscoelastic or perfluorocarbon to elevate the device was helpful in the safe removal of the FA implant device. Surgeons performing FA implant exchange should be aware of this potential complication and anticipate the possible need for vitreoretinal instrumentation and personnel. Patients undergoing FA explantation or exchange should be counseled regarding this potential complication prior to surgery.

  16. [Implantable artificial heart].

    PubMed

    Nojiri, Chisato

    2005-11-01

    Heart transplants have been decreasing globally due to the lack of available donor hearts. As a result, the increased use of artificial hearts is anticipated as an alternative therapy. Although biocompatibility issues, such as thrombus formation/thromboembolism and infection, are still the main cause of mortality associated with artificial hearts, more than 20 different types are now clinically available after a half-century of development and experimental trials. These devices range from extracorporeal pneumatic to implantable battery-powered artificial hearts. The early development of artificial hearts logically focused on volumetric pump designs incorporating functions similar to the natural heart. Today, development has shifted toward designs that are significantly different from the natural heart. These pumps utilize axial or centrifugal flow allowing for a much simpler design, which is smaller in size and has very few moving parts. With rapid advances in technology, this new generation of artificial heart pumps is beginning to emerge as an alternative to heart transplants.

  17. Implantable, multifunctional, bioresorbable optics

    PubMed Central

    Tao, Hu; Kainerstorfer, Jana M.; Siebert, Sean M.; Pritchard, Eleanor M.; Sassaroli, Angelo; Panilaitis, Bruce J. B.; Brenckle, Mark A.; Amsden, Jason J.; Levitt, Jonathan; Fantini, Sergio; Kaplan, David L.; Omenetto, Fiorenzo G.

    2012-01-01

    Advances in personalized medicine are symbiotic with the development of novel technologies for biomedical devices. We present an approach that combines enhanced imaging of malignancies, therapeutics, and feedback about therapeutics in a single implantable, biocompatible, and resorbable device. This confluence of form and function is accomplished by capitalizing on the unique properties of silk proteins as a mechanically robust, biocompatible, optically clear biomaterial matrix that can house, stabilize, and retain the function of therapeutic components. By developing a form of high-quality microstructured optical elements, improved imaging of malignancies and of treatment monitoring can be achieved. The results demonstrate a unique family of devices for in vitro and in vivo use that provide functional biomaterials with built-in optical signal and contrast enhancement, demonstrated here with simultaneous drug delivery and feedback about drug delivery with no adverse biological effects, all while slowly degrading to regenerate native tissue. PMID:23150544

  18. Convex optimization of MRI exposure for mitigation of RF-heating from active medical implants

    NASA Astrophysics Data System (ADS)

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2015-09-01

    Local RF-heating of elongated medical implants during magnetic resonance imaging (MRI) may pose a significant health risk to patients. The actual patient risk depends on various parameters including RF magnetic field strength and frequency, MR coil design, patient’s anatomy, posture, and imaging position, implant location, RF coupling efficiency of the implant, and the bio-physiological responses associated with the induced local heating. We present three constrained convex optimization strategies that incorporate the implant’s RF-heating characteristics, for the reduction of local heating of medical implants during MRI. The study emphasizes the complementary performances of the different formulations. The analysis demonstrates that RF-induced heating of elongated metallic medical implants can be carefully controlled and balanced against MRI quality. A reduction of heating of up to 25 dB can be achieved at the cost of reduced uniformity in the magnitude of the B1+ field of less than 5%. The current formulations incorporate a priori knowledge of clinically-specific parameters, which is assumed to be available. Before these techniques can be applied practically in the broader clinical context, further investigations are needed to determine whether reduced access to a priori knowledge regarding, e.g. the patient’s anatomy, implant routing, RF-transmitter, and RF-implant coupling, can be accepted within reasonable levels of uncertainty.

  19. Computer-aided design provisionalization and implant insertion combined with optical scanning of plaster casts and computed tomography data

    PubMed Central

    Hara, Shingo; Mitsugi, Masaharu; Kanno, Takahiro; Tatemoto, Yukihiro

    2014-01-01

    The conventional implant prosthesis planning process currently involves confirmation of two-dimensional anatomical findings or the quantity and quality of bones using panoramic X-ray images. The introduction of computed tomography (CT) into the field has enabled the previously impossible confirmation of three-dimensional findings, making implant planning in precise locations possible. However, artifacts caused by the presence of metal prostheses can become problematic and can result in obstacles to diagnosis and implant planning. The most updated version of SimPlant® Pro has made it possible to integrate plaster cast images with CT data using optical scanning. Using this function, the obstacles created by metal prostheses are eliminated, facilitating implant planning at the actual intraoral location. Furthermore, a SurgiGuide® based on individual patient information can be created on plaster casts, resulting in easier and more precise implant insertion. PMID:24987602

  20. Microsystems Technology for Retinal Implants

    NASA Astrophysics Data System (ADS)

    Weiland, James

    2005-03-01

    The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

  1. Patient-Specific Orthopaedic Implants.

    PubMed

    Haglin, Jack M; Eltorai, Adam E M; Gil, Joseph A; Marcaccio, Stephen E; Botero-Hincapie, Juliana; Daniels, Alan H

    2016-11-01

    Patient-specific orthopaedic implants are emerging as a clinically promising treatment option for a growing number of conditions to better match an individual's anatomy. Patient-specific implant (PSI) technology aims to reduce overall procedural costs, minimize surgical time, and maximize patient outcomes by achieving better biomechanical implant fit. With this commercially-available technology, computed tomography or magnetic resonance images can be used in conjunction with specialized computer programs to create preoperative patient-specific surgical plans and to develop custom cutting guides from 3-D reconstructed images of patient anatomy. Surgeons can then place these temporary guides or "jigs" during the procedure, allowing them to better recreate the exact resections of the computer-generated surgical plan. Over the past decade, patient-specific implants have seen increased use in orthopaedics and they have been widely indicated in total knee arthroplasty, total hip arthroplasty, and corrective osteotomies. Patient-specific implants have also been explored for use in total shoulder arthroplasty and spinal surgery. Despite their increasing popularity, significant support for PSI use in orthopaedics has been lacking in the literature and it is currently uncertain whether the theoretical biomechanical advantages of patient-specific orthopaedic implants carry true advantages in surgical outcomes when compared to standard procedures. The purpose of this review was to assess the current status of patient-specific orthopaedic implants, to explore their future direction, and to summarize any comparative published studies that measure definitive surgical characteristics of patient-specific orthopaedic implant use such as patient outcomes, biomechanical implant alignment, surgical cost, patient blood loss, or patient recovery.

  2. Actual and Potential Returns to Schooling in Spain

    ERIC Educational Resources Information Center

    Prieto, Carmen Garcia; Roman, Angel Martin; Dominguez, Carlos Perez

    2005-01-01

    The returns to formal schooling in Spain are estimated in this paper. The main difference between this and previous papers on this subject is that, here, a distinction is made between the increase in the workers' potential maximum wage due to schooling and the actual registered increase. This difference (or underpayment) can be justified on the…

  3. Comparison of Actual Surgical Outcomes and 3D Surgical Simulations

    PubMed Central

    Tucker, Scott; Cevidanes, Lucia; Styner, Martin; Kim, Hyungmin; Reyes, Mauricio; Proffit, William; Turvey, Timothy

    2009-01-01

    Purpose The advent of imaging software programs have proved to be useful for diagnosis, treatment planning, and outcome measurement, but precision of 3D surgical simulation still needs to be tested. This study was conducted to determine if the virtual surgery performed on 3D models constructed from Cone-beam CT (CBCT) can correctly simulate the actual surgical outcome and to validate the ability of this emerging technology to recreate the orthognathic surgery hard tissue movements in 3 translational and 3 rotational planes of space. Methods Construction of pre- and post-surgery 3D models from CBCTs of 14 patients who had combined maxillary advancement and mandibular setback surgery and 6 patients who had one-piece maxillary advancement surgery was performed. The post-surgery and virtually simulated surgery 3D models were registered at the cranial base to quantify differences between simulated and actual surgery models. Hotelling T-test were used to assess the differences between simulated and actual surgical outcomes. Results For all anatomic regions of interest, there was no statistically significant difference between the simulated and the actual surgical models. The right lateral ramus was the only region that showed a statistically significant, but small difference when comparing two- and one-jaw surgeries. Conclusions Virtual surgical methods were reliably reproduced, oral surgery residents could benefit from virtual surgical training, and computer simulation has the potential to increase predictability in the operating room. PMID:20591553

  4. Progressive Digressions: Home Schooling for Self-Actualization.

    ERIC Educational Resources Information Center

    Rivero, Lisa

    2002-01-01

    Maslow's (1971) theory of primary creativeness is used as the basis for a self-actualization model of education. Examples of how to use the model in creative homeschooling are provided. Key elements include digressive and immersion learning, self-directed learning, and the integration of work and play. Teaching suggestions are provided. (Contains…

  5. Actual Leisure Participation of Norwegian Adolescents with Down Syndrome

    ERIC Educational Resources Information Center

    Dolva, Anne-Stine; Kleiven, Jo; Kollstad, Marit

    2014-01-01

    This article reports the actual participation in leisure activities by a sample of Norwegian adolescents with Down syndrome aged 14. Representing a first generation to grow up in a relatively inclusive context, they live with their families, attend mainstream schools, and are part of common community life. Leisure information was obtained in…

  6. Actual and Virtual Reality: Making the Most of Field Trips.

    ERIC Educational Resources Information Center

    Bellan, Jennifer Marie; Scheurman, Geoffrey

    1998-01-01

    Argues that a virtual field trip can complement and enhance a real one. Discusses the benefits and pitfalls of both types of field trips. Outlines a series of student and teacher activities combining an actual field trip and a virtual one to Fort Snelling in St. Paul, Minnesota. (MJP)

  7. William Brennan and the Failed "Theory" of Actual Malice.

    ERIC Educational Resources Information Center

    Gillmor, Donald M.

    This paper contains an analysis of Justice William Brennan's Supreme Court opinions concerning cases on freedom of expression and his interpretations of Alexander Meiklejohn's theory of actual malice in cases of libel. Particular attention is paid to Brennan's landmark contribution to the law of libel, his opinion in "New York Times v.…

  8. Fair Equality of Opportunity in Our Actual World

    ERIC Educational Resources Information Center

    Sachs, Benjamin

    2016-01-01

    Fair equality of opportunity, a principle that governs the competition for desirable jobs, can seem irrelevant in our actual world, for two reasons. First, parents have broad liberty to raise their children as they see fit, which seems to undermine the fair equality of opportunity-based commitment to eliminating the effects of social circumstances…

  9. Venture actualization in nursing. An analysis of innovation.

    PubMed

    Neidlinger, S H; Bartleson, B J; Drews, N; Hukari, D

    1992-01-01

    From innovations shared by nurse executives and nurse intrapreneurs in acute care hospitals, The Venture Actualization in Nursing Model emerged. Derived from a nursing perspective, this model captures the steps of the nurse innovation process, linking the nurse executive and nurse intrapreneur role components to the process that leads to venture success.

  10. Computer/PERT technique monitors actual versus allocated costs

    NASA Technical Reports Server (NTRS)

    Houry, E.; Walker, J. D.

    1967-01-01

    A computer method measures the users performance in cost-type contracts utilizing the existing nasa program evaluation review technique without imposing any additional reporting requirements. progress is measured by comparing actual costs with a value of work performed in a specific period.

  11. 24 CFR 200.96 - Certificates of actual cost.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... URBAN DEVELOPMENT GENERAL INTRODUCTION TO FHA PROGRAMS Requirements for Application, Commitment, and... Continuing Eligibility Requirements for Existing Projects Cost Certification § 200.96 Certificates of actual... before final endorsement, except that in the case of an existing project that does not...

  12. Probability: Actual Trials, Computer Simulations, and Mathematical Solutions.

    ERIC Educational Resources Information Center

    Walton, Karen Doyle; Walton, J. Doyle

    The purpose of this teaching unit is to approach elementary probability problems in three ways. First, actual trials are performed and results are recorded. Second, a simple computer simulation of the problem provided on diskette and written for Apple IIe and IIc computers, is run several times. Finally, the mathematical solution of the problem is…

  13. Preschool Children's Judgments about Hypothetical and Actual Transgressions.

    ERIC Educational Resources Information Center

    Smetana, Judith G.; And Others

    1993-01-01

    Examined three and four year olds' judgments about transgressions. Children judged moral transgressions to be more serious, punishable, and wrong than conventional transgressions; hypothetical transgressions to be more wrong independent of rules than actual transgressions; and hypothetical moral transgressions to be more independent of rules than…

  14. Student Exposure to Actual Patients in the Classroom.

    ERIC Educational Resources Information Center

    Chisholm, Marie A.; McCall, Charles Y.; Francisco, George E., Jr.; Poirier, Sylvie

    1997-01-01

    Two clinical courses for first-year dental students were designed to develop students' interaction skills through actual patient case presentations and discussions and an interdisciplinary teaching approach. Results indicate students preferred the case presentations, with or without lecture, to the lecture-only approach and felt they learned more…

  15. A Taxometric Analysis of Actual Internet Sports Gambling Behavior

    ERIC Educational Resources Information Center

    Braverman, Julia; LaBrie, Richard A.; Shaffer, Howard J.

    2011-01-01

    This article presents findings from the first taxometric study of actual gambling behavior to determine whether we can represent the characteristics of extreme gambling as qualitatively distinct (i.e., taxonic) or as a point along a dimension. We analyzed the bets made during a 24-month study period by the 4,595 most involved gamblers among a…

  16. Fair Equality of Opportunity in Our Actual World

    ERIC Educational Resources Information Center

    Sachs, Benjamin

    2016-01-01

    Fair equality of opportunity, a principle that governs the competition for desirable jobs, can seem irrelevant in our actual world, for two reasons. First, parents have broad liberty to raise their children as they see fit, which seems to undermine the fair equality of opportunity-based commitment to eliminating the effects of social circumstances…

  17. 24 CFR 242.42 - Certificates of actual cost.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES MORTGAGE INSURANCE FOR HOSPITALS Endorsement for Insurance § 242.42 Certificates of actual cost. (a) The... case of an existing hospital that does not require substantial rehabilitation and where the commitment...

  18. A Taxometric Analysis of Actual Internet Sports Gambling Behavior

    ERIC Educational Resources Information Center

    Braverman, Julia; LaBrie, Richard A.; Shaffer, Howard J.

    2011-01-01

    This article presents findings from the first taxometric study of actual gambling behavior to determine whether we can represent the characteristics of extreme gambling as qualitatively distinct (i.e., taxonic) or as a point along a dimension. We analyzed the bets made during a 24-month study period by the 4,595 most involved gamblers among a…

  19. 26 CFR 513.8 - Addressee not actual owner.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 19 2014-04-01 2010-04-01 true Addressee not actual owner. 513.8 Section 513.8 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) REGULATIONS UNDER TAX... such partnership is not entitled to the reduced rate of tax provided in Article VI(1) of the convention...

  20. Progressive Digressions: Home Schooling for Self-Actualization.

    ERIC Educational Resources Information Center

    Rivero, Lisa

    2002-01-01

    Maslow's (1971) theory of primary creativeness is used as the basis for a self-actualization model of education. Examples of how to use the model in creative homeschooling are provided. Key elements include digressive and immersion learning, self-directed learning, and the integration of work and play. Teaching suggestions are provided. (Contains…

  1. MLCMS Actual Use, Perceived Use, and Experiences of Use

    ERIC Educational Resources Information Center

    Asiimwe, Edgar Napoleon; Grönlund, Åke

    2015-01-01

    Mobile learning involves use of mobile devices to participate in learning activities. Most e-learning activities are available to participants through learning systems such as learning content management systems (LCMS). Due to certain challenges, LCMS are not equally accessible on all mobile devices. This study investigates actual use, perceived…

  2. Actualizing Concepts in Home Management: Proceedings of a National Conference.

    ERIC Educational Resources Information Center

    American Home Economics Association, Washington, DC.

    The booklet prints the following papers delivered at a national conference: Actualizing Concepts in Home Management: Decision Making, Dorothy Z. Price; Innovations in Teaching: Ergonomics, Fern E. Hunt; Relevant Concepts of Home Management: Innovations in Teaching, Kay P. Edwards; Standards in a Managerial Context, Florence S. Walker; Organizing:…

  3. 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.

  4. Mechanical behavior of the human lumbar intervertebral disc with polymeric hydrogel nucleus implant: An experimental and finite element study

    NASA Astrophysics Data System (ADS)

    Joshi, Abhijeet Bhaskar

    The origin of the lower back pain is often the degenerated lumbar intervertebral disc (IVD). We are proposing replacement of the degenerated nucleus by a PVA/PVP polymeric hydrogel implant. We hypothesize that a polymeric hydrogel nucleus implant can restore the normal biomechanics of the denucleated IVD by mimicking the natural load transfer phenomenon as in case of the intact IVD. Lumbar IVDs (n = 15) were harvested from human cadavers. In the first part, specimens were tested in four different conditions for compression: Intact, bone in plug, denucleated and Implanted. Hydrogel nucleus implants were chosen to have line-to-line fit in the created nuclear cavity. In the second part, nucleus implant material (modulus) and geometric (height and diameter) parameters were varied and specimens (n = 9) were tested. Nucleus implants with line-to-line fit significantly restored (88%) the compressive stiffness of the denucleated IVD. The synergistic effect between the implant and the intact annulus resulted in the nonlinear increase in implanted IVD stiffness, where Poisson effect of the hydrogel played major role. Nucleus implant parameters were observed to have a significant effect on the compressive stiffness. All implants with modulus in the tested range restored the compressive stiffness. The undersize implants resulted in incomplete restoration while oversize implants resulted in complete restoration compared to the BI condition. Finite element models (FEM) were developed to simulate the actual test conditions and validated against the experimental results for all conditions. The annulus (defined as hyperelastic, isotropic) mainly determined the nonlinear response of the IVD. Validated FEMs predicted 120--3000 kPa as a feasible range for nucleus implant modulus. FEMs also predicted that overdiameter implant would be more effective than overheight implant in terms of stiffness restoration. Underdiameter implants, initially allowed inward deformation of the annulus and

  5. Male chest enhancement: pectoral implants.

    PubMed

    Benito-Ruiz, J; Raigosa, J M; Manzano-Surroca, M; Salvador, L

    2008-01-01

    The authors present their experience with the pectoral muscle implant for male chest enhancement in 21 patients. The markings and technique are thoroughly described. The implants used were manufactured and custom made. The candidates for implants comprised three groups: group 1 (18 patients seeking chest enhancement), group 2 (1 patient with muscular atrophy), and group 3 (2 patients with muscular injuries). Because of the satisfying results obtained, including significant enhancement of the chest contour and no major complications, this technique is used for an increasing number of male cosmetic surgeries.

  6. [Considerations for optimizing joint implants].

    PubMed

    Tensi, H M; Orloff, S; Gese, H; Hooputra, H

    1994-09-01

    Despite the increasing use of orthopaedic implants, there is still a lack of adequate testing procedures and legal guidelines. Examples of the consequences of this neglect are given. Modern techniques for the calculation of stresses (finite element method [FEM]) and the prediction of life cycle duration are presented. Such methods, applied in the development and manufacturing phases of standard and special implants, may ensure an adequate prosthetic life cycle, with particular emphasis being placed on the biomedical optimization of the implant/bone interface and surrounding bone.

  7. [Calculation of the implant: is it a useless luxury?].

    PubMed

    Risse, J F; Guillaume, J B; Boissonnot, M

    1989-03-01

    Analysis of the means by which accuracy of intraocular lens power calculation could be improved with theoretical and linear regression formulas. The postoperative refractive errors with the lenses selected by the surgeon were compared with those observed with the emmetropic calculated power lenses and with a standard 20 diopters lens. A consecutive series of 100 eyes with less than 4.50 diopters of pre-operative myopia or hypermyopia, is evaluated. Postoperative refractive errors are out of the range -4; +4 diopters in 6% for standard lens, 4% for actually implanted lens, and 1% for emmetropic power calculated lens.

  8. Occlusion on oral implants: current clinical guidelines.

    PubMed

    Koyano, K; Esaki, D

    2015-02-01

    Proper implant occlusion is essential for adequate oral function and the prevention of adverse consequences, such as implant overloading. Dental implants are thought to be more prone to occlusal overloading than natural teeth because of the loss of the periodontal ligament, which provides shock absorption and periodontal mechanoreceptors, which provide tactile sensitivity and proprioceptive motion feedback. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Thus, we performed a narrative literature review to ascertain the influence of implant occlusion on the occurrence of complications of implant treatment and discuss the clinical considerations focused on the overloading factors at present. The search terms were 'dental implant', 'dental implantation', 'dental occlusion' and 'dental prosthesis'. The inclusion criteria were literature published in English up to September 2013. Randomised controlled trials (RCTs), prospective cohort studies and case-control studies with at least 20 cases and 12 months follow-up interval were included. Based on the selected literature, this review explores factors related to the implant prosthesis (cantilever, crown/implant ratio, premature contact, occlusal scheme, implant-abutment connection, splinting implants and tooth-implant connection) and other considerations, such as the number, diameter, length and angulation of implants. Over 700 abstracts were reviewed, from which more than 30 manuscripts were included. We found insufficient evidence to establish firm clinical guidelines for implant occlusion. To discuss the ideal occlusion for implants, further well-designed RCTs are required in the future.

  9. Accidental Implant Screwdriver Ingestion: A Rare Complication during Implant Placement

    PubMed Central

    Jain, Anshul; Baliga, Shridhar D

    2014-01-01

    One of the complications during a routine dental implant placement is accidental ingestion of the implant instruments, which can happen when proper precautions are not taken. Appropriate radiographs should be taken to locate the correct position of foreign body; usually the foreign body passes asymptomatically from gastrointestinal tract but sometimes it may lead to intestinal obstruction, perforations and impactions. The aim of this article is to report accidental ingestion of 19 mm long screw driver by a senile patient. PMID:25628702

  10. Implant retention systems for implant-retained overdentures.

    PubMed

    Laverty, D P; Green, D; Marrison, D; Addy, L; Thomas, M B M

    2017-03-10

    Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those that are edentate. This article aims to inform the reader of a variety of retention systems that are available to retain an implant overdenture and to understand how these systems work, their advantages and disadvantages and to outline some of the clinical and treatment planning considerations involved in selecting the most appropriate retention system for patients.

  11. In vivo assessments of bioabsorbable AZ91 magnesium implants coated with nanostructured fluoridated hydroxyapatite by MAO/EPD technique for biomedical applications.

    PubMed

    Razavi, Mehdi; Fathi, Mohammadhossein; Savabi, Omid; Vashaee, Daryoosh; Tayebi, Lobat

    2015-03-01

    Although magnesium (Mg) is a unique biodegradable metal which possesses mechanical property similar to that of the natural bone and can be an attractive material to be used as orthopedic implants, its quick corrosion rate restricts its actual clinical applications. To control its rapid degradation, we have modified the surface of magnesium implant using fluoridated hydroxyapatite (FHA: Ca10(PO4)6OH2-xFx) through the combined micro-arc oxidation (MAO) and electrophoretic deposition (EPD) techniques, which was presented in our previous paper. In this article, the biocompatibility examinations were conducted on the coated AZ91 magnesium alloy by implanting it into the greater trochanter area of rabbits. The results of the in vivo animal test revealed a significant enhancement in the biocompatibility of FHA/MAO coated implant compared to the uncoated one. By applying the FHA/MAO coating on the AZ91 implant, the amount of weight loss and magnesium ion release in blood plasma decreased. According to the histological results, the formation of the new bone increased and the inflammation decreased around the implant. In addition, the implantation of the uncoated AZ91 alloy accompanied by the release of hydrogen gas around the implant; this release was suppressed by applying the coated implant. Our study exemplifies that the surface coating of magnesium implant using a bioactive ceramic such as fluoridated hydroxyapatite may improve the biocompatibility of the implant to make it suitable as a commercialized biomedical product.

  12. Rehabilitation of malpositioned implants with a CAD/CAM milled implant overdenture: a clinical report.

    PubMed

    Moeller, Mauricio S; Duff, Renee E; Razzoog, Michael E

    2011-03-01

    Dentists may be faced with the challenge of restoring unfavorably placed implants. In some instances, previously integrated implants may be from different manufacturers. This clinical report describes the rehabilitation of a patient with a maxillary CAD/CAM implant bar-supported overdenture that presented with malpositioned implants, from different manufacturers, including one from a discontinued implant system.

  13. Relationship of the actual thick intraocular lens optic to the thin lens equivalent.

    PubMed

    Holladay, J T; Maverick, K J

    1998-09-01

    To theoretically derive and empirically validate the relationship between the actual thick intraocular lens and the thin lens equivalent. Included in the study were 12 consecutive adult patients ranging in age from 54 to 84 years (mean +/- SD, 73.5 +/- 9.4 years) with best-corrected visual acuity better than 20/40 in each eye. Each patient had bilateral intraocular lens implants of the same style, placed in the same location (bag or sulcus) by the same surgeon. Preoperatively, axial length, keratometry, refraction, and vertex distance were measured. Postoperatively, keratometry, refraction, vertex distance, and the distance from the vertex of the cornea to the anterior vertex of the intraocular lens (AV(PC1)) were measured. Alternatively, the distance (AV(PC1)) was then back-calculated from the vergence formula used for intraocular lens power calculations. The average (+/-SD) of the absolute difference in the two methods was 0.23 +/- 0.18 mm, which would translate to approximately 0.46 diopters. There was no statistical difference between the measured and calculated values; the Pearson product-moment correlation coefficient from linear regression was 0.85 (r2 = .72, F = 56). The average intereye difference was -0.030 mm (SD, 0.141 mm; SEM, 0.043 mm) using the measurement method and +0.124 mm (SD, 0.412 mm; SEM, 0.124 mm) using the calculation method. The relationship between the actual thick intraocular lens and the thin lens equivalent has been determined theoretically and demonstrated empirically. This validation provides the manufacturer and surgeon additional confidence and utility for lens constants used in intraocular lens power calculations.

  14. Safety of Outpatient Implantation of the Implantable Cardioverter-defibrillator.

    PubMed

    Datino, Tomás; Miracle Blanco, Ángel; Núñez García, Alberto; González-Torrecilla, Esteban; Atienza Fernández, Felipe; Arenal Maíz, Ángel; Hernández-Hernández, Jesús; Ávila Alonso, Pablo; Eidelman, Gabriel; Fernández-Avilés, Francisco

    2015-07-01

    Strategies are needed to reduce health care costs and improve patient care. The objective of our study was to analyze the safety of outpatient implantation of cardioverter-defibrillators. A retrospective study was conducted in 401 consecutive patients who received an implantable cardioverter-defibrillator between 2007 and 2012. The rate of intervention-related complications was compared between 232 patients (58%) whose implantation was performed in the outpatient setting and 169 patients (42%) whose intervention was performed in the inpatient setting. The mean age (standard deviation) of the patients was 62 (14) years; 336 (84%) were male. Outpatients had lower left ventricular ejection fraction and a higher percentage had an indication for primary prevention of sudden death, compared to inpatients. Only 21 outpatients (9%) required subsequent hospitalization. The rate of complications until the third month postimplantation was similar for outpatients (6.0%) and inpatients (5.3%); P = .763. In multivariate analysis, only previous anticoagulant therapy was related to the presence of complications (odds ratio = 3.2; 95% confidence interval, 1.4-7.4; P < .01), mainly due to an increased rate of pocket hematomas. Each outpatient implantation saved approximately €735. Outpatient implantation of implantable cardioverter-defibrillators is safe and reduces costs. Close observation is recommended for patients receiving chronic anticoagulation therapy due to an increased risk of complications. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  15. Miniscrew implant applications in contemporary orthodontics.

