Sample records for cuarto molar supernumerario

  1. Lmite de prazas para o curso 2014-2015 ACCESO AO CUARTO CURSO DE GRAO OU A OUTROS

    E-print Network

    Fraguela, Basilio B.

    Límite de prazas para o curso 2014-2015 ACCESO AO CUARTO CURSO DE GRAO OU A OUTROS CURSOS DE TITULADOS UDC 2014-2015 2013-2014 Primeiro curso do grao en Empresariais 0 45 Cuarto curso do grao en Enfermaría (A Coruña) 10 10 Cuarto curso do grao en Enfermaría (Ferrol) 10 10 Cuarto curso do grao en

  2. Taurodontism in deciduous molars

    PubMed Central

    Bafna, Yash; Kambalimath, H V; Khandelwal, Vishal; Nayak, Prathibha

    2013-01-01

    Taurodont teeth are characterised by large pulp chambers at the expense of roots. An enlarged pulp chamber, apical displacement of the pulpal floor and no constriction at the level of the cement-enamel junction are the characteristic features of taurodont tooth. It appears more frequently as an isolated anomaly but its association with syndromes and other abnormalities have also been reported. Permanent dentition is more commonly affected than deciduous dentition. This paper presents a case report of taurodontism in relation to mandibular deciduous second molars. PMID:23737594

  3. Molar versus as a paradigm clash.

    PubMed Central

    Baum, W M

    2001-01-01

    The molar view of behavior arose in response to the demonstrated inadequacy of explanations based on contiguity. Although Dinsmoor's (2001) modifications to two-factor theory render it irrefutable, a more basic criticism arises when we see that the molar and molecular views differ paradigmatically. The molar view has proven more productive. PMID:11453623

  4. Molar Malocclusions in Pine Voles (Microtus pinetorum)

    PubMed Central

    Harvey, Stephen B; Alworth, Leanne C; Blas-Machado, Uriel

    2009-01-01

    Here we describe 5 cases of molar malocclusions in adult pine voles (Microtus pinetorum) used for behavioral endocrinology studies. This species belongs to the subfamily Microtinae, which possess aradicular hypsodont molars. The abnormal molars identified caused apparent difficulty in mastication, resulting in poor body condition necessitating euthanasia. Postmortem examination of the oral cavity revealed grossly elongated mandibular and maxillary molars with abnormal wear at occlusal surfaces. This colony health problem was addressed successfully by adding autoclaved hardwood sticks to each cage as an enrichment tool. PMID:19653952

  5. Molar size sequence in Australian Aboriginals.

    PubMed

    Townsend, G C; Brown, T

    1983-01-01

    Percentage frequencies for molar size sequence of first and second molars were calculated in a group of contemporary Australian Aboriginals using mesiodistal and buccolingual dimensions, as well as crown areas. Comparisons were made between sexes, arches, and dimensions within the Aboriginal group and also between Aboriginal data and those published for other populations. The frequencies of the M2 greater than M1 molar size sequence in the Aboriginals fell within the range of frequencies reported for other contemporary populations. Differences in the frequencies of the M2 greater than M1 sequence between the sexes and between arches, together with the relatively high frequency of asymmetry in molar size sequence within Aboriginals, supported the notion that local environmental conditions acting during odontogenesis, together with differential responses to other environmental influences, play an important role in determining observed patterns of molar tooth size. PMID:6869504

  6. Expressly Fabricated Molar Tube Bases: Enhanced Adhesion

    PubMed Central

    Phull, Tarun Singh; Rana, Tarun; Kumar, Varun

    2014-01-01

    Clinicians, Orthodontists and their patients’ parents often expect the best results in the shortest time span possible. Orthodontic bonding of molar tubes has been an acceptable risk in a modern era of refined biomaterials and instrumentation. Although many orthodontists still prefer banding to bonding, it is the failure rate of the tubes on molars which accounts to an impedance in molar bonding. One of the reasons for molar attachment failures is attributed to improper adaptation of the buccal tube base with or without increased thickness of composite. Merits of banding the second molars especially when these are the terminal teeth for anchorage have been overemphasized in the literature. The present article presents a simple and relatively less time consuming technique of preparing molar tubes to be bonded on tooth surfaces which may be quite difficult to isolate especially for bonding, for example, mandibular second molars. The increased surface area of the composite scaffold helps not only in enhanced bond strength but also serves to reduce the incidence of plaque accumulation given the dexterity of invitro preparation. The removal of the occlusal part of the molar tube scaffold helps in prevention of open / raised bite tendencies. The present innovation, therefore, is not merely serendipity but a structured technique to overcome a common dilemma for the clinical orthodontist. The present dictum of banding being superior to molar tube bonding may prove to be futile with trendsetting molar attachments. It is also an established fact that bonding proves to be a lesser expensive modality when compared to banding procedures. PMID:25121070

  7. Role of third molars in orthodontics.

    PubMed

    Almpani, Konstantinia; Kolokitha, Olga-Elpis

    2015-02-16

    The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too. PMID:25685759

  8. Efficiency of a pendulum appliance for molar distalization related to second and third molar eruption stage

    Microsoft Academic Search

    Gero S. M Kinzinger; Ulrike B Fritz; Franz-Günter Sander; Peter R Diedrich

    2004-01-01

    A modified pendulum appliance, including a distal screw and special preactivated pendulum springs (built-in straightening activation and toe-in bending), was used for bilateral maxillary molar distalization in 36 adolescent patients in various stages of the molar dentition. The patients were divided into 3 groups (PG 1-3) according to the stage of eruption of their second and third molars. In PG

  9. Distribution patterns of benthic diatoms in a Pampean river exposed to seasonal floods: the Cuarto River (Argentina)

    Microsoft Academic Search

    Ana L. Martínez De Fabricius; N. Maidana; N. Gómez; S. Sabater

    2003-01-01

    The diatom community growing on cobbles and sand substrata along the Cuarto River (Córdoba, Argentina) was studied during 2000 and 2001. Multivariate analyses of the data (PCA and CCA) showed distinct differences in water chemistry and substrata types between the upstream sites (sites 1–10) and downstream sites (sites 11–19). Sites 1–10 supported an epilithic diatom community associated with low water

  10. Orthodontic extrusion of horizontally impacted mandibular molars

    PubMed Central

    Ma, Zhigui; Yang, Chi; Zhang, Shanyong; Xie, Qianyang; Shen, Yuqing; Shen, Pei

    2014-01-01

    Objective: To introduce and evaluate a novel approach in treating horizontally impacted mandibular second and third molars. Materials and methods: An orthodontic technique was applied for treatment of horizontally impacted mandibular second and third molars, which included a push-type spring for rotation first, and then a cantilever for extrusion. There were 8 mandibular third molars (M3s) and 2 second molars (M2s) in this study. Tooth mobility, extraction time, the inclination and parallelism of the impacted tooth, alveolar bone height of the adjacent tooth, and the relationship of impacted M3 and the inferior alveolar nerve (IAN) were evaluated. Results: Two horizontally impacted M2s could be upright in the arch and good occlusal relationships were obtained after treatment. All impacted M3s were successfully separated from the IAN, without any neurologic consequences. The average extraction time was 5 minutes. There was a significant change in the inclination and parallelism of the impacted tooth after treatment. A new bone apposition with the average height of 3.2 mm was noted distal to the adjacent tooth. Conclusions: This two-step orthodontic technique as presented here may be a safe and feasible alternative in management of severely horizontally impacted mandibular molars, which achieves a successful separation of M3s from the IAN and an excellent position for M2s. PMID:25419364

  11. CANAL MORPHOLOGY OF MAXILLARY MOLARS: Clinical Observations of Canal Configurations

    Microsoft Academic Search

    John J. Stropko

    An examination of 1732 conventionally treated maxillary molars was made in an attempt to deter-mine the percentage of MB2 canals that could be located routinely. The teeth examined were 1096 first molars, 611 second molars, and 25 third mo-lars. The results were recorded on a modified computer program over an 8-yr period of time. An in-teresting trend was noted. The

  12. Molar tubal ectopic pregnancy: Report of two cases.

    PubMed

    Mbarki, Chaouki; Jerbi, Emna; Hsayaoui, Najeh; Zouari, Fatma; Ben Brahim, Ehsen; Oueslati, Hedhili

    2015-06-01

    Ectopic molar pregnancy is a rare occurrence and consequently not often considered as a diagnostic possibility. We report two cases of molar hydatidiform tubal pregnancy. Diagnosis of ectopic pregnancy was confirmed on clinical biological and sonographic investigations. Diagnosis of molar pregnancy was done on histopathology. The clinical course was favorable for both patients. Although rare, molar changes can occur at any site of an ectopic pregnancy. Clinical diagnosis of a molar pregnancy is difficult but histopathology is the gold standard for diagnosis. PMID:25510265

  13. Standard molar enthalpy of formation, vapour pressures, and standard molar enthalpy of sublimation of benzanthrone

    Microsoft Academic Search

    Manuel A. V. Ribeiro da Silva; M. Lu??sa C. C. H. Ferrão; Manuel J. S. Monte; Jorge M. Gonçalves; Fang Jiye

    1999-01-01

    The standard (po= 0.1 MPa) molar enthalpy of combustion atT= 298.15 K of crystalline benzanthrone was determined as?cHmo=?(8114.7 ± 2.0)kJ · mol?1by static-bomb calorimetry, and the standard molar enthalpy of formation of the crystal atT= 298.15 K was derived as?fHmo(cr) =?(4.1 ± 3.0)kJ · mol?1. Vapour pressure as a function of temperature was measured using the mass-loss Knudsen effusion technique,

  14. Restorative management of severely ankylosed primary molars.

    PubMed

    de Moura, Marcoeli Silva; Pontes, Alessandra Silva; Brito, Maria Hellen Sâmia Fortes; de Deus Moura, Lucia; de Deus Moura de Lima, Marina; de Melo Simplício, Alexandre Henrique

    2015-01-01

    Severe dentoalveolar ankylosis is an etiological factor for malocclusion. When infraocclusion occurs early, it progresses with time, leading to severe consequences in young children because of compensatory supra-eruption of the antagonist tooth and mesialization of adjacent teeth. Early diagnosis allows for interception of the problem and may prevent orthodontic treatment. The purpose of this manuscript is to report two cases of infraocclusion of primary mandibular second molars that were diagnosed early and were treated with composite resin crowns. The use of indirect composite restorations for ankylosed teeth is a good option for primary teeth with a moderate/ severe degree of ankylosis. PMID:25909842

  15. Molar Incisor Hypomineralization, Prevalence, and Etiology

    PubMed Central

    Allazzam, Sulaiman Mohammed; Alaki, Sumer Madani; El Meligy, Omar Abdel Sadek

    2014-01-01

    Aim. To evaluate the prevalence and possible etiological factors associated with molar incisor hypomineralization (MIH) among a group of children in Jeddah, Saudi Arabia. Methods. A group of 8-12-year-old children were recruited (n = 267) from the Pediatric Dental Clinics at the Faculty of Dentistry, King Abdulaziz University. Children had at least one first permanent molar (FPM), erupted or partially erupted. Demographic information, children's medical history, and pregnancy-related data were obtained. The crowns of the FPM and permanent incisors were examined for demarcated opacities, posteruptive breakdown (PEB), atypical restorations, and extracted FPMs. Children were considered to have MIH if one or more FPM with or without involvement of incisors met the diagnostic criteria. Results. MIH showed a prevalence of 8.6%. Demarcated opacities were the most common form. Maxillary central incisors were more affected than mandibular (P = 0.01). The condition was more prevalent in children with history of illnesses during the first four years of life including tonsillitis (P = 0.001), adenoiditis (P = 0.001), asthma (P = 0.001), fever (P = 0.014), and antibiotics intake (P = 0.001). Conclusions. The prevalence of MIH is significantly associated with childhood illnesses during the first four years of life including asthma, adenoid infections, tonsillitis, fever, and antibiotics intake. PMID:24949012

  16. Bilateral maxillary fused second and third molars: a rare occurrence

    PubMed Central

    Liang, Rui-Zhen; Wu, Jin-Tao; Wu, You-Nong; Smales, Roger J; Hu, Ming; Yu, Jin-Hua; Zhang, Guang-Dong

    2012-01-01

    This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months. PMID:23222992

  17. Calcium chromate synthesis molar ratio and drying studies

    Microsoft Academic Search

    Dillard

    1977-01-01

    The purpose of this study was to determine the effect of varying the molar ratio of reactants and the sample drying temperature on the chemical and physical properties of the calcium chromate product. Calcium chromate samples were prepared using standard operating procedures developed at GEND with molar ratios of reactants ranging from stoichiometric amounts for neutralization of chromic acid to

  18. Functional Patterns of Molar Occlusion in Platyrrhine Primates

    E-print Network

    Rosenberger, Alfred H.