    PubMed

    Chang, Hong-Po; Tseng, Yu-Chuan

    2014-03-01

    The need for orthodontic treatment modalities that provide maximal anchorage control but with minimal patient compliance requirements has led to the development of implant-assisted orthodontics and dentofacial orthopedics. Skeletal anchorage with miniscrew implants has no patient compliance requirements and has been widely incorporated in orthodontic practice. Miniscrew implants are now routinely used as anchorage devices in orthodontic treatment. This review summarizes recent data regarding the interpretation of bone data (i.e., bone quantity and quality) obtained by preoperative diagnostic computed tomography (CT) or by cone-beam computed tomography (CBCT) prior to miniscrew implant placement. Such data are essential when selecting appropriate sites for miniscrew implant placement. Bone characteristics that are indications and contraindications for treatment with miniscrew implants are discussed. Additionally, bicortical orthodontic skeletal anchorage, risks associated with miniscrew implant failure, and miniscrew implants for nonsurgical correction of occlusal cant or vertical excess are reviewed. Finally, implant stability is compared between titanium alloy and stainless steel miniscrew implants.

  16. Radiographic determinants of implant performance.

    PubMed

    Reddy, M S; Wang, I C

    1999-06-01

    This paper reviews and compares the strengths and weaknesses of radiographic techniques including periapical, occlusal, panoramic, direct digital, motion tomography, and computed tomography. Practical considerations for each method, including availability and accessibility, are discussed. To date, digital subtraction radiography is the most versatile and sensitive method for measuring boss loss. It can detect both bone height and bone mass changes on root-form or blade-form dental implants. Criteria for implant success have changed substantially over the past two decades. In clinical trials of dental implants, the outcomes require certain radiographic analyses to address the hypothesis or clinical question adequately. Radiographic methods best suited to the objective assessment of implant performance and hypothesis were reviewed.

  17. Implants for draining neovascular glaucoma.

    PubMed Central

    Molteno, A C; Van Rooyen, M M; Bartholomew, R S

    1977-01-01

    The implant design, surgical technique, and pharmacological methods of controlling bleb fibrosis, used to treat neovascular glaucoma, are described, together with the results of 14 operations performed on 12 eyes. Images PMID:843508

  18. [Implantation in severe myopia cataract].

    PubMed

    Metge, P; Ginestet, X; Morin, B; Platon, O

    1989-01-01

    Based upon biometric and statistical analysis of 163 eyes (26 mm or longer), it appears that high myopia cataract occur all the earlier as the eye is long; on average, these were operated on ten years earlier than cataracts in the general population. Extra-capsular extraction and intercapsular implantation were generally used. Pre and post-operative complications are remarkably rare for such abnormal eyes. After a mean period of 22 months, detachment of the retina was observed in 1.84% of patients and secondary capsulotomy performed in 8%. Because they prevent secondary capsular opacification and anterior vitreous propagation, it appears that such barrier-type implants should be systematically placed. Current large-diameter implants allow for vitreoretinal observation. Based upon this patient population, a formula for implant power calculation specific to high myopia has been elaborated. The desired degree of refraction varies with age and patient activity.

  19. Advances in lens implant technology

    PubMed Central

    Kampik, Anselm; Dexl, Alois K.; Zimmermann, Nicole; Glasser, Adrian; Baumeister, Martin; Kohnen, Thomas

    2013-01-01

    Cataract surgery is one of the oldest and the most frequent outpatient clinic operations in medicine performed worldwide. The clouded human crystalline lens is replaced by an artificial intraocular lens implanted into the capsular bag. During the last six decades, cataract surgery has undergone rapid development from a traumatic, manual surgical procedure with implantation of a simple lens to a minimally invasive intervention increasingly assisted by high technology and a broad variety of implants customized for each patient’s individual requirements. This review discusses the major advances in this field and focuses on the main challenge remaining – the treatment of presbyopia. The demand for correction of presbyopia is increasing, reflecting the global growth of the ageing population. Pearls and pitfalls of currently applied methods to correct presbyopia and different approaches under investigation, both in lens implant technology and in surgical technology, are discussed. PMID:23413369

  20. Breast Implants: Saline vs. Silicone

    MedlinePlus

    ... be inserted at the same time. If an MRI scan detects an implant rupture but you don't ... require additional, specialized views. You might need routine MRI scans. The Food and Drug Administration recommends monitoring silicone ...

  1. [Imaging in silicone breast implantation].

    PubMed

    Gielens, Maaike P M; Koolen, Pieter G L; Hermens, Roland A E C; Rutten, Matthieu J C M

    2013-01-01

    Recently, there have been concerns regarding the use of breast implants from Poly Implant Prothèse (PIP, Seyne sur Mer, France) for breast augmentation due to their tendency to rupture and the possibility of having toxic contents. MRI using a specific silicone-sensitive sequence has proven to be the most sensitive and specific technique in the detection of intra- and extracapsular implant rupture. However, given its high costs, it is important that this technique is used sparingly. In this clinical lesson, we compare the sensitivity and specificity of mammography, ultrasound, CT and MRI for the detection of breast implant rupture. Based on two cases, a diagnostic approach is given in order to reduce health care costs.

  2. Surgical Tooth Implants, Combat and Field.

    DTIC Science & Technology

    1984-07-15

    and identify by block number) --- This Annual Report summarizes progress to date on a long-term implant study of a serrated ceramic dental implant...upper two parts of the implant, post and core and crown, are conventional metaT materials. A series of graded dental implants have been produced to...throughout the experimental period. Periodic radio- graphic analyses of dental implants verify this observation. Gross and microscopic patho- logic analyses

  3. Surgical Tooth Implants, Combat and Field.

    DTIC Science & Technology

    1985-11-15

    development of dental implantology must not be overlooked. The early stages of this project clearly defined that rigid fixation of an implant device...block number) .-... This report summarizes progress on a long-ter implant study of a serrated ceramic dental implant designed for fresh extraction...implant, post and core and crown, are conventional metal materials, A series of graded dental implants have been produced to provide an interference fit

  4. Biocompatibility of radiolucent breast implants.

    PubMed

    Young, V L; Lund, H; Destouet, J; Pidgeon, L; Ueda, K

    1991-09-01

    Current implants for breast augmentation containing silicone gel, saline, or both are radiopaque on mammographic examination and can totally obscure microcalcifications and soft-tissue masses. The effect of these implants on the detection of early breast cancers in patients who have undergone augmentation mammaplasty remains unproven and controversial. Implants filled with medium-chain triglycerides (peanut oil) are radiolucent on mammographic examination and allow visualization of both soft-tissue masses and microcalcifications. To investigate the biocompatibility of radiolucent implants, 10 cc of sterile, nonpyrogenic peanut oil was injected subcutaneously into rats using silicone gel as a control. Twenty-one rabbits had two 125-cc silicone shell implants inserted on either side of the chest wall. The right-sided shell was filled with 125 cc of sterile saline, and the left-sided shell was filled with 125 cc of sterile, nonpyrogenic peanut oil. Results were determined by both histologic and radiographic examination. Rats injected with peanut oil equivalent to 7 percent of their body weight rapidly absorbed the freely injected oil without detriment. Histologic examination of the lungs, liver, kidneys, and tissues adjacent to the injection sites demonstrated no abnormalities. There was no evidence of allergic, toxic, inflammatory, or neoplastic response. Eighteen of 21 rabbits survived more than 3 months. Radiographs showed the oil-filled implants to be radiolucent, whereas the saline-filled controls obscured the surrounding soft and bony tissues. Histologic examination demonstrated a fibrous capsule surrounding both types of implants. Histologic examination of the lungs, liver, and kidneys showed no significant abnormalities. These and previous studies have shown peanut oil to be biocompatible when freely injected either intramuscularly or subcutaneously. This study demonstrates that a radiolucent, peanut oil-filled implant is biocompatible in animals and that

  5. Implant-related nerve injuries.

    PubMed

    Steinberg, Mark J; Kelly, Patrick D

    2015-04-01

    Injuries to branches of the trigeminal nerves are a known complication during dental implant placement. These injuries tend to be more severe than those experienced during other dentoalveolar procedures. This article reviews the types of nerve injuries and areas and situations of which clinicians should be cognizant when placing dental implants. Strategies to avoid injuries, and a management algorithm for suspected nerve injuries, are also discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Cochlear implants in young children.

    PubMed

    Niparko, John K; Blankenhorn, Rebecca

    2003-01-01

    The cochlear implant is best characterized as a device that provides access to the sound environment. The device enables the hearing pathway to respond to environmental and speech sounds, providing informational cues from the surroundings and from others that may escape visual detection. As the developmental effects of a profound hearing loss are multiple, cochlear implants have been applied to ever younger children in an attempt to promote a more normal level of developmental learning through audition. In deafness, transducer elements of the inner ear fail to trigger auditory nerve afferent nerves in the presence of sound input. However, large reserves of afferent fibers exist even in the auditory nerve of a profoundly deaf patient. Furthermore, these nerve fibers retain the ability to respond to prosthetic activation. Through developmental learning in the early, formative years, auditory centers of the brain appear capable of processing information from the implant to provide speech comprehension and oral language development. Multichannel implants have replaced original single channel designs. multichannel devices enable larger percentages of recipients to recognize the spoken word without visual cues because they provide spectral information in addition to temporal and intensity cues. Testing under conditions of auditory (implant)-only input reveals significant open-set speech understanding capabilities in more than 75% of children after three years of device use. The benefit provided by implants may vary with a number of conditions including: hearing history, age of deafness onset, age at implantation, etiology of deafness, linguistic abilities, and the presence of a motivated system of support of oral language development. Patient variables should be given individual consideration in judging candidacy for a cochlear implant and in planning rehabilitative and education services after surgery and activation of the device. Copyright 2003 Wiley-Liss, Inc.

  7. [Guidelines for nursing methodology implantation].

    PubMed

    Alberdi Castell, Rosamaría; Artigas Lelong, Berta; Cuxart Ainaud, Núria; Agüera Ponce, Ana

    2003-09-01

    The authors introduce three guidelines as part of the process to implant the nursing methodology based on the Virginia Henderson Conceptual Model; they propose to help nurses adopt the aforementioned method in their daily practice. These three guidelines shall be published in successive articles: Guidelines to identify attitudes and aptitudes related to the nursing profession; Guidelines to implant the nursing methodology based on the Virginia Henderson Conceptual Model; and Guidelines to plan areas for improvement.

  8. EEG and implanted sources in the brain.

    PubMed

    van Burik, M; Peters, M

    1999-12-01

    Localisation procedures are based on models of the EEG that are relatively simple. The models are based on assumptions and choices of parameters that can be mistaken. Thus, it is crucial to validate the localisation procedures used in EEG. One of the options is to use the data obtained with electrodes that are implanted within the brain of an epileptic patient as part of the pre-surgical evaluation. When one of two neighbouring electrodes is used as a current source and the other as a current sink this can be regarded as a current dipole. The current injected has to be below the threshold for activation of cells. The position of this dipole can be deduced from magnetic resonance or X-ray images. The current dipole gives rise to a potential distribution at the scalp that can be measured by EEG. The measurements can be compared with the potential distribution that is calculated in a forward computation. Another method is to use the measured potential at the scalp to localize the source and to compare the result with the actual position of the dipole. In this paper the measured potential distributions at the scalp due to implanted dipoles were used to evaluate different volume conductor models. Since intracerebral and subdural electrodes were introduced through trephine holes over the fronto-central areas, and the diameter of the holes was rather large, approximately 23 mm, special effort was put into modelling the skull. Two important assumptions could be validated in this study: the electric currents within the head are Ohmic and a dipole can be used to model the induced electric activity of pairs of contacts on subdural electrodes or intra cerebral electrodes.

  9. The manufacture of generic replicas of implants for arthroplasty of the hip and knee: is it regulated and will it save money?

    PubMed

    Atrey, A; Heylen, S; Gosling, O; Porteous, M J L; Haddad, F S

    2016-07-01

    Joint replacement of the hip and knee remain very satisfactory operations. They are, however, expensive. The actual manufacturing of the implant represents only 30% of the final cost, while sales and marketing represent 40%. Recently, the patents on many well established and successful implants have expired. Companies have started producing and distributing implants that purport to replicate existing implants with good long-term results. The aims of this paper are to assess the legality, the monitoring and cost saving implications of such generic implants. We also assess how this might affect the traditional orthopaedic implant companies. Cite this article: Bone Joint J 2016;98-B:892-900. ©2016 The British Editorial Society of Bone & Joint Surgery.

  10. Nanostructured surfaces of dental implants.

    PubMed

    Bressan, Eriberto; Sbricoli, Luca; Guazzo, Riccardo; Tocco, Ilaria; Roman, Marco; Vindigni, Vincenzo; Stellini, Edoardo; Gardin, Chiara; Ferroni, Letizia; Sivolella, Stefano; Zavan, Barbara

    2013-01-17

    The structural and functional fusion of the surface of the dental implant with the surrounding bone (osseointegration) is crucial for the short and long term outcome of the device. In recent years, the enhancement of bone formation at the bone-implant interface has been achieved through the modulation of osteoblasts adhesion and spreading, induced by structural modifications of the implant surface, particularly at the nanoscale level. In this context, traditional chemical and physical processes find new applications to achieve the best dental implant technology. This review provides an overview of the most common manufacture techniques and the related cells-surface interactions and modulation. A Medline and a hand search were conducted to identify studies concerning nanostructuration of implant surface and their related biological interaction. In this paper, we stressed the importance of the modifications on dental implant surfaces at the nanometric level. Nowadays, there is still little evidence of the long-term benefits of nanofeatures, as the promising results achieved in vitro and in animals have still to be confirmed in humans. However, the increasing interest in nanotechnology is undoubted and more research is going to be published in the coming years.

  11. Clinical experiences with dental implants.

    PubMed

    Henry, P J

    1999-06-01

    The clinical utilization of dental implants has accelerated in recent years, and new applications continue to emerge. Concomitantly, alternative implant systems have introduced conceptually different approaches to treatment using altered protocols. The purpose of this paper is to address some of the background issues pertinent to the long-term success, survival, safety, and effectiveness of these devices. The requirements for clinical acceptance of implants are controlled initially by regulatory bodies; however, the dentist eventually must make a decision on which type of implant should be used in clinical practice. This clinical decision-making process should involve the strategy of using an evidence-based approach to ensure quality of care and reduction of liability for negligent care. This is particularly the case when treatment is undertaken in identified high-risk categories. While short- to medium-term data have been accumulated on the success rates of several implant systems, it is apparent that long-term data comparing and contrasting the various advantages and disadvantages of different systems do not exist, and adequate criteria applicable to the collective clinical experience need to be defined. Expanding areas of application are dependent on continuous improvements in implant hardware, surgical protocol development, and rationalized osteopromotive and site installation augmentation technology. Many treatment endeavors are still largely at the pilot study level of development, and long-term prospective clinical trials on large numbers of patients are required to document results adequately and to elucidate the most likely productive areas for future investigation.

  12. Ceramic-coated implant systems.

    PubMed

    Meffert, R M

    1999-06-01

    Practitioners have used hydroxyapatite-coated (HA-coated) endosseous and subperiosteal implants in various forms for many years. These have included root forms in both screw and cylindrical shapes, blades, and subperiosteals. The clinical predictability remains controversial and subject to claims and counterclaims. The early days of dental implantology involving root-form implants recommended their placement in fully edentulous cases only, and anterior to the maxillary sinus and mental foramen. Today's philosophy and rationale of dental implantology include the placement of a single implant replacing a missing natural tooth (especially where the teeth adjacent to the edentulous site have no caries or restorative experience). Implants are used to replace the natural dentition in one quadrant/segment, often preceded or accompanied by ridge augmentation and/or sinus grafting if sufficient bone is not present. So we have to address the clinical predictability of survival in terms of indications, quantity, and quality of bone. Clinical data and experience suggest that hydroxyapatite-coated (HA) dental implants may (and possibly should) be used in (1) Type IV bone, (2) fresh extraction sites, (3) grafted maxillary and/or nasal sinuses, or (4) with short implants (< or = 10 mm in length).

  13. Ion implanted dielectric elastomer circuits

    NASA Astrophysics Data System (ADS)

    O'Brien, Benjamin M.; Rosset, Samuel; Anderson, Iain A.; Shea, Herbert R.

    2013-06-01

    Starfish and octopuses control their infinite degree-of-freedom arms with panache—capabilities typical of nature where the distribution of reflex-like intelligence throughout soft muscular networks greatly outperforms anything hard, heavy, and man-made. Dielectric elastomer actuators show great promise for soft artificial muscle networks. One way to make them smart is with piezo-resistive Dielectric Elastomer Switches (DES) that can be combined with artificial muscles to create arbitrary digital logic circuits. Unfortunately there are currently no reliable materials or fabrication process. Thus devices typically fail within a few thousand cycles. As a first step in the search for better materials we present a preliminary exploration of piezo-resistors made with filtered cathodic vacuum arc metal ion implantation. DES were formed on polydimethylsiloxane silicone membranes out of ion implanted gold nano-clusters. We propose that there are four distinct regimes (high dose, above percolation, on percolation, low dose) in which gold ion implanted piezo-resistors can operate and present experimental results on implanted piezo-resistors switching high voltages as well as a simple artificial muscle inverter. While gold ion implanted DES are limited by high hysteresis and low sensitivity, they already show promise for a range of applications including hysteretic oscillators and soft generators. With improvements to implanter process control the promise of artificial muscle circuitry for soft smart actuator networks could become a reality.

  14. Retinal implants: a systematic review.

    PubMed

    Chuang, Alice T; Margo, Curtis E; Greenberg, Paul B

    2014-07-01

    Retinal implants present an innovative way of restoring sight in degenerative retinal diseases. Previous reviews of research progress were written by groups developing their own devices. This systematic review objectively compares selected models by examining publications describing five representative retinal prostheses: Argus II, Boston Retinal Implant Project, Epi-Ret 3, Intelligent Medical Implants (IMI) and Alpha-IMS (Retina Implant AG). Publications were analysed using three criteria for interim success: clinical availability, vision restoration potential and long-term biocompatibility. Clinical availability: Argus II is the only device with FDA approval. Argus II and Alpha-IMS have both received the European CE Marking. All others are in clinical trials, except the Boston Retinal Implant, which is in animal studies. Vision restoration: resolution theoretically correlates with electrode number. Among devices with external cameras, the Boston Retinal Implant leads with 100 electrodes, followed by Argus II with 60 electrodes and visual acuity of 20/1262. Instead of an external camera, Alpha-IMS uses a photodiode system dependent on natural eye movements and can deliver visual acuity up to 20/546. Long-term compatibility: IMI offers iterative learning; Epi-Ret 3 is a fully intraocular device; Alpha-IMS uses intraocular photosensitive elements. Merging the results of these three criteria, Alpha-IMS is the most likely to achieve long-term success decades later, beyond current clinical availability.

  15. Auditory Midbrain Implant: A Review

    PubMed Central

    Lim, Hubert H.; Lenarz, Minoo; Lenarz, Thomas

    2009-01-01

    The auditory midbrain implant (AMI) is a new hearing prosthesis designed for stimulation of the inferior colliculus in deaf patients who cannot sufficiently benefit from cochlear implants. The authors have begun clinical trials in which five patients have been implanted with a single shank AMI array (20 electrodes). The goal of this review is to summarize the development and research that has led to the translation of the AMI from a concept into the first patients. This study presents the rationale and design concept for the AMI as well a summary of the animal safety and feasibility studies that were required for clinical approval. The authors also present the initial surgical, psychophysical, and speech results from the first three implanted patients. Overall, the results have been encouraging in terms of the safety and functionality of the implant. All patients obtain improvements in hearing capabilities on a daily basis. However, performance varies dramatically across patients depending on the implant location within the midbrain with the best performer still not able to achieve open set speech perception without lip-reading cues. Stimulation of the auditory midbrain provides a wide range of level, spectral, and temporal cues, all of which are important for speech understanding, but they do not appear to sufficiently fuse together to enable open set speech perception with the currently used stimulation strategies. Finally, several issues and hypotheses for why current patients obtain limited speech perception along with several feasible solutions for improving AMI implementation are presented. PMID:19762428

  16. Cochlear implants and medical tourism.

    PubMed

    McKinnon, Brian J; Bhatt, Nishant

    2010-09-01

    To compare the costs of medical tourism in cochlear implant surgery performed in India as compared to the United States. In addition, the cost savings of obtaining cochlear implant surgery in India were compare d to those of other surgical interventions obtained as a medical tourist. Searches were conducted on Medline and Google using the search terms: 'medical tourism', 'medical offshoring', 'medical outsourcing', 'cochlear implants' and 'cochlear implantation'. The information regarding cost of medical treatment was obtained from personal communication with individuals familiar with India's cochlear implantation medical tourism industry. The range of cost depended on length of stay as well as the device chosen. Generally the cost, inclusive of travel, surgery and device, was in the range of $21,000-30,000, as compared to a cost range of $40,000-$60,000 in the US. With the escalating cost of healthcare in the United States, it is not surprising that some patients would seek to obtain surgical care overseas at a fraction of the cost. Participants in medical tourism often have financial resources, but lack health insurance coverage. While cardiovascular and orthopedic surgery performed outside the United States in India at centers that cater to medical tourists are often performed at one-quarter to one-third of the cost that would have been paid in the United States, the cost differential for cochlear implants is not nearly as favorable.

  17. Biomechanics of Corneal Ring Implants

    PubMed Central

    2015-01-01

    Purpose: To evaluate the biomechanics of corneal ring implants by providing a related mathematical theory and biomechanical model for the treatment of myopia and keratoconus. Methods: The spherical dome model considers the inhomogeneity of the tunica of the eye, dimensions of the cornea, lamellar structure of the corneal stroma, and asphericity of the cornea. It is used in this study for calculating a strengthening factor sf for the characterization of different ring-shaped corneal implant designs. The strengthening factor is a measure of the amount of strengthening of the cornea induced by the implant. Results: For ring segments and incomplete rings, sf = 1.0, which indicates that these implants are not able to strengthen the cornea. The intracorneal continuous complete ring (MyoRing) has a strengthening factor of up to sf = 3.2. The MyoRing is, therefore, able to strengthen the cornea significantly. Conclusions: The result of the presented biomechanical analysis of different ring-shaped corneal implant designs can explain the different postoperative clinical results of different implant types in myopia and keratoconus. PMID:26312619

  18. Therapy using implanted organic bioelectronics

    PubMed Central

    Jonsson, Amanda; Song, Zhiyang; Nilsson, David; Meyerson, Björn A.; Simon, Daniel T.; Linderoth, Bengt; Berggren, Magnus

    2015-01-01

    Many drugs provide their therapeutic action only at specific sites in the body, but are administered in ways that cause the drug’s spread throughout the organism. This can lead to serious side effects. Local delivery from an implanted device may avoid these issues, especially if the delivery rate can be tuned according to the need of the patient. We turned to electronically and ionically conducting polymers to design a device that could be implanted and used for local electrically controlled delivery of therapeutics. The conducting polymers in our device allow electronic pulses to be transduced into biological signals, in the form of ionic and molecular fluxes, which provide a way of interfacing biology with electronics. Devices based on conducting polymers and polyelectrolytes have been demonstrated in controlled substance delivery to neural tissue, biosensing, and neural recording and stimulation. While providing proof of principle of bioelectronic integration, such demonstrations have been performed in vitro or in anesthetized animals. Here, we demonstrate the efficacy of an implantable organic electronic delivery device for the treatment of neuropathic pain in an animal model. Devices were implanted onto the spinal cord of rats, and 2 days after implantation, local delivery of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) was initiated. Highly localized delivery resulted in a significant decrease in pain response with low dosage and no observable side effects. This demonstration of organic bioelectronics-based therapy in awake animals illustrates a viable alternative to existing pain treatments, paving the way for future implantable bioelectronic therapeutics. PMID:26601181

  19. Mechanical characterization and numerical simulation of polyether-ether-ketone (PEEK) cranial implants.

    PubMed

    El Halabi, F; Rodriguez, J F; Rebolledo, L; Hurtós, E; Doblaré, M

    2011-11-01

    Cranial implants have experienced a significant evolution in the last decade in different aspects such as materials, method of fixation, and the structure. In addition, patient-specific cranial implants have recently been started to be developed. To achieve this objective, efficient mechanical characterization and numerical modeling of the implant are required to guarantee its functionality on each patient as well as to facilitate further developments. In this work, mechanical characterization and numerical models have been performed for patient-specific Polyaryletherketone (PEEK) scaffold cranial implants. Mechanical characterization has been performed at the scaffold and the whole implant levels under displacement control tests. Two different implant designs for the same patient but with different scaffold structure were experimentally characterized, and finite element models of the implants were developed within the framework of linear elasticity. Two types of finite element models were developed: a detailed finite element model with the actual scaffold geometry, and a solid shell-like model with effective material properties. These effective material properties were obtained by means of the Asymptotic Expansion Homogenization (AEH) theory which accounts for the periodicity of the underlying structure of the material. Experimental results showed a linear response of the material and the implant up to failure, therefore supporting the use of linear elastic models for simulation. Numerical models showed excellent agreement with experiments regarding load-displacement response. Models also showed a very consistent behavior with regard to the location and the value of the maximum principal stress in the implant when subjected to the maximum load of the experiments. The two numerical models were compared. The homogenized model gave results that were very close to those obtained with the detailed model, while reducing the number of degrees of freedom by 90%, and

  20. Actual expense associated with patients with Alzheimer's disease in Colombia.

    PubMed

    Prada, Sergio I; Takeuchi, Yuri; Merchán-Galvis, Angela M; Ariza-Araújo, Yoseth

    2017-06-08

    There is paucity in the level of knowledge on the actual insurer expenses associated with patients suffering with dementia in the developing world. Less is known about direct costs by severity and how costs vary because of the presence of other comorbidities. Using claims data from an insurer for three years, we identified patients with AD with an algorithm that takes advantage of information on age, primary diagnosis, and services and drugs provided. Distribution by dementia stage was as follows: mild 21%, moderate 53%, severe 17%, and undetermined 9%. Expenses paid for all causes by the insurer were at least double than estimated in the literature and were increasing annually at rates higher than 30%. Also, 92% of patients have at least another chronic condition. Worldwide costs of dementia estimates maybe underestimating the actual costs to health systems in the developing world.

  1. Tourism guide cloud service quality: What actually delights customers?

    PubMed

    Lin, Shu-Ping; Yang, Chen-Lung; Pi, Han-Chung; Ho, Thao-Minh

    2016-01-01

    The emergence of advanced IT and cloud services has beneficially supported the information-intensive tourism industry, simultaneously caused extreme competitions in attracting customers through building efficient service platforms. On response, numerous nations have implemented cloud platforms to provide value-added sightseeing information and personal intelligent service experiences. Despite these efforts, customers' actual perspectives have yet been sufficiently understood. To bridge the gap, this study attempts to investigate what aspects of tourism cloud services actually delight customers' satisfaction and loyalty. 336 valid survey questionnaire answers were analyzed using structural equation modeling method. The results prove positive impacts of function quality, enjoyment, multiple visual aids, and information quality on customers' satisfaction as well as of enjoyment and satisfaction on use loyalty. The findings hope to provide helpful references of customer use behaviors for enhancing cloud service quality in order to achieve better organizational competitiveness.