    Functional Patterns of Molar Occlusion in Platyrrhine Primates ALFRED L ROSENBERGERZ AND WARREN G mechanics . Dentition Molars . Occlusion Tooth wear Platyrrhine. ABSTRACT Mechanico-functional features are adapted to loading foods under relatively high occlusal pressure; those of Pithe- cia and Cebus, under

  19. Presence of third molars in orthodontic patients from northern Greece

    PubMed Central

    Barka, Georgia; Tretiakov, Georgios; Theodosiou, Theodosios; Ioannidou-Marathiotou, Ioulia

    2012-01-01

    Objective The purpose of the present study was to investigate the frequency of presence of third molar teeth and their distribution in each jaw and each side, according to sex, in a group of orthodontic patients with permanent dentition from northern Greece. Methods The sample included panoramic radiographs from 220 patients with permanent dentition (mean age 13.62 ± 1.81). The ?2 test was used to assess the relationships between the variables, and the Fisher’s exact test was used in cases where the expected frequencies in each cell were <5. Results The frequency of third molar presence was 79.1%, and 20.9% was the frequency of third molar agenesis. Intersexual differences in the number of third molars was not statistically significant. There was a correlation between the distribution of third molars on the right and the left side (Fisher’s exact test = 100.788; P = 0). The two sides showed the same tendency toward the presence or absence of third molars. A correlation was also found between the distribution of maxillary and mandibular third molars (Fisher’s exact test = 24.372; P = 0). In each jaw, the presence or absence of third molars was highly related to the number of third molars found in the other jaw. Conclusion The present results showed that in this orthodontic group of northern Greek patients, presence accounted for 79.1% and agenesis for 20.9%. No significant difference was found between the frequencies of third molar presence on the left and right sides in either the maxilla or mandible. PMID:22701086

  20. Continuous multi-criteria methods for crop and soil conservation planning on La Colacha (Río Cuarto, Province of Córdoba, Argentina)

    NASA Astrophysics Data System (ADS)

    Antón, J. M.; Grau, J. B.; Cisneros, J. M.; Laguna, F. V.; Aguado, P. L.; Cantero, J. J.; Andina, D.; Sánchez, E.

    2012-08-01

    Agro-areas of Arroyos Menores (La Colacha) west and south of Río Cuarto (Prov. of Córdoba, Argentina) basins are very fertile but have high soil loses. Extreme rain events, inundations and other severe erosions forming gullies demand urgently actions in this area to avoid soil degradation and erosion supporting good levels of agro production. The authors first improved hydrologic data on La Colacha, evaluated the systems of soil uses and actions that could be recommended considering the relevant aspects of the study area and applied decision support systems (DSS) with mathematic tools for planning of defences and uses of soils in these areas. These were conducted here using multi-criteria models, in multi-criteria decision making (MCDM); first of discrete MCDM to chose among global types of use of soils, and then of continuous MCDM to evaluate and optimize combined actions, including repartition of soil use and the necessary levels of works for soil conservation and for hydraulic management to conserve against erosion these basins. Relatively global solutions for La Colacha area have been defined and were optimised by Linear Programming in Goal Programming forms that are presented as Weighted or Lexicographic Goal Programming and as Compromise Programming. The decision methods used are described, indicating algorithms used, and examples for some representative scenarios on La Colacha area are given.

  1. Replacement of a first molar and 3 second molars by the mesial inclination of 4 impacted third molars in an adult with a Class II Division 1 malocclusion.

    PubMed

    Tomonari, Hiroshi; Yagi, Takakazu; Kuninori, Takaharu; Ikemori, Takahiro; Miyawaki, Shouichi

    2015-06-01

    This case report presents the successful replacement of 1 first molar and 3 second molars by the mesial inclination of 4 impacted third molars. A woman, 23 years 6 months old, had a chief complaint of crowding of her anterior teeth and linguoclination of a second molar on the left side. The panoramic radiographic images showed that the maxillary and mandibular third molars on both sides were impacted. Root resorption on the distal surfaces of the maxillary second molars was suspected. The patient was given a diagnosis of Angle Class II Division 1 malocclusion with severe crowding of the anterior teeth and 4 impacted third molars. After we extracted the treated maxillary second premolars and the second molars on both sides, the treated mandibular second premolar and the second molar on the left side, and the root canal-filled mandibular first molar on the right side, the 4 impacted third molars were uprighted and formed part of the posterior functional occlusion. The total active treatment period was 39 months. The maxillary and mandibular third molars on both sides successfully replaced the first and second molars. The replacement of a damaged molar by an impacted third molar is a useful treatment option for using sound teeth. PMID:26038080

  2. Determining Molar Combining Ratios Using Radioisotopes--A Student Experiment

    ERIC Educational Resources Information Center

    Sears, Jerry A.

    1976-01-01

    Outlines an experimental procedure in which an iodine radioisotope is used to determine molar combining ratios of lead and silver with the iodine. Tables and graphs show the definitive results that should be attainable. (CP)

  3. Endodontic management of middle mesial canal of the mandibular molar.

    PubMed

    Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

    2013-01-01

    Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

  4. Endodontic management of middle mesial canal of the mandibular molar

    PubMed Central

    Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

    2013-01-01

    Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

  5. Hypothetical considerations in the regenerative treatment of molar furcation defects.

    PubMed

    Hutchens, L H

    1996-01-01

    Treatment of the molar furcation defect is a challenge to the dental professional. Responses of molar furcation sites to both closed and open surgical debridement have not been shown to result in significant clinical improvement or bone fill. Regenerative techniques using grafting materials, guided tissue regeneration with resorbable and nonresorbable membranes, coronally positioned flaps, and combination techniques are more frequently used to treat class II molar furcations. The clinical responses to these surgical approaches have shown varied results. This article reviews some of the studies on regeneration in furcation defects as well as some of the uniqueness and complexities of the furcation problem. The bone morphology differences in molar bifurcation and trifurcation defects are discussed, and a bone morphologic classification is presented in an effort to standardize future regenerative studies in class II furcations. PMID:8624561

  6. Evolution of molar enamel microstructure in North American Notharctidae (primates)

    Microsoft Academic Search

    M. C. Maas; M. O'Leary

    1996-01-01

    Evolutionary changes in gross dental morphology and body size of early to middle Eocene North American notharctids is thought to reflect a dietary shift from frugivory to folivory;Cantiusspp. were largely frugivorous, whereasNotharctusspp. andCopelemurwere probably more folivorous. Here we report on the evolution of molar enamel microstructure in the notharctid clade and its relationship to adaptive change. Molar teeth of ten

  7. Recurrent molar pregnancies associated with clomiphene citrate and human gonadotropins.

    PubMed

    Mor-Joseph, S; Anteby, S O; Granat, M; Brzezinsky, A; Evron, S

    1985-04-15

    A 34-year-old patient, gravida 7, para 0, with three consecutive spontaneous abortions followed by four recurrent molar pregnancies is described. The patient conceived only with clomiphene citrate or human gonadotropin treatment. The occurrence of molar pregnancies succeeded spontaneous abortions with one remaining pregnancy progressing to gestational trophoblastic disease. The role of clomiphene citrate and human gonadotropins in the pathogenesis of this disease is discussed. PMID:3920913

  8. Influence of molar ratios on properties of magnesium oxychloride cement

    SciTech Connect

    Li Zongjin [Department of Civil Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong (China)]. E-mail: zongjin@ust.hk; Chau, C.K. [Department of Civil Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong (China)

    2007-06-15

    A parametric study has been conducted to investigate the influences of the molar ratios of MgO/MgCl{sub 2} and H{sub 2}O/MgCl{sub 2} on the properties of magnesium oxychloride (MOC) cement. By an integrated assessment of the experimental studies of strength development and X-ray diffractograms, together with application of the relevant phase diagram, it is recognized that the molar ratios of MgO/MgCl{sub 2} and H{sub 2}O/MgCl{sub 2} can significantly affect the properties of MOC cement. For a MOC cement paste possessing a dominance of 5MgO.MgCl{sub 2}.8H{sub 2}O (phase 5) crystals, the molar ratios of MgO/MgCl{sub 2} of 11-17 and H{sub 2}O/MgCl{sub 2} of 12-18 are found to be the most favorite ranges for design purpose. The choose of the molar ratio of H{sub 2}O/MgCl{sub 2} is, however, largely depends on the molar ratio of MgO/MgCl{sub 2} mainly for controlling workability of paste. Therefore, the most critical parameter to be selected in the design process is the molar ratio of MgO/MgCl{sub 2}, although the reactivity of the MgO powder is also important. Besides, the molar ratio can also be affected by the reactivity of the MgO powder to be employed. It is believed that a molar ratio of MgO/MgCl{sub 2} of 13, the most suitable one shown in this study, can be used as a starting point in the normal practice.

  9. Standardised studies on Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM): a need.

    PubMed

    Elfrink, M E C; Ghanim, A; Manton, D J; Weerheijm, K L

    2015-06-01

    In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) was performed. A search of PubMed online databases was conducted for relevant articles published until November 2014. The reference lists of all retrieved articles were hand-searched. Studies were included after assessing the eligibility of the full-text article. Out of 1078 manuscripts, a total of 157 English written publications were selected based on title and abstract. Of these 157, 60 were included in the study and allocated as 52 MIH and 5 HSPM, and 3 for both MIH and HSPM. These studies utilised the European Academy of Paediatric Dentistry judgment criteria, the modified index of developmental defects of enamel (mDDE) and self-devised criteria, and demonstrated a wide variation in the reported prevalence (MIH 2.9-44 %; HSPM 0-21.8 %). Most values mentioned were representative for specific areas. More studies were performed in cities compared with rural areas. A great variation was found in calibration methods, number of participants, number of examiners and research protocols between the studies. The majority of the prevalence studies also investigated possible aetiological factors. To compare MIH and HSPM prevalence and or aetiological data around the world, standardisation of such studies seems essential. Standardisation of the research protocol should include a clearly described sample of children (minimum number of 300 for prevalence and 1000 for aetiology studies) and use of the same calibration sets and methods whereas aetiological studies need to be prospective in nature. A standardised protocol for future MIH and HSPM prevalence and aetiology studies is recommended. PMID:25894247

  10. Prevalence of missing and impacted third molars in adults aged 25 years and above

    PubMed Central

    Jung, Yun-Hoa

    2013-01-01

    Purpose The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. Materials and Methods The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. Results A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. Conclusion The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health. PMID:24380060

  11. Genetic integration of molar cusp size variation in baboons

    PubMed Central

    Koh, Christina; Bates, Elizabeth; Broughton, Elizabeth; Do, Nicholas T.; Fletcher, Zachary; Mahaney, Michael C.; Hlusko, Leslea J.