  2. Actual curriculum development practices instrument: Testing for factorial validity

    NASA Astrophysics Data System (ADS)

    Foi, Liew Yon; Bakar, Kamariah Abu; Hamzah, Mohd Sahandri Gani; Alwi, Nor Hayati

    2014-09-01

    The Actual Curriculum Development Practices Instrument (ACDP-I) was developed and the factorial validity of the ACDP-I was tested (n = 107) using exploratory factor analysis procedures in the earlier work of [1]. Despite the ACDP-I appears to be content and construct valid instrument with very high internal reliability qualities for using in Malaysia, the accumulated evidences are still needed to provide a sound scientific basis for the proposed score interpretations. Therefore, the present study addresses this concern by utilising the confirmatory factor analysis to further confirm the theoretical structure of the variable Actual Curriculum Development Practices (ACDP) and enrich the psychometrical properties of ACDP-I. Results of this study have practical implication to both researchers and educators whose concerns focus on teachers' classroom practices and the instrument development and validation process.

  3. A study to evaluate whether CTR increases refractive unpredictability between predicted and actual IOL position

    PubMed Central

    Baranwal, V.K.; Kumar, Santosh; Mishra, Avinash; Dutta, Ajay K.

    2012-01-01

    Background The surgical management of cataract associated with extensive zonular loss presents a challenge for ophthalmic surgeon. Capsular Tension Ring (CTR) is commonly being used to stabilize the capsular bag in patients with zonular dialysis. CTR helps to avoid capsular collapse and vitreous presentation in AC during surgery and maintains the capsular bag, allowing the circular contour of the capsular bag, allowing intra ocular lens to be easily placed in the bag. The aim of the study was to know if there is any shift of IOL following use of CTR ring. Method We did a Ultrabiomicroscopy (UBM) examination to find out shift in PCIOL in cases in which CTR ring and compared it with cases without CTR ring. Result It was found out through UBM in this study that there is actually a posterior shift of PCIOL after use of CTR ring leading to hypermetropic correction needed after surgery. Conclusion It is suggested that posterior shift of IOL following use of CTR should be kept in mind and the IOL implanted should be of + 1.0 to 2.0 D more than that calculated preoperatively. PMID:24623945

  4. Dental implant management and maintenance: How to improve long-term implant success?

    PubMed

    Clark, Danielle; Levin, Liran

    2016-01-01

    Although dental implants are proven to be a predictable longterm treatment for patients, it is important to realize that not all implants that survive are necessarily successful. Successful implants are those that remain fully functional and healthy within the oral cavity. Peri-implantitis is a disease that is associated with implant failure, and is becoming rather prevalent. Assessing risk factors and stabilizing existing oral disease prior to the placement of implants will aid in preventing implant disease and failure. After implant placement, a strict follow-up regime with a dental professional should be implemented in order to monitor the implant and surrounding teeth for disease. The dental professional should continually encourage the patient to adhere to consistent homecare to prevent peri-implantitis from occurring, and in turn increase the success of their implants. Early diagnosis and elimination of inflammatory processes around the implants will improve the longterm prognosis as well.

  5. 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.

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

    PubMed Central

    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. PMID:25741821

  7. 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.

  8. 63. VIEW OF AUTOTRANSFERS. THE ACTUAL AUTOTRANSFERS ARE ENCLOSED IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. VIEW OF AUTOTRANSFERS. THE ACTUAL AUTOTRANSFERS ARE ENCLOSED IN THE OIL FILLED CYLINDERS ON THE RIGHT OF THE PHOTOGRAPH. THESE ELECTRICAL DEVICES BOOSTED THE GENERATOR OUTPUT OF 11,000 VOLTS TO 22,000 VOLTS PRIOR TO TRANSMISSION OUT TO THE MAIN FEEDER LINES. A SPARE INNER UNIT IS CONTAINED IN THE METAL BOX AT THE LEFT OF THE PHOTOGRAPH. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  9. Physician job satisfaction related to actual and preferred job size.

    PubMed

    Schmit Jongbloed, Lodewijk J; Cohen-Schotanus, Janke; Borleffs, Jan C C; Stewart, Roy E; Schönrock-Adema, Johanna

    2017-05-11

    Job satisfaction is essential for physicians' well-being and patient care. The work ethic of long days and hard work that has been advocated for decades is acknowledged as a threat for physicians' job satisfaction, well-being, and patient safety. Our aim was to determine the actual and preferred job size of physicians and to investigate how these and the differences between them influence physicians' job satisfaction. Data were retrieved from a larger, longitudinal study among physicians starting medical training at Groningen University in 1982/83/92/93 (N = 597). Data from 506 participants (85%) were available for this study. We used regression analysis to investigate the influence of job size on physicians' job satisfaction (13 aspects) and ANOVA to examine differences in job satisfaction between physicians wishing to retain, reduce or increase job size. The majority of the respondents (57%) had an actual job size less than 1.0 FTE. More than 80% of all respondents preferred not to work full-time in the future. Respondents' average actual and preferred job sizes were .85 FTE and .81 FTE, respectively. On average, respondents who wished to work less (35% of respondents) preferred a job size reduction of 0.18 FTE and those who wished to work more (12%) preferred an increase in job size of 0.16 FTE. Job size influenced satisfaction with balance work-private hours most (β = -.351). Physicians who preferred larger job sizes were - compared to the other groups of physicians - least satisfied with professional accomplishments. A considerable group of physicians reported a gap between actual and preferred job size. Realizing physicians' preferences as to job size will hardly affect total workforce, but may greatly benefit individual physicians as well as their patients and society. Therefore, it seems time for a shift in work ethic.

  10. FRACTIONAL CRYSTALLIZATION FLOWSHEET TESTS WITH ACTUAL TANK WASTE

    SciTech Connect

    HERTING, D.L.

    2007-04-13

    Laboratory-scale flowsheet tests of the fractional crystallization process were conducted with actual tank waste samples in a hot cell at the 2224 Laboratory. The process is designed to separate medium-curie liquid waste into a low-curie stream for feeding to supplemental treatment and a high-curie stream for double-shell tank storage. Separations criteria (for Cesium-137 sulfate and sodium) were exceeded in all three of the flowsheet tests that were performed.

  11. FRACTIONAL CRYSTALLIZATION FLOWSHEET TESTS WITH ACTUAL TANK WASTE

    SciTech Connect

    HERTING, D.L.

    2006-10-18

    Laboratory-scale flowsheet tests of the fractional crystallization process were conducted with actual tank waste samples in a hot cell at the 222-S Laboratory. The process is designed to separate medium-curie liquid waste into a low-curie stream for feeding to supplemental treatment and a high-curie stream for double-shell tank storage. Separations criteria (for Cs-137 sulfate, and sodium) were exceeded in all three of the flowsheet tests that were performed.

  12. The actual citation impact of European oncological research.

    PubMed

    López-Illescas, Carmen; de Moya-Anegón, Félix; Moed, Henk F

    2008-01-01

    This study provides an overview of the research performance of major European countries in the field Oncology, the most important journals in which they published their research articles, and the most important academic institutions publishing them. The analysis was based on Thomson Scientific's Web of Science (WoS) and calculated bibliometric indicators of publication activity and actual citation impact. Studying the time period 2000-2006, it gives an update of earlier studies, but at the same time it expands their methodologies, using a broader definition of the field, calculating indicators of actual citation impact, and analysing new and policy relevant aspects. Findings suggest that the emergence of Asian countries in the field Oncology has displaced European articles more strongly than articles from the USA; that oncologists who have published their articles in important, more general journals or in journals covering other specialties, rather than in their own specialist journals, have generated a relatively high actual citation impact; and that universities from Germany, and--to a lesser extent--those from Italy, the Netherlands, UK, and Sweden, dominate a ranking of European universities based on number of articles in oncology. The outcomes illustrate that different bibliometric methodologies may lead to different outcomes, and that outcomes should be interpreted with care.

  13. Reasons for failures of oral implants.

    PubMed

    Chrcanovic, B R; Albrektsson, T; Wennerberg, A

    2014-06-01

    This study reviews the literature regarding the factors contributing to failures of dental implants. An electronic search was undertaken including papers from 2004 onwards. The titles and abstracts from these results were read to identify studies within the selection criteria. All reference lists of the selected studies were then hand-searched, this time without time restrictions. A narrative review discussed some findings from the first two parts where separate data from non-comparative studies may have indicated conclusions different from those possible to draw in the systematic analysis. It may be suggested that the following situations are correlated to increase the implant failure rate: a low insertion torque of implants that are planned to be immediately or early loaded, inexperienced surgeons inserting the implants, implant insertion in the maxilla, implant insertion in the posterior region of the jaws, implants in heavy smokers, implant insertion in bone qualities type III and IV, implant insertion in places with small bone volumes, use of shorter length implants, greater number of implants placed per patient, lack of initial implant stability, use of cylindrical (non-threaded) implants and prosthetic rehabilitation with implant-supported overdentures. Moreover, it may be suggested that the following situations may be correlated with an increase in the implant failure rate: use of the non-submerged technique, immediate loading, implant insertion in fresh extraction sockets, smaller diameter implants. Some recently published studies suggest that modern, moderately rough implants may present with similar results irrespective if placed in maxillas, in smoking patients or using only short implants.

  14. Three-dimensional accuracy of guided implant placement: indirect assessment of clinical outcomes.

    PubMed

    Platzer, Susanne; Bertha, Georg; Heschl, Alexander; Wegscheider, Walther A; Lorenzoni, Martin

    2013-10-01

    Precise preoperative implant planning and its exact intraoperative transfer are crucial for successful implant-supported rehabilitation of partially or completely edentulous patients. In the present pilot study, optical laser scanning was used to evaluate deviations between three-dimensional computer-assisted planned and actual implant positions by indirect methods. Five patients receiving a total of 15 implants were included in this study. The used planning software was SimPlant 12.0 (Materialise Dental, Leuven, Belgium) to visualize the implant positions, and with an appropriate guided surgery protocol (Navigator™, Biomet 3i, Palm Beach Gardens, FL, USA) implant positions were implemented via tooth-supported stereolithografic surgical guides. All implants (Osseotite™, Biomet 3i) were inserted in a flapless approach and immediately provided with prefabricated temporary splinted restorations. Intraoral pickup impressions were taken postoperatively, and the implant positions of the master casts were compared with presurgical casts. Implant replica deviations were evaluated by three-dimensional optical laser scanning providing distances and angulations between implant replicas. Overall, the postsurgical implant replica positions were found to deviate from the positions in the preoperative cast by a mean of 0.46 ± 0.21 mm (range: 0.09-0.85 mm). Positional deviations were 0.27 ± 0.19 mm (range: 0.04-0.60 mm) along the x-axis representing the buccal-lingual directions, 0.15 ± 0.13 mm (range: 0.0-0.34 mm) along the y-axis representing the ventrodorsal direction, and 0.28 ± 0.19 mm (range: 0.02-0.59 mm) along the z-axis representing cranial and apical directions. Rotational deviations amounted to 14.04 ± 11.6° (range: 0.09-36.47°). The results of this pilot study demonstrate precise transfer of implant replica position by means of simulated guided implant insertion into a preoperative cast and a postoperative cast obtained from impressioning. Further studies

  15. Implant maintenance treatment and peri-implant health.

    PubMed

    Howe, Mark-Steven

    2017-03-01

    Data sourcesMedline (PubMed), Embase, Cochrane Central Register of Controlled Trials and Cochrane Oral Health Group Trials Register databases and a manual search of the Journal of Dental Research, Journal of Clinical Periodontology, Journal of Periodontology and the International Journal of Periodontics and Restorative Dentistry from January 2014 to February 2015.Study selectionProspective, retrospective, randomised or not, case-controlled or case series trials showing the incidence or recurrence of peri-implant disease plus or minus PIMT over more than six months.Data extraction and synthesisThree reviewers independently selected studies and abstracted data with two reviewers assessing study quality using the Newcastle-Ottawa Scale (NOS). A multivariate binomial regression was used to examine the data.ResultsThirteen studies were included with ten contributing to the meta-analysis. The average quality assessment score (NOS) was 5.3 out of a possible nine, only one paper achieved eight. At patient level mucositis ranged from 18.5-74.2% and peri-implantitis from 8-28%, with significant effects being seen for treatment (z= -14.36, p<0.001). Mucositis was affected by history of periodontitis and mean PIMT at implant and patient levels, respectively. For peri-implantitis there were also significant effects of treatment (z = -16.63, p<0.001). Increased peri-implantitis was observed for patients with a history of periodontal disease. (z=3.76, p<0.001). Implants under PIMT have 0.958 the incident event compared to those with no PIMT.ConclusionsWithin the limitations of the present systematic review it can be concluded that implant therapy must not be limited to placement and restoration of dental implants, but to the implementation of PIMT to potentially prevent biological complications and heighten the long-term success rate. Although it must be tailored to a patients risk profiling, our findings suggest reason to claim a minimum recall PIMT interval of five to six

  16. Tolerable versus actual soil erosion rates in Europe

    NASA Astrophysics Data System (ADS)

    Verheijen, F. G. A.; Jones, R. J. A.; Rickson, R. J.; Smith, C. J.

    2009-05-01

    Erosion is a major threat to soil resources in Europe, and may impair their ability to deliver a range of ecosystem goods and services. This is reflected by the European Commission's Thematic Strategy for Soil Protection, which recommends an indicator-based approach for monitoring soil erosion. Defined baseline and threshold values are essential for the evaluation of soil monitoring data. Therefore, accurate spatial data on both soil loss and soil genesis are required, especially in the light of predicted changes in climate patterns, notably frequency, seasonal distribution and intensity of precipitation. Rates of soil loss are reported that have been measured, modelled or inferred for most types of soil erosion in a variety of landscapes, by studies across the spectrum of the Earth sciences. Natural rates of soil formation can be used as a basis for setting tolerable soil erosion rates, with soil formation consisting of mineral weathering as well as dust deposition. This paper reviews the concept of tolerable soil erosion and summarises current knowledge on rates of soil formation, which are then compared to rates of soil erosion by known erosion types, for assessment of soil erosion monitoring at the European scale. A modified definition of tolerable soil erosion is proposed as 'any actual soil erosion rate at which a deterioration or loss of one or more soil functions does not occur,' actual soil erosion being 'the total amount of soil lost by all recognised erosion types.' Even when including dust deposition in soil formation rates, the upper limit of tolerable soil erosion, as equal to soil formation, is ca. 1.4 t ha - 1 yr - 1 while the lower limit is ca. 0.3 t ha - 1 yr - 1 , for conditions prevalent in Europe. Scope for spatio-temporal differentiation of tolerable soil erosion rates below this upper limit is suggested by considering (components of) relevant soil functions. Reported rates of actual soil erosion vary much more than those for soil formation

  17. The peri-implantitis: implant surfaces, microstructure, and physicochemical aspects.

    PubMed

    Mouhyi, Jaafar; Dohan Ehrenfest, David M; Albrektsson, Tomas

    2012-04-01

    There are two ways of looking at secondary failures of osseointegration; one is to reflect on possible causes for the failure, the other focuses on the pathology per se. In the first case, background factors such as mechanical trauma (adverse loading) or inflammations/infections are being discussed as the cause of failure. Then peri-implantitis is a term reserved for implant disturbance due to inflammation/infections only. However, irrespective of the original reason for the failure being adverse loading or inflammation/infection, the end result with bone resorption and inflammation may be very similar. Hence, in the present article, an alternative outlook has been chosen. Trigerring factors for peri-implantitis are generally gathered under four categories: lesions of peri-implant attachment, presence of aggressive bacteria, excessive mechanical stress, and corrosion. If only one of these factors would start a chain reaction leading to lesions, then the other factors may combine to worsen the condition. With other words, peri-implantitis is a general term dependent on a synergy of several factors, irrespective of the precise reason for first triggering off symptoms. © 2009 Wiley Periodicals, Inc.

  18. Peri-implant mucositis and peri-implantitis: clinical and histopathological characteristics and treatment.

    PubMed

    Khammissa, R A G; Feller, L; Meyerov, R; Lemmer, J

    2012-04-01

    Osseointegrated dental implants are used routinely in dentistry in the confidence of predictable success. However, if the implant surfaces become colonised by pathogenic bacteria, the plaque-induced inflammation around the implants may cause peri-implant tissue destruction. Peri-implant mucositis is a reversible, plaque-induced inflammatory lesion confined to the peri-implant soft tissue unit and clinically is characterised by redness, swelling and bleeding on gentle probing. Peri-implantitis is an extension of peri-implant mucositis to involve the bone supporting the implant: it is characterised by loss of osseointegration of the coronal part of the implant, by increased probing depth and by bleeding and/or suppuration on probing. Established peri-implantitis does not respond predictably to treatment. The best management of plaque-induced peri-implant inflammatory diseases is prevention. Regular personal and professional cleaning of the implant is mandatory to minimise bacterial load. Despite our best efforts, plaque-induced peri-implant inflammatory diseases will occur frequently, and as these diseases respond best to early treatment, early detection of peri-implant mucositis by regular assessment will permit timely treatment. Peri-implant mucositis is readily treated non-surgically. Peri-implantitis is more difficult to treat largely because of the problem of decontamination of the roughened, threaded surfaces of exposed implants. As a rule, surgical treatment will be necessary, and even then success is not assured.

  19. Investigation of a bioresorbable orbital implant.

    PubMed

    Jordan, David R; Brownstein, Seymour; Gilberg, Steve; Matthew, Benjamin; Mawn, Louise; Khouri, Lucie

    2002-09-01

    To analyze a new bioresorbable orbital implant (open-celled polylactic acid, also known as OPLA). The implants were examined macroscopically, with chemical analysis (Fourier transform infrared spectroscopy), and microscopically with scanning electron microscopy. Animal implantation of OPLA implants was carried out in 9 adult male New Zealand albino rabbits. Implant vascularization was evaluated by histopathologic sectioning. The OPLA implant is porous and lightweight but fragile. Histopathologically it stimulated primarily a multinucleated giant cell granulomatous reaction with little fibrovascular ingrowth seen at 4 and 8 weeks. By 20 and 24 weeks, the implant was replaced predominantly by necrotic debris and peripheral giant cells. The OPLA implant is not an acceptable alternative to other currently available orbital implants.

  20. Deuterium implantation in magnetic garnets

    SciTech Connect

    Wilts, C.H.; Urai, A.

    1988-11-01

    The magnetic effects of deuterium implantation and subsequent annealing were measured in Gd, Tm, and Ga-substituted yttrium iron garnet films for comparison with measurements made earlier with hydrogen implantation. Implantation energy was 60 keV and the dose ranged from 0.5 to 3 x 10/sup 16/ ions/cm/sup 2/ for D/sup +//sub 2/ ions, as compared to an energy of 120 keV and a dose from 0.3 to 4 x 10/sup 16/ ions/cm/sup 2/ for H/sup +//sub 2/ in the earlier study. Measurements made included x-ray rocking curves and ferromagnetic resonance spectra measured at 9.5 GHz. For all doses the implanted layer remained crystalline. Implanted layer thickness was about 4200 A and peak strain occured at a depth of 2600 A. Peak strain increased monotonically, but departed from a linear relation with dose. For the highest dose, the peak strain was 2.5%. Relaxation of strain with annealing was intermediate between that found earlier for hydrogen and neon implantation. As compared to all other implant elements, both deuterium and hydrogen show a large anomalous magnetic anisotropy which can exceed 10 000 Oe for either ion. The absence of this effect for He, Ne, and other ions supports the conjecture that the effect is chemical and related to electronic bonding rather than strain or disorder. The anomalous anisotropy for deuterium decreases and shifts location with annealing. It has largely disappeared at temperatures of 300--350 /sup 0/C. The shape of the profile is consistent with the hypothesis that the shift in anisotropy is associated with diffusion of the deuterium atoms to the surface of the garnet film. At the highest dose, crystalline damage in the region of highest strain is sufficient to radically alter magnetic properties and in particular reduces even the excess anisotropy so that a two-peak profile results until modified by annealing.

  1. Multicomponent Implant Releasing Dexamethasone

    NASA Astrophysics Data System (ADS)

    Nikkola, L.; Vapalahti, K.; Ashammakhi, N.

    2008-02-01

    Several inflammatory conditions are usually treated with corticosteroids. There are various problems like side effects with traditional applications of steroids, e.g. topical, or systemic routes. Local drug delivery systems have been studied and developed to gain more efficient administration with fewer side effects. Earlier, we reported on developing Dexamethasone (DX) releasing biodegradable fibers. However, their drug release properties were not satisfactory in terms of onset of drug release. Thus, we assessed the development of multicomponent (MC) implant to enhance earlier drug release from such biodegradable fibers. Poly (lactide-co-glycolide) (PLGA) and 2 wt-% and 8 wt-% DX were compounded and extruded with twin-screw extruder to form of fibers. Some of the fibers were sterilized to obtain a change in drug release properties. Four different fiber classes were studied: 2 wt-%, 8 wt-%, sterilized 2 wt-%, and sterilized 8 wt-%. 3×4 different DX-releasing fibers were then heat-pressed to form one multicomponent rod. Half of the rods where sterilized. Drug release was measured from initial fibers and multicomponent rods using a UV/VIS spectrometer. Shear strength and changes in viscosity were also measured. Drug release studies showed that drug release commenced earlier from multicomponent rods than from component fibers. Drug release from multicomponent rods lasted from day 30 to day 70. The release period of sterilized rods extended from day 23 to day 57. When compared to the original component fibers, the drug release from MC rods commenced earlier. The initial shear strength of MC rods was 135 MPa and decreased to 105 MPa during four weeks of immersion in phosphate buffer solution. Accordingly, heat pressing has a positive effect on drug release. After four weeks in hydrolysis, no disintegration was observed.

  2. New Osseodensification Implant Site Preparation Method to Increase Bone Density in Low-Density Bone: In Vivo Evaluation in Sheep

    PubMed Central

    Trisi, Paolo; Falco, Antonello; Podaliri Vulpiani, Michele

    2016-01-01

    Purpose: The aim of this study was to evaluate a new surgical technique for implant site preparation that could allow to enhance bone density, ridge width, and implant secondary stability. Materials and Methods: The edges of the iliac crests of 2 sheep were exposed and ten 3.8 × 10-mm Dynamix implants (Cortex) were inserted in the left sides using the conventional drilling method (control group). Ten 5 × 10-mm Dynamix implants (Cortex) were inserted in the right sides (test group) using the osseodensification procedure (Versah). After 2 months of healing, the sheep were killed, and biomechanical and histological examinations were performed. Results: No implant failures were observed after 2 months of healing. A significant increase of ridge width and bone volume percentage (%BV) (approximately 30% higher) was detected in the test group. Significantly better removal torque values and micromotion under lateral forces (value of actual micromotion) were recorded for the test group in respect with the control group. Conclusion: Osseodensification technique used in the present in vivo study was demonstrated to be able to increase the %BV around dental implants inserted in low-density bone in respect to conventional implant drilling techniques, which may play a role in enhancing implant stability and reduce micromotion. PMID:26584202

  3. New Osseodensification Implant Site Preparation Method to Increase Bone Density in Low-Density Bone: In Vivo Evaluation in Sheep.

    PubMed

    Trisi, Paolo; Berardini, Marco; Falco, Antonello; Podaliri Vulpiani, Michele

    2016-02-01

    The aim of this study was to evaluate a new surgical technique for implant site preparation that could allow to enhance bone density, ridge width, and implant secondary stability. The edges of the iliac crests of 2 sheep were exposed and ten 3.8 × 10-mm Dynamix implants (Cortex) were inserted in the left sides using the conventional drilling method (control group). Ten 5 × 10-mm Dynamix implants (Cortex) were inserted in the right sides (test group) using the osseodensification procedure (Versah). After 2 months of healing, the sheep were killed, and biomechanical and histological examinations were performed. No implant failures were observed after 2 months of healing. A significant increase of ridge width and bone volume percentage (%BV) (approximately 30% higher) was detected in the test group. Significantly better removal torque values and micromotion under lateral forces (value of actual micromotion) were recorded for the test group in respect with the control group. Osseodensification technique used in the present in vivo study was demonstrated to be able to increase the %BV around dental implants inserted in low-density bone in respect to conventional implant drilling techniques, which may play a role in enhancing implant stability and reduce micromotion.

  4. Medical implants and methods of making medical implants

    DOEpatents

    Shaw, Wendy J; Yonker, Clement R; Fulton, John L; Tarasevich, Barbara J; McClain, James B; Taylor, Doug

    2014-09-16

    A medical implant device having a substrate with an oxidized surface and a silane derivative coating covalently bonded to the oxidized surface. A bioactive agent is covalently bonded to the silane derivative coating. An implantable stent device including a stent core having an oxidized surface with a layer of silane derivative covalently bonded thereto. A spacer layer comprising polyethylene glycol (PEG) is covalently bonded to the layer of silane derivative and a protein is covalently bonded to the PEG. A method of making a medical implant device including providing a substrate having a surface, oxidizing the surface and reacting with derivitized silane to form a silane coating covalently bonded to the surface. A bioactive agent is then covalently bonded to the silane coating. In particular instances, an additional coating of bio-absorbable polymer and/or pharmaceutical agent is deposited over the bioactive agent.

  5. Cochlear implantation updates: the Dallas Cochlear Implant Program.

    PubMed

    Tobey, Emily A; Britt, Lana; Geers, Ann; Loizou, Philip; Loy, Betty; Roland, Peter; Warner-Czyz, Andrea; Wright, Charles G

    2012-06-01

    This report provides an overview of many research projects conducted by the Dallas Cochlear Implant Program, a joint enterprise between the University of Texas at Dallas, the University of Texas Southwestern Medical Center, and Children's Medical Center. The studies extend our knowledge of factors influencing communication outcomes in users of cochlear implants. Multiple designs and statistical techniques are used in the studies described including both cross sectional and longitudinal analyses. Sample sizes vary across the studies, and many of the samples represent large populations of children from North America. Multiple statistical techniques are used by the team to analyze outcomes. The team has provided critical information regarding electrode placement, signal processing, and communication outcomes in users of cochlear implants. American Academy of Audiology.

  6. Cochlear Implantation Updates: The Dallas Cochlear Implant Program

    PubMed Central

    Tobey, Emily A.; Britt, Lana; Geers, Ann; Loizou, Philip; Loy, Betty; Roland, Peter; Warner-Czyz, Andrea; Wright, Charles G.

    2013-01-01

    This report provides an overview of many research projects conducted by the Dallas Cochlear Implant Program, a joint enterprise between The University of Texas at Dallas, The University of Texas Southwestern Medical Center and Children’s Medical Center. The studies extend our knowledge of factors influencing communication outcomes in users of cochlear implants. Multiple designs and statistical techniques are used in the studies described including both cross sectional and longitudinal analyses. Sample sizes vary across the studies and many of the samples represent large populations of children from North America. Multiple statistical techniques are used by the team to analyze outcomes. The team has provided critical information regarding electrode placement, signal processing, and communication outcomes in users of cochlear implants. PMID:22668764

  7. Periodontitis and dental implant loss.

    PubMed

    Lee, Dong Won

    2014-06-01

    Medline, the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews, Database of Abstracts of Review of Effect, Science Direct, and SCOPUS databases were searched. A manual search was performed of issues of the last 15 years of the Journal of Periodontology, International Journal of Periodontics and Restorative Dentistry, Journal of Clinical Periodontology, Journal of Dental Research, Journal of Periodontal Research, Journal of Dentistry, Clinical Oral Investigations, Clinical Oral Implant Research and Clinical Implant Dentistry and Related Research. Prospective cohort studies that compared patients with periodontal disease (PD) to periodontally healthy patients and that reported data on implant loss, peri-implant bone changes or incidence of peri-implantitis were included. Case series, reviews, case reports and retrospective studies were not included. Study selection and risk of bias assessment using the Newcastle-Ottawa Scale was undertaken independently by two reviewers. Dichotomous data were expressed as risk ratios (RRs) and 95% confidence intervals (CIs). Continuous data were expressed as standardised mean differences (SMDs) and random-effects meta-analysis conducted. Fourteen studies were included with sample sizes ranging from 10-717. Meta-analysis (11 studies) showed a higher and significant risk for implant loss in patients affected by PD (RR: 1.89, 95% CI: 1.35-2.66, P = 0.0002) with no evidence of heterogeneity (v2 = 4.31, P = 0.93; I2 = 0%). Significant implant bone loss was present in patients with PD compared with periodontally healthy patients (SMD: 0.44, 95% CI: 0.19-0.69, P = 0.0006) (three studies), with no evidence of heterogeneity (v2 = 2.463, P = 0.27; I2 = 24%). Periodontally compromised patients also showed an increased risk of peri-implantitis compared with patients without PD (RR: 2.21, 95% CI: 1.42-3.43, P = 0.0004), with moderate but not significant heterogeneity (v2 = 7.35, P = 0.12; I2 = 46

  8. Implantable biomedical devices on bioresorbable substrates

    DOEpatents

    Rogers, John A; Kim, Dae-Hyeong; Omenetto, Fiorenzo; Kaplan, David L; Litt, Brian; Viventi, Jonathan; Huang, Yonggang; Amsden, Jason

    2014-03-04

    Provided herein are implantable biomedical devices, methods of administering implantable biomedical devices, methods of making implantable biomedical devices, and methods of using implantable biomedical devices to actuate a target tissue or sense a parameter associated with the target tissue in a biological environment. Each implantable biomedical device comprises a bioresorbable substrate, an electronic device having a plurality of inorganic semiconductor components supported by the bioresorbable substrate, and a barrier layer encapsulating at least a portion of the inorganic semiconductor components. Upon contact with a biological environment the bioresorbable substrate is at least partially resorbed, thereby establishing conformal contact between the implantable biomedical device and the target tissue in the biological environment.

  9. Nasal dorsal augmentation with silicone implants.

    PubMed

    Erlich, Mark A; Parhiscar, Afshin

    2003-11-01

    Silicone rubber has been used safely and effectively for facial augmentation for nearly 5 decades in eastern Asia. We have used silicone rubber nasal implants in primary ethnic rhinoplasty and have found consistent and long-lasting results with low complication rates. Silicone dorsal nasal augmentation in primary rhinoplasty avoids donor site morbidity and implant resorption as seen with autogenous implants. Silicone nasal implants have a low extrusion and infection rate. In the appropriate patient with proper placement, silicone nasal implant is nearly the ideal implant material.

  10. Cochlear Implantation in Older Adults

    PubMed Central

    Lin, Frank R.; Chien, Wade W.; Li, Lingsheng; Niparko, John K.; Francis, Howard W.

    2012-01-01

    Cochlear implants allow individuals with severe-to-profound hearing loss access to sound and spoken language. The number of older adults in the United States who are potential candidates for cochlear implantation is approximately 150,000 and will continue to increase with the aging of the population. Should cochlear implantation (CI) be routinely recommended for these older adults, and do these individuals benefit from CI? We reviewed our 12 year experience with cochlear implantation in adults ≥60 years (n = 445) at Johns Hopkins to investigate the impact of CI on speech understanding and to identify factors associated with speech performance. Complete data on speech outcomes at baseline and 1 year post-CI were available for 83 individuals. Our results demonstrate that cochlear implantation in adults ≥60 years consistently improved speech understanding scores with a mean increase of 60. 0% (S. D. 24. 1) on HINT sentences in quiet . The magnitude of the gain in speech scores was negatively associated with age at implantation such that for every increasing year of age at CI the gain in speech scores was 1. 3 percentage points less (95% CI: 0. 6 – 1. 9) after adjusting for age at hearing loss onset. Conversely, individuals with higher pre-CI speech scores (HINT scores between 40–60%) had significantly greater post-CI speech scores by a mean of 10. 0 percentage points (95% CI: 0. 4 – 19. 6) than those with lower pre-CI speech scores (HINT <40%) after adjusting for age at CI and age at hearing loss onset. These results suggest that older adult CI candidates who are younger at implantation and with higher preoperative speech scores obtain the highest speech understanding scores after cochlear implantation with possible implications for current Medicare policy. Finally, we provide an extended discussion of the epidemiology and impact of hearing loss in older adults. Future research of CI in older adults should expand beyond simple speech outcomes to take into

  11. Feasibility of an implanted microphone for cochlear implant listening.

    PubMed

    Gérard, Jean-Marc; Demanez, Laurent; Salmon, Caroline; Vanpoucke, Filiep; Walraevens, Joris; Plasmans, Anke; De Siati, Daniele; Lefèbvre, Philippe

    2017-03-01

    This study aimed at evaluating the feasibility of an implanted microphone for cochlear implants (CI) by comparison of hearing outcomes, sound quality and patient satisfaction of a subcutaneous microphone to a standard external microphone of a behind-the-ear sound processor. In this prospective feasibility study with a within-subject repeated measures design comparing the microphone modalities, ten experienced adult unilateral CI users received an implantable contralateral subcutaneous microphone attached to a percutaneous plug. The signal was pre-processed and fed into their CI sound processor. Subjects compared listening modes at home for a period of up to 4 months. At the end of the study the microphone was explanted. Aided audiometric thresholds, speech understanding in quiet, and sound quality questionnaires were assessed. On average thresholds (250, 500, 750, 1k, 2k, 3k, 4k and 6 kHz) with the subcutaneous microphone were 44.9 dB, compared to 36.4 dB for the external mode. Speech understanding on sentences in quiet was high, within approximately 90% of performance levels compared to hearing with an external microphone. Body sounds were audible but not annoying to almost all subjects. This feasibility study with a research device shows significantly better results than previous studies with implanted microphones. This is attributed to technology enhancements and careful fitting. Listening effort was somewhat increased with an implanted microphone. Under good sound conditions, speech performance is nearly similar to that of external microphones demonstrating that an implanted microphone is feasible in a range of normal listening conditions.

  12. SURFACE CHEMISTRY INFLUENCE IMPLANT BIOCOMPATIBILITY

    PubMed Central

    Thevenot, Paul; Hu, Wenjing; Tang, Liping

    2011-01-01

    Implantable medical devices are increasingly important in the practice of modern medicine. Unfortunately, almost all medical devices suffer to a different extent from adverse reactions, including inflammation, fibrosis, thrombosis and infection. To improve the safety and function of many types of medical implants, a major need exists for development of materials that evoked desired tissue responses. Because implant-associated protein adsorption and conformational changes thereafter have been shown to promote immune reactions, rigorous research efforts have been emphasized on the engineering of surface property (physical and chemical characteristics) to reduce protein adsorption and cell interactions and subsequently improve implant biocompatibility. This brief review is aimed to summarize the past efforts and our recent knowledge about the influence of surface functionality on protein:cell:biomaterial interactions. It is our belief that detailed understandings of bioactivity of surface functionality provide an easy, economic, and specific approach for the future rational design of implantable medical devices with desired tissue reactivity and, hopefully, wound healing capability. PMID:18393890

  13. Implantable drug-delivery systems.

    PubMed

    Blackshear, P J

    1979-12-01

    Implantable drug-delivery systems are being developed to release drugs to the bloodstream continuously as well as free patients from being hospitalized to receive intravenous infusions or frequent injections. One technique is implantation of a pellet in the subcutaneous tissue so the pellet may be released by erosion. Drugs are also diffused through silicone rubber capsules but only polyacrylamide is able to release large molecules. Contraceptive rings containing progesterone and placed in the uterus or vagina and implanted silicone-rubber capsules use these principles. Disadvantages to the subcutaneous delivery of drugs include: 1) release of the drug in subcutaneous tissue rather than in the bloodstream directly; 2) entry into the circulatory system is controlled by surrounding blood supplies which vary with fat; 3) diffusion may be difficult due to dense layers of fibrous tissue; and 4) drug amounts cannot be readily regulated. The Ommaya reservoir uses a container with a self-sealing membrane implanted in the scalp and connected to a cerebral ventricle to treat forms of leukemia and fungal meningitis. Another development is an implantable disk-shaped infusion pump with 2 compartments, the outer one containing a propellant and the inner chamber containing the drug, holds 45 milliliters and releases about 1 milliliter/day. In the future these systems may release drugs in response to biochemical feedback or deliver a drug to 1 specific area.

  14. Capacitive Feedthroughs for Medical Implants

    PubMed Central

    Grob, Sven; Tass, Peter A.; Hauptmann, Christian

    2016-01-01

    Important technological advances in the last decades paved the road to a great success story for electrically stimulating medical implants, including cochlear implants or implants for deep brain stimulation. However, there are still many challenges in reducing side effects and improving functionality and comfort for the patient. Two of the main challenges are the wish for smaller implants on one hand, and the demand for more stimulation channels on the other hand. But these two aims lead to a conflict of interests. This paper presents a novel design for an electrical feedthrough, the so called capacitive feedthrough, which allows both reducing the size, and increasing the number of included channels. Capacitive feedthroughs combine the functionality of a coupling capacitor and an electrical feedthrough within one and the same structure. The paper also discusses the progress and the challenges of the first produced demonstrators. The concept bears a high potential in improving current feedthrough technology, and could be applied on all kinds of electrical medical implants, even if its implementation might be challenging. PMID:27660602

  15. Actual drawing of histological images improves knowledge retention.

    PubMed

    Balemans, Monique C M; Kooloos, Jan G M; Donders, A Rogier T; Van der Zee, Catharina E E M

    2016-01-01

    Medical students have to process a large amount of information during the first years of their study, which has to be retained over long periods of nonuse. Therefore, it would be beneficial when knowledge is gained in a way that promotes long-term retention. Paper-and-pencil drawings for the uptake of form-function relationships of basic tissues has been a teaching tool for a long time, but now seems to be redundant with virtual microscopy on computer-screens and printers everywhere. Several studies claimed that, apart from learning from pictures, actual drawing of images significantly improved knowledge retention. However, these studies applied only immediate post-tests. We investigated the effects of actual drawing of histological images, using randomized cross-over design and different retention periods. The first part of the study concerned esophageal and tracheal epithelium, with 384 medical and biomedical sciences students randomly assigned to either the drawing or the nondrawing group. For the second part of the study, concerning heart muscle cells, students from the previous drawing group were now assigned to the nondrawing group and vice versa. One, four, and six weeks after the experimental intervention, the students were given a free recall test and a questionnaire or drawing exercise, to determine the amount of knowledge retention. The data from this study showed that knowledge retention was significantly improved in the drawing groups compared with the nondrawing groups, even after four or six weeks. This suggests that actual drawing of histological images can be used as a tool to improve long-term knowledge retention.

  16. Augmentation of peri-implant bone improves implant stability: quantification using simulated bone loss.

    PubMed

    Wirth, Andreas J; Müller, Ralph; van Lenthe, G Harry

    2012-02-01

    Low bone quality, such as induced by osteoporosis, is considered a main factor leading to failure of fracture fixations. Peri-implant bone augmentation has been proposed as a means of reducing failure rates in osteoporotic bone by improving implant stability. The beneficial effects of pharmacological augmentation of bone in the immediate vicinity of the implant have been demonstrated. Yet, a quantitative understanding of the role of peri-implant bone in implant stability is lacking. Therefore, the aim of our study was to quantify the effects of bone loss and peri-implant bone augmentation on implant stability using image-based finite element analyses. Using a validated model, we simulated how osteoporotic bone loss would affect implant stability in human humeral heads. We also quantified how augmentation of peri-implant bone can enhance implant stability. Our simulations revealed that a 30% reduction in bone mass led to a 50% decrease in implant stability. We also found that peri-implant bone augmentation increased implant stability and that the efficiency of bone augmentation decreased with increasing peri-implant distance. These findings highlight the strong effect that bone loss has on implant fixation and the potential of peri-implant bone augmentation for improving implant anchorage in low quality bone. Copyright © 2011 Orthopaedic Research Society.

  17. Lullament: lullaby and lament therapeutic qualities actualized through music therapy.

    PubMed

    O'Callaghan, Clare

    2008-01-01

    Lullabies and laments promote new awareness, enculturation, adaptation, and grief expression. These concepts' relevance to palliative care, however, has not been examined. In this study, a music therapist used a grounded theory-informed design to reflexively analyze lullaby and lament qualities, evident in more than 20 years of personal palliative care practice. Thus, the construct "lullament" emerged, which signified helpful moments when patients' and families' personal and sociohistorical relationship with lullabies and laments were actualized. Specific music could be both a lullaby and a lament. A music therapist can enable the lullament through providing opportunities for music-contextualized "restorative resounding," expressed psychobiologically, verbally, musically, and metaphorically.

  18. The Frictional Force with Respect to the Actual Contact Surface

    NASA Technical Reports Server (NTRS)

    Holm, Ragnar

    1944-01-01

    Hardy's statement that the frictional force is largely adhesion, and to a lesser extent, deformation energy is proved by a simple experiment. The actual contact surface of sliding contacts and hence the friction per unit of contact surface was determined in several cases. It was found for contacts in normal atmosphere to be about one-third t-one-half as high as the macroscopic tearing strength of the softest contact link, while contacts annealed in vacuum and then tested, disclosed frictional forces which are greater than the macroscopic strength.

  19. Power Delivery from an Actual Thermoelectric Generation System

    NASA Astrophysics Data System (ADS)

    Kaibe, Hiromasa; Kajihara, Takeshi; Nagano, Kouji; Makino, Kazuya; Hachiuma, Hirokuni; Natsuume, Daisuke

    2014-06-01

    Similar to photovoltaic (PV) and fuel cells, thermoelectric generators (TEGs) supply direct-current (DC) power, essentially requiring DC/alternating current (AC) conversion for delivery as electricity into the grid network. Use of PVs is already well established through power conditioning systems (PCSs) that enable DC/AC conversion with maximum-power-point tracking, which enables commercial use by customers. From the economic, legal, and regulatory perspectives, a commercial PCS for PVs should also be available for TEGs, preferably as is or with just simple adjustment. Herein, we report use of a PV PCS with an actual TEG. The results are analyzed, and proper application for TEGs is proposed.

  20. The actual practice of air cleaning in Belgian nuclear facilities

    SciTech Connect

    Goossens, W.R.

    1995-02-01

    With 60% of its power generation from nuclear stations Belgium has 7 nuclear power stations in operation with a total capacity of 5.4 MWe. Enriched uranium is imported and converted to fuel assemblies. The actinides of reprocessed fuel are recycled as MOX fuel. A main waste conditioning operation has been performed in the PAMELA vitrifier. The actual practice of nuclear air cleaning in the Belgian PWR station DOEL-4 and in the PAMELA -vitrification plant for high level liquid waste is reviewed.

  1. Monitoring based maintenance utilizing actual stress sensory technology

    NASA Astrophysics Data System (ADS)

    Sumitro, Sunaryo; Kurokawa, Shoji; Shimano, Keiji; Wang, Ming L.

    2005-06-01

    In recent years, many infrastructures have been deteriorating. In order to maintain sustainability of those infrastructures which have significant influence on social lifelines, economical and rational maintenance management should be carried out to evaluate the life cycle cost (LCC). The development of structural health monitoring systems, such as deriving evaluation techniques for the field structural condition of existing structures and identification techniques for the significant engineering properties of new structures, can be considered as the first step in resolving the above problem. New innovative evaluation methods need to be devised to identify the deterioration of infrastructures, e.g. steel tendons, cables in cable-stayed bridges and strands embedded in pre- or post-tensioned concrete structures. One of the possible solutions that show 'AtoE' characteristics, i.e., (a)ccuracy, (b)enefit, (c)ompendiousness, (d)urability and (e)ase of operation, elasto-magnetic (EM) actual stress sensory technology utilizing the sensitivity of incremental magnetic permeability to stress change, has been developed. Numerous verification tests on various steel materials have been conducted. By comparing with load cell, strain gage and other sensory technology measurement results, the actual stresses of steel tendons in a pre-stressed concrete structure at the following stages have been thoroughly investigated: (i) pre-stress change due to set-loss (anchorage slippage) at the tendon fixation stage; (ii) pre-stress change due to the tendon relaxation stage; (iii) concrete creep and shrinkage at the long term pre-stressing stage; (iv) pre-stress change in the cyclic fatigue loading stage; and (v) pre-stress change due to the re-pre-stress setting stage. As the result of this testing, it is confirmed that EM sensory technology enables one to measure actual stress in steel wire, strands and steel bars precisely without destroying the polyethylene covering sheath and enables

  2. Dieting: really harmful, merely ineffective or actually helpful?

    PubMed

    Lowe, Michael R; Timko, C Alix

    2004-08-01

    Dieting has developed a negative reputation among many researchers and health care professionals. However, 'dieting' can refer to a variety of behavioural patterns that are associated with different effects on eating and body weight. The wisdom of dieting depends on what kind of dieting is involved, who is doing it, and why. Thus, depending on what one means by the term, dieting can be quite harmful, merely ineffective or actually beneficial. The present paper considers examples of all three. In particular, we argue that judgements about the desirability of dieting should consider the likely consequences to particular individuals of engaging in, or not engaging in, dieting behaviour.

  3. Managing an extreme peri-implantitis.

    PubMed

    Materni, A

    2013-09-01

    Peri-implantitis leads to gradual peri-implant bone loss. Severe and extreme cases lead to complete implant failure and imply lost implants have to be removed. The aim of the present report is to present a case where an extreme peri-implantitis, causing complete peri-implant bone loss, was managed successfully. A patient already rehabilitated with a prosthesis supported by two implants at positions 3.4 and 3.6 presented with severe peri-implantitis affecting both implants. Initial probing depths were 11 and 9 mm respectively. Implant at position 3.4 showed a bone-implant gap ≥3 mm all around it, but was kept firmly in place by the prosthesis, still supported by the other implant. The patient refused to have her prosthesis removed. In an attempt to save it anyway, after debridement, sandblasting and decontamination of both implant surfaces an enzyme-deantigenic collagenic bone substitute was grafted. Controls followed at 1, 3, 5 and 12 months after surgery. Radiographic exams showed radio-opacity at the grafted sites to gradually increase over time. Postoperative probing depth gain, 7 and 6 mm respectively at position 3.4 and 3.6 remained unchanged at all follow-up controls. After 12 months the patient is asymptomatic and the failed implant can be considered restored. The way we managed this extreme peri-implantitis case has allowed to give clinical success even if, to comply to the patient's will, the best clinical, evidence-based treatment, was not performed. The implant that was otherwise lost was successfully recovered. As an hypothesis, a new osseointegration process could have occurred between the implant and the newly formed bone.

  4. Extraoral implants in the rehabilitation of craniofacial defects: implant and prosthesis survival rates and peri-implant soft tissue evaluation.

    PubMed

    Curi, Marcos Martins; Oliveira, Marcelo Ferraz; Molina, Giuliano; Cardoso, Camila Lopes; Oliveira, Loretta De Groot; Branemark, Per-Ingvar; Ribeiro, Karina de Cássia Braga

    2012-07-01

    Few reports have evaluated cumulative survival rates of extraoral rehabilitation and peri-implant soft tissue reaction at long-term follow-up. The objective of this study was to evaluate implant and prosthesis survival rates and the soft tissue reactions around the extraoral implants used to support craniofacial prostheses. A retrospective study was performed of patients who received implants for craniofacial rehabilitation from 2003 to 2010. Two outcome variables were considered: implant and prosthetic success. The following predictor variables were recorded: gender, age, implant placement location, number and size of implants, irradiation status in the treated field, date of prosthesis delivery, soft tissue response, and date of last follow-up. A statistical model was used to estimate survival rates and associated confidence intervals. We randomly selected 1 implant per patient for analysis. Data were analyzed using the Kaplan-Meier method and log-rank test to compare survival curves. A total of 150 titanium implants were placed in 56 patients. The 2-year overall implant survival rates were 94.1% for auricular implants, 90.9% for nasal implants, 100% for orbital implants, and 100% for complex midfacial implants (P = .585). The implant survival rates were 100% for implants placed in irradiated patients and 94.4% for those placed in nonirradiated patients (P = .324). The 2-year overall prosthesis survival rates were 100% for auricular implants, 90.0% for nasal implants, 92.3% for orbital implants, and 100% for complex midfacial implants (P = .363). The evaluation of the peri-implant soft tissue response showed that 15 patients (26.7%) had a grade 0 soft tissue reaction, 30 (53.5%) had grade 1, 6 (10.7%) had grade 2, and 5 (8.9%) had grade 3. From this study, it was concluded that craniofacial rehabilitation with extraoral implants is a safe, reliable, and predictable method to restore the patient's normal appearance. Copyright © 2012 American Association of Oral

  5. Implant rehabilitation in bruxism patient

    PubMed Central

    Goiato, Marcelo Coelho; Sonego, Mariana Vilela; dos Santos, Daniela Micheline; da Silva, Emily Vivianne Freitas

    2014-01-01

    A white female patient presented to the university clinic to obtain implant retained prostheses. She had an edentulous maxillary jaw and presented three teeth with poor prognosis (33, 34 and 43). The alveolar bone and the surrounding tissues were healthy. The patient did not report any relevant medical history contraindicating routine dental treatment or implant surgery, but self-reported a dental history of asymptomatic nocturnal bruxism. The treatment plan was set and two Branemark protocols supported by six implants in each arch were installed after a 6-month healing period. A soft occlusal splint was made due to the patient's history of bruxism, and the lack of its use by the patient resulted in an acrylic fracture. The prosthesis was repaired and the importance of using the occlusal splint was restated. In the 4-year follow-up no fractures were reported. PMID:24907215

  6. Silicone implants in augmentation rhinoplasty.

    PubMed

    Zeng, Yanjun; Wu, Weihua; Yu, Hongmei; Yang, Jian; Chen, Guangshen

    2002-01-01

    During the past six years, we have treated 406 patients with classical silicon augmentation rhinoplasty. The types and incidence of complications after subcutaneous or subfascial implantation were examined and discussed. We proposed that most complications are related to the depth of the implant and the character of the tissues. In order to improve our operation and prove our hypothesis, we performed subperiosteal augmentation rhinoplasty in 22 cases with satisfactory results. At the same time, we investigated the biomechanical properties of human nasal periosteum and fascia, including tensile strength, stress-strain relationship and stress relaxation characters under uniaxial tension. Although less elastic, the periosteum has more tensile strength than fascia. So, in the view of biomechanics, the periosteum is thicker, tougher, and stiffer than fascia, thus more suitable for covering silicon implants.

  7. Silicone implant in augmentation rhinoplasty.

    PubMed

    Zeng, Yanjun; Wu, Weihua; Yu, Hongmei; Yang, Jian; Chen, Guangshen

    2002-11-01

    During the past 6 years the authors have treated 406 patients with classic silicone augmentation rhinoplasty. The types and incidence of complications after subcutaneous or subfascial implantation are examined and discussed. They propose that most complications are related to the depth of the implant and the character of the tissues. To improve their operation and to prove their hypothesis, they performed subperiosteal augmentation rhinoplasty in 22 patients with satisfactory results. At the same time, they investigated the biomechanical properties of human nasal periosteum and fascia, including tensile strength, the stress-strain relationship, and stress relaxation characteristics under uniaxial tension. Although it has less failure strain, the periosteum has more tensile strength than fascia. So, in the view of biomechanics, the periosteum is thicker, tougher, and stiffer than fascia, and thus more suitable for covering silicone implants.

  8. Implant rehabilitation in bruxism patient.

    PubMed

    Goiato, Marcelo Coelho; Sonego, Mariana Vilela; dos Santos, Daniela Micheline; da Silva, Emily Vivianne Freitas

    2014-06-06

    A white female patient presented to the university clinic to obtain implant retained prostheses. She had an edentulous maxillary jaw and presented three teeth with poor prognosis (33, 34 and 43). The alveolar bone and the surrounding tissues were healthy. The patient did not report any relevant medical history contraindicating routine dental treatment or implant surgery, but self-reported a dental history of asymptomatic nocturnal bruxism. The treatment plan was set and two Branemark protocols supported by six implants in each arch were installed after a 6-month healing period. A soft occlusal splint was made due to the patient's history of bruxism, and the lack of its use by the patient resulted in an acrylic fracture. The prosthesis was repaired and the importance of using the occlusal splint was restated. In the 4-year follow-up no fractures were reported.

  9. Carbon Fiber Biocompatibility for Implants

    PubMed Central

    Petersen, Richard

    2016-01-01

    Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-reinforced composite stimulated osseointegration inside the tibia bone marrow measured as percent bone area (PBA) to a great extent when compared to the titanium-6-4 alloy at statistically significant levels. PBA increased significantly with the carbon-fiber composite over the titanium-6-4 alloy for distances from the implant surfaces of 0.1 mm at 77.7% vs. 19.3% (p < 10−8) and 0.8 mm at 41.6% vs. 19.5% (p < 10−4), respectively. The review focuses on carbon fiber properties that increased PBA for enhanced implant osseointegration. Carbon fibers acting as polymer coated electrically conducting micro-biocircuits appear to provide a biocompatible semi-antioxidant property to remove damaging electron free radicals from the surrounding implant surface. Further, carbon fibers by removing excess electrons produced from the cellular mitochondrial electron transport chain during periods of hypoxia perhaps stimulate bone cell recruitment by free-radical chemotactic influences. In addition, well-studied bioorganic cell actin carbon fiber growth would appear to interface in close contact with the carbon-fiber-reinforced composite implant. Resulting subsequent actin carbon fiber/implant carbon fiber contacts then could help in discharging the electron biological overloads through electrochemical gradients to lower negative charges and lower concentration. PMID:26966555

  10. Carbon Fiber Biocompatibility for Implants.

    PubMed

    Petersen, Richard

    Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-reinforced composite stimulated osseointegration inside the tibia bone marrow measured as percent bone area (PBA) to a great extent when compared to the titanium-6-4 alloy at statistically significant levels. PBA increased significantly with the carbon-fiber composite over the titanium-6-4 alloy for distances from the implant surfaces of 0.1 mm at 77.7% vs. 19.3% (p < 10(-8)) and 0.8 mm at 41.6% vs. 19.5% (p < 10(-4)), respectively. The review focuses on carbon fiber properties that increased PBA for enhanced implant osseointegration. Carbon fibers acting as polymer coated electrically conducting micro-biocircuits appear to provide a biocompatible semi-antioxidant property to remove damaging electron free radicals from the surrounding implant surface. Further, carbon fibers by removing excess electrons produced from the cellular mitochondrial electron transport chain during periods of hypoxia perhaps stimulate bone cell recruitment by free-radical chemotactic influences. In addition, well-studied bioorganic cell actin carbon fiber growth would appear to interface in close contact with the carbon-fiber-reinforced composite implant. Resulting subsequent actin carbon fiber/implant carbon fiber contacts then could help in discharging the electron biological overloads through electrochemical gradients to lower negative charges and lower concentration.

  11. Actual and actuarial probabilities of competing risks: apples and lemons.

    PubMed

    Grunkemeier, Gary L; Jin, Ruyun; Eijkemans, Marinus J C; Takkenberg, Johanna J M

    2007-05-01

    The probability of a type of failure that is not inevitable, but can be precluded by other events such as death, is given by the cumulative incidence function. In cardiac research articles, it has become known as the actual probability, in contrast to the actuarial methods of estimation, usually implemented by the Kaplan-Meier (KM) estimate. Unlike cumulative incidence, KM attempts to predict what the latent failure probability would be if death were eliminated. To do this, the KM method assumes that the risk of dying and the risk of failure are independent. But this assumption is not true for many cardiac applications in which the risks of failure and death are negatively correlated (ie, patients with a higher risk of dying have a lower risk of failure, and patients with a lower risk of death have a higher risk of failure, which is a condition called informative censoring). Recent editorials in two cardiac journals have promoted the use of the KM method (actuarial estimate) for competing risk events (specifically for heart valve performance) and criticized the use of the cumulative incidence (actual) estimates. This report has two aims: to explain the difference between these two estimates and to show why the KM is generally not appropriate. In the process we will rely on alternative representations of the KM estimator (using redistribution to the right and inverse probability weighting) to explain the difference between the two estimates and to show how it may be possible to adjust KM to overcome the informative censoring.