    2010-01-01

    Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the non-occluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. PMID:20034010

  12. Western Saudi adolescent age estimation utilising third molar development

    PubMed Central

    Alshihri, Amin M.; Kruger, Estie; Tennant, Marc

    2014-01-01

    Objective: The aim of this study was to establish reference data on third molar morphology/development for age estimation in Western Saudi adolescents, between ages 14 and 23 years of old. Materials and Methods: The orthopantomograms of 130 individuals (males and females), were examined, and the stage of third molar development were evaluated. Results: Mean ages, standard deviations, and percentile distributions are presented for each stage of development. The mean estimated age for all participants (n = 130) was 219.7 months, and this differed significantly (P < 0.05) from the mean chronological age (226.5 months). Deviations of predicted age from real age showed 28.5% of all participants had their age estimated within 1 year (±12 months) of their chronological age. Most (43%) had their age underestimated by more than 12 months and the remaining 28.5% had their age overestimated by more than 12 months of their chronological age. Differences in left-right symmetry information of third molars were detected and were higher in the maxilla (92%) than in the mandible (82%). For all molars reaching stage “H” most individuals (males and females) were over the age 18 years of old. Males reach the developmental stages earlier than females. Conclusion: Third molar tooth development can be reliably used to generate mean age and the estimated age range for an individual of unknown chronological age. Further studies with large populations are needed for better statistical results. PMID:25202206

  13. Management of impacted third molars among Nigerian dentists.

    PubMed

    Owotade, F J; Ugboko, V I; Fatusi, O A; Akinmoladun, V I; Obuekwe, O N; Olasoji, H O

    2002-03-01

    Seventy-five Nigerian dentists were interviewed on their approach to the management of impacted third molars. The mean age of the dentists was 34.8 years, with a male/female ratio of 3.4:1. Most of the female dentists were found in the training institutions (p = 0.005). More than half of the dentists (58.7%) practiced in institutions with dental schools (training institutions), majority preferred the buccal approach (92%), and all the dentists (100%) preferred third molar disimpaction under local analgesia. Most dentists (88%) prescribe antibiotics following third molar surgery. Fifty dentists (66.7%) routinely reviewed all patients postoperatively while 12 dentists (16%) were of the opinion that all impacted third molars should be extracted. Only 21 dentists (28%) were aware of any protocol on the management of impacted teeth. More dentists in the training institutions performed third molar surgery less frequently than dentists in other hospitals (p = 0.07) who tend to employ chisels/mallet for bone removal (p = 0.0004). The need for continuing education and the formulation of guidelines in order to assist dentists to make informed decisions is emphasised. This will help conserve scarce resources and enhance the operation of the newly introduced National Health Insurance Scheme. PMID:12061244

  14. Requirement of alveolar bone formation for eruption of rat molars

    PubMed Central

    Wise, Gary E.; He, Hongzhi; Gutierrez, Dina L.; Ring, Sherry; Yao, Shaomian

    2011-01-01

    Tooth eruption is a localized event that requires a dental follicle (DF) to regulate the resorption of alveolar bone to form an eruption pathway. During the intra-osseous phase of eruption, the tooth moves through this pathway. The mechanism or motive force that propels the tooth through this pathway is controversial but many studies have shown that alveolar bone growth at the base of the crypt occurs during eruption. To determine if this bone growth (osteogenesis) was causal, experiments were designed in which the expression of an osteogenic gene in the DF, bone morphogenetic protein-6 (BMP6), was inhibited by injection of the 1st mandibular molar of the rat with an siRNA targeted against BMP6. The injection was followed by electroporation to promote uptake of the siRNA. In 45 first molars injected, eruption either was delayed or completely inhibited (7 molars). In the impacted molars, an eruption pathway formed but bone growth at the base of the crypt was greatly reduced as compared to the erupted first molar controls. These studies show that alveolar bone growth at the base of the crypt is required for tooth eruption and that BMP6 may be an essential gene for promoting this growth. PMID:21896048

  15. Aberration in the palatal root of the maxillary first molar.

    PubMed

    Rajalbandi, Sandeep; Shingte, Sandhya Narayan; Sundaresh, K J; Mallikarjuna, Rachappa

    2013-01-01

    Thorough knowledge of root canal morphology is essential for the endodontic therapy. Variations in the root and root canal morphology, especially in multirooted teeth, are a constant challenge for diagnosis and management. The dentist needs to be familiar with the various root canal configurations and their variations for successful endodontic therapy. There are rare variations in canal number and configuration in maxillary molars, which could affect treatment outcome. Two lingual root structures are occasionally found on human permanent maxillary molars. One of these is the normal lingual root, which is always present, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis) or distolingually (radix distolingualis). The purpose of this paper is to review the literature and to demonstrate a case report which describes the successful non-surgical endodontic management of an unusual maxillary first molar with four separate roots and four canals. PMID:23632609

  16. Sex assessment by molar odontometrics in North Indian population

    PubMed Central

    Narang, Ramandeep Singh; Manchanda, Adesh S.; Singh, Balwinder

    2015-01-01

    Introduction: Human identification is based on scientific principles, mainly involving dental records, fingerprints, estimation of age, postmortem reports, differentiation by blood groups, and DNA comparisons. Sex assessment is one of the prime factors employed to assist with the identification of an individual. Aims and Objective: To investigate univariate sex differences in the dimensions of permanent first molars and to assess sex, based on buccolingual (BL) and mesiodistal (MD) dimensions of permanent first molars in a population of north India. In addition, the study intended to evaluate the reliability of dimensional variation of these teeth in assessment of sex among the population. Materials and Methods: The study sample consists of 410 adult individuals (200 males and 210 females), from a north Indian population. The BL and MD diameters of the permanent first molars were measured using digital vernier callipers. Results: It was observed statistically significant difference between males and females with P < 0.05, in maxillary casts in both BL and MD dimensions; but only in the MD dimension in mandibular casts. A high level of sexual dimorphism of 7.7% was found in the BL dimension of the maxillary right first molar. The accuracy of sex assessment by each dimension was deliberated by univariate analyses with an overall accuracy ranging from 67.5 to 88% for various dimensions. Conclusion: Sexual dimorphism of teeth is population specific and among north Indian population, BL and MD dimensions in maxillary first molar and MD dimension in mandibular first molar can be used for sex assessment. PMID:25709321

  17. Treatment of Ectopic Mandibular Second Permanent Molar with Elastic Separators

    PubMed Central

    Rajesh, R.; Naveen, V.; Amit, S.; Baroudi, Kusai; Sampath Reddy, C.; Namineni, Srinivas

    2014-01-01

    Ectopic eruption is a developmental disturbance in which the tooth fails to follow its normal eruption pathway. Ectopic eruption of the second molar is relatively rare. This paper presents the case of thirteen-year-old male with an ectopic mandibular second permanent molar. The condition was corrected with surgical exposure and placement of elastic separators. This case report lays emphasis on the practice of basic methods to obtain acceptable results rather than extensive surgical or orthodontic corrections. It is advised that ectopic teeth should not be neglected especially when it concerns developing caries and malocclusion. PMID:25050182

  18. Solutions : WtPercentToMolarity (4 Variations)

    NSDL National Science Digital Library

    A common concentration unit used commercially is percent weight per volume (%W/V) which is the number of grams of solute in 100 mL of solution. A bottle of vinegar contains 5 %W/V acetic acid (CH 3 COOH). What is the molar concentration of acetic acid in the vinegar?

  19. Prognosis of single molar implants: a retrospective study.

    PubMed

    Kim, Young-Kyun; Kim, Su-Gwan; Yun, Pil-Young; Hwang, Jung-Won; Son, Mee-Kyoung

    2010-08-01

    The purpose of this study was to evaluate the short- and mid-term prognosis of maxillary and mandibular single molar implants, prosthetic complications, and factors mediating the effects seen on them. Eighty-seven patients were enrolled consecutively in this study and 96 implants were placed into a single molar defect site by one oral and maxillofacial surgeon from March 2004 to December 2006. Primary osseointegration failure developed in two implants and delayed implant failure occurred at four implants. The fraction surviving interval was 97% to 100%, and at the last follow-up observation, the cumulative survival rate was 91.1%. All failed implants occurred in second molar sites, and the failure rate, according to implant site, showed a significant difference. Prosthetic complications, such as screw loosening, showed a significant correlation to the mesiodistal cantilever. Furthermore, crestal bone loss 3 years after loading was 0.2 mm on average and a very stable result was obtained. Based on the results, the risk of failure for maxillary and mandibular single molar implants is high and the possibility of developing prosthetic complications during loading is also high. Therefore, to minimize the cantilever, implants must be placed precisely and followed carefully and maintained for a long period of time. PMID:20664842

  20. Spontaneous emergence of overgrown molar teeth in a colony of Prairie voles (Microtus ochrogaster).

    PubMed

    Jheon, Andrew H; Prochazkova, Michaela; Sherman, Michael; Manoli, Devanand S; Shah, Nirao M; Carbone, Lawrence; Klein, Ophir

    2015-03-01

    Continuously growing incisors are common to all rodents, which include the Microtus genus of voles. However, unlike many rodents, voles also possess continuously growing molars. Here, we report spontaneous molar defects in a population of Prairie voles (Microtus ochrogaster). We identified bilateral protuberances on the ventral surface of the mandible in several voles in our colony. In some cases, the protuberances broke through the cortical bone. The mandibular molars became exposed and infected, and the maxillary molars entered the cranial vault. Visualisation upon soft tissue removal and microcomputed tomography (microCT) analyses confirmed that the protuberances were caused by the overgrowth of the apical ends of the molar teeth. We speculate that the unrestricted growth of the molars was due to the misregulation of the molar dental stem cell niche. Further study of this molar phenotype may yield additional insight into stem cell regulation and the evolution and development of continuously growing teeth. PMID:25634121

  1. Molar distalization with the assistance of Temporary Anchorage Devices.

    PubMed

    Palencar, Adrian J

    2015-01-01

    This article describes efficient techniques for distalization of maxillary and mandibular molars with the assistance of Temporary Anchorage Devices (TADs). There are numerous occasions where the distalization of molars is required in lieu of the odontectomy of bicuspids. In the past, extra-oral force has been used, (i.e. Cervical or Combination Head Gear, or intra-oral force, i.e. Posterior Sagittal Appliance, Modified Greenfield Appliance, Williams DMJ 20001, CD Distalizer, Magill Sagittal, Pendulum Appliance, etc.). All the intra-oral appliances have a common denominator the orthodontic clinician has to deal with, the undesirable expression of the Third Law of Newton. The utilization of TADs allows us to circumvent this shortcoming, establishing an absolute anchorage, and thus completely negate the expression of the Third Law of Newton. PMID:25881377

  2. Partial molar volumes of amino acid derivatives in water

    Microsoft Academic Search

    Fereidoon Shahidi

    1983-01-01

    The partial molar volumes at infinite dilution for a number of hydrochlorides and sodium salts of N-methyl derivatives of a, ?-aminocarboxylic acids in water at 25°C are measured and related to their van der Waals volumes. Results indicate that 4.96±0.48 water molecules hydrate a betaine hydrochloride. Volumes of proton ionization and interaction terms are evaluated. Group contributions to the partial

  3. Extrusion of impacted mandibular second molar using removable appliance

    PubMed Central

    Karthikeyan, M. K.; Prabhakar, Ramachandran; Saravanan, R.; Vikram, N. Raj; Kumar, R. Vinoth; Prasath, R. Eshwara

    2014-01-01

    The purpose of this article is to review the principles of case management of impacted mandibular molars and to illustrate their potential to respond well to treatment. Although the scope of treatment may be influenced by the patient's age, past dental history, severity of impaction, dentoalveolar development, and root form, the case reports demonstrate the inherent potential for good treatment outcome even in the most unfavorable circumstances. PMID:25210378

  4. Unrecognised displacement of mandibular molar root into the submandibular space.

    PubMed

    Nusrath, M A; Banks, R J

    2010-09-25

    We describe a case of swelling in the right submandibular and sublingual space caused by displacement of a lower second molar root in the submandibular space. This displacement was not recognised at the time of extraction. The techniques used to minimise the risk of accidental displacement of teeth and roots, during extraction are discussed. The importance of recognising this complication and methods of retrieval are highlighted. PMID:20871549

  5. Fate of the Molar Dental Lamina in the Monophyodont Mouse

    PubMed Central

    Dosed?lová, Hana; Dumková, Jana; Lesot, Hervé; Glocová, Kristýna; Kunová, Michaela; Tucker, Abigail S.; Veselá, Iva; Krej?í, Pavel; Tichý, František; Hampl, Aleš; Buchtová, Marcela

    2015-01-01

    The successional dental lamina (SDL) plays an essential role in the development of replacement teeth in diphyodont and polyphyodont animals. A morphologically similar structure, the rudimental successional dental lamina (RSDL), has been described in monophyodont (only one tooth generation) lizards on the lingual side of the developing functional tooth. This rudimentary lamina regresses, which has been proposed to play a role in preventing the formation of future generations of teeth. A similar rudimentary lingual structure has been reported associated with the first molar in the monophyodont mouse, and we show that this structure is common to all murine molars. Intriguingly, a lingual lamina is also observed on the non-replacing molars of other diphyodont mammals (pig and hedgehog), initially appearing very similar to the successional dental lamina on the replacing teeth. We have analyzed the morphological as well as ultrastructural changes that occur during the development and loss of this molar lamina in the mouse, from its initiation at late embryonic stages to its disappearance at postnatal stages. We show that loss appears to be driven by a reduction in cell proliferation, down-regulation of the progenitor marker Sox2, with only a small number of cells undergoing programmed cell death. The lingual lamina was associated with the dental stalk, a short epithelial connection between the tooth germ and the oral epithelium. The dental stalk remained in contact with the oral epithelium throughout tooth development up to eruption when connective tissue and numerous capillaries progressively invaded the dental stalk. The buccal side of the dental stalk underwent keratinisation and became part of the gingival epithelium, while most of the lingual cells underwent programmed cell death and the tissue directly above the erupting tooth was shed into the oral cavity. PMID:26010446

  6. Fate of the molar dental lamina in the monophyodont mouse.

    PubMed

    Dosed?lová, Hana; Dumková, Jana; Lesot, Hervé; Glocová, Kristýna; Kunová, Michaela; Tucker, Abigail S; Veselá, Iva; Krej?í, Pavel; Tichý, František; Hampl, Aleš; Buchtová, Marcela

    2015-01-01

    The successional dental lamina (SDL) plays an essential role in the development of replacement teeth in diphyodont and polyphyodont animals. A morphologically similar structure, the rudimental successional dental lamina (RSDL), has been described in monophyodont (only one tooth generation) lizards on the lingual side of the developing functional tooth. This rudimentary lamina regresses, which has been proposed to play a role in preventing the formation of future generations of teeth. A similar rudimentary lingual structure has been reported associated with the first molar in the monophyodont mouse, and we show that this structure is common to all murine molars. Intriguingly, a lingual lamina is also observed on the non-replacing molars of other diphyodont mammals (pig and hedgehog), initially appearing very similar to the successional dental lamina on the replacing teeth. We have analyzed the morphological as well as ultrastructural changes that occur during the development and loss of this molar lamina in the mouse, from its initiation at late embryonic stages to its disappearance at postnatal stages. We show that loss appears to be driven by a reduction in cell proliferation, down-regulation of the progenitor marker Sox2, with only a small number of cells undergoing programmed cell death. The lingual lamina was associated with the dental stalk, a short epithelial connection between the tooth germ and the oral epithelium. The dental stalk remained in contact with the oral epithelium throughout tooth development up to eruption when connective tissue and numerous capillaries progressively invaded the dental stalk. The buccal side of the dental stalk underwent keratinisation and became part of the gingival epithelium, while most of the lingual cells underwent programmed cell death and the tissue directly above the erupting tooth was shed into the oral cavity. PMID:26010446

  7. Efficacy of Postoperative Prophylactic Antibiotic Therapy in Third Molar Surgery

    PubMed Central

    Reddy B, Praveen

    2014-01-01

    Introduction: Surgical extraction of mandibular third molar is the most frequently performed procedure in oral surgery. This procedure is associated with significant postoperative sequelae such as trismus, swelling, pain and infection. The need of antibiotic therapy during the removal of mandibular third molar has been a contentious issue. Method: This study investigated a regimen by using amoxycillin and metronidazole in one group and without using antibiotics in the other. Both the groups were assessed postoperatively on the 1st, 2nd, 5th, 7th and 10th days by the same observer for post operative mouth opening (interincisal distance), presence of a purulent discharge at the site of surgery, pain and swelling. Result: Overall, no statistically significant difference was seen between both the treatment groups when interincisal distance, pain, swelling and purulent discharge were considered. Conclusion: The results of this study failed to show any advantage which was associated with the routine postoperative use of antibiotics in asymptomatic third molar surgeries. PMID:24995236

  8. Molar volumes of molten indium at high pressures measured in a diamond Guoyin Shen,a)

    E-print Network

    Shen, Guoyin

    Molar volumes of molten indium at high pressures measured in a diamond anvil cell Guoyin Shen for publication 18 June 2002 Molar volumes of molten indium have been measured in an isothermal compression up the molar volume of amorphous materials in a DAC and report the results on molten indium in an isothermal

  9. Sub-10-Minute Characterization of an Ultrahigh Molar Mass Polymer by Multi-detector Hydrodynamic Chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molar mass averages, distributions, and architectural information of polymers are routinely obtained using size-exclusion chromatography (SEC). It has previously been shown that ultrahigh molar mass polymers may experience degradation during SEC analysis, leading to inaccurate molar mass averages a...

  10. Relationship between mandibular condyle and angle fractures and the presence of mandibular third molars

    PubMed Central

    Mah, Deuk-Hyun; Moon, Seong-Yong; Oh, Ji-Su; You, Jae-Seek

    2015-01-01

    Objectives We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures. Materials and Methods This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured. Results Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001). Conclusion The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures. PMID:25741462

  11. Anchorage reinforcement with a fixed functional appliance during protraction of the mandibular second molars into the first molar extraction sites.

    PubMed

    Chhibber, Aditya; Upadhyay, Madhur

    2015-07-01

    Protraction of posterior teeth into edentulous spaces is a challenge. This report describes the treatment of a 19-year-old woman with missing mandibular first molars owing to caries. A fixed functional appliance was used for anchorage reinforcement during mandibular second molar protraction. Eight millimeters of bilateral protraction was done with bodily mesial movement of the molars and no lingual tipping of the incisors. PMID:26124039

  12. Apparent molar and partial molar volumes of aqueous ceric ammonium nitrate solutions at 20, 25, 30, and 35°C

    NASA Astrophysics Data System (ADS)

    Deosarkar, S. D.; Wanale, S. G.; Shelke, M. P.

    2014-07-01

    Present paper reports the measured densities (?) and refractive indices ( n D) of aqueous solutions of ceric ammonium nitrate (CAN) at 20, 25, 30, and 35°C in different concentrations of solution. Apparent molar volumes (?v) have been calculated from the density data at different temperatures and fitted to Massons relation to get limiting partial molar volumes (?{v/0}) of CAN. Refractive index data were fitted to linear dependence over concentration of solutions and values of constant K and n {D/0} for different temperatures were evaluated. Specific refractions ( R D) of solutions were calculated from the refractive index and density data. Concentration and temperature effects on experimental and derived properties have been discussed in terms of structural interactions.

  13. Anxiety before extraction of impacted lower third molars

    PubMed Central

    Tarazona, Beatriz; Tarazona-Álvarez, Pablo; Peñarrocha-Oltra, David; Rojo-Moreno, Juan

    2015-01-01

    Objetives: Assess levels of trait anxiety, state anxiety and dental anxiety before extraction of lower third molars and check the correlation and reliability of the scales used for the measurement of preoperative anxiety. Study Design: A prospective study of patients treated with extraction of a lower third molar between September 2010 to December 2010 was carried out. A total of 125 patients were included in the study. All of them were patients of the Oral Surgery and Implantology Department (Valencia University Medical and Dental School, Valencia, Spain). Before surgery, patients had to complete a preoperative protocol with 4 scales: the STAI-T (State-Trait Anxiety Inventory-Trait) for measuring trait anxiety, the STAI-S (State-Trait Anxiety Inventory-State) for measuring state anxiety, and DAS (Dental anxiety Scale of N. Corah) and APAIS (Amsterdam Preoperative anxiety and Information Scale) for measuring dental anxiety. Results: Patients undergoing extractions of an impacted lower third molar showed low levels of trait anxiety and moderate levels of state anxiety and dental anxiety. Higher levels of trait anxiety were obtained for older patients. Women had higher mean levels of dental anxiety and state anxiety that men with a statistically significant difference in STAI-S scales, DAS, and APAIS. Patients with higher trait anxiety and state anxiety showed higher levels of dental anxiety. A significant correlation (p ? 0.01) (p = 0.00) was found between the four scales used to measure anxiety. The scale showed higher correlation was STAI-S scale. The 4 scales showed high reliability (? of C.> 0.80). Conclusions: Patients with highest levels of trait anxiety and state anxiety, had more dental anxiety. The STAI-T, STAI-S, DAS and APAIS scales provided useful information about anxiety before the extraction of lower impacted third molars. The STAI-S is the scale with highest correlation and reliability. Key words:Extraction of impacted lower third molars, preoperative anxiety, dental anxiety, trait anxiety, state anxiety. PMID:25662541

  14. Cameriere's third molar maturity index in assessing age of majority.

    PubMed

    Gali?, Ivan; Lauc, Tomislav; Brki?, Hrvoje; Vodanovi?, Marin; Gali?, Elizabeta; Biazevic, Maria Gabriela Haye; Brakus, Ivan; Badrov, Jozo; Cameriere, Roberto

    2015-07-01

    Estimation of chronological age of an individual is one of the main challenges in forensic science. Legally to be able to treat a person as a minor or an adult, it is necessary to determine whether their age of majority (if they are older or younger than 18, in most countries). Methods for estimating age are especially important when an individual in question lacks personal documents or other means of identification. As the dental age differs in various populations, the aim of this study was to evaluate applicability of third molar method for assessing age of majority in Croatia. Cameriere's third molar maturity index (I3M) value of 0.08, measured by the open apices of the teeth, was verified in sample of 1336 panoramic images aged between 14 and 23 years. Chronological age gradually decreased as I3M increased in both genders. Males showed statistically significant advanced maturation when I3M was between 0.0 and 0.3 value. The results indicate that the sensitivity of the test for 0.08 value was 84.3% (95%CI 80.6%, 87.5%) for females and 91.2% (95%CI 88.7%, 93.1) for males. Specificity was 95.4% (95%CI 92.5%, 97.5%) and 91.9% (95%CI 88.8%, 94.3%). The proportions of accurately classified males were 88.8% and that of females 91.5%. The estimated post-test probabilities, of individuals, in other word the probability that a Croatian individual with an I3M<0.08 is 18 years or older is 94.5% for females, and 96.5% for males. With high accuracy, the third molar maturity index should be used as a determinant of the age of majority in Croatia. PMID:26013667

  15. Unilateral single-rooted primary mandibular first molar.

    PubMed

    Chaudhari, Purva; Mallikarjuna, Rachappa; Swadas, Milan; Dave, Bhavna

    2013-01-01

    A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned. PMID:23893279

  16. Unilateral single-rooted primary mandibular first molar

    PubMed Central

    Chaudhari, Purva; Mallikarjuna, Rachappa; Swadas, Milan; Dave, Bhavna

    2013-01-01

    A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned. PMID:23893279

  17. Unilateral failure of development of mandibular premolars and molars in an Eastern Grey kangaroo (Macropus giganteus) and its effects on molar progression.

    PubMed

    Barber, D; Campbell, J; Davey, J; Luke, T; Agren, E; Beveridge, I

    2008-01-01

    An adult male Eastern Grey kangaroo from a wildlife reserve near Melbourne was submitted for necropsy examination and was discovered to have abnormal dentition. There was no evidence that any premolars or molars had ever been present on the right mandible, whilst the incisors were normal. The age of the kangaroo was estimated to be 1 year 9 months using the right maxillary molars and 2 years 4 months old using the contralateral side, presumably due to the asymmetry of the dental arcades. 'Lumpy jaw', a common periodontal disease of kangaroos, from which Bacteroides sp was cultured, was present on the base of the vertical ramus of the left mandible. Complete unilateral absence of premolar and molar teeth in the mandible of a kangaroo has not been described. This condition affected molar progression in both sets of maxillary molars. PMID:18271832

  18. Wheat antixenosis, antibiosis, and tolerance to infestation by Delphacodes kuscheli (Hemiptera: Delphacidae), a vector of "Mal de Río Cuarto" in Argentina.