  12. Actual ratio of triacylglycerol positional isomers in milk and cheese.

    PubMed

    Gotoh, Naohiro; Matsumoto, Yumiko; Nagai, Toshiharu; Mizobe, Hoyo; Yoshinaga, Kazuaki; Kojima, Koichi; Kuroda, Ikuma; Kitamura, Yohei; Shimizu, Takashi; Ishida, Hiroki; Wada, Shun

    2012-01-01

    Actual ratios of triacylglycerol (TAG) positional isomers in human, rat, and cow milk fat and cow, buffalo, goat, and sheep cheese fat were analyzed using HPLC-UV-atmospheric pressure chemical ionization-MS/MS system equipped with an octacosyl silylation column or polymeric ODS column. We substituted cheese fats for milk fats in parts of our study because milks from ruminants, with the exception of cows, are difficult to get in Japan. The actual ratio of β-PPC (the TAG consisting of two palmitic acids (P) and one capric acid (C), with the palmitic acid located at the β position) and β-PCP in human milk was different from those in ruminants, with more than half of the medium-chain fatty acids located at the β position even though other fats possessed it mainly at the α position. Palmitic acid was mainly located at the β position for human milk and rat milk; however, the location in ruminant cheese fat was mainly at the α position. The location of fatty acids is thought to be very important for infant nutrition. Particularly, the location of palmitic acid in case of human milk and of medium-chain fatty acids in case of ruminant milk was very characteristic and is considered to be very important to the fatty acids in milk fat.

  13. What do tests of formal reasoning actually measure?

    NASA Astrophysics Data System (ADS)

    Lawson, Anton E.

    Tests of formal operational reasoning derived from Piagetian theory have been found to be effective predictors of academic achievement. Yet Piaget's theory regarding the underlying nature of formal operations and their employment in specific contexts has run into considerable empirical difficulty. The primary purpose of this study was to present the core of an alternative theory of the nature of advanced scientific reasoning. That theory, referred to as the multiple-hypothesis theory, argues that tests of formal operational reasoning actually measure the extent to which persons have acquired the ability to initiate reasoning with more than one specific antecedent condition, or if they are unable to imagine more than one antecedent condition, they are aware that more than one is possible; therefore conclusions that are drawn are tempered by this possibility. As a test of this multiple-hypothesis theory of advanced reasoning and the contrasting Piagetian theory of formal operations, a sample of 922 college students were first classified as concrete operational, transitional, or formal operational, based upon responses to standard Piagetian measures of formal operational reasoning. They were then administered seven logic tasks. Actual response patterns to the tasks were analyzed and found to be similar to predicted response patterns derived from the multiple-hypothesis theory and were different from those predicted by Piagetian theory. Therefore, support was obtained for the multiple-hypothesis theory. The terms intuitive and reflective were suggested to replace the terms concrete operational and formal operational to refer to persons at varying levels of intellectual development.

  14. Experimental study on the regenerator under actual operating conditions

    NASA Astrophysics Data System (ADS)

    Nam, Kwanwoo; Jeong, Sangkwon

    2002-05-01

    An experimental apparatus was prepared to investigate thermal and hydrodynamic characteristics of the regenerator under its actual operating conditions. The apparatus included a compressor to pressurize and depressurize regenerator with various operating frequencies. Cold end of the regenerator was maintained around 100 K by means of liquid nitrogen container and heat exchanger. Instantaneous gas temperature and mass flow rate were measured at both ends of the regenerator during the whole pressure cycle. Pulsating pressure and pressure drop across the regenerator were also measured. The operating frequency of the pressure cycle was varied between 3 and 60 Hz, which are typical operating frequencies of Gifford-McMahon, pulse tube, and Stirling cryocoolers. First, friction factor for the wire screen mesh was directly determined from room temperature experiments. When the operating frequency was less than 9 Hz, the oscillating flow friction factor was nearly same as the steady flow friction factor for Reynolds number up to 100. For 60 Hz operations, the ratio of oscillating flow friction factor to steady flow one was increased as hydraulic Reynolds number became high. When the Reynolds number was 100, this ratio was about 1.6. Second, ineffectiveness of the regenerator was obtained when the cold-end was maintained around 100 K and the warm-end at 300 K to simulate the actual operating condition of the regenerator in cryocooler. Effect of the operating frequency on ineffectiveness of regenerator was discussed at low frequency range.

  15. The origin of children's implanted false memories: memory traces or compliance?

    PubMed

    Otgaar, Henry; Verschuere, Bruno; Meijer, Ewout H; van Oorsouw, Kim

    2012-03-01

    A longstanding question in false memory research is whether children's implanted false memories represent actual memory traces or merely result from compliance. The current study examined this question using a response latency based deception task. Forty-five 8-year-old children received narratives about a true (first day at school) and false event (hot air balloon ride). Across two interviews, 58/32% of the participants developed a partial/full false memory. Interestingly, these children also showed higher false recall on an unrelated DRM paradigm compared to children without a false memory. The crucial finding, however, was that the results of the deception task revealed that children with partial and full false memories were faster to confirm than to deny statements relating to the false event. This indicates that children's implanted false memories reflect actual memory traces, and are unlikely to be explained by mere compliance. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Radiographic evaluation of hip implants.

    PubMed

    Chang, Connie Y; Huang, Ambrose J; Palmer, William E

    2015-02-01

    Serial radiographs are the mainstay in the longitudinal assessment of hip implants. The prosthesis, periprosthetic bone, and juxta-articular soft tissues are inspected for fracture, periosteal reaction, stress shielding, calcar resorption, osteolysis, bony remodeling, metallic debris, and heterotopic ossification. Comparison radiographs best confirm implant migration, subsidence, and aseptic loosening. Infection, particle disease, reaction to metal, and mechanical impingement are important causes of postsurgical pain, but in their earliest stages they may be difficult to diagnose using radiographs. This article addresses the role of radiography following hip arthroplasty. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  17. A reconnectable multiway implantable connector.

    PubMed

    Rushton, D N; Tromans, A M; Donaldson, N de N

    2002-12-01

    A well-tried plug-and-socket connector system designed for connecting multichannel implanted cables was adapted so as to allow disconnection and reconnection during surgery. Five different sealing techniques were tested in vitro, and it was found that only one of them had the required qualities of high leakage path impedance (taken as more than one megaohm for the worst sample) after three months of saline soak, together with demountability under surgical conditions. The system has subsequently been successfully implemented in a patient in whom reconnection was required two years after implantation.

  18. A Percutaneously Implantable Fetal Pacemaker

    PubMed Central

    Zhou, Li; Vest, Adriana N.; Chmait, Ramen H.; Bar-Cohen, Yaniv; Pruetz, Jay; Silka, Michael; Zheng, Kaihui; Peck, Ray; Loeb, Gerald E.

    2015-01-01

    A miniaturized, self-contained pacemaker that could be implanted with a minimally invasive technique would dramatically improve the survival rate for fetuses that develop hydrops fetalis as a result of congenital heart block. We are currently validating a device that we developed to address this bradyarrhythmia. Preclinical studies in a fetal sheep model are underway to demonstrate that the device can be implanted via a minimally invasive approach, can mechanically withstand the harsh bodily environment, can induce effective contractions of the heart muscle with an adequate safety factor, and can successfully operate for the required device lifetime of three months using the previously-developed closed loop transcutaneous recharging system. PMID:25570982

  19. Mutation breeding by ion implantation

    NASA Astrophysics Data System (ADS)

    Yu, Zengliang; Deng, Jianguo; He, Jianjun; Huo, Yuping; Wu, Yuejin; Wang, Xuedong; Lui, Guifu

    1991-07-01

    Ion implantation as a new mutagenic method has been used in the rice breeding program since 1986, and for mutation breeding of other crops later. It has been shown, in principle and in practice, that this method has many outstanding advantages: lower damage rate; higher mutation rate and wider mutational spectrum. Many new lines of rice with higher yield rate; broader disease resistance; shorter growing period but higher quality have been bred from ion beam induced mutants. Some of these lines have been utilized for the intersubspecies hybridization. Several new lines of cotton, wheat and other crops are now in breeding. Some biophysical effects of ion implantation for crop seeds have been studied.

  20. Physiological and molecular determinants of embryo implantation

    PubMed Central

    Zhang, Shuang; Lin, Haiyan; Kong, Shuangbo; Wang, Shumin; Wang, Hongmei; Wang, Haibin; Armant, D. Randall

    2014-01-01

    Embryo implantation involves the intimate interaction between an implantation-competent blastocyst and a receptive uterus, which occurs in a limited time period known as the window of implantation. Emerging evidence shows that defects originating during embryo implantation induce ripple effects with adverse consequences on later gestation events, highlighting the significance of this event for pregnancy success. Although a multitude of cellular events and molecular pathways involved in embryo-uterine crosstalk during implantation have been identified through gene expression studies and genetically engineered mouse models, a comprehensive understanding of the nature of embryo implantation is still missing. This review focuses on recent progress with particular attention to physiological and molecular determinants of blastocyst activation, uterine receptivity, blastocyst attachment and uterine decidualization. A better understanding of underlying mechanisms governing embryo implantation should generate new strategies to rectify implantation failure and improve pregnancy rates in women. PMID:23290997

  1. The epithelial interface with osseointegrated implants.

    PubMed

    Kellett, M; Smith, G A

    1991-01-01

    The development of osseointegration has generated interest in the field of intraoral and maxillofacial implantology. There is well documented evidence of a high level of success in achieving osseointegration, using titanium and alumina-ceramic implant materials. Long term retention of intraoral implants appears in part, to be dependent upon the integrity of the epithelium/implant interface. This paper presents the design features of two commercially available systems Intra-Mobile-Zylinder (IMZ) and Tubingen (Frialit), which represent titanium and alumina-ceramic implants respectively, and reviews current knowledge of the nature of the epithelial junction to implant materials and the bacterial flora associated with successful and failing implants. Implant failure may be caused by a site specific infection with a similar ecosystem and bacterial flora to that found in periodontal disease. Care in patient selection and maintenance of a healthy epithelial junction are essential for the long term function of osseointegrated implants.

  2. Educational Challenges for Children with Cochlear Implants.

    ERIC Educational Resources Information Center

    Chute, Patricia M.; Nevins, Mary Ellen

    2003-01-01

    This article addresses educational challenges for children with severe to profound hearing loss who receive cochlear implants. Despite the implants, these children face acoustic challenges, academic challenges, attention challenges, associative challenges, and adjustment challenges. (Contains references.) (Author/DB)

  3. Scientists Design Heat-Activated Penis Implant

    MedlinePlus

    ... implant, Le used a heat-activated exoskeleton of nitinol, a metal known for its elasticity. A urologist could do a simplified operation to insert the nitinol implant, which would remain flaccid at body temperature ...

  4. Visualization of Medpor implants using surface rendering.

    PubMed

    Wang, Meng; Gui, Lai; Liu, Xiao-Jing

    2011-09-01

    The Medpor surgical implant is one of the easiest implants in clinical practice, especially in craniomaxillofacial surgery. It is often used as a bone substitute material for the repair of skull defects and facial deformities. The Medpor implant has several advantages but its use is limited because it is radiolucent in both direct radiography and conventional computed tomography, causing serious problems with visualization. In this study, a new technique for visualizing Medpor implants was evaluated in 10 patients who had undergone facial reconstruction using the material. Continuous volume scans were made using a 16-channel tomographic scanner and 3D reconstruction software was used to create surface renderings. The threshold values for surface renderings of the implant ranged from -70 HU to -20 HU, with bone as the default. The shape of the implants and the spatial relationship between bone and implant could both be displayed. Surface rendering can allow successful visualization of Medpor implants in the body.

  5. Implants in free fibula flap supporting dental rehabilitation - Implant and peri-implant related outcomes of a randomized clinical trial.

    PubMed

    Kumar, Vinay V; Ebenezer, Supriya; Kämmerer, Peer W; Jacob, P C; Kuriakose, Moni A; Hedne, Naveen; Wagner, Wilfried; Al-Nawas, Bilal

    2016-11-01

    The objective of this study was to assess the difference in success rates of implants when using two or four implant-supported-overdentures following segmental mandibular reconstruction with fibula free flap. This prospective, parallel designed, randomized clinical study was conducted with 1:1 ratio. At baseline, all participants already had segmental reconstruction of mandible with free fibula flap. The participants were randomized into two groups: Group-I received implant-supported-overdentures on two tissue-level implants and Group-II received implant-supported-overdentures on four tissue-level implants. Success rates of the implants were evaluated at 3 months, 6 months and 12 months following implant loading using marginal bone level changes as well as peri-implant indices (Buser et al., 1990). 52 patients were randomized into two treatment groups (26 each), out of which 18 patients (36 implants) of Group-I and 17 patients (68 implants) of Group-II were evaluated. One implant in Group-I was lost due to infective complications and one patient in the same group had superior barrel necrosis. There was a statistically significant increase at both time points (p = 0.03, p = 0.04 at 6 months, 12 months) in the amount of marginal bone loss in Group-I (0.4 mm, 0.5 mm at 6 months, 12 months) as compared to Group-II (0.1 mm, 0.2 mm at 6 months, 12 months). There were no clinically significant changes peri-implant parameters between both groups. Peri-implant soft tissue hyperplasia was seen in both groups, 32% of implants at 3-months, 26% at 6-months and 3% at 12-months follow-up. The results of this study show that patients with 2-implant-supported-overdentures had higher marginal bone loss as compared to patients with 4-implant-supported-overdentures. There were no clinically significant differences in peri-implant soft tissue factors in patients with 2- or 4-implant-supported-overdentures. Hyperplastic peri-implant tissues are common in the early implant

  6. Implants and Ethnocide: Learning from the Cochlear Implant Controversy

    ERIC Educational Resources Information Center

    Sparrow, Robert

    2010-01-01

    This paper uses the fictional case of the "Babel fish" to explore and illustrate the issues involved in the controversy about the use of cochlear implants in prelinguistically deaf children. Analysis of this controversy suggests that the development of genetic tests for deafness poses a serious threat to the continued flourishing of Deaf…

  7. Implantation of hydroxyapatite-titanium corneal implants in rat cornea.

    PubMed

    Fang, Yin Dong; Xiao, Ma; Fei, Huang Yi

    2011-01-01

    To evaluate the biocompatibility of hydroxyapatite-coated titanium (HA/Ti) corneal implants at the molecular levels with histopathology. Eighty Sprague-Dawley rats were divided into 2 equal groups. In the study group, HA/Ti prosthetics were implanted into the right corneal stroma. The control group received a sham incision. Corneas were collected and studied with histopathological examination (HE), immunohistochemical, and other stains, including scanned electron microscopy and reverse transcription-polymerase chain reaction, to evaluate inflammatory reactions, tissue repair, and expression of various biological factors during healing. In the control group, corneal neovascularization occurred 7 days after surgery, and the corneas recovered 28 days after surgery. In the study group, corneal vascularization increased substantially on day 7 and stabilized on day 28. For both groups, reverse transcription-polymerase chain reaction detected expressions of 6 primers at all time points. The amplified sequences were consistent with the designed sequences. The expression of matrix metalloproteinase-2, matrix metalloproteinase-9, bFGF, vascular endothelial growth factor, and type III collagen were delayed in the study group compared with the control group. Histological analyses showed a tight attachment of the corneal tissue to the HA/Ti implant on day 28. The HA/Ti corneal implants can remain stable in corneal tissue for a long time, induce corneal neovascularization, and stimulate inflammatory cells and keratocytes to synthesize or activate matrix metalloproteinases. Artificial cornea made from this material show enhanced stability and biocompatibility in vivo.

  8. Implants and Ethnocide: Learning from the Cochlear Implant Controversy

    ERIC Educational Resources Information Center

    Sparrow, Robert

    2010-01-01

    This paper uses the fictional case of the "Babel fish" to explore and illustrate the issues involved in the controversy about the use of cochlear implants in prelinguistically deaf children. Analysis of this controversy suggests that the development of genetic tests for deafness poses a serious threat to the continued flourishing of Deaf…

  9. Implant dentistry in postgraduate university education. Present conditions, potential, limitations and future trends.

    PubMed

    Mattheos, N; Wismeijer, D; Shapira, L

    2014-03-01

    In recent years, opportunities for postgraduate university education in implant dentistry have increased significantly, with an increase in both the number but also the complexity of available postgraduate programmes. However, there appears to be a lack of standards directing the learning outcomes of such programmes. A scientific literature search was conducted for publications reporting on university programmes within implant dentistry, including description of programmes and evaluation of learning outcomes. A separate Internet search was conducted to collect information on existing university programmes as presented on university websites. Implant dentistry has reached a critical mass of an independent, multidisciplinary and vibrant domain of science, which combines knowledge and discovery from many clinical and basic sciences. Many university programmes conclude with a master's or equivalent degree, but there appears to be a great diversity with regard to duration and learning objectives, as well as targeted skills and competences. The importance of implant dentistry has also increased within established specialist training programmes. There was little indication, however, that the comprehensive aspects of implant dentistry are present in all specialist training programmes where implants are being covered. Although universities should maintain the options of designing academic programmes as they best see fit, it is imperative for them to introduce some form of transparent and comparable criteria, which will allow the profession and the public to relate the degree and academic credentials to the actual skills and competences of the degree holder. With regard to established specialist training programmes, the interdisciplinary and comprehensive nature of implant dentistry needs to be emphasised, covering both surgical and restorative aspects. Finally, implant dentistry is not, at present, a dental specialty. The profession has not reached a consensus as to whether

  10. Management of implant failure during transcatheter aortic valve implantation.

    PubMed

    Ussia, Gian Paolo; Barbanti, Marco; Immè, Sebastiano; Scarabelli, Marilena; Mulè, Massimiliano; Cammalleri, Valeria; Aruta, Patrizia; Pistritto, Anna Maria; Capodanno, Davide; Deste, Wanda; Di Pasqua, Maria Concetta; Tamburino, Corrado

    2010-09-01

    Transcatheter aortic valve implantation (TAVI) is an emerging alternative to palliative medical therapy for nonsurgical patients with severe aortic stenosis. There is a paucity of detailed data on the management and outcome of complications related to the sub-optimal deployment of the prosthesis. We appraised the incidence and management of early implant failure occurring during TAVI. Of 110 patients who underwent TAVI using the third generation 18-French CoreValve ReValving System (Medtronic, MN) in our Institution between June 2007 and January 2010, we identified those experiencing early implant failure and reported on their management and clinical outcome. The primary endpoint was the incidence of major adverse cardiovascular and cerebrovascular event (MACCE) at 30 days and mid-term follow up. Early implant failure occurred in 18 of 110 patients (16.3%). The most common cause was prosthesis under-expansion conditioning moderate to severe peri-valvular leak (44.4%). Prosthesis deployment too low or too high with respect to the aortic annulus leading to severe peri-valvular leak occurred in 22.2% and 5.5% of patients, respectively. Need of valve retrieve after the first attempt of deployment occurred in four cases (22.2%). Prosthesis embolization in the ascending aorta occurred in 5.5% of patients who experienced early implant failure. All implant failure cases were managed percutaneously with gain in aortic valve area from 0.44 ± 0.17 to 1.28 ± 0.27 cm(2) (P < 0.001), decrease of mean transaortic gradient from 55.00 ± 19.51 to 11.58 ± 5.91 mmHg (P < 0.001) and no MACCE at 30 days. After 11 ± 6 months, MACCE occurred cumulatively in two patients (11.1%). Early implant failure can complicate the TAVI procedure with the CoreValve system, but it can be managed safely and effectively with bailout transcatheter techniques, avoiding surgery, with good early and mid-term clinical and echocardiographic results.

  11. Corrosion and fatigue of surgical implants

    NASA Technical Reports Server (NTRS)

    Lisagor, W. B.

    1975-01-01

    Implants for the treatment of femoral fractures, mechanisms leading to the failure or degradation of such structures, and current perspectives on surgical implants are discussed. Under the first heading, general usage, materials and procedures, environmental conditions, and laboratory analyses of implants after service are considered. Corrosion, crevice corrosion, stress corrosion cracking, intergranular corrosion, pitting corrosion, fatigue, and corrosion fatigue are the principal degradation mechanisms described. The need for improvement in the reliability of implants is emphasized.

  12. Positron annihilation study of P implanted Si

    SciTech Connect

    Asoka-Kumar, P.; Au, H.L.; Lynn, K.G. ); Sferlazzo, P. . SED Division)

    1992-01-01

    High-energy ion implantation (above 200 keV) is now commonly used in a variety of VLSI processes. The high energy required for these implants is often achieved by implanting multiply charged ions, which inevitably brings in the problem of low-energy ion contamination. The low-energy contamination is difficult to diagnose and detect. Positron annihilation spectroscopy is used to examine the defect distributions in these high energy implants with varying degrees of contamination.

  13. Positron annihilation study of P implanted Si

    SciTech Connect

    Asoka-Kumar, P.; Au, H.L.; Lynn, K.G.; Sferlazzo, P.

    1992-12-01

    High-energy ion implantation (above 200 keV) is now commonly used in a variety of VLSI processes. The high energy required for these implants is often achieved by implanting multiply charged ions, which inevitably brings in the problem of low-energy ion contamination. The low-energy contamination is difficult to diagnose and detect. Positron annihilation spectroscopy is used to examine the defect distributions in these high energy implants with varying degrees of contamination.

  14. A simplified impression technique for dental implants.

    PubMed

    Vogel, Robert E

    2002-03-01

    Dental implants have been considered an acceptable form of dental treatment since the early 1980s. A number of studies have been published describing impression techniques for dental implants. Many of the techniques described are so complex that they may seem daunting to the average restorative dentist. Most general practitioners do not wish to attempt to restore dental implants. This article describes a very simple, yet extremely accurate, technique for making impressions of dental implant fixtures.

  15. Corrosion and fatigue of surgical implants

    NASA Technical Reports Server (NTRS)

    Lisagor, W. B.

    1975-01-01

    Implants for the treatment of femoral fractures, mechanisms leading to the failure or degradation of such structures, and current perspectives on surgical implants are discussed. Under the first heading, general usage, materials and procedures, environmental conditions, and laboratory analyses of implants after service are considered. Corrosion, crevice corrosion, stress corrosion cracking, intergranular corrosion, pitting corrosion, fatigue, and corrosion fatigue are the principal degradation mechanisms described. The need for improvement in the reliability of implants is emphasized.

  16. [Cochlear implantation in a child with congenital sensorineural deafness due to 35 DELG mutation in GJB2 (connexin 26) gene].

    PubMed

    Teriutin, F M; Barashkov, N A; Dzhemileva, L U; Posukh, O L; Fedotova, E E; Gurinova, E E; Fedorova, S A; Tavartkiladze, G A; Khusnutdinova, E K

    2009-01-01

    This paper reports the first case of cochlear implantation performed in this country in a child with congenital non-syndromic sensorineural loss of hearing having hereditary etiology and attributable to autosomal-recessive 35 delG mutation in locus DFNB1 (13q.11-q12) of GJB2 (connexin 26) gene.

  17. Experimental and failure analysis of the prosthetic finger joint implants

    NASA Astrophysics Data System (ADS)

    Naidu, Sanjiv H.

    Small joint replacement arthroplasty of the hand is a well accepted surgical procedure to restore function and cosmesis in an individual with a crippled hand. Silicone elastomers have been used as prosthetic material in various small hand joints for well over three decades. Although the clinical science aspects of silicone elastomer failure are well known, the physical science aspects of prosthetic failure are scant and vague. In the following thesis, using both an animal model, and actual retrieved specimens which have failed in human service, experimental and failure analysis of silicone finger joints are presented. Fractured surfaces of retrieved silicone trapezial implants, and silicone finger joint implants were studied with both FESEM and SEM; the mode of failure for silicone trapezium is by wear polishing, whereas the finger joint implants failed either by fatigue fracture or tearing of the elastomer, or a combination of both. Thermal analysis revealed that the retrieved elastomer implants maintained its viscoelastic properties throughout the service period. In order to provide for a more functional and physiologic arthroplasty a novel finger joint (Rolamite prosthesis) is proposed using more recently developed thermoplastic polymers. The following thesis also addresses the outcome of the experimental studies of the Rolamite prosthesis in a rabbit animal model, in addition to the failure analysis of the thermoplastic polymers while in service in an in vivo synovial environment. Results of retrieved Rolamite specimens suggest that the use for thermoplastic elastomers such as block copolymer based elastomers in a synovial environment such as a mammalian joint may very well be limited.

  18. Off-pump replacement of the INCOR implantable axial-flow pump.

    PubMed

    Nakashima, Kuniki; Kirsch, Matthias E W; Vermes, Emmanuelle; Rosanval, Odile; Loisance, Daniel

    2009-02-01

    Owing to the actual increase of mechanical circulatory support durations, total or partial replacement of ventricular assist devices (VADs) will most certainly have to be performed with increasing frequency. Herein we report the case of a patient in whom an INCOR (Berlin Heart AG, Berlin) implantable axial-flow pump was replaced without the use of cardiopulmonary bypass (CPB), underscoring some of the unique features provided by this system.

  19. Impacts of 3D bone-to- implant contact and implant diameter on primary stability of dental implant.

    PubMed

    Hsu, Jui-Ting; Shen, Yen-Wen; Kuo, Chih-Wei; Wang, Ruei-Teng; Fuh, Lih-Jyh; Huang, Heng-Li

    2017-08-01

    This study investigated the effects of three three-dimensional (3D) bone-to-implant contact (BIC) parameters-potential BIC area (pBICA), BIC area (BICA), and 3D BIC percentage (3D BIC%; defined as BICA divided by pBICA)-in relation to the implant diameter on primary implant stability, as well as their correlations were also evaluated. Dental implants with diameters of 3.75, 4, 5, and 6 mm and artificial bone specimens were scanned by microcomputed tomography to construct 3D models for calculating pBICA, BICA, and 3D BIC%. Indexes of the primary implant stability including the insertion torque value (ITV), Periotest value (PTV), and implant stability quotient (ISQ) were measured after implants with various diameters were placed into bone specimens. The Kruskal-Wallis test, Wilcoxon rank-sum test with Bonferroni adjustment, and Spearman correlations were all performed as statistical and correlation analyses. The implant diameter significantly influenced pBICA and BICA, but not 3D BIC%. ITV and PTV were more sensitive to implant diameter than was ISQ. The coefficients of determination were high (>0.92) for the correlations between pBICA (or BICA) and indexes of the primary implant stability. This study revealed how the implant diameter and the three-dimensional (3D) BIC influence the primary stabilities of dental implant. ITV and PTV were more sensitively influenced by the implant diameter than ISQ. The pBICA and BICA seem to be more important than 3D BIC % for using wider implant in treatment plan, since those two parameters are highly predictive of variations in the primary stability of dental implant. Copyright © 2017. Published by Elsevier B.V.

  20. Effects of helium implantation on the tensile properties and microstructure of Ni₇₃P₂₇ metallic glass nanostructures

    DOE PAGES

    Liontas, Rachel; Gu, X. Wendy; Fu, Engang; ...

    2014-09-10

    We report fabrication and nanomechanical tension experiments on as-fabricated and helium-implanted ~130 nm diameter Ni₇₃P₂₇ metallic glass nano-cylinders. The nano-cylinders were fabricated by a templated electroplating process and implanted with He⁺ at energies of 50, 100, 150, and 200 keV to create a uniform helium concentration of ~3 at. % throughout the nano-cylinders. Transmission electron microscopy (TEM) imaging and through-focus analysis reveal that the specimens contained ~2 nm helium bubbles distributed uniformly throughout the nano-cylinder volume. In-situ tensile experiments indicate that helium-implanted specimens exhibit enhanced ductility as evidenced by a 2-fold increase in plastic strain over as-fabricated specimens, with nomore » sacrifice in yield and ultimate tensile strengths. This improvement in mechanical properties suggests that metallic glasses may actually exhibit a favorable response to high levels of helium implantation.« less

  1. Effects of helium implantation on the tensile properties and microstructure of Ni₇₃P₂₇ metallic glass nanostructures

    SciTech Connect

    Liontas, Rachel; Gu, X. Wendy; Fu, Engang; Wang, Yongqiang; Li, Nan; Mara, Nathan; Greer, Julia R.

    2014-09-10

    We report fabrication and nanomechanical tension experiments on as-fabricated and helium-implanted ~130 nm diameter Ni₇₃P₂₇ metallic glass nano-cylinders. The nano-cylinders were fabricated by a templated electroplating process and implanted with He⁺ at energies of 50, 100, 150, and 200 keV to create a uniform helium concentration of ~3 at. % throughout the nano-cylinders. Transmission electron microscopy (TEM) imaging and through-focus analysis reveal that the specimens contained ~2 nm helium bubbles distributed uniformly throughout the nano-cylinder volume. In-situ tensile experiments indicate that helium-implanted specimens exhibit enhanced ductility as evidenced by a 2-fold increase in plastic strain over as-fabricated specimens, with no sacrifice in yield and ultimate tensile strengths. This improvement in mechanical properties suggests that metallic glasses may actually exhibit a favorable response to high levels of helium implantation.

  2. Effects of helium implantation on the tensile properties and microstructure of Ni73P27 metallic glass nanostructures.

    PubMed

    Liontas, Rachel; Gu, X Wendy; Fu, Engang; Wang, Yongqiang; Li, Nan; Mara, Nathan; Greer, Julia R

    2014-09-10

    We report fabrication and nanomechanical tension experiments on as-fabricated and helium-implanted ∼130 nm diameter Ni73P27 metallic glass nanocylinders. The nanocylinders were fabricated by a templated electroplating process and implanted with He(+) at energies of 50, 100, 150, and 200 keV to create a uniform helium concentration of ∼3 atom % throughout the nanocylinders. Transmission electron microscopy imaging and through-focus analysis reveal that the specimens contained ∼2 nm helium bubbles distributed uniformly throughout the nanocylinder volume. In situ tensile experiments indicate that helium-implanted specimens exhibit enhanced ductility as evidenced by a 2-fold increase in plastic strain over as-fabricated specimens with no sacrifice in yield and ultimate tensile strengths. This improvement in mechanical properties suggests that metallic glasses may actually exhibit a favorable response to high levels of helium implantation.

  3. Actual Versus Predicted Cardiovascular Demands in Submaximal Cycle Ergometer Testing.

    PubMed

    Hoehn, Amanda M; Mullenbach, Megan J; Fountaine, Charles J

    The Astrand-Rhyming cycle ergometer test (ARCET) is a commonly administered submaximal test for estimating aerobic capacity. Whereas typically utilized in clinical populations, the validity of the ARCET to predict VO2max in a non-clinical population, especially female, is less clear. Therefore, the purpose of this study was to determine the accuracy of the ARCET in a sample of healthy and physically active college students. Subjects (13 females, 10 males) performed a maximal cycle ergometer test to volitional exhaustion to determine VO2max. At least 48 hours later, subjects performed the ARCET protocol. Predicted VO2max was calculated following the ARCET format using the age corrected factor. There was no significant difference (p=.045) between actual (41.0±7.97 ml/kg/min) and predicted VO2max (40.3±7.58 ml/kg/min). When split for gender there was a significant difference between actual and predicted VO2 for males, (45.1±7.74 vs. 42.7±8.26 ml/kg/min, p=0.029) but no significant difference observed for females, (37.9±6.9 vs. 38.5±6.77 ml/kg/min, p=0.675). The correlation between actual and predicted VO2 was r=0.84, p<0.001 with an SEE= 4.3 ml/kg/min. When split for gender, the correlation for males was r=0.94, p<0.001, SEE=2.72 ml/kg/min; for females, r=0.74, p=0.004, SEE=4.67 ml/kg/min. The results of this study indicate that the ARCET accurately estimated VO2max in a healthy college population of both male and female subjects. Implications of this study suggest the ARCET can be used to assess aerobic capacity in both fitness and clinical settings where measurement via open-circuit spirometry is either unavailable or impractical.

  4. Self-Actualization in a Marathon Growth Group: Do the Strong Get Stronger?

    ERIC Educational Resources Information Center

    Kimball, Ronald; Gelso, Charles J.

    1974-01-01

    This study examined the effects of a weekend marathon on the level of self-actualization of college students and the relationship between ego strength and extent of change in self-actualization. The group experience did increase self-actualization, but participants' initial level of ego strength was unrelated to changes in self-actualization.…

  5. Self-Actualization in a Marathon Growth Group: Do the Strong Get Stronger?

    ERIC Educational Resources Information Center

    Kimball, Ronald; Gelso, Charles J.

    1974-01-01

    This study examined the effects of a weekend marathon on the level of self-actualization of college students and the relationship between ego strength and extent of change in self-actualization. The group experience did increase self-actualization, but participants' initial level of ego strength was unrelated to changes in self-actualization.…

  6. 29 CFR 801.24 - Rights of examinee-actual testing phase.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Rights of examinee-actual testing phase. 801.24 Section 801... Exemptions § 801.24 Rights of examinee—actual testing phase. (a) The actual testing phase refers to that time... examinee and then analyzes the charts derived from the test. Throughout the actual testing phase, the...

  7. Penile prosthesis implantation: past, present and future.

    PubMed

    Simmons, M; Montague, D K

    2008-01-01

    Penile prosthesis implantation is the oldest effective treatment for erectile dysfunction. This review examines the past, present and future of penile prosthesis implantation. Advances in prosthetic design and implantation techniques have resulted today in devices that produce nearly normal flaccid and erect states, and have remarkable freedom from mechanical failure. The future of prosthetic design holds promises for even more improvements.

  8. 21 CFR 522.1350 - Melatonin implant.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Melatonin implant. 522.1350 Section 522.1350 Food... Melatonin implant. (a) Specifications. The drug is a silicone rubber elastomer implant containing 2.7 milligrams of melatonin. (b) Sponsor. See No. 053923 in § 510.600(c) of this chapter. (c) Conditions of use...

  9. 21 CFR 522.1350 - Melatonin implant.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Melatonin implant. 522.1350 Section 522.1350 Food... Melatonin implant. (a) Specifications. The drug is a silicone rubber elastomer implant containing 2.7 milligrams of melatonin. (b) Sponsor. See No. 053923 in § 510.600(c) of this chapter. (c) Conditions of use...

  10. Myths about Cochlear Implants: A Family Perspective.

    ERIC Educational Resources Information Center

    Luetke-Stahlman, B.

    1994-01-01

    A parent of two young children who received cochlear implant surgery addresses common myths about this procedure including "deaf people don't support the use of cochlear implants,""if you choose cochlear implant surgery, you are choosing the hearing world,""hearing parents are not qualified to decide," and "the deaf child him/herself should…

  11. [The elementary discussion on digital implant dentistry].

    PubMed

    Su, Y C

    2016-04-09

    It is a digital age today. Exposed to all kinds of digital products in many fields. Certainly, implant dentistry is not exception. Digitalization could improve the outcomes and could decrease the complications of implant dentistry. This paper introduces the concepts, definitions, advantages, disadvantages, limitations and errors of digital implant dentistry.

  12. Rescuing failed oral implants via Wnt activation

    PubMed Central

    Yin, Xing; Li, Jingtao; Chen, Tao; Mouraret, Sylvain; Dhamdhere, Girija; Brunski, John B.; Zou, Shujuan; Helms, Jill A.

    2016-01-01

    Aim Implant osseointegration is not always guaranteed and once fibrous encapsulation occurs clinicians have few options other than implant removal. Our goal was to test whether a WNT protein therapeutic could rescue such failed implants. Material and Methods Titanium implants were placed in over-sized murine oral osteotomies. A lack of primary stability was verified by mechanical testing. Interfacial strains were estimated by finite element modelling and histology coupled with histomorphometry confirmed the lack of peri-implant bone. After fibrous encapsulation was established peri-implant injections of a liposomal formulation of WNT3A protein (L-WNT3A) or liposomal PBS (L-PBS) were then initiated. Quantitative assays were employed to analyse the effects of L-WNT3A treatment. Results Implants in gap-type interfaces exhibited high interfacial strains and no primary stability. After verification of implant failure, L-WNT3A or L-PBS injections were initiated. L-WNT3A induced a rapid, significant increase in Wnt responsiveness in the peri-implant environment, cell proliferation and osteogenic protein expression. The amount of peri-implant bone and bone in contact with the implant were significantly higher in L-WNT3A cases. Conclusions These data demonstrate L-WNT3A can induce peri-implant bone formation even in cases where fibrous encapsulation predominates. PMID:26718012

  13. Using Aerospace Technology To Design Orthopedic Implants

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Mraz, P. J.; Davy, D. T.

    1996-01-01

    Technology originally developed to optimize designs of composite-material aerospace structural components used to develop method for optimizing designs of orthopedic implants. Development effort focused on designing knee implants, long-term goal to develop method for optimizing designs of orthopedic implants in general.

  14. Using Aerospace Technology To Design Orthopedic Implants

    NASA Technical Reports Server (NTRS)

    Saravanos, D. A.; Mraz, P. J.; Davy, D. T.

    1996-01-01

    Technology originally developed to optimize designs of composite-material aerospace structural components used to develop method for optimizing designs of orthopedic implants. Development effort focused on designing knee implants, long-term goal to develop method for optimizing designs of orthopedic implants in general.

  15. 21 CFR 522.1350 - Melatonin implant.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Melatonin implant. 522.1350 Section 522.1350 Food... Melatonin implant. (a) Specifications. The drug is a silicone rubber elastomer implant containing 2.7 milligrams of melatonin. (b) Sponsor. See No. 053923 in § 510.600(c) of this chapter. (c) Conditions of...

  16. 21 CFR 522.1350 - Melatonin implant.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Melatonin implant. 522.1350 Section 522.1350 Food... Melatonin implant. (a) Specifications. The drug is a silicone rubber elastomer implant containing 2.7 milligrams of melatonin. (b) Sponsor. See No. 053923 in § 510.600(c) of this chapter. (c) Conditions of...

  17. Predicting water suppy and actual evapotranspiration of street trees

    NASA Astrophysics Data System (ADS)

    Wessolek, Gerd; Heiner, Moreen; Trinks, Steffen

    2017-04-01

    It's well known that street trees cool air temperature in summer-time by transpiration and shading and also reduce runoff. However, it's difficult to analyse if trees have water shortage or not. This contribution focus on predicting water supply, actual evapotranspiration, and runoff by using easily available climate data (precipiation, potential evapotranspiration) and site characteristics (water retention, space, sealing degree, groundwater depth). These parameter were used as input data for Hydro-Pedotransfer-Functions (HPTFs) allowing the estimation of the annual water budget. Results give statements on water supply of trees, drought stress, and additional water demand by irrigation. Procedure also analyse, to which extent the surrounding partly sealed surfaces deliver water to the trees. Four representative street canyons of Berlin City were analysed and evaluated within in training program for M.A. students of „Urban Eco-system Science" at the Technische Universität Berlin.

  18. Photovoltaic performance models: an evaluation with actual field data

    NASA Astrophysics Data System (ADS)

    TamizhMani, Govindasamy; Ishioye, John-Paul; Voropayev, Arseniy; Kang, Yi

    2008-08-01

    Prediction of energy production is crucial to the design and installation of the building integrated photovoltaic systems. This prediction should be attainable based on the commonly available parameters such as system size, orientation and tilt angle. Several commercially available as well as free downloadable software tools exist to predict energy production. Six software models have been evaluated in this study and they are: PV Watts, PVsyst, MAUI, Clean Power Estimator, Solar Advisor Model (SAM) and RETScreen. This evaluation has been done by comparing the monthly, seasonaly and annually predicted data with the actual, field data obtained over a year period on a large number of residential PV systems ranging between 2 and 3 kWdc. All the systems are located in Arizona, within the Phoenix metropolitan area which lies at latitude 33° North, and longitude 112 West, and are all connected to the electrical grid.

  19. An evaluation of contractor projected and actual costs

    NASA Technical Reports Server (NTRS)

    Kwiatkowski, K. A.; Buffalano, C.

    1974-01-01

    GSFC contractors with cost-plus contracts provide cost estimates for each of the next four quarters on a quarterly basis. Actual expenditures over a two-year period were compared to the estimates, and the data were sorted in different ways to answer several questions and give quantification to observations, such as how much does the accuracy of estimates degrade as they are made further into the future? Are estimates made for small dollar amounts more accurate than for large dollar estimates? Other government agencies and private companies with cost-plus contracts may be interested in this analysis as potential methods of contract management for their organizations. It provides them with the different methods one organization is beginning to use to control costs.

  20. Motion fading is driven by perceived, not actual angular velocity.

    PubMed

    Kohler, P J; Caplovitz, G P; Hsieh, P-J; Sun, J; Tse, P U

    2010-06-01

    After prolonged viewing of a slowly drifting or rotating pattern under strict fixation, the pattern appears to slow down and then momentarily stop. Here we examine the relationship between such 'motion fading' and perceived angular velocity. Using several different dot patterns that generate emergent virtual contours, we demonstrate that whenever there is a difference in the perceived angular velocity of two patterns of dots that are in fact rotating at the same angular velocity, there is also a difference in the time to undergo motion fading for those two patterns. Conversely, whenever two patterns show no difference in perceived angular velocity, even if in fact rotating at different angular velocities, we find no difference in the time to undergo motion fading. Thus, motion fading is driven by the perceived rather than actual angular velocity of a rotating stimulus.

  1. Catalytic combustion of actual low and medium heating value gases

    NASA Technical Reports Server (NTRS)

    Bulzan, D. L.

    1982-01-01

    Catalytic combustion of both low and medium heating value gases using actual coal derived gases obtained from operating gasifiers was demonstrated. A fixed bed gasifier with a complete product gas cleanup system was operated in an air blown mode to produce low heating value gas. A fluidized bed gasifier with a water quench product gas cleanup system was operated in both an air enriched and an oxygen blown mode to produce low and medium, heating value gas. Noble metal catalytic reactors were evaluated in 12 cm flow diameter test rigs on both low and medium heating value gases. Combustion efficiencies greater than 99.5% were obtained with all coal derived gaseous fuels. The NOx emissions ranged from 0.2 to 4 g NO2 kg fuel.

  2. Prediction of individual implant bone levels and the existence of implant "phenotypes".

    PubMed

    Papantonopoulos, Georgios; Gogos, Christos; Housos, Efthymios; Bountis, Tassos; Loos, Bruno G

    2017-07-01

    To cluster implants placed in patients of a private practice and identify possible implant "phenotypes" and predictors of individual implant mean bone levels (IIMBL). Clinical and radiographical variables were collected from 72 implant-treated patients with 237 implants and a mean 7.4 ± 3.5 years of function. We clustered implants using the k-means method guided by multidimensional unfolding. For predicting IIMBL, we used principal component analysis (PCA) as a variable reduction method for an ensemble selection (ES) and a support vector machines models (SVMs). Network analysis investigated variable interactions. We identified a cluster of implants susceptible to peri-implantitis (96% of the implants in the cluster were affected by peri-implantitis) and two overlapping clusters of implants resistant to peri-implantitis. The cluster susceptible to peri-implantitis showed a mean IIMBL of 5.2 mm and included implants placed mainly in the lower front jaw and in mouths having a mean of eight teeth. PCA extracted the parameters such as number of teeth, full-mouth plaque scores, implant surface, periodontitis severity, age and diabetes as significant in explaining the data variability. ES and SVMs showed good results in predicting IIMBL (root-mean-squared error of 0.133 and 0.149, 10-fold cross-validation error of 0.147 and 0.150, respectively). Network analysis revealed limited interdependencies of variables among peri-implantitis-affected and non-affected implants and supported the hypothesis of the existence of distinct implant "phenotypes." Two implant "phenotypes" were identified, one with susceptibility and another with resistance to peri-implantitis. Prediction of IIMBL could be achieved by using six variables. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Electrophonic hearing and cochlear implants.

    PubMed

    Risberg, A; Agelfors, E; Lindström, B; Bredberg, G

    1990-01-01

    It has been difficult to explain the good speech understanding obtained by some cochlear implant patients fitted with a single-channel electrode and analog transmissions of the speech signal (Vienna/3M implant). It has also been difficult to explain the variation in results reported by different groups using the same implant. One hypothesis asserts that the above differences can be explained by the observation that electric stimulation with an implanted electrode might result in two different auditory sensations, the first resulting from the stimulation of the remaining hair cells (electrophonic component) and the second from the electric stimulation of the auditory nerve (electro-neural component). The two sensations are very different. As a result of different definitions of total deafness (functional or threshold definition), patients with remaining hair cells are operated on by some groups, but not by other groups. Some published results from different studies are discussed with reference to the above hypothesis and the possible consequences for the selection of the patients, the use of extra- or intracochlear electrodes, and the selection of the speech coding strategy are discussed.

  4. High current metal ion implantation

    NASA Astrophysics Data System (ADS)

    Brown, Ian G.

    1990-04-01

    This report summarizes the research and development that has been carried out at Lawrence Berkeley Laboratory to develop a novel kind of high current metal ion source for metallurgical surface modification application. In ion implantation, an energetic ion beam is injected into a solid surface with the result that the surface composition is changed. For the case when the surface is a metal, the tribological properties of the new metallurgical surface can be significantly improved over the unimplanted surface. Previously, however, very intense metal ion beams have not been available, and this has been an impedance to the development of the field. With the MEVVA (Metal Vapor Vacuum Arc) ion source, metal ion beam currents of very high intensity have become available. This report outlines the progress made under the funded program in the four areas addressed: development of the MEVVA ion source for ion implantation application; research on the ion beam characteristics and behavior; development of the ion implantation facility; metallurgical ion implantation research that was performed.

  5. Orthodontic palatal implants: clinical technique.

    PubMed

    Tinsley, D; O'Dwyer, J J; Benson, P E; Doyle, P T; Sandler, J

    2004-03-01

    The aim of this paper is to familiarize the readers with some of the clinical considerations necessary to ensure successful use of mid-palatal implants. Both surgical and technical aspects will be discussed along with a description of impression techniques used.

  6. Cortical Plasticity after Cochlear Implantation

    PubMed Central

    Petersen, B.; Gjedde, A.; Wallentin, M.; Vuust, P.

    2013-01-01

    The most dramatic progress in the restoration of hearing takes place in the first months after cochlear implantation. To map the brain activity underlying this process, we used positron emission tomography at three time points: within 14 days, three months, and six months after switch-on. Fifteen recently implanted adult implant recipients listened to running speech or speech-like noise in four sequential PET sessions at each milestone. CI listeners with postlingual hearing loss showed differential activation of left superior temporal gyrus during speech and speech-like stimuli, unlike CI listeners with prelingual hearing loss. Furthermore, Broca's area was activated as an effect of time, but only in CI listeners with postlingual hearing loss. The study demonstrates that adaptation to the cochlear implant is highly related to the history of hearing loss. Speech processing in patients whose hearing loss occurred after the acquisition of language involves brain areas associated with speech comprehension, which is not the case for patients whose hearing loss occurred before the acquisition of language. Finally, the findings confirm the key role of Broca's area in restoration of speech perception, but only in individuals in whom Broca's area has been active prior to the loss of hearing. PMID:24377050

  7. Will Retinal Implants Restore Vision?

    NASA Astrophysics Data System (ADS)

    Zrenner, Eberhart

    2002-02-01

    A number of research groups are developing electrical implants that can be attached directly to the retina in an attempt to restore vision to patients suffering from retinal degeneration. However, despite promising results in animal experiments, there are still several major obstacles to overcome before retinal prostheses can be used clinically.

  8. Bioceramic Coatings for Orthopaedic Implants

    SciTech Connect

    Campbell, Allison A.

    2003-11-02

    During the past century, man-made materials and devices have been developed to the point at which they have been used successfully to replace and/or restore function to diseased or damaged tissues. In the field of orthopaedics, the use of metal implants has significantly improved the quality of life for countless individuals. Critical factors for implant success include proper design, material selection, and biocompatibility. While early research focused on the understanding biomechanical properties of the metal device, recent work has turned toward improving the biological properties of these devices. This has lead to the introduction of calcium phosphate (CaP) bioceramics as a bioactive interface between the bulk metal impart and the surrounding tissue. The first calcium phosphate coatings where produced via vapor phase routes but more recently, there has been the emergence of solution based and biomimetic methods. While each approach has its own intrinsic materials and biological properties, in general CaP coatings have the promise to improve implant biocompatibility and ultimately implant longevity.

  9. Wearable and implantable pancreas substitutes.

    PubMed

    Ricotti, Leonardo; Assaf, Tareq; Dario, Paolo; Menciassi, Arianna

    2013-03-01

    A lifelong-implanted and completely automated artificial or bioartificial pancreas (BAP) is the holy grail for type 1 diabetes treatment, and could be a definitive solution even for other severe pathologies, such as pancreatitis and pancreas cancer. Technology has made several important steps forward in the last years, providing new hope for the realization of such devices, whose feasibility is strictly connected to advances in glucose sensor technology, subcutaneous and intraperitoneal insulin pump development, the design of closed-loop control algorithms for mechatronic pancreases, as well as cell and tissue engineering and cell encapsulation for biohybrid pancreases. Furthermore, smart integration of the mentioned components and biocompatibility issues must be addressed, bearing in mind that, for mechatronic pancreases, it is most important to consider how to recharge implanted batteries and refill implanted insulin reservoirs without requiring periodic surgical interventions. This review describes recent advancements in technologies and concepts related to artificial and bioartificial pancreases, and assesses how far we are from a lifelong-implanted and self-working pancreas substitute that can fully restore the quality of life of a diabetic (or other type of) patient.

  10. A totally implantable electrical heart.

    PubMed

    Jufer, M

    1985-01-01

    A totally implantable artificial heart, electrically actuated by magnetical energy transmission was developed in Switzerland. The pusher-plates and roller-screw model was used for the pump. The main advantages of such a mechanical heart are discussed, in particular, the motor that transforms electrical energy into mechanical energy, and allows accurate control of the output and pressures of the artificial ventricles. The system includes the heart, the electronic control of the power supply, the microprocessor for the control of the mechanical heart's performance, a buffer battery, a rectifier and the secondary of the energy transmission. All these elements are implanted. Outside of the body are the main battery, the chopper and the primary of the energy transmission. At present, a left ventricle device for external assistance and a totally artificial heart have both been developed and implanted in calves. An optimized totally artificial heart is in construction, its size being compatible for human implantation; its volume is 500 mL and its total weight is 450 g.

  11. Advancing Binaural Cochlear Implant Technology

    PubMed Central

    McAlpine, David

    2015-01-01

    This special issue contains a collection of 13 papers highlighting the collaborative research and engineering project entitled Advancing Binaural Cochlear Implant Technology—ABCIT—as well as research spin-offs from the project. In this introductory editorial, a brief history of the project is provided, alongside an overview of the studies. PMID:26721929

  12. Cochlear implant optimized noise reduction

    NASA Astrophysics Data System (ADS)

    Mauger, Stefan J.; Arora, Komal; Dawson, Pam W.

    2012-12-01

    Noise-reduction methods have provided significant improvements in speech perception for cochlear implant recipients, where only quality improvements have been found in hearing aid recipients. Recent psychoacoustic studies have suggested changes to noise-reduction techniques specifically for cochlear implants, due to differences between hearing aid recipient and cochlear implant recipient hearing. An optimized noise-reduction method was developed with significantly increased temporal smoothing of the signal-to-noise ratio estimate and a more aggressive gain function compared to current noise-reduction methods. This optimized noise-reduction algorithm was tested with 12 cochlear implant recipients over four test sessions. Speech perception was assessed through speech in noise tests with three noise types; speech-weighted noise, 20-talker babble and 4-talker babble. A significant speech perception improvement using optimized noise reduction over standard processing was found in babble noise and speech-weighted noise and over a current noise-reduction method in speech-weighted noise. Speech perception in quiet was not degraded. Listening quality testing for noise annoyance and overall preference found significant improvements over the standard processing and over a current noise-reduction method in speech-weighted and babble noise types. This optimized method has shown significant speech perception and quality improvements compared to the standard processing and a current noise-reduction method.

  13. Cochlear implant optimized noise reduction.

    PubMed

    Mauger, Stefan J; Arora, Komal; Dawson, Pam W

    2012-12-01

    Noise-reduction methods have provided significant improvements in speech perception for cochlear implant recipients, where only quality improvements have been found in hearing aid recipients. Recent psychoacoustic studies have suggested changes to noise-reduction techniques specifically for cochlear implants, due to differences between hearing aid recipient and cochlear implant recipient hearing. An optimized noise-reduction method was developed with significantly increased temporal smoothing of the signal-to-noise ratio estimate and a more aggressive gain function compared to current noise-reduction methods. This optimized noise-reduction algorithm was tested with 12 cochlear implant recipients over four test sessions. Speech perception was assessed through speech in noise tests with three noise types; speech-weighted noise, 20-talker babble and 4-talker babble. A significant speech perception improvement using optimized noise reduction over standard processing was found in babble noise and speech-weighted noise and over a current noise-reduction method in speech-weighted noise. Speech perception in quiet was not degraded. Listening quality testing for noise annoyance and overall preference found significant improvements over the standard processing and over a current noise-reduction method in speech-weighted and babble noise types. This optimized method has shown significant speech perception and quality improvements compared to the standard processing and a current noise-reduction method.

  14. Non-actual motion: phenomenological analysis and linguistic evidence.

    PubMed

    Blomberg, Johan; Zlatev, Jordan

    2015-09-01

    Sentences with motion verbs describing static situations have been seen as evidence that language and cognition are geared toward dynamism and change (Talmy in Toward a cognitive semantics, MIT Press, Cambridge, 2000; Langacker in Concept, image, and symbol: the cognitive basis of grammar, Mouton de Gruyter, Berlin and New York, 1990). Different concepts have been used in the literature, e.g., fictive motion, subjective motion and abstract motion to denote this. Based on phenomenological analysis, we reinterpret such concepts as reflecting different motivations for the use of such constructions (Blomberg and Zlatev in Phenom Cogn Sci 13(3):395-418, 2014). To highlight the multifaceted character of the phenomenon, we propose the concept non-actual motion (NAM), which we argue is more compatible with the situated cognition approach than explanations such as "mental simulation" (e.g., Matlock in Studies in linguistic motivation, Mouton de Gruyter, Berlin, 2004). We investigate the expression of NAM by means of a picture-based elicitation task with speakers of Swedish, French and Thai. Pictures represented figures that either afford human motion or not (±afford); crossed with this, the figure extended either across the picture from a third-person perspective (3 pp) or from a first-person perspective (1 pp). All picture types elicited NAM-sentences with the combination [+afford, 1 pp] producing most NAM-sentences in all three languages. NAM-descriptions also conformed to language-specific patterns for the expression of actual motion. We conclude that NAM shows interaction between pre-linguistic motivations and language-specific conventions.