    PubMed

    Brentassi, M E; Corrales, C; Snape, J W; Dixon, A F G; Castro, A M

    2009-10-01

    "Mal de Rio Cuarto", is the most important virus disease of corn, Zea mays L., in Argentina. It is caused by the Mal de Rio Cuarto virus (family Reoviridae, genus Fijivirus. MRCV), which is a persistent virus transmitted by Delphacodes kuscheli (Fennah 1955) (Hemiptera: Delphacidae). Because corn is not a natural host of D. kuscheli, it has little protection from this pest. In contrast, wheat, Triticum aestivum L., is one of the main hosts of this vector and a reservoir of MRCV. The aim of this work was to identify genes involved in antixenosis, antibiosis, and tolerance of infestation by D. kuscheli in wheat, which might be used to reduce the population level of this vector on corn. A set of recombinant dihaploid (RDH) lines for chromosome 6A derived from the F1 cross between 'Chinese Spring' (CS) X 'Chinese Spring (Synthetic 6A)' (S6A) substitution line, was used for mapping. The S6A parental line is resistant to the MRCV vector. Antixenosis, antibiosis, and tolerance were evaluated using conventional tests in controlled environmental conditions. Most of the RDH and S6A showed higher levels of antixenosis against D. kuscheli than the parental line CS. The RDH lines showed highly significant antibiosis in terms of the duration of first, third, and fifth nymphal instars, developmental time (days), survival and fecundity. There were highly significant differences in the tolerance to D. kuscheli based on the chlorophyll content of the first and second leaves, foliar area, and aboveground fresh and dry weights. The duration of the fifth nymphal instar and the developmental period were significantly associated with Xgwm1017 marker loci, located at 48 cM on 6AL. Another quantitative trait locus accounting for the variation in chlorophyll content of the first leaf was associated with the interval between loci Xgwm459 and Xgwm334a, located in the telomeric region of the 6AS chromosome arm. The alleles with positive effects came from S6A. Antibiotic resistance of RDH could be useful for controlling the population increase of the MRCV vector on wheat, because prolonging the duration of development increases the period between two subsequent generations, so reducing the abundance of infective populations colonizing corn. PMID:19886444

  19. Effectiveness of a personalized device in the evaluation of mandibular second molar periodontal healing after surgical extraction of adjacent third molar

    PubMed Central

    Pippi, Roberto

    2013-01-01

    Summary Aim The primary aim of the present study was to validate the effectiveness of a personalized device able to guide periodontal probing in evaluation of second molar periodontal healing after adjacent third molar surgical extraction. Secondarily, the study analyzed if any patient and tooth related factors affected the second molar periodontal healing as well as if they were able to affect the periodontal probing depth performed with or without the personalized device. Materials and methods Thirty-five lower second molars were evaluated after extraction of the adjacent third molar. Pre-operative as well as 3 and 12 month post-operative probing depths of the distal surface of the second molar were evaluated. All measurements were taken by two different methods: standard two-point and four-point probing using a personalized onlay-type guide. Periapical radiographs were also evaluated. The Pearson product moment and the general linear model with backward stepwise procedure were used for inferential statistics. Results The mean 12-month post-operative probing depth/mean pre-operative probing depth ratio obtained with the guided probing method showed a highly significant effect on the 12-month radiographic post-operative/pre-operative radiographic measure ratio. None of the examined patient- or tooth-related factors showed a significant effect on pre-operative/12-month post-operative radiographic measure ratio. Conclusions The use of the proposed personalized device seems to provide a more reliable estimate of second molar periodontal healing after adjacent third molar surgical extraction. No patient-or tooth-related factors seem to be able to affect either second molar periodontal healing or probing depth measures obtained with or without the personalized device in individuals younger than 25 years old. It can be therefore recommended that lower third molar surgical extraction be performed in young adults. PMID:24611086

  20. Nanoparticle counting: towards accurate determination of the molar concentration.

    PubMed

    Shang, Jing; Gao, Xiaohu

    2014-11-01

    Innovations in nanotechnology have brought tremendous opportunities for the advancement of many research frontiers, ranging from electronics, photonics, energy, to medicine. To maximize the benefits of nano-scaled materials in different devices and systems, precise control of their concentration is a prerequisite. While concentrations of nanoparticles have been provided in other forms (e.g., mass), accurate determination of molar concentration, arguably the most useful one for chemical reactions and applications, has been a major challenge (especially for nanoparticles smaller than 30 nm). Towards this significant yet chronic problem, a variety of strategies are currently under development. Most of these strategies are applicable to a specialized group of nanoparticles due to their restrictions on the composition and size range of nanoparticles. As research and uses of nanomaterials are being explored in an unprecedented speed, it is necessary to develop universal strategies that are easy to use and are compatible with nanoparticles of different sizes, compositions, and shapes. This review outlines the theories and applications of current strategies to measure nanoparticle molar concentration, discusses the advantages and limitations of these methods, and provides insights into future directions. PMID:25099190

  1. Solvent-mediated molar conductivity of protic ionic liquids.

    PubMed

    Thawarkar, Sachin; Khupse, Nageshwar D; Kumar, Anil

    2015-01-01

    The molar conductivity, ?m, of protic ionic liquids (PILs) in molecular solvents is measured at 298.15 K. The decrease in the ?m values of PILs is observed with an increase in the concentration of PILs. The limiting molar conductivities, ?m(0), were obtained for each PIL in different molecular solvents using a least squares method. The ?m(0) data for PILs were correlated with the structural aspects of PILs and solvent properties. The polar protic solvents show poor ionic association as compared to the polar aprotic solvents, which is discussed on the basis of the hydrogen bond donating (HBD) ability of solvents and PILs. The alkyl chain substitution of anions plays a significant role in the ionic association of the PILs. The diffusion coefficient D(0) and the transport number t were determined, which were consistent with the ?m(0) values of PILs in water. The ?m(0) and D(0) values are dependent on the hydrodynamic radius of anions of these ionic liquids. The extent of ionic association for each PIL was discussed using temperature dependent ?m data for aqueous PIL systems in terms of the Walden plot. PMID:25406387

  2. An in vitro morphological investigation of the endodontic spaces of third molars.

    PubMed

    Cosi?, Jozo; Gali?, Nada; Vodanovi?, Marin; Njemirovskij, Vera; Segovi?, Sanja; Paveli?, Bozidar; Ani?, Ivica

    2013-06-01

    Aim of this paper was to investigate the particular anatomic features of the endodontic space of third molars in the general population of Croatia. A total of 106 fully developed third molars (56 maxillar and 50 mandibular) has been analyzed. The respective number of roots and of root canals, the structure of the roots, and the curvature and absolute length of the root-canals were analyzed. In most cases, upper third molars had three roots (83.9%), while most of the lower molars were single rooted (56.0%). Upper third molars had mostly three root canals (75.1%), lower third molars two (90.0%). In both jaws, most third molars had curved canals (60.7% in the upper and 84.0% in the lower jaw). 12.5% of upper third molars had lateral and accessory canals, whereas only 4.0% of the lower third molars were found to have them. The Student t-test showed statistically significant differences (p < 0.05) in the length of the root-canals, mesiobuccal and distobuccal canals being significantly shorter than palatinal canals. The same test showed that in the lower third molars the mesial root canals were significantly longer that the distal ones, although slightly. The results obtained are in compliance with similar results by other authors; however, they tend to show some specific population-related features. PMID:23940986

  3. Partial molar volumes of uni-univalent electrolytes in methanol + water; 1: Lithium chloride, sodium chloride, and potassium chloride

    SciTech Connect

    Takenaka, Nobuo; Takemura, Takeshi; Sakurai, Masao (Hokkaido Univ., Sapporo (Japan). Research Inst. for Electronic Science)

    1994-04-01

    Densities of methanol + water + lithium chloride, + sodium chloride, and + potassium chloride were measured at 15, 25, 35, and 45 C. The apparent molar volumes of the electrolytes in these mixtures were calculated, and the apparent molar volumes at infinite dilution, the partial molar volumes, and partial molar thermal expansivities were evaluated.

  4. Age estimation using development of third molars in South Indian population: A radiological study

    PubMed Central

    Priyadharshini, K. Indra; Idiculla, Jose Joy; Sivapathasundaram, B.; Mohanbabu, V.; Augustine, Dominic; Patil, Shankargouda

    2015-01-01

    Aim: To assess the estimation of chronological age based on the stages of third molar development following the eight stages (A–H) method of Demirjian et al. in Chennai population of South India. Materials and Methods: A sample consisting of 848 individuals (471 males and 377 females) aged between 14 and 30 years was randomly selected for the clinical evaluation and 323 orthopantomograms with clinically missing third molars were taken for radiological evaluation using Demirjian's method from a Chennai population of known chronological age and sex. Statistical analysis was performed using Pearson's Chi-square test and mean values were compared between the study groups using t-test or analysis of variance (ANOVA) followed by Tukey's highly significant difference (HSD). In the present study, P < 0.05 was considered as the level of significance. Results: The results showed that the mean age of having clinically completely erupted maxillary third molars was 22.41 years in male subjects and 23.81 years in female subjects and that of mandibular third molars was 21.49 years in male subjects and 23.34 years in female subjects. Mandibular third molars were clinically missing more often in females than in males. Eruption of mandibular third molars was generally ahead of the emergence of maxillary third molars into the oral cavity. Third molar development between male and female subjects showed statistically significant differences at calcification stage F and stage G in maxillary third molars and stage F in mandibular third molars (P < 0.05). Conclusion: There are differences indicating that maxillary and mandibular third molar eruption reached Demirjian's formation stages earlier in males than in females. It is suggested that in future studies, to increase the accuracy of age determination, indications of sexual maturity and ossification should also be evaluated in addition to third molar mineralization. PMID:25984465

  5. Standard molar enthalpies of formation of three branched alkyl carboxylic acids

    Microsoft Academic Search

    Manuel A. V. Ribeiro da Silva; M. L. C. C. H. Ferrão; Adelina M. R. O. Alves da Silva

    1999-01-01

    The standard (po= 0.1 MPa) molar enthalpies of combustion in oxygen at T= 298.15 K of three branched alkyl chain carboxylic acids, 2-methylpropanoic, 2,2-dimethylpropanoic, and 3-methylbutanoic, were measured by static bomb combustion calorimetry, from which their standard molar enthalpies of formation were derived.The standard molar enthalpies of formation at T= 298.15 K of the gaseous carboxylic acids were derived using

  6. UPPER VS. LOWER MOLARS FOR CEMENTUM ANNULI AGE DETERMINATION OF DEER

    Microsoft Academic Search

    DALE R. McCULLOUGH; PAUL BEIER

    Ages were determined for 23 black-tailed deer (Odocoileus hemionus columbianus) and 14 white-tailed deer (0. virginianus) by examination of cementum annuli of both upper and lower 1st molars. Although estimated ages were virtually the same for both upper and lower molars, the clarity of annuli was significantly greater in upper molars for both species. Abstract: Ages were determined for 23

  7. [The pendulis appliance: a palatal miniscrew supported molar distalization device].

    PubMed

    Nappée-Miévilly, Magali; Nappée, François-Joseph; Kerbrat, Jean-Baptiste; Goudot, Patrick

    2014-09-01

    The maxillary molar distalization is a valuable therapeutic option in some clinical cases. Its biomechanics is challenging and difficult to obtain. Historically, various devices have been described offering successful solutions to this problem such as the Hilgers Pendulum Appliance (1992) and variants linked to mini screws which recently have shown interesting clinical potential. This article presents a new Pendulum variant using a miniscrew, the "pendulis". It follows the original concept (titanium-molybdenum alloy distalization springs and polymethyl-methacrylate pellet) but dental support is replaced by a single palatal miniscrew (median adults, para-median in children) to which the device is fixed by means of a metal welded cap easily positioned and removable by the practitioner. This allows for better control of the oral hygiene and completely controlled extraoral activation. Fabrication steps are described and instruction of use is illustrated with clinical documentation. PMID:25158749

  8. Rotation of rectangular wire in rectangular molar tubes. Part I.

    PubMed

    Raphael, E; Sandrik, J L; Klapper, L

    1981-08-01

    The degree of angular rotation of rectangular orthodontic wires in rectangular molar tubes was measured using a rotatable mechanical stage on a Unitron metallograph and compared to theoretical data. It was found that square 0.016 inch wire did not bind in 0.018 by 0.022 inch or larger mandrel- or inconel-formed tubes, whereas rotations of 11 to 23 degrees were noted in cast tubes of this dimension. Although 0.016 by 0.022 inch wire did bind in these tubes, the degree of rotation was far greater than expected on the basis of theoretical calculations or clinical expectations. The results indicated that it was unrealistic to expect fine control of a few degrees of torque to occur as expected for delicate clinical control. PMID:6943934

  9. Molar uprighting with extrusion for implant site bone regeneration and improvement of the periodontal environment.

    PubMed

    Maeda, Sachiko; Ono, Yoshihiro; Nakamura, Kimio; Kuwahara, Toshiya

    2008-08-01

    This case report describes the treatment of a 55-year-old man who presented with a missing maxillary first molar and mesially inclined neighboring second molar with a severe circumferential bone defect. After bone regeneration therapy with bone grafting, the second molar was uprighted orthodontically to improve the inclination and crown-to-root ratio. These treatments minimized the bone defect and developed a suitable site for an implant in the first molar position. An interdisciplinary approach using periodontal, orthodontic, and prosthodontic treatments can create a more predictable and maintainable situation. PMID:18717376

  10. Appearance of dentin gamma-carboxyglutamic acid-containing proteins in developing rat molars in vitro

    SciTech Connect

    Finkelman, R.D.; Butler, W.T.