  15. Drone based estimation of actual evapotranspiration over different forest types

    NASA Astrophysics Data System (ADS)

    Marzahn, Philip; Gampe, David; Castro, Saulo; Vega-Araya, Mauricio; Sanchez-Azofeifa, Arturo; Ludwig, Ralf

    2017-04-01

    Actual evapotranspiration (Eta) plays an important role in surface-atmosphere interactions. Traditionally, Eta is measured by means of lysimeters, eddy-covariance systems or fiber optics, providing estimates which are spatially restricted to a footprint from a few square meters up to several hectares . In the past, several methods have been developed to derive Eta by means of multi-spectral remote sensing data using thermal and VIS/NIR satellite imagery of the land surface. As such approaches do have their justification on coarser scales, they do not provide Eta information on the fine resolution plant level over large areas which is mandatory for the detection of water stress or tree mortality. In this study, we present a comparison of a drone based assessment of Eta with eddy-covariance measurements over two different forest types - a deciduous forest in Alberta, Canada and a tropical dry forest in Costa Rica. Drone based estimates of Eta were calculated applying the Triangle-Method proposed by Jiang and Islam (1999). The Triangle-Method estimates actual evapotranspiration (Eta) by means of the Normalized Difference Vegetation Index (NDVI) and land surface temperature (LST) provided by two camera systems (MicaSense RedEdge, FLIR TAU2 640) flown simultaneously on an octocopter. . Results indicate a high transferability of the original approach from Jiang and Islam (1999) developed for coarse to medium resolution satellite imagery tothe high resolution drone data, leading to a deviation in Eta estimates of 10% compared to the eddy-covariance measurements. In addition, the spatial footprint of the eddy-covariance measurement can be detected with this approach, by showing the spatial heterogeneities of Eta due to the spatial distribution of different trees and understory vegetation.

  16. Actual application of hot repairing technology to operating coke oven

    SciTech Connect

    Ohtani, Susumu; Ito, Hidekuni; Numazawa, Makoto; Yamazaki, Takao; Narita, Yuji; Kondo, Toshio

    1993-01-01

    In Wakayama Steel Works, the coke ovens have been operating for 23 [approximately] 25 years, and many over-aged parts can be seen. However the investment for the construction of a new coke oven is so huge that the maximum prolongation of the existing coke ovens life becomes very important. In the Wakayama Steel Works, it is thought that the coking chamber repairing technology can be the key to that prolongation. While, repairing the coking chamber, the area near the wall head can be observed by the naked eye and repaired using conventional methods, such a welding repairment by metal oxidation heat, partial chamber wall brick re-laying in the hot stage. However, these repairing methods are limited to the area near the wall head, and successful repair methods for the central portion of chamber wall have not, heretofore, been found. In the Wakayama Steel Works, the development of a new welding repairing machine for the central portion of the chamber wall was started and the actual repairing machine has been completed with practical use tests on operating coke ovens. This repairing machine has the following characteristic; (1) Repair of the central portion of ovens under high temperature (over 1,000 C); (2) Capability to seal narrow cracks or open brick joints and to smooth out brick roughness into a flat surface; (3) High working efficiency (max. welding capacity [equals] 30K g/h); (4) Compact and fully automatic operation with a high level of man/machine control interface; and (5) No disturbance of coke oven operation and no cooling of the chamber wall. In this paper, the outline of the actual hot repairing machine and its application results in the Wakayama operating coke ovens are reported.

  17. Thermoregulation during prolonged actual and laboratory-simulated bicycling.

    PubMed

    Brown, S L; Banister, E W

    1985-01-01

    Thermoregulatory and cardiorespiratory responses to bicycling 55 km (mean speed 9.7 m X s-1) outdoors (15 degrees C DB) were compared to equivalent cycle ergometry (90 min at 65% VO2max) in the laboratory (20-23 degrees C DB, 50% RH) in 7 trained cyclists. Outdoor environmental conditions were simulated with fans and lamps, and were contrasted with standard no-wind, no-sun laboratory conditions. Sweating rate was similar during outdoor and laboratory simulated outdoor cycling (0.90 and 0.87 to 0.94 1 X h-1 respectively). During outdoor bicycling, mean heart rate (161 bt X min-1) was 7-13% higher (p less than .05) than under laboratory conditions, suggesting a greater strain for a similar external work rate. The increase in rectal temperature (0.8 degrees C) was 33-50% less (p less than 0.05) at the cooler outdoor ambient temperature than in the laboratory. Thermoregulatory stress was greater under the no-fan, no-lamp laboratory condition than during simulated outdoor conditions (36-38% greater (p less than 0.05) sweating rate, 15-18% greater (p less than 0.01) mean skin temperature, 6.4 to 7.8 fold greater (p less than 0.01) amount of clothing-retrained sweat). The cooling wind encountered in actual road bicycling apparently reduces thermoregulatory and circulatory demands compared with stationary cycle ergometry indoors. Failure to account for this enhanced cooling may result in overestimation of the physiological stress of actual road cycling.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Histrelin Hydrogel Implant--Valera: Histrelin implant, LHRH-Hydrogel implant, RL 0903, SPD 424.

    PubMed

    2005-01-01

    Valera Pharmaceuticals, formerly Hydro Med Sciences, is developing a once-yearly Histrelin Hydrogel Implant [Histrelin implant, LHRH-Hydrogel implant, RL 0903, SPD 424, Vantas], a subcutaneous (s.c.) reservoir device capable of long-term delivery of histrelin at constant release rates for the treatment of prostate cancer. Histrelin is a luteinising hormone-releasing hormone agonist (LHRH). A different formulation of the LHRH implant is currently in development for the treatment of central precocious puberty (CPP). On 4 September 2003, Hydro Med Sciences announced that it had changed its name to Valera Pharmaceuticals. Shire Pharmaceuticals had an option to market and distribute the histrelin implant outside the US, but in a realigned agreement announced in January 2002, Shire stated that HydroMed (now Valera) would be responsible for concluding the phase III studies, filing for regulatory approval and producing the implant, while also gaining marketing rights in the US. Shire has no further involvement in development, but retains an option to market and distribute the product outside the US. The product is available for rest-of-the-world licensing through Valera Pharmaceuticals' business development division. Paladin Labs has received the exclusive rights for the sale and marketing of histrelin hydrogel implant in Canada. Valera Pharmaceuticals will have the responsibility for manufacturing and completing development of the product. In July 2004, Paladin announced it had filed for regulatory approval with Health Canada for the treatment of prostate cancer. Phase III trials have been conducted and initially involved two open-labelled, randomised, parallel studies that compared the hydrogel implant with the active comparators, leuprorelin acetate 22.5 mg depot (TAP Pharmaceutical's Lupron Depot) and a 3-month implant of goserelin acetate (Astra Zeneca's Zoladex). However, because of financial constraints, HydroMed discontinued recruitment in a phase II European study

  19. Single vs 2 Implants on Peri-implant Marginal Bone Level and Implant Failures in Mandibular Implant Overdentures: A Systematic Review With Meta-analysis.

    PubMed

    Ahmed Elawady, Dina Mohamed; Kaddah, Amal Fathy; Talaat Khalifa, Mohamed

    2017-09-01

    As a consensus, the 2-implant supported overdentures (ODs) are considered as the first choice of treatment for the edentulous mandible. In the same context, there is increased evidence supporting the use of single-implant OD. The aim of any design is to preserve the remaining structures and allow the longevity of the treatment. To evaluate the impact of single implant vs 2 implants on the peri-implant marginal bone loss (MBL) and number of implant failures in mandibular implant overdentures. A literature search of electronic databases (PubMed and Cochrane) was performed up to March 2016 and complemented by hand search. Randomized clinical trials (RCTs) that evaluated MBL and number of implant failures relative to single-implant mandibular overdenture (MOD) were selected. The review and meta-analysis were performed using meta-analytic statistical package and in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five RCTs met the inclusion criteria for systematic review and qualitative synthesis. The observation period ranged from 12 months to 5 years in the selected RCTs. The comparison included in the meta-analysis is single- vs 2-implant MODs. Pooled data revealed that single-implant MODs significantly decreased the MBL (mean difference: 0.27, 95% confidence interval: 0.20-0.34, P < .0001, I(2) = 0%) and number of implant failures (risk ratio: 3.26, 95% confidence interval: 1.18-8.97), P = .02; I(2) = 0%). Single-implant MOD was found to be better than 2-implant MOD in terms of MBL and number of implant failures. However, this result should be interpreted with caution due to limited number of analyzed studies with different loading protocols and short follow-up period. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Factors influencing severity of peri-implantitis.

    PubMed

    Saaby, Martin; Karring, Eva; Schou, Søren; Isidor, Flemming

    2016-01-01

    To retrospectively assess the influence of potential risk factors, primarily smoking and a prior history of periodontitis, on the severity of peri-implantitis in patients referred for treatment of peri-implantitis. Among 98 patients referred for treatment of peri-implantitis, 34 patients fulfilled the inclusion criteria: one or several implants with peri-implant marginal bone loss ≥2 mm concomitant with bleeding and/or pus on probing. Information about health status, smoking habits, reason for tooth loss, and performed implant treatment were obtained from the patient charts and interviews. Moreover, a detailed extra- and intraoral examination was performed, including intraoral radiographs of all implants. Risk factors were evaluated by a two-way anova at patient level. Smoking and a prior history of periodontitis were significant risk factors for increased severity of peri-implantitis. Furthermore, the presence of both smoking and a prior history of periodontitis did not further increase the severity of peri-implantitis, as compared to either of these two factors alone. Poor marginal fit of the suprastructure and extensive gingival imitations on implant-supported fixed full prostheses may also be potential risk factors. The study indicated that smoking and a prior history of periodontitis were important risk factors for increased severity of peri-implantitis, while concomitant presence of these two risk factors did not further increase the severity of peri-implantitis, as compared to either of these two risk factors alone. Therefore, early diagnosis and adequate treatment of peri-implantitis are important in patients with a prior history of periodontitis and in smokers to minimize the risk of advanced peri-implantitis in conjunction with focus on known risk factors, including meticulous infection control before implant treatment and a systematic maintenance care program. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Equicrestal and subcrestal dental implants: a histologic and histomorphometric evaluation of nine retrieved human implants.

    PubMed

    Degidi, Marco; Perrotti, Vittoria; Shibli, Jamil A; Novaes, Arthur B; Piattelli, Adriano; Iezzi, Giovanna

    2011-05-01

    Stability of peri-implant crestal bone plays a relevant role relative to the presence or absence of interdental papilla. Several factors can contribute to the crestal bone resorption observed around two-piece implants, such as the presence of a microgap at the level of the implant-abutment junction, the type of connection between implant and prosthetic components, the implant positioning relative to the alveolar crest, and the interimplant distance. Subcrestal positioning of dental implants has been proposed to decrease the risk of exposure of the metal of the top of the implant or of the abutment margin, and to get enough space in a vertical dimension to create a harmoniously esthetic emergence profile. The present retrospective histologic study was performed to evaluate dental implants retrieved from human jaws that had been inserted in an equicrestal or subcrestal position. A total of nine implants were evaluated: five of these had been inserted in an equicrestal position, whereas the other four had been positioned subcrestally (1 to 3 mm). In all subcrestally placed implants, preexisting and newly formed bone was found over the implant shoulder. In the equicrestal implants, crestal bone resorption (0.5 to 1.5 mm) was present around all implants. The subcrestal position of the implants resulted in bone located above the implant shoulder.

  2. Effectiveness of Implant Therapy Analyzed in a Swedish Population: Prevalence of Peri-implantitis.

    PubMed

    Derks, J; Schaller, D; Håkansson, J; Wennström, J L; Tomasi, C; Berglundh, T

    2016-01-01

    Peri-implantitis is an inflammatory disease affecting soft and hard tissues surrounding dental implants. As the global number of individuals that undergo restorative therapy through dental implants increases, peri-implantitis is considered as a major and growing problem in dentistry. A randomly selected sample of 588 patients who all had received implant-supported therapy 9 y earlier was clinically and radiographically examined. Prevalence of peri-implantitis was assessed and risk indicators were identified by multilevel regression analysis. Forty-five percent of all patients presented with peri-implantitis (bleeding on probing/suppuration and bone loss >0.5 mm). Moderate/severe peri-implantitis (bleeding on probing/suppuration and bone loss >2 mm) was diagnosed in 14.5%. Patients with periodontitis and with ≥4 implants, as well as implants of certain brands and prosthetic therapy delivered by general practitioners, exhibited higher odds ratios for moderate/severe peri-implantitis. Similarly, higher odds ratios were identified for implants installed in the mandible and with crown restoration margins positioned ≤1.5 mm from the crestal bone at baseline. It is suggested that peri-implantitis is a common condition and that several patient- and implant-related factors influence the risk for moderate/severe peri-implantitis (ClinicalTrials.gov NCT01825772). © International & American Associations for Dental Research 2015.

  3. Effects of implant diameter, drug loading and end-capping on praziquantel release from PCL implants.

    PubMed

    Li, Changyan; Cheng, Liang; Zhang, Yaqiong; Guo, Shengrong; Wu, Weiping

    2010-02-15

    Praziquantel (PZQ)-loaded poly(epsilon-caprolactone) (PCL) cylindrical implants were fabricated and characterized. Implant diameter (3, 4 and 8mm), drug loading (25% and 50%), and the end-capping were investigated to evaluate their effects on drug release. The evolution of implants with release time was conducted in terms of implant microstructure, crystallinity, drug content and molecular weight of PCL. The results showed that drug release was fastest for the implant with a diameter of 3mm and slowest for the implant with a diameter of 8mm; drug release from the implant with a drug content of 50% was faster than that from the implant with a drug content of 25%; the release of PZQ from the end-capped implants was slightly slower than that from the corresponding end-uncapped implants. The effect of drug loadings on PZQ release was related with diameter of the implants and the effect was weakened as diameter of the implants increased. The drug release data for all the implants were best fitted with Ritger-Peppas model, therefore Fickian diffusion was the predominant release mechanism. The evolution of implants with release time verified that PZQ was gradually released from the exterior to the interior of the implants.

  4. Simplifying fixed implant dental prosthetics.

    PubMed

    Tischler, Michael

    2011-01-01

    Through following the FPPD protocol for multiple adjacent implants, and delivering final abutments, picking up the metal framework, and delivering provisionals, many benefits are gained. The benefits of following the FPPD protocol are as follows: The restorative dentist is trying-in and delivering the final abutments in one visit as opposed to removing them and placing them multiple times. This requires less chair time and time for the patient. It also reduces the mechanical stress on the abutment screw and implant body due to the elimination of multiple try-in appointments. When the metal framework is tried-in and verified for fit, the restorative dentist has the opportunity check the retention, check the margins, and make any corrections that might be needed. The abutments will be staying in the mouth when the framework is picked up. This metal try-in allows for a verification of the bite to be given to the dental lab. The delivery of provisionals manufactured by the dental laboratory offers many advantages in the FPPD technique. The patient has a form of tooth much earlier in the traditional appointment sequence. The patient can now offer feedback to the doctor and laboratory for fabrication of the permanent prosthesis with regards to shape and color. The laboratory-fabricated provisionals offer progressive loading to the implants through having a reduced occlusion yet allowing food to stimulate the implants. Overall, the FPPD technique offers shorter appointment times, more rapid delivery of fixed supported teeth, improved doctor-technician communication, and less mechanical wear on the implant parts.

  5. Peri-implant esthetics assessment and management

    PubMed Central

    Balasubramaniam, Aarthi S.; Raja, Sunitha V.; Thomas, Libby John

    2013-01-01

    Providing an esthetic restoration in the anterior region of the mouth has been the basis of peri-implant esthetics. To achieve optimal esthetics, in implant supported restorations, various patient and tooth related factors have to be taken into consideration. Peri-implant plastic surgery has been adopted to improve the soft tissue and hard tissue profiles, during and after implant placement. The various factors and the procedures related to enhancement of peri-implant esthetics have been discussed in this review article. PMID:23878557

  6. IMPORTANCE OF COCHLEAR HEALTH FOR IMPLANT FUNCTION

    PubMed Central

    Pfingst, Bryan E.; Zhou, Ning; Colesa, Deborah J.; Watts, Melissa M.; Strahl, Stefan B.; Garadat, Soha N.; Schvartz-Leyzac, Kara C.; Budenz, Cameron L.; Raphael, Yehoash; Zwolan, Teresa A.

    2014-01-01

    Amazing progress has been made in providing useful hearing to hearing-impaired individuals using cochlear implants, but challenges remain. One such challenge is understanding the effects of partial degeneration of the auditory nerve, the target of cochlear implant stimulation. Here we review studies from our human and animal laboratories aimed at characterizing the health of the implanted cochlea and the auditory nerve. We use the data on cochlear and neural health to guide rehabilitation strategies. The data also motivate the development of tissue-engineering procedures to preserve or build a healthy cochlea and improve performance obtained by cochlear implant recipients or eventually replace the need for a cochlear implant. PMID:25261772

  7. Choice of a dental implant system.

    PubMed

    Hunt, Peter R; Gartner, Judith L; Norkin, Frederic J

    2005-04-01

    Many dentists are bewildered by the intricacies and complexities of dental implants. They are constantly besieged by product advertisements and can find it difficult to choose which systems to work with. Some dentists are so intimidated by the subject that they choose to avoid getting involved with implants and instead stick to traditional tooth replacement systems. By breaking implants down into 4 main components, the body, collar, connection, and restorative post, it is easier to understand the structure and function of dental implants. Each portion should be designed to achieve certain objectives. Once these structural components are understood, it is easier to compare and contrast differing implant systems.

  8. Brain plasticity under cochlear implant stimulation.

    PubMed

    Kral, Andrej; Tillein, Jochen

    2006-01-01

    The benefit of cochlear implantation crucially depends on the ability of the brain to learn to classify neural activity evoked by the cochlear implant. Brain plasticity is a complex property with massive developmental changes after birth. The present paper reviews the experimental work on auditory plasticity and focuses on the plasticity required for adaptation to cochlear implant stimulation. It reviews the data on developmental sensitive periods in auditory plasticity of hearing, hearing-impaired and deaf, cochlear-implanted, animals. Based on the analysis of the above findings in animals and comparable data from humans, a cochlear implantation within the first 2 years of age is recommended.

  9. Translation of First North American 50 and 70 cc Total Artificial Heart Virtual and Clinical Implantations: Utility of 3D Computed Tomography to Test Fit Devices.

    PubMed

    Ferng, Alice S; Oliva, Isabel; Jokerst, Clinton; Avery, Ryan; Connell, Alana M; Tran, Phat L; Smith, Richard G; Khalpey, Zain

    2017-08-01

    Since the creation of SynCardia's 50 cc Total Artificial Hearts (TAHs), patients with irreversible biventricular failure now have two sizing options. Herein, a case series of three patients who have undergone successful 50 and 70 cc TAH implantation with complete closure of the chest cavity utilizing preoperative "virtual implantation" of different sized devices for surgical planning are presented. Computed tomography (CT) images were used for preoperative planning prior to TAH implantation. Three-dimensional (3D) reconstructions of preoperative chest CT images were generated and both 50 and 70 cc TAHs were virtually implanted into patients' thoracic cavities. During the simulation, the TAHs were projected over the native hearts in a similar position to the actual implantation, and the relationship between the devices and the atria, ventricles, chest wall, and diaphragm were assessed. The 3D reconstructed images and virtual modeling were used to simulate and determine for each patient if the 50 or 70 cc TAH would have a higher likelihood of successful implantation without complications. Subsequently, all three patients received clinical implants of the properly sized TAH based on virtual modeling, and their chest cavities were fully closed. This virtual implantation increases our confidence that the selected TAH will better fit within the thoracic cavity allowing for improved surgical outcome. Clinical implantation of the TAHs showed that our virtual modeling was an effective method for determining the correct fit and sizing of 50 and 70 cc TAHs. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  10. Epidemiology of silicone-gel breast implants.

    PubMed

    Brown, S Lori

    2002-05-01

    Silicone breast implants have been marketed in the United States since 1963. Questions remain unanswered on the safety of these medical devices despite their popularity and availability. In 1992, the Food and Drug Administration restricted the availability of silicone-gel breast implants to women requiring them for reconstruction after breast cancer or for other medical indications. Inflatable saline breast implants have remained available for either reconstruction or for cosmetic augmentation while manufacturers completed studies addressing issues of safety and effectiveness. The Food and Drug Administration (FDA) has less concern today regarding a putative association between breast implants and autoimmune disease because of epidemiologic studies that have indicated that there is not a large increase in risk for connective tissue disease in women with breast implants. These studies have not ruled out a small increase in risk of connective tissue disease to these women nor have they addressed the issue of an atypical syndrome related to silicone. The FDA has continuing concerns over local complications that are related to breast implants. The current review provides a brief discussion of the regulatory history of silicone implants and of FDA concerns over breast implants, implant prevalence, studies of systemic and local complications related to breast implants, and a brief description of the FDA study of silicone-gel breast implant rupture.

  11. Early History and Challenges of Implantable Electronics

    PubMed Central

    KO, WEN H.

    2013-01-01

    Implantable systems for biomedical research and clinical care are now a flourishing field of activities in academia as well as industrial institutions. The broad field includes experimental explorations in electronics, mechanical, chemical, and biological components and systems, and the combination of all these. Today virtually all implants involve both electronic circuits and micro-electro-mechanical-systems (MEMS). This article offers a very brief glance back at the early history of implant electronics in the period from the 1950s to the 1970s, by employing selected examples from the author’s research. This short review also discusses the challenges of implantable electronics at present, and suggests some potentially important trends in the future research and development of implantable microsystems. It is aimed as an introduction of implantable/attached electronic systems to research engineers that are interested in implantable systems as a section of Biomedical Instrumentations. PMID:24791159

  12. Surface modification of implants in long bone.

    PubMed

    Förster, Yvonne; Rentsch, Claudia; Schneiders, Wolfgang; Bernhardt, Ricardo; Simon, Jan C; Worch, Hartmut; Rammelt, Stefan

    2012-01-01

    Coatings of orthopedic implants are investigated to improve the osteoinductive and osteoconductive properties of the implant surfaces and thus to enhance periimplant bone formation. By applying coatings that mimic the extracellular matrix a favorable environment for osteoblasts, osteoclasts and their progenitor cells is provided to promote early and strong fixation of implants. It is known that the early bone ongrowth increases primary implant fixation and reduces the risk of implant failure. This review presents an overview of coating titanium and hydroxyapatite implants with components of the extracellular matrix like collagen type I, chondroitin sulfate and RGD peptide in different small and large animal models. The influence of these components on cells, the inflammation process, new bone formation and bone/implant contact is summarized.

  13. Hydroxyapatite motility implants in ocular prosthetics.

    PubMed

    Cowper, T R

    1995-03-01

    For the past 5 years, an increasing number of ophthalmologists have been using hydroxyapatite (HA) motility implants after uncomplicated enucleation or evisceration of the eye. Unlike previous implant materials, HA promotes fibrovascular ingrowth and seemingly true integration of the motility implant to the residual ocular structures. As a result, a more stable defect and greater movement of the overlying prosthesis is produced. In addition, the problems of long-term orbital implant migration and the vexing postenucleation socket syndrome are thought to be minimized. This article briefly reviews the history and development of orbital implants and HA implant surgical and prosthetic procedures. It is concluded that HA implant rehabilitation is indicated after most uncomplicated enucleations or eviscerations where there is small likelihood of complication.

  14. Implant fractures: Rare but not exceptional

    PubMed Central

    Sanivarapu, Sahitya; Moogla, Srinivas; Kuntcham, Rupa Sruthi; Kolaparthy, Lakshmi Kanth

    2016-01-01

    Fabrication of dentures aided with implants has become a preferred treatment option for rehabilitation of completely and partially edentulous patients when durability is concerned. Simulation to natural teeth in terms of esthetics and to a greater extent in function can be considered as key elements in the raise of implant dentistry worldwide. Despite its high success rate, therapy with osseointegrated dental implants is not free of complications. Implant failure can occur for other reasons, with implant fracture being one of the major reasons for late failure. Although the incidence of implant fractures may be low, it invariably effects the patient and also clinician. Thus, sound evidence based knowledge of cause of fracture is mandatory for that careful treatment that can reduce the incidence of fracture helping in a better treatment plan. The aim of this review is to enlighten the various causes of implant fracture. PMID:27041830

  15. [Mammary implant selection or chest implants fabrication with computer help].

    PubMed

    Chavoin, J-P; André, A; Bozonnet, E; Teisseyre, A; Arrue, J; Moreno, B; Gangloff, D; Grolleau, J-L; Garrido, I

    2010-10-01

    Authors present their personal and original experience in the use of computer to enhance the precision in the good choice of volumes and shapes in the field of mammary reconstruction and aesthetic augmentation (800 cases). Concerning funnel chest (163 cases) and Poland syndrome (12 cases), they use computer-assisted conception and custom-made implants, much more precise than traditional plaster cast.

  16. Peri-implantitis: associated microbiota and treatment.

    PubMed

    Ata-Ali, Javier; Candel-Marti, María Eugenia; Flichy-Fernández, Antonio Juan; Peñarrocha-Oltra, David; Balaguer-Martinez, José Francisco; Peñarrocha Diago, María

    2011-11-01

    Peri-implantitis is a late complication of dental implant treatment, induced by microbiological changes. Since the disorder is frequent, a review is indicated of the microorganisms that influence it and of the existing treatment options. To conduct a literature review of the microbiota associated to peri-implantitis and the existing treatment options. A PubMed literature search was made of the studies on the microbiota associated to dental implants in healthy patients and patients with peri-implantitis, as well as of the latest treatment developments, using the following key words: "peri-implantitis AND microbiota", "periimplantitis AND microbiota", "peri-implantitis AND treatment", and "periimplantitis AND treatment". Only clinical studies in humans were considered. The following criteria were applied for including articles in the analysis: a) for the peri-implant microbiota, the search limits were human studies after the year 2000; and b) for the treatment of peri-implantitis, the search limits were randomized and controlled clinical trials (RCTs) in humans, with a minimum follow-up of 4 months, and publication after the year 2000. A total of 18 articles were selected in relation to peri-implant microbiota, and 13 in relation to the treatment of peri-implantitis (8 involving nonsurgical mechanical treatments and 5 surgical procedures). Evaluation of the literature has shown the microbiota associated to peri-implantitis to be more complex than that found under healthy peri-implant conditions - the main flora consisting of anaerobic gramnegative bacteria. No clear criteria have been identified for the diagnosis and treatment of peri-implantitis.

  17. Tutorial on Actual Space Environmental Hazards For Space Systems (Invited)

    NASA Astrophysics Data System (ADS)

    Mazur, J. E.; Fennell, J. F.; Guild, T. B.; O'Brien, T. P.

    2013-12-01

    It has become common in the space science community to conduct research on diverse physical phenomena because they are thought to contribute to space weather. However, satellites contend with only three primary environmental hazards: single event effects, vehicle charging, and total dose, and not every physical phenomenon that occurs in space contributes in substantial ways to create these hazards. One consequence of the mismatch between actual threats and all-encompassing research is the often-described gap between research and operations; another is the creation of forecasts that provide no actionable information for design engineers or spacecraft operators. An example of the latter is the physics of magnetic field emergence on the Sun; the phenomenon is relevant to the formation and launch of coronal mass ejections and is also causally related to the solar energetic particles that may get accelerated in the interplanetary shock. Unfortunately for the research community, the engineering community mitigates the space weather threat (single-event effects from heavy ions above ~50 MeV/nucleon) with a worst-case specification of the environment and not with a prediction. Worst-case definition requires data mining of past events, while predictions involve large-scale systems science from the Sun to the Earth that is compelling for scientists and their funding agencies but not actionable for design or for most operations. Differing priorities among different space-faring organizations only compounds the confusion over what science research is relevant. Solar particle impacts to human crew arise mainly from the total ionizing dose from the solar protons, so the priority for prediction in the human spaceflight community is therefore much different than in the unmanned satellite community, while both communities refer to the fundamental phenomenon as space weather. Our goal in this paper is the presentation of a brief tutorial on the primary space environmental phenomena

  18. Assessment of Stability of Craniofacial Implants by Resonant Frequency Analysis.

    PubMed

    Ivanjac, Filip; Konstantinović, Vitomir S; Lazić, Vojkan; Dordević, Igor; Ihde, Stefan

    2016-03-01

    Implant stability is a principal precondition for the success of implant therapy. Extraoral implants (EO) are mainly used for anchoring of maxillofacial epithesis. However, assessment of implant stability is mostly based on principles derived from oral implants. The aim of this study was to investigate clinical stability of EO craniofacial disk implants (single, double, and triple) by resonance frequency analysis at different stages of the bone's healing. Twenty patients with orbital (11), nasal (5), and auricular (4) defects with 50 EO implants placed for epithesis anchorage were included. Implant stability was measured 3 times; after implant placement, at 3 months and at least after 6 months. A significant increase in implant stability values was noted between all of the measurements, except for triple-disk implants between third and sixth months, and screw implants between 0 and third months. Disk implants showed lower implant stability quotient (ISQ) values compared with screw implants. Triple-disk implants showed better stability compared with single and double-disk implants. Based on resonance frequency analysis values, disk implants could be safely loaded when their ISQ values are 38 (single disks), 47 (double disks), and 48 (triple disks). According to resonance frequency analysis, disk implant stability increased over time, which showed good osseointegration and increasing mineralization. Although EO screw implants showed higher ISQ values than disk implants, disk-type implants can be safely loaded even if lower values of stability are measured.