    1985-07-01

    An in vitro model of mineralization was devised in order to study the developmental appearance of dentin gamma-carboxyglutamic acid-containing proteins (DGPs) in relation to the onset of mineralization. Maxillary third molars from 11-day-old rats were cultured with or without fetal calf serum (FCS) as modified from Navia et al. Molars were incubated without radiolabel, or with either /sup 45/CaCl/sub 2/ (5 microCi/ml) for 24 hr at various stages of a ten-day culture period or (/sup 3/H)-leucine (10 microCi/ml) for 24 hr at the eighth day of culture. Molars were lyophilized and extracted with 10% formic acid overnight at 4 degrees C. DGPs in extracts were detected by immunologic and chromatographic techniques; DGPs in molar sections were detected by immunolocalization using indirect immunofluorescence. Molar development was evaluated histologically using the Von Kossa staining technique. Molars cultured with FCS showed histologic evidence for mineralized dentin and enamel and a significant increase in /sup 45/Ca uptake after the sixth day in vitro. Eleven-day-old molars in vivo and molars cultured without FCS showed no evidence of the presence of mineralized tissues. (/sup 3/H)-Leucine-labeled DGPs were isolated and identified by affinity and reversed-phase high-performance liquid chromatography and by gel electrophoresis from both mineralized and unmineralized molars. DGP antigens were localized immunohistochemically using rabbit anti-rat antibodies raised against a highly purified DGP preparation. In the unmineralized molar, antigenicity was seen in odontoblasts but not in predentin matrix, preodontoblasts, or in any other cell type. Antigens in the mineralized molar were localized to odontoblasts and dentin.

  11. The influence of impaction to the third molar mineralization in northwestern Chinese population.

    PubMed

    Guo, Yu-cheng; Yan, Chun-xia; Lin, Xing-wei; Zhang, Wen-tao; Zhou, Hong; Pan, Feng; Wei, Lai; Tang, Zheng; Liang, Feng; Chen, Teng

    2014-07-01

    Age estimation by third molar mineralization has been developed for a period of time. Recent studies showed that impaction status has an influence on the rate of the third molar mineralization in Europids and male Black African populations. In this regard, the present study was conducted to determine whether the impaction status could delay the chronological process of third molar mineralization in northwestern Chinese population too. A total of 3,512 digital orthopantomograms of 1,255 male and 2,257 female northwestern Chinese subjects aged from 11 to 26 years were assessed based on the formation stages described by Demirjian et al. with two modifications. Mineralization stage and impaction status were determined for all third molars. Statistical measures were calculated at stages C-H in the male and female gender for both impacted and non-impacted third molars. It was ascertained that the mean ages with impacted third molars at stages C-H were 0.02-1.42 years higher in males and 0.04-1.52 years higher in females than those with non-impacted third molars, but statistical differences were only found at stages C, D, and E in males and stages D and E in females. The probabilities of being under 14, 16, or 18 years of age with non-impacted third molars were all higher than those with impacted third molars. The results prove that impacted third molars show significant slower mineralization than non-impacted ones at stages D and E in both males and females of northwestern Chinese population. It is recommended to consider the influence of impaction on the rate of third molar mineralization for dental age estimation. PMID:24532176

  12. Influence of cervical preflaring on determinationof apical file size in mandibular molars: SEM analysis

    Microsoft Academic Search

    Marcia da Silva Schmitz; Roberto Santos; Alexandre Capelli; Marcos Jacobovitz; Júlio César Emboava Spanó; Jesus Djalma Pécora

    2008-01-01

    This study investigated the influence of cervical preflaring with different rotary instruments on determination of the initial apical file (IAF) in mesiobuccal roots of mandibular molars. Fifty human mandibular molars whose mesial roots presented two clearly separated apical foramens (mesiobuccal and mesiolingual) were used. After standard access opening and removal of pulp tissue, the working length (WL) was determined at

  13. Phase-separation-induced fractionation in molar mass in aqueous mixtures of gelatin and dextran.

    PubMed

    Edelman, M W; Tromp, R H; van der Linden, E

    2003-02-01

    An overview of the effects of phase separation of aqueous mixtures of gelatin and dextran on the fractionation in molar mass of these two components is given. Molar mass distributions in coexisting phases were investigated using size exclusion chromatography with multiangle laser light scattering. The initial molar mass of the native material, concentration, and temperature were varied. The results show a strong fractionation in molar mass for both components. The molar mass of the native material and concentration appeared to be the only factors that affected the final molar mass distributions, temperature having no effect. The results show that in the molar mass range where fractionation is the strongest, i.e., roughly below the maximum in the distribution, fractionation is governed by a Boltzmann factor e(-deltaG/kT), where deltaG denotes the free energy involved in transferring a polymer with a certain length from the enriched to the depleted phase, and in this case turns out to be proportional to the molar mass. Comparison of the results of phase separation with results on dialysis shows that water affinity is not the driving force for the phase separation of gelatin and dextran in aqueous solution. The gelation properties of gelatin in both phases were also determined. The gelation properties of gelatin in the coexisting phases differ from those of native gelatin. In particular, the gelatin in the gelatin-poor phase shows strong differences compared to the native material. PMID:12636676

  14. 40 CFR 1066.610 - Mass-based and molar-based exhaust emission calculations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Mass-based and molar-based exhaust emission...PROCEDURES Calculations § 1066.610 Mass-based and molar-based exhaust emission calculations. (a) Calculate your total mass of emissions over a test cycle as...

  15. 40 CFR 1066.610 - Mass-based and molar-based exhaust emission calculations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Mass-based and molar-based exhaust emission...PROCEDURES Calculations § 1066.610 Mass-based and molar-based exhaust emission calculations. (a) Calculate your total mass of emissions over a test cycle as...

  16. Molar crown formation in the Late Miocene Asian hominoids, Sivapithecus parvada and Sivapithecus indicus

    E-print Network

    Smith, Tanya M.

    Molar crown formation in the Late Miocene Asian hominoids, Sivapithecus parvada and Sivapithecus and geographic perspective on evolutionary devel- opmental biology in Miocene hominoids. Here we report some for the protocone of S. indicus lie within the range of first molar (M1) formation times for the majority of Miocene

  17. A new method to correct lingual rolling of lower molars (Amini twister).

    PubMed

    Amini, Fariborz; Poosti, Maryam

    2013-01-01

    In this report, we present an uncomplicated approach to overcome lingual rolling of mandibular molars during orthodontic treatment, by using rectangular NiTi arch wire in twist fashion through the molar tube. The sequential steps of the twist manoeuvre on a typodont and a case report are exhibited in this article. PMID:23729138

  18. Second mesiobuccal canal detection in maxillary first molars using microscopy and ultrasonics

    Microsoft Academic Search

    Tayfun Alaçam; Ali Cemal Tinaz; Özgür Genç; Guven Kayaoglu

    2008-01-01

    The aim of this study was to investigate whether the use of operating micro- scope in combination with ultrasonics increased the rate of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. A hundred extracted human maxillary first molars were assessed. After location of the main canals, the MB2 canal was sought in all teeth first without microscopy,

  19. Influence of overlay restorative materials and load cusps on the fatigue resistance of endodontically treated molars

    Microsoft Academic Search

    Pascal Magne; Alena Knezevic

    Objectives: To assess the influence of restorative materials and load cusps on the fatigue resistance of endodontically treated molars. Method and Materials: Thirty extracted molars received root canal treatment followed by a standardized tooth preparation (3-mm cuspal reduction and immediate dentin sealing). Twenty Cerec 3 overlays (Sirona Dental Systems) were milled in the ceramic Vita MKII block (Vident; groups MKIIGL

  20. Regenerative therapy in the treatment of maxillary molar Class II furcations: case reports.

    PubMed

    Rosen, P S; Marks, M H; Bowers, G M

    1997-12-01

    This report demonstrates the use of regenerative therapy in the treatment of maxillary molar Class II furcations. The predominant therapy provided was open debridement in combination with DFDBA, e-PTFE membranes, and citric acid root conditioning. Case reports of consecutively treated patients that include radiographs and reentry photographs demonstrate that maxillary molar furcations can be successfully treated with predictability. PMID:9497738

  1. The third molar controversy: Framing the controversy as a public health policy issue

    Microsoft Academic Search

    William G Flick

    1999-01-01

    Purpose: This article summarizes the current research available concerning the removal of impacted third molars, and provides a background from which practitioners, public health policy advocates, and third-party payers can more objectively assess the the issues of appropriateness of care and overutilization of third molar surgery.Materials and Methods: A literature review was undertaken, with emphasis on noninterventional outcome studies and

  2. Pattern of caries experience in permanent molars in a 15-year-old African population.

    PubMed

    Johnson, A S; Gjermo, P

    1989-01-01

    Some epidemiologic studies from Africa report higher DMF values in second than in first molars. It is generally accepted that the maturation of dental enamel influences the susceptibility of teeth to caries. The purpose of the present study was to test the hypothesis that DMF values of second molars will be higher than those of first molars if the first molars have reached a high degree of maturation before being exposed to increased cariogenic challenge. The study was carried out in a group of 15-year-old students attending secondary schools in Botswana (n = 287). The results showed that in children who assumingly had had a traditional diet during childhood the DMF values were higher in second molars than in first molars. In children who grew up in a more urbanized setting, the results were opposite. The observed differences were due to differences in caries experience in first molars only. The DMF values of second molars did not vary among the groups. Oral hygiene, sugar consumption and knowledge level at age 15 seemed to have no effect upon the caries pattern studied. It is concluded that the results support the hypothesis tested. PMID:2598231

  3. Dietary inference from upper and lower molar morphology in platyrrhine primates.

    PubMed

    Allen, Kari L; Cooke, Siobhán B; Gonzales, Lauren A; Kay, Richard F

    2015-01-01

    The correlation between diet and dental topography is of importance to paleontologists seeking to diagnose ecological adaptations in extinct taxa. Although the subject is well represented in the literature, few studies directly compare methods or evaluate dietary signals conveyed by both upper and lower molars. Here, we address this gap in our knowledge by comparing the efficacy of three measures of functional morphology for classifying an ecologically diverse sample of thirteen medium- to large-bodied platyrrhines by diet category (e.g., folivore, frugivore, hard object feeder). We used Shearing Quotient (SQ), an index derived from linear measurements of molar cutting edges and two indices of crown surface topography, Occlusal Relief (OR) and Relief Index (RFI). Using SQ, OR, and RFI, individuals were then classified by dietary category using Discriminate Function Analysis. Both upper and lower molar variables produce high classification rates in assigning individuals to diet categories, but lower molars are consistently more successful. SQs yield the highest classification rates. RFI and OR generally perform above chance. Upper molar RFI has a success rate below the level of chance. Adding molar length enhances the discriminatory power for all variables. We conclude that upper molar SQs are useful for dietary reconstruction, especially when combined with body size information. Additionally, we find that among our sample of platyrrhines, SQ remains the strongest predictor of diet, while RFI is less useful at signaling dietary differences in absence of body size information. The study demonstrates new ways for inferring the diets of extinct platyrrhine primates when both upper and lower molars are available, or, for taxa known only from upper molars. The techniques are useful in reconstructing diet in stem representatives of anthropoid clade, who share key aspects of molar morphology with extant platyrrhines. PMID:25738266