  19. 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

  20. Successful rehabilitation of partial edentulous maxilla and mandible with new type of implants: molecular precision implants.

    PubMed

    Danza, Matteo; Lauritano, Dorina; Carinci, Francesco

    2014-01-01

    The extraction of teeth results in rapid bone resorption both vertically and horizontally in the first month. The loss of alveolar ridge reduces the chance of implant rehabilitation. Atraumatic extraction, implant placement in extraction socket, and an immediate prosthesis have been proposed as alternative therapies to maintain the volume and contours tissue and reduce time and cost of treatment. The immediate load of implants is a universally practiced procedure; nevertheless a successful procedure requires expertise in both the clinical and the reconstructive stages using a solid implant system. Excellent primary stability and high bone-implant contact are only minimal requirements for any type of implant procedure. In this paper we present a case report using a new type of implants. The new type of implants, due to its sophisticated control system of production, provides to the implantologist a safe and reliable implant, with a macromorphology designed to ensure a close contact with the surrounding bone.

  1. Successful Rehabilitation of Partial Edentulous Maxilla and Mandible with New Type of Implants: Molecular Precision Implants

    PubMed Central

    Danza, Matteo; Carinci, Francesco

    2014-01-01

    The extraction of teeth results in rapid bone resorption both vertically and horizontally in the first month. The loss of alveolar ridge reduces the chance of implant rehabilitation. Atraumatic extraction, implant placement in extraction socket, and an immediate prosthesis have been proposed as alternative therapies to maintain the volume and contours tissue and reduce time and cost of treatment. The immediate load of implants is a universally practiced procedure; nevertheless a successful procedure requires expertise in both the clinical and the reconstructive stages using a solid implant system. Excellent primary stability and high bone-implant contact are only minimal requirements for any type of implant procedure. In this paper we present a case report using a new type of implants. The new type of implants, due to its sophisticated control system of production, provides to the implantologist a safe and reliable implant, with a macromorphology designed to ensure a close contact with the surrounding bone. PMID:25525437

  2. ['Which breast implant do I have?'; the importance of the Dutch Breast Implant Registry].

    PubMed

    Hommes, Juliëtte; Mureau, Marc A M; Harmsen, Manuel; Rakhorst, Hinne

    2015-01-01

    About 1 in 300 women in the Netherlands has a breast implant but many patients do not know what type of implant was inserted. The quality of breast implants is currently monitored by the implant manufacturers. Sufficient incidents have occurred to show that an independent registry is required to measure the quality of breast implants and to facilitate a national recall, if necessary. Good national and international collaboration with the government, the manufacturers and other specialist associations is crucial for setting up an implant registry. Since April 2015, data about patients and their implants have been collected, independently and prospectively, in the Dutch Breast Implant Registry to increase patient safety in cases of breast implant surgery in the Netherlands.

  3. Does the number of implants have any relation with peri-implant disease?

    PubMed

    Passoni, Bernardo Born; Dalago, Haline Renata; Schuldt Filho, Guenther; Oliveira de Souza, João Gustavo; Benfatti, César Augusto Magalhães; Magini, Ricardo de Souza; Bianchini, Marco Aurélio

    2014-01-01

    The aim of this study was to evaluate the relationship between the number of pillar implants of implant-supported fixed prostheses and the prevalence of periimplant disease. Clinical and radiographic data were obtained for the evaluation. The sample consisted of 32 patients with implant-supported fixed prostheses in function for at least one year. A total of 161 implants were evaluated. Two groups were formed according to the number of implants: G1) ≤5 implants and G2) >5 implants. Data collection included modified plaque index (MPi), bleeding on probing (BOP), probing depth (PD), width of keratinized mucosa (KM) and radiographic bone loss (BL). Clinical and radiographic data were grouped for each implant in order to conduct the diagnosis of mucositis or peri-implantitis. Clinical parameters were compared between groups using Student's t test for numeric variables (KM, PD and BL) and Mann-Whitney test for categorical variables (MPi and BOP). KM and BL showed statistically significant differences between both groups (p<0.001). Implants from G1 - 19 (20.43%)--compared with G2 - 26 (38.24%)--showed statistically significant differences regarding the prevalence of peri-implantitis (p=0.0210). It seems that more than 5 implants in total fixed rehabilitations increase bone loss and consequently the prevalence of implants with periimplantitis. Notwithstanding, the number of implants does not have any influence on the prevalence of mucositis.

  4. Does the number of implants have any relation with peri-implant disease?

    PubMed Central

    PASSONI, Bernardo Born; DALAGO, Haline Renata; SCHULDT FILHO, Guenther; OLIVEIRA DE SOUZA, João Gustavo; BENFATTI, César Augusto Magalhães; MAGINI, Ricardo de Souza; BIANCHINI, Marco Aurélio

    2014-01-01

    Objective The aim of this study was to evaluate the relationship between the number of pillar implants of implant-supported fixed prostheses and the prevalence of periimplant disease. Material and Methods Clinical and radiographic data were obtained for the evaluation. The sample consisted of 32 patients with implant-supported fixed prostheses in function for at least one year. A total of 161 implants were evaluated. Two groups were formed according to the number of implants: G1) ≤5 implants and G2) >5 implants. Data collection included modified plaque index (MPi), bleeding on probing (BOP), probing depth (PD), width of keratinized mucosa (KM) and radiographic bone loss (BL). Clinical and radiographic data were grouped for each implant in order to conduct the diagnosis of mucositis or peri-implantitis. Results Clinical parameters were compared between groups using Student's t test for numeric variables (KM, PD and BL) and Mann-Whitney test for categorical variables (MPi and BOP). KM and BL showed statistically significant differences between both groups (p<0.001). Implants from G1 – 19 (20.43%) – compared with G2 – 26 (38.24%) – showed statistically significant differences regarding the prevalence of peri-implantitis (p=0.0210). Conclusion It seems that more than 5 implants in total fixed rehabilitations increase bone loss and consequently the prevalence of implants with periimplantitis. Notwithstanding, the number of implants does not have any influence on the prevalence of mucositis. PMID:25466474

  5. Custom Cast Ball Attachments Used on Outdated Implants to Restore a Maxillary Implant-Supported Overdenture.

    PubMed

    Leite, Andressa Rosa Perin; Marin, Danny Omar Mendoza; Giro, Gabriela; Pero, Ana Carolina; Pinelli, Ligia Antunes Pereira; Reis, José Maurício Dos Santos Nunes

    2017-08-01

    The lack of compatible prosthetic components can be a complication during oral rehabilitation using outdated implants. The aim of the present clinical report was to describe an alternative technique for the fabrication of a maxillary implant-supported overdenture in a patient with 20-year-old dental implants using castable spherical patterns and ball attachments. The patient had been wearing a relined bar/clip overdenture in the mandible on 4 external-hexagon dental implants and a relined complete denture in the maxilla on 4 internal-hexagon implants due to abutment screw fracture inside of the implants, losing the attachment system. The remaining maxillary dental implants did not possess attachments compatible with current systems due to configuration changes by the manufacturer in the dental implant's platform and the components over time. Therefore, castable spherical patterns and cast ball attachments were used to fabricate a maxillary implant-supported overdenture. The mandible rehabilitation was performed using 4 osseointegrated dental implants with a fixed implant-supported prosthesis. The use of cast ball attachments on the maxillary dental implants avoided invasive procedures on the remaining implants. Considering the lack of available compatible prosthetic components for the osseointegrated implants, this technique was considered a viable and satisfactory treatment option.

  6. Development of a Patient-Specific Finite Element Model for Predicting Implant Failure in Pelvic Ring Fracture Fixation

    PubMed Central

    Höch, Andreas; Peldschus, Steffen

    2017-01-01

    Introduction. The main purpose of this study is to develop an efficient technique for generating FE models of pelvic ring fractures that is capable of predicting possible failure regions of osteosynthesis with acceptable accuracy. Methods. Patient-specific FE models of two patients with osteoporotic pelvic fractures were generated. A validated FE model of an uninjured pelvis from our previous study was used as a master model. Then, fracture morphologies and implant positions defined by a trauma surgeon in the preoperative CT were manually introduced as 3D splines to the master model. Four loading cases were used as boundary conditions. Regions of high stresses in the models were compared with actual locations of implant breakages and loosening identified from follow-up X-rays. Results. Model predictions and the actual clinical outcomes matched well. For Patient A, zones of increased tension and maximum stress coincided well with the actual locations of implant loosening. For Patient B, the model predicted accurately the loosening of the implant in the anterior region. Conclusion. Since a significant reduction in time and labour was achieved in our mesh generation technique, it can be considered as a viable option to be implemented as a part of the clinical routine to aid presurgical planning and postsurgical management of pelvic ring fracture patients. PMID:28255332

  7. Development of a Patient-Specific Finite Element Model for Predicting Implant Failure in Pelvic Ring Fracture Fixation.

    PubMed

    Shim, Vickie; Höch, Andreas; Grunert, Ronny; Peldschus, Steffen; Böhme, Jörg

    2017-01-01

    Introduction. The main purpose of this study is to develop an efficient technique for generating FE models of pelvic ring fractures that is capable of predicting possible failure regions of osteosynthesis with acceptable accuracy. Methods. Patient-specific FE models of two patients with osteoporotic pelvic fractures were generated. A validated FE model of an uninjured pelvis from our previous study was used as a master model. Then, fracture morphologies and implant positions defined by a trauma surgeon in the preoperative CT were manually introduced as 3D splines to the master model. Four loading cases were used as boundary conditions. Regions of high stresses in the models were compared with actual locations of implant breakages and loosening identified from follow-up X-rays. Results. Model predictions and the actual clinical outcomes matched well. For Patient A, zones of increased tension and maximum stress coincided well with the actual locations of implant loosening. For Patient B, the model predicted accurately the loosening of the implant in the anterior region. Conclusion. Since a significant reduction in time and labour was achieved in our mesh generation technique, it can be considered as a viable option to be implemented as a part of the clinical routine to aid presurgical planning and postsurgical management of pelvic ring fracture patients.

  8. Some aspects of language development in normal-hearing children and children with cochlear implants.

    PubMed

    Szagun, G

    1997-11-01

    This article presents some important processes of normal child language acquisition and applies them to language acquisition data of children with cochlear implants. Modern studies of language acquisition, covering various languages, have demonstrated a close link between linguistic and cognitive development. Sensorimotor intelligence provides a construction of reality on which the first grammatical structures are built, encoding a number of relations which hold between objects, persons, events, and localizations. When acquiring the more complex morphological and syntactic aspects of their mother-tongue, children use a number of characteristic information processing strategies which make some formal markings easier to learn than others. There is considerable variability across children with respect to rate of acquisition, the use of imitation, and analytic versus holistic processing strategies. Caregivers' language input can facilitate language acquisition, notably the use of expansions and reformulations, and a generally accepting style. EMPIRICAL STUDY OF CHILDREN WITH COCHLEAR IMPLANTS: Language acquisition data from two children with cochlear implants show great differences with respect to rate of acquisition, construction of the German case system, and syntax. Whereas one child discovers the regularities of the case inflectional system quickly, the other child appears to prefer holistic and rote learning processes and uses a sequential strategy for combining words. It is suggested that variability between children with cochlear implants may be due to different frequencies of actually processed linguistic items. Future research should compare language development in children with cochlear implants and those with normal hearing making use of psycholinguistic methods of research design and analysis.

  9. Determination of the length of zygomatic implants through computed tomography: establishing a protocol.

    PubMed

    Pena, N; Campos, P S F; de Almeida, S M; Bóscolo, F N

    2008-12-01

    The aim of this study was to establish and verify an examination protocol using CT to estimate the length of zygomatic implants, thus rendering the surgical process safer and more predictable, and exposing the patient to a minimal level of radiation. Paracoronal CT scan was carried out on ten dry human crania (n = 20) and the zygomatic implant sites were measured (L(CT)) bilaterally. A standard surgical zygomatic implant placement procedure was carried out and the actual lengths (L(Real)) and clinical lengths (L(Clin)) determined. The averages of the L(CT), L(Clin) and L(Real) were 45.73 +/- 4.82 mm, 42.63 +/- 4.33 mm, and 44.73 +/- 4.53 mm, respectively. Student's t-test revealed no statistically significant differences between the L(Real) and L(CT) averages (P = 0.1532), whereas the L(Real) and L(Clin) averages were statistically different (P < 0.0001). The proposed protocol proved to be precise and efficacious in the determination of zygomatic implant length, with the advantage to the patient of a relatively low level of exposure to radiation due to the small quantity of tomographic slices used. Although there were no major repercussions, the clinical probe in the zygomatic implant kit commonly used in this surgical procedure proved to be a rather imprecise tool.

  10. Small computer algorithms for comparing therapeutic performances of single-plane iridium implants.

    PubMed

    Murphy, D J; Doss, L L

    1984-01-01

    We present a uniform method for selecting an optimum implant geometry by presenting techniques for evaluating the therapeutically significant maximum dose rate (herein referred to as the "maximum dose rate"), the reference isodose (85% of the maximum dose rate), and the area enclosed by the reference isodose contour. The therapeutic performances of planar iridium implants may be compared by evaluating their respective maximum dose rates, reference isodoses , and areas within the reference isodose contours. Because these parameters are mathematically defined, they reproducibly describe each implant geometry. We chose a small microcomputer to develop these comparison algorithms so that the radiotherapist need not have large, expensive computer facilities available to conduct his own studies. The development of these algorithms led to some significant conclusions and recommendations regarding the placement of interstitial implants. Using seeds that are centrally located in the array to evaluate the maximum dose contour avoids underestimating the array's maximum dose rate. This could occur if edge or corner seeds were used. Underestimating the maximum dose rate (and hence the reference isodose contour area) may have a serious therapeutic outcome, because the actual total treatment dosage may be excessive. As ribbon spacing is increased, there is a point beyond which the reference isodose contours become decoupled. At this point, a single relatively uniform reference isodose contour separates into several contours. This effect not only complicates the planimetry calculations, but it also adversely affects the therapeutic efficacy of the implant by producing therapeutically "cold" regions.

  11. Dental implants with versus without peri-implant bone defects treated with guided bone regeneration

    PubMed Central

    Peñarrocha-Oltra, David; Peñarrocha-Diago, Maria; Peñarrocha-Diago, Miguel

    2015-01-01

    Background The guided bone regeneration (GBR) technique is highly successful for the treatment of peri-implant bone defects. The aim was to determine whether or not implants associated with GBR due to peri-implant defects show the same survival and success rates as implants placed in native bone without defects. Material and Methods Patients with a minimum of two submerged dental implants: one suffering a dehiscence or fenestration defect during placement and undergoing simultaneous guided bone regeneration (test group), versus the other entirely surrounded by bone (control group) were treated and monitored annually for three years. Complications with the healing procedure, implant survival, implant success and peri-implant marginal bone loss were assessed. Statistical analysis was performed with non-parametric tests setting an alpha value of 0.05. Results Seventy-two patients and 326 implants were included (142 test, 184 control). One hundred and twenty-five dehiscences (average height 1.92±1.11) and 18 fenestrations (average height 3.34±2.16) were treated. At 3 years post-loading, implant survival rates were 95.7% (test) and 97.3% (control) and implant success rates were 93.6% and 96.2%, respectively. Mean marginal bone loss was 0.54 (SD 0.26 mm) for the test group and 0.43 (SD 0.22 mm) for the control group. No statistically significant differences between both groups were found. Conclusions Within the limits of this study, implants with peri-implant defects treated with guided bone regeneration exhibited similar survival and success rates and peri-implant marginal bone loss to implants without those defects. Large-scale randomized controlled studies with longer follow-ups involving the assessment of esthetic parameters and hard and soft peri-implant tissue stability are needed. Key words:Guided bone regeneration, peri-implant defects, dental implants, marginal bone level, success rate, survival rate. PMID:26330931

  12. Reimplantation of dental implants following ligature-induced peri-implantitis: a pilot study in dogs.

    PubMed

    Levin, Liran; Zigdon, Hadar; Coelho, Paulo G; Suzuki, Marcelo; Machtei, Eli E

    2013-02-01

    This preliminary investigation aimed to evaluate the potential of contaminated implants to reosseointegrate into pristine sites and, in addition, to assess the potential of osseointegration of new implants in peri-implantitis sockets in a canine model. All mandibular premolars were bilaterally extracted from two mongrel dogs. Following 12 weeks of healing, two dental implants were inserted on each hemiarch. Forty-five days following implant placement, a silk ligature secured with cyanoacrylate was placed around the implants' cervical region in order to induce peri-implantitis. After another 45 days from ligature placement, the implants were mechanically removed using counter rotation with a ratchet and were reimplanted without any decontamination (neither rinsing nor chemical or mechanical cleaning) in adjacent pristine zones. In sites where implants were removed, new, wider-diameter implants were placed in the infected sockets. Forty-five days following reimplantation surgery, the dogs were sacrificed; nondecalcified specimens were processed and toluidine blue stained for morphologic and morphometric (bone-to-implant contact [BIC]) assessment under an optical microscope. In dog 1 all the implants (both in the pristine and in the infected sites) survived and osseointegrated while in dog 2, six out of eight implants failed to osseointegrate and exfoliated. Overall, the mean BIC of all implants was 51.08% (SD 20.54). The mean BIC for the infected implants placed into pristine sites was 51.48% ± 26.29% (SD) and the mean BIC for the new implants in peri-implantitis socket was 50.58% ± 14.27% (SD). Within the limitations of this preliminary investigation, especially the small number of animals, osseointegration seems to be achievable both in infected sites and around contaminated implant surfaces. © 2011 Wiley Periodicals, Inc.

  13. Extent and location of bone loss at dental implants in patients with peri-implantitis.

    PubMed

    Serino, Giovanni; Turri, Alberto

    2011-01-11

    Peri-implantitis is an infectious disease, which leads to loss of supporting bone around dental implants. To evaluate the extent and location of bone loss, 43 patients with peri-implantitis were examined. The bone loss was clinically measured at the time of dental surgery. Data revealed that 25% of subjects had bone loss associated with all their implants although the majority of the subjects had fewer than 50% of their implants affected by bone loss. A total number of 264 implants were examined and 131 of those had peri-implantitis associated bone loss. The pattern of bone loss at implants varied between and within subjects and location in the jaws. The highest proportion of implants with peri-implantitis was found in the upper jaw and within this group, at implants located in the incisor area of the upper jaw; the lowest was the canine area of the lower jaw. The highest proportion of implants that lost ≥ 2/3 of their bone support was found in the incisor area of the maxilla. We concluded that in the presence of peri-implant inflammation, bone quantity and characteristics may influence the progression of peri-implantitis bone loss at dental implants. We hypothesize that the ability of the bone to withstand occlusal forces will be altered as consequence of the loss of bone at the neck of the implants. To achieve an understanding of the local degradation of bone due to peri-implantitis, we need to analyze the microstructure of the bone as well the cellular biology of the peri-implant inflammation. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Remotely sensed actual evapotranspiration: implications for groundwater management in Botswana.

    NASA Astrophysics Data System (ADS)

    Timmermans, W. J.; Meijerink, A. M. J.

    In order to determine evapotranspiration losses from the groundwater of an aquifer in Botswana during the dry season, the multi-step Surface Energy Balance Algorithm for Land (SEBAL) was applied using sequential Landsat TM and NOAA-AVHRR data. During satellite overpasses, continuous data on surface temperatures and soil moisture were available from a meteorological tower and field observations for calibration and partial validation of the results. The SEBAL method yielded high actual evapotranspiration (E a) rates (1.5 - 3 mm/d), if relatively dense savannah vegetation was present, even when the water-table was over 30 m deep, as is the case in the upper part of the aquifer. No relationship between Ea and depth to water-table was found, except in the valleys, where riverine forests are fed by a system of discharging groundwater flow. The patterns on a vegetation map, based on a supervised classification using TM data, including thermal bands, showed similarity with the E a patterns. The spatial distributions of vegetation types and of E a have been interpreted as important uptake of water by deep roots; this is supported by increasing evidence from other parts of the world. Sap flow was measured in tall bushes near the tower site. The upper part (2 m) of the soil was dry. The results have implications for the groundwater recharge mechanism and the management of groundwater. Further validation studies have been initiated.

  16. Is transferring an educational innovation actually a process of transformation?

    PubMed

    Varpio, Lara; Bell, Robert; Hollingworth, Gary; Jalali, Alireza; Haidet, Paul; Levine, Ruth; Regehr, Glenn

    2012-08-01

    Recent debates question the extent to which adopting an educational innovation requires compromise between the innovation's original design and the adoption site's context. Through compromises, the innovation's fundamental principles may be transferred, transformed, or abandoned. This paper analyzes such compromises during the piloting of Team-Based Learning (TBL). We ask: When is the process of transferring an innovation actually a process of transformation? This study is an autoethnography of our research team's implementation process. Autoethnographies are personalized accounts where authors draw on their own experiences to extend understanding of a particular topic. To conduct this autoethnography, we used an in-depth, interactive interview with the piloting clinician educator. In the analysis of TBL's fundamental principles, some aspects of the principles transferred easily, while others were transformed. Analysis raised concerns that the transformations threatened the foundational principles of TBL. While an educational innovation's techniques may seem to be surface structures, they are realizations of deeper fundamental principles. The fundamental principles are themselves realizations of the innovation's foundational philosophy. When techniques and/or principles are modified to a context, it is important to analyze if the modifications continue to uphold the innovation's philosophy.

  17. Reconciling actual and perceived rates of predation by domestic cats.

    PubMed

    McDonald, Jennifer L; Maclean, Mairead; Evans, Matthew R; Hodgson, Dave J

    2015-07-01

    The predation of wildlife by domestic cats (Felis catus) is a complex problem: Cats are popular companion animals in modern society but are also acknowledged predators of birds, herpetofauna, invertebrates, and small mammals. A comprehensive understanding of this conservation issue demands an understanding of both the ecological consequence of owning a domestic cat and the attitudes of cat owners. Here, we determine whether cat owners are aware of the predatory behavior of their cats, using data collected from 86 cats in two UK villages. We examine whether the amount of prey their cat returns influences the attitudes of 45 cat owners toward the broader issue of domestic cat predation. We also contribute to the wider understanding of physiological, spatial, and behavioral drivers of prey returns among cats. We find an association between actual prey returns and owner predictions at the coarse scale of predatory/nonpredatory behavior, but no correlation between the observed and predicted prey-return rates among predatory cats. Cat owners generally disagreed with the statement that cats are harmful to wildlife, and disfavored all mitigation options apart from neutering. These attitudes were uncorrelated with the predatory behavior of their cats. Cat owners failed to perceive the magnitude of their cats' impacts on wildlife and were not influenced by ecological information. Management options for the mitigation of cat predation appear unlikely to work if they focus on "predation awareness" campaigns or restrictions of cat freedom.

  18. Reconciling actual and perceived rates of predation by domestic cats

    PubMed Central

    McDonald, Jennifer L; Maclean, Mairead; Evans, Matthew R; Hodgson, Dave J

    2015-01-01

    The predation of wildlife by domestic cats (Felis catus) is a complex problem: Cats are popular companion animals in modern society but are also acknowledged predators of birds, herpetofauna, invertebrates, and small mammals. A comprehensive understanding of this conservation issue demands an understanding of both the ecological consequence of owning a domestic cat and the attitudes of cat owners. Here, we determine whether cat owners are aware of the predatory behavior of their cats, using data collected from 86 cats in two UK villages. We examine whether the amount of prey their cat returns influences the attitudes of 45 cat owners toward the broader issue of domestic cat predation. We also contribute to the wider understanding of physiological, spatial, and behavioral drivers of prey returns among cats. We find an association between actual prey returns and owner predictions at the coarse scale of predatory/nonpredatory behavior, but no correlation between the observed and predicted prey-return rates among predatory cats. Cat owners generally disagreed with the statement that cats are harmful to wildlife, and disfavored all mitigation options apart from neutering. These attitudes were uncorrelated with the predatory behavior of their cats. Cat owners failed to perceive the magnitude of their cats’ impacts on wildlife and were not influenced by ecological information. Management options for the mitigation of cat predation appear unlikely to work if they focus on “predation awareness” campaigns or restrictions of cat freedom. PMID:26306163

  19. Virtual reality as telemedicine tool: technology, ergonomics and actual applications.

    PubMed

    Riva, G; Gamberini, L

    2000-01-01

    This paper surveys the state of the art in telemedicine applications of virtual environments (VEs) and related technologies for health care. The possible use of VEs as telemedicine tool has attracted much interest in medicine. Actually this technology is commonly used in remote or augmented surgery, and surgical training, which are critically dependent upon eye-hand coordination. Recently, however, different researchers have tried to use VEs in anatomic learning and for the assessment and rehabilitation in neuro-psychology. To date, such applications have improved the quality of health care, and later they will lead to substantial cost savings. Tools that respond to the needs of present VE systems are being refined or developed. However, the possible use of VEs in telemedicine is not linked to the solution of technical problems only. In fact telemedicine is not simply a technology but a complex process whose successful exploitation needs significant attention to ergonomics, human factors and organizational changes in the structure of the relevant health service.

  20. Alternate corrections for estimating actual wetland evapotranspiration from potential evapotranspiration

    USGS Publications Warehouse

    Barclay, Shoemaker W.; Sumner, D.M.

    2006-01-01

    Corrections can be used to estimate actual wetland evapotranspiration (AET) from potential evapotranspiration (PET) as a means to define the hydrology of wetland areas. Many alternate parameterizations for correction coefficients for three PET equations are presented, covering a wide range of possible data-availability scenarios. At nine sites in the wetland Everglades of south Florida, USA, the relatively complex PET Penman equation was corrected to daily total AET with smaller standard errors than the PET simple and Priestley-Taylor equations. The simpler equations, however, required less data (and thus less funding for instrumentation), with the possibility of being corrected to AET with slightly larger, comparable, or even smaller standard errors. Air temperature generally corrected PET simple most effectively to wetland AET, while wetland stage and humidity generally corrected PET Priestley-Taylor and Penman most effectively to wetland AET. Stage was identified for PET Priestley-Taylor and Penman as the data type with the most correction ability at sites that are dry part of each year or dry part of some years. Finally, although surface water generally was readily available at each monitoring site, AET was not occurring at potential rates, as conceptually expected under well-watered conditions. Apparently, factors other than water availability, such as atmospheric and stomata resistances to vapor transport, also were limiting the PET rate. ?? 2006, The Society of Wetland Scientists.