  4. Joubert syndrome: congenital cerebellar ataxia with the “molar tooth”

    PubMed Central

    Romani, Marta; Micalizzi, Alessia; Valente, Enza Maria

    2013-01-01

    Joubert syndrome (JS) is a congenital cerebellar ataxia with autosomal recessive or X-linked inheritance, which diagnostic hallmark is a unique cerebellar and brainstem malformation recognizable on brain imaging, the “molar tooth sign”. Neurological signs are present from neonatal age and include hypotonia evolving into ataxia, global developmental delay, ocular motor apraxia and breathing dysregulation. These are variably associated with multiorgan involvement, mainly of the retina, kidneys, skeleton and liver. To date, 21 causative genes have been identified, all encoding for proteins of the primary cilium or its apparatus. This is a subcellular organelle that plays key roles in development and in many cellular functions, making JS part of the expanding family of ciliopathies. There is marked clinical and genetic overlap among distinct ciliopathies, which may co-occur even within families. Such variability is likely explained by an oligogenic model of inheritance, in which mutations, rare variants and polymorphisms at distinct loci interplay to modulate the expressivity of the ciliary phenotype. PMID:23870701

  5. Molar crown inner structural organization in Javanese Homo erectus.

    PubMed

    Zanolli, Clément

    2015-01-01

    This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia. PMID:25209431

  6. Use of opioid pain relievers following extraction of third molars.

    PubMed

    Weiland, Breanna M; Wach, Anthony G; Kanar, Brent P; Castele, Matthew T; Sosovicka, Mark F; Cooke, Matthew R; Moore, Paul A

    2015-02-01

    Following extraction of third molars, it is common practice for oral and maxillofacial surgeons to provide a prescription for an opioid-containing analgesic such as hydrocodone with acetaminophen. Because the instructions for use most often indicate that these analgesics are to be taken "as needed for pain," it is unknown how many of the prescribed postoperative analgesic tablets are needed and actually taken. Therefore, an assessment of patient pain experiences and actual opioid analgesic usage was carried out using structured telephone interviews of patients performed 1 and 7 days following their thirdmolar extraction surgery. Forty-eight adolescents and young adults, ages 15 to 30 years, participated in this assessment. A review of the surgeon's notes indicated that the median number of prescribed opioid-containing analgesics (ie, Vicodin®, Norco®, Lorcet®, Percocet®) was 20 tablets (range 10 to 40). The median consumption during the first 24 hours was reported to be three tablets (range 0 to 10), and the total consumption for all 7 days was eight tablets (range 0 to 34). Four patients reported nausea or vomiting in the first 24 hours, and six patients reported nausea or vomiting during the following 6 days of recovery. The initial prescriptions provided adequate relief for 45 of the 48 patients. Higher consumption of opioid pain relievers (OPRs) was associated with a longer duration of surgery and the occurrence of postoperative infections. PMID:25822637

  7. How many patients have third molars and how many have one or more asymptomatic, disease-free third molars?

    PubMed

    Dodson, Thomas B

    2012-09-01

    The purpose of this report was to summarize the frequencies of third molars (M3s) in general and asymptomatic, disease-free M3s specifically. Estimates of M3 prevalence range so widely (ie, 6.0% to 96%) as to be of little use. The estimates vary depending on definitions, age, clinical versus radiographic assessment, and patient versus population samples. For patient management, it may be more valuable to estimate the prevalence of M3s grouped by clinical rather than anatomic status. Many times, however, M3s are categorized simply as asymptomatic. In many pathologic processes, from cancer to cardiovascular disease, the term asymptomatic does not equal an absence of disease. As such, M3s should be categorized based on symptom and disease status. Subjects with all M3s asymptomatic and absent of disease ranged from 12% in a sample of patients referred for M3 evaluation to 29% in a nonpatient volunteer sample. In the patient sample, 37% of the M3s evaluated were asymptomatic and free of disease. PMID:22916698

  8. Name: Seetin Question: In patients with mixed dentition, who have lost a single primary 2nd molar and require space

    E-print Network

    Goldman, Steven A.

    Name: Seetin Question: In patients with mixed dentition, who have lost a single primary 2nd molar, comparison, outcome) P: Mixed dentition, lost single primary 2nd molar I: Unilateral space maintainer

  9. Analysis of quantitative trait locus effects on the size and shape of mandibular molars in mice.

    PubMed Central

    Workman, Michael Scott; Leamy, Larry J; Routman, Eric J; Cheverud, James M

    2002-01-01

    While >50 genes have been found to influence the development of teeth in mice, we still know very little about the genetic basis for the adaptive characteristics of teeth, such as size and shape. We applied interval mapping procedures to Procrustes size and shape data obtained from 10 morphological landmarks on the mandibular molar row of the F(2) progeny from a cross between the LG/J and SM/J strains of mice. This revealed many more QTL for molar shape (18) than for molar centroid size (3), although levels of dominance effects were comparable among QTL for size and shape. Comparisons of patterns of Procrustes additive and dominance shape effects and ordination of QTL effects by principal components analysis suggested that the effects of the shape QTL were dispersed among the three molars and thus that none of these molars represents a genetically distinct developmental structure. The results of an analysis of co-occurrence of QTL for molar shape, mandible shape, and cranial dimensions in these mice suggested that many of the QTL for molar shape may be the same as those affecting these other sets of characters, although in some cases this could be due to effects of closely linked genes. PMID:11973311

  10. National clinical guidelines for the extraction of first permanent molars in children.

    PubMed

    Cobourne, M T; Williams, A; Harrison, M

    2014-12-01

    This article summarises recently updated guidelines produced by the Clinical Governance Directorate of the British Orthodontic Society through the Clinical Standards Committee of the Faculty of Dental Surgery, Royal College of Surgeons of England (FDSRCS) on the extraction of first permanent molars in children. The first permanent molar is susceptible to chronological enamel defects, molar-incisor hypomineralisation and caries, which may necessitate enforced extraction in the developing dentition. In the right circumstances, the extraction of these teeth can be followed by successful eruption of the second permanent molar and ultimately, third molar eruption to complete the molar dentition. For this reason, elective extraction of first permanent molars with a questionable long-term prognosis should be considered when planning enforced extractions. However, a number of factors can influence the decision-making process, including the necessity for a general anaesthetic to allow extraction, potential cooperation with restorative or orthodontic treatment and likely future preventative practice within the family. Moreover, the presence of any underlying malocclusion also needs to be evaluated within the context of extraction planning. The current available evidence has been evaluated and awarded a grade based upon those recommended by the Scottish Intercollegiate Guidelines Network. PMID:25476643

  11. Non Syndromic Bilateral Microdontia of Maxillary Second Molars: A Very Rare Finding

    PubMed Central

    Chander, Subhash; Ahluwalia, Amrit Singh; Chinna, Harleen

    2015-01-01

    Dental anomalies are the formative defects caused by genetic disturbances or environmental factors during tooth morphogenesis. The term microdontia is defined as the condition of having abnormally small teeth. Clinically, microdontia in the permanent dentition, excluding the third molars, is found in 0.8-8.4% of the population. One of the commonest forms of localized microdontia is that which affects the maxillary lateral incisor, a condition called Peg laterals. The next tooth which can be affected is the third molars. Few cases of microdontia in canines have been reported. Localised microdontia of maxillary second molar has never been reported in literature before. PMID:26023663

  12. Endodontic Management of Maxillary First Molar with Type I Canal Configuration– A Rare Case Report

    PubMed Central

    Desai, Niranjan; Raghavendra, Srinidhi Surya; Mittal, Priya; Patil, Gururaj

    2015-01-01

    Thorough knowledge about the root canal variations is essential for the predictable endodontic treatment outcome. The root and root canal anatomy of maxillary first molar varies greatly. A Pub-med literature search about single rooted single canalled maxillary first molar was done to know its details such as incidence, diagnostic method used, age, sex and ethnic background of patient. This article presented report of a single rooted single canalled maxillary first molar in a 27-year-old healthy Asian female. PMID:26023655

  13. Non syndromic bilateral microdontia of maxillary second molars: a very rare finding.

    PubMed

    Hans, Manoj Kumar; Chander, Subhash; Ahluwalia, Amrit Singh; Chinna, Harleen

    2015-04-01

    Dental anomalies are the formative defects caused by genetic disturbances or environmental factors during tooth morphogenesis. The term microdontia is defined as the condition of having abnormally small teeth. Clinically, microdontia in the permanent dentition, excluding the third molars, is found in 0.8-8.4% of the population. One of the commonest forms of localized microdontia is that which affects the maxillary lateral incisor, a condition called Peg laterals. The next tooth which can be affected is the third molars. Few cases of microdontia in canines have been reported. Localised microdontia of maxillary second molar has never been reported in literature before. PMID:26023663

  14. Endodontic management of maxillary first molar with type I canal configuration- a rare case report.

    PubMed

    Desai, Niranjan; Jadhav, Ganesh Ranganath; Raghavendra, Srinidhi Surya; Mittal, Priya; Patil, Gururaj

    2015-04-01

    Thorough knowledge about the root canal variations is essential for the predictable endodontic treatment outcome. The root and root canal anatomy of maxillary first molar varies greatly. A Pub-med literature search about single rooted single canalled maxillary first molar was done to know its details such as incidence, diagnostic method used, age, sex and ethnic background of patient. This article presented report of a single rooted single canalled maxillary first molar in a 27-year-old healthy Asian female. PMID:26023655

  15. Age at first molar emergence in early Miocene Afropithecus turkanensis and life-history evolution in the Hominoidea

    Microsoft Academic Search

    Jay Kelley; Tanya M. Smith

    2003-01-01

    Among primates, age at first molar emergence is correlated with a variety of life history traits. Age at first molar emergence can therefore be used to broadly infer the life histories of fossil primate species. One method of determining age at first molar emergence is to determine the age at death of fossil individuals that were in the process of

  16. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...use its respective mean C d and other constants you determined according to § 1065.640 and calculate its molar flow rate n...venturis, you may use its respective mean, K v , and other constants you determined...

  17. Influence of the carrier gas molar mass on the particle formation in a vapor phase.

    PubMed

    Braun, S; Römer, F; Kraska, T

    2009-08-14

    The influence of the molar mass of a carrier gas on the formation of nanoparticles in the vapor phase is investigated. The function of the carrier gas atmosphere is the regulation of the particle temperature by collisions with the cluster surface. The aim of this work is to optimize the carrier gas in a simulation in order to mimic a large amount of carrier gas atoms by few gas atoms with effective parameters. In this context the efficiency of the heat exchange with the carrier gas depending on its molar mass is analyzed. As a result one finds for varying molar masses and unchanged interaction parameters a competition between the efficiency and the number of the collisions. For too small molar masses the energy exchange per collision is too small while for too high masses the carrier gas atoms become very slow, decreasing the number of collisions. PMID:19691389

  18. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...s (c) CFV molar flow rate. Some CFV flow meters consist of a single venturi and some consist of multiple venturis, where different combinations of venturis are used to meter different flow rates. If you use multiple venturis and...

  19. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...s (c) CFV molar flow rate. Some CFV flow meters consist of a single venturi and some consist of multiple venturis, where different combinations of venturis are used to meter different flow rates. If you use multiple venturis and...

  20. Accidental Displacement of Third Molar into the Sublingual Space: a Case Report

    PubMed Central

    Garcia, Robson Rodrigues; Botelho, Tessa Lucena; Franco, Ademir; Silva, Rhonan Ferreira

    2014-01-01

    ABSTRACT Background Successful extraction of third molars depends on preoperative diagnosis and planning. Gold standard preoperative examinations are performed through computed tomography, decreasing risks and avoiding potential accidents. The present report highlights the value of preoperative examinations in face of accidentally displaced third molars. Methods An 18-years-old female patient underwent a third mandibular molar extraction with a general dentist. Accidentally, the mandibular left third molar was displaced into the sublingual space, making necessary a second surgical step. The surgery was interrupted and the patient was referred to an expert in maxillofacial surgery. Results After 21 days awaiting an asymptomatic health status, the second surgical step was successfully performed using multislice computed tomography as preoperative imaging guide. Conclusions The present case report highlights the clinical usefulness of imaging planning and informed consents in face of legal and ethic potential complaints. PMID:25386232

  1. How Many Digits Should We Use in Formula or Molar Mass Calculations?

    ERIC Educational Resources Information Center

    Svensson, Christer

    2004-01-01

    The calculations of uncertainties in the formula or molar masses of compounds are streamlined. Three rules of increasing complexity are proposed, which overestimate the uncertainty so there is little if any risk that the true values are missed.

  2. Identification of a nonsense mutation in the PAX9 gene in molar oligodontia.

    PubMed

    Nieminen, P; Arte, S; Tanner, D; Paulin, L; Alaluusua, S; Thesleff, I; Pirinen, S

    2001-10-01

    Development of dentition is controlled by numerous genes, as has been shown by experimental animal studies and mutations that have been identified by genetic studies in man. Here we report a nonsense mutation in the PAX9 gene that is associated with molar tooth agenesis in a Finnish family. The A340T transversion creates a stop codon at lysine 114, and truncates the coded PAX9 protein at the end of the DNA-binding paired-box. All the affected members of the family were heterozygous for the mutation. The tooth agenesis phenotype involves all permanent second and third molars and most of the first molars and resembles the earlier reported phenotype that was also associated with a PAX9 mutation. The phenotype is presumably a consequence of haploinsufficiency of PAX9. In another Finnish family with molar tooth agenesis, we could not find similar sequence changes in PAX9. PMID:11781684

  3. Influence of the carrier gas molar mass on the particle formation in a vapor phase

    NASA Astrophysics Data System (ADS)

    Braun, S.; Römer, F.; Kraska, T.

    2009-08-01

    The influence of the molar mass of a carrier gas on the formation of nanoparticles in the vapor phase is investigated. The function of the carrier gas atmosphere is the regulation of the particle temperature by collisions with the cluster surface. The aim of this work is to optimize the carrier gas in a simulation in order to mimic a large amount of carrier gas atoms by few gas atoms with effective parameters. In this context the efficiency of the heat exchange with the carrier gas depending on its molar mass is analyzed. As a result one finds for varying molar masses and unchanged interaction parameters a competition between the efficiency and the number of the collisions. For too small molar masses the energy exchange per collision is too small while for too high masses the carrier gas atoms become very slow, decreasing the number of collisions.

  4. A geometric morphometric analysis of hominin lower molars: Evolutionary implications and overview of postcanine dental variation.

    PubMed

    Gómez-Robles, Aida; Bermúdez de Castro, José María; Martinón-Torres, María; Prado-Simón, Leyre; Arsuaga, Juan Luis

    2015-05-01

    Lower molars have been extensively studied in the context of hominin evolution using classic and geometric morphometric analyses, 2D and 3D approaches, evaluations of the external (outer enamel surface) and internal anatomy (dentine, pulp chamber, and radicular canals), and studies of the crown and root variation. In this study, we present a 2D geometric morphometric analysis of the crown anatomy of lower first, second, and third molars of a broad sample of hominins, including Pliocene and Lower, Middle, and Upper Pleistocene species coming from Africa, Asia, and Europe. We show that shape variability increases from first to second and third molars. While first molars tend to retain a relatively stable 5-cusped conformation throughout the hominin fossil record, second and third molars show marked distal reductions in later Homo species. This trend to distal reduction is similar to that observed in previous studies of premolars and upper second and third molars, and points to a correlated reduction of distal areas across the whole postcanine dentition. Results on lower molar variation, as well as on other postcanine teeth, show certain trends in European Pleistocene populations from the Atapuerca sites. Middle Pleistocene hominins from Sima de los Huesos show Neanderthal affinities and strong dental reduction, especially in the most distal molars. The degree of dental reduction in this population is stronger than that observed in classic Neanderthals. Homo antecessor hominins from Gran Dolina-TD6 have primitive lower teeth that contrast with their more derived upper teeth. The evolutionary implications of these dental affinities are discussed in light of recent paleogenetic studies. PMID:25840859

  5. Intrusion of an overerupted molar using orthodontic miniscrew implant: A preprosthodontic therapy

    PubMed Central

    Sivakumar, Indumathi; Sivakumar, Arunachalam

    2014-01-01

    The purpose of this case report is to demonstrate the use of orthodontic miniscrew implant in the intrusion of overerupted molar as a preprosthodontic therapy. A 37-year-old woman with an overerupted maxillary right first molar encroaching on the opposing mandibular edentulous space was successfully intruded using a single miniscrew implant and partial fixed orthodontic appliance. The prosthodontic clinician may adopt this conservative and cost-effective strategy in their routine practice and avoid clinical crown reduction. PMID:25191088

  6. Third molars in the establishment of adult status--a case report.

    PubMed

    Nambiar, P; Yaacob, H; Menon, R

    1996-12-01

    Teeth are the most durable structures in the human body. The timing and sequence of their development, as contained in dental development charts, have been used as valid criteria for age determination. The third molars however are the last teeth to erupt and are regarded as the most variable in the dentition. Age estimation in a legal context, using developing third molars must be carefully applied otherwise justice may miscarry. A case of wrongful use of the technique is presented here. PMID:9227080

  7. Standard molar enthalpy of formation of 4-iodobenzoic acid by static and rotating-bomb calorimetry

    Microsoft Academic Search

    M. A. V. Ribeiro da Silva; M. L. C. C. H. Ferrão; I. M. S. Costa

    1999-01-01

    The standard (po= 0.1 MPa) molar enthalpy of combustion of 4-iodobenzoic acid, at T= 298.15 K, was measured by static-bomb and rotating-bomb calorimetry, from which the standard molar enthalpy of formation, in the crystalline state, was derived.The values obtained confirm that 4-iodobenzoic acid is a satisfactory test substance for combustion of organo-iodine compounds. Using a literature value for its standard

  8. MOLAR: adaptive runtime support for high-end computing operating and runtime systems

    Microsoft Academic Search

    Christian Engelmann; Stephen L. Scott; David E. Bernholdt; Narasimha R. Gottumukkala; Chokchai Leangsuksun; Jyothish S. Varma; Chao Wang; Frank Mueller; Aniruddha G. Shet; Ponnuswamy Sadayappan

    2006-01-01

    http:\\/\\/www.fastos.org\\/molar ABSTRACT MOLAR is a multi-institutional research eort that con- centrates on adaptive, reliable, and ecient operating and runtime system (OS\\/R) solutions for ultra-scale, high-end scientific computing on the next generation of supercom- puters. This research addresses the challenges outlined in FAST-OS (forum to address scalable technology for runtime and operating systems) and HECRTF (high-end computing revitalization task force) activities

  9. Sinus augmentation at the time of molar tooth removal: modification of jensen technique.

    PubMed

    Block, Michael S

    2015-06-01

    When a maxillary molar tooth needs to be removed, the treatment plan often includes subsequent dental implant placement. However, there may be less than 5 mm of bone available in the central fossa region of the proposed implant site. This report describes a technique to use a precise osteotomy within the maxillary molar socket to mobilize a segment of bone and superiorly raise it to provide increased alveolar bone height using grafting. This technique eliminates the need for lateral window surgery. PMID:25659359

  10. Determination of the anti-inflammatory effects of methylprednisolone on the sequelae of third molar surgery

    Microsoft Academic Search

    Emin Esen; Ferda Ta?ar; Okan Akhan

    1999-01-01

    Purpose: The anti-inflammatory effect and adrenal suppressive side effect of methylprednisolone sodium succinate (MP) on the postoperative sequelae of third molar surgery were evaluated using objective methods in a double-blind, crossover study.Patients and Methods: Twenty patients who were to undergo surgical removal of bilateral, symmetrically placed lower third molars were studied. Each patient was given 125 mg MP intravenously before

  11. Mandibular molar root morphology in Neanderthals and Late Pleistocene and recent Homo sapiens.

    PubMed

    Kupczik, Kornelius; Hublin, Jean-Jacques

    2010-11-01

    Neanderthals have a distinctive suite of dental features, including large anterior crown and root dimensions and molars with enlarged pulp cavities. Yet, there is little known about variation in molar root morphology in Neanderthals and other recent and fossil members of Homo. Here, we provide the first comprehensive metric analysis of permanent mandibular molar root morphology in Middle and Late Pleistocene Homo neanderthalensis, and Late Pleistocene (Aterian) and recent Homo sapiens. We specifically address the question of whether root form can be used to distinguish between these groups and assess whether any variation in root form can be related to differences in tooth function. We apply a microtomographic imaging approach to visualise and quantify the external and internal dental morphologies of both isolated molars and molars embedded in the mandible (n=127). Univariate and multivariate analyses reveal both similarities (root length and pulp volume) and differences (occurrence of pyramidal roots and dental tissue volume proportion) in molar root morphology among penecontemporaneous Neanderthals and Aterian H. sapiens. In contrast, the molars of recent H. sapiens are markedly smaller than both Pleistocene H. sapiens and Neanderthals, but share with the former the dentine volume reduction and a smaller root-to-crown volume compared with Neanderthals. Furthermore, we found the first molar to have the largest average root surface area in recent H. sapiens and Neanderthals, although in the latter the difference between M(1) and M(2) is small. In contrast, Aterian H. sapiens root surface areas peak at M(2). Since root surface area is linked to masticatory function, this suggests a distinct occlusal loading regime in Neanderthals compared with both recent and Pleistocene H. sapiens. PMID:20719359

  12. Investigation on the utility of permanent maxillary molar cusp areas for sex estimation

    Microsoft Academic Search

    P. James Macaluso Jr

    2011-01-01

    Digital photogrammetric methods were employed to assess the level of sexual dimorphism present in permanent maxillary molar\\u000a cusp areas of black South Africans (130 males, 105 females). Odontometric standards were then developed for diagnosing sex,\\u000a based on the cusp area data derived for these teeth. Results demonstrated that all cusp area measurements of both the first\\u000a and second maxillary molars

  13. Occlusal morphology of permanent mandibular first and second molars in Gujarati population

    PubMed Central

    Dholia, Bhavik; Manjunatha, Bhari Sharanesha

    2015-01-01

    Background: Dental identification has been used since long time for disaster victim identification protocol. There is a difference of opinion regarding whether ethnicity influences dental morphology or not. Few studies have shown the associations between these dental features and crown traits in humans using quantitative methods. The present study is an attempt to find correlation of occlusal morphology of Gujarati population with forensic Odontology. Aim: To study different occlusal morphology of permanent mandibular first and second molars in Gujarati Population. Materials and Methods: This study comprised of a total of 100 participants of Gujarati origin, selected by random sampling method. Total number of cusps and groove patterns of mandibular first and second molar were examined clinically and photographs of the same were taken. A descriptive statistics, Chi-square test and Student t-test were used for analysis of data. Results: Mandibular first molar with 5 cusps in 71%, 4 cusps in 18% and 6 cusps in 11% were noted in the study. Mandibular first molars with “+” groove pattern in 39.5% and “Y” groove pattern in 60.5% were recorded. Mandibular second molar with 5 cusps in 6.5% and 4 cusps in 93.5% were recorded in the study. Mandibular second molars with “+” groove pattern in 93.5% and “Y” groove pattern in 6.5% were recorded. Conclusion: The most common occlusal morphology in permanent mandibular first molar is “5 cusp” and “Y” groove pattern in about 47% and for second molar is “4 cusp” and “+” groove pattern in 88.5% of Gujarati population. It may be concluded that variation in degree of expression and frequency of teeth in dentitions of different populations is different, which may help in forensic identification. PMID:26005303

  14. A novel chitin binding crayfish molar tooth protein with elasticity properties.

    PubMed

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D; Sagi, Amir

    2015-01-01

    The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties. PMID:26010981

  15. A reliable method for evaluating upper molar distalization: Superimposition of three-dimensional digital models

    PubMed Central

    Nalcaci, Ruhi; Bicakci, Ali Altug; Ozturk, Firat; Babacan, Hasan

    2015-01-01

    Objective The aim of this study was to evaluate the reliability of measurements obtained after the superimposition of three-dimensional (3D) digital models by comparing them with those obtained from lateral cephalometric radiographs and photocopies of plaster models for the evaluation of upper molar distalization. Methods Data were collected from plaster models and lateral cephalometric radiographs of 20 Class II patients whose maxillary first molars were distalized with an intraoral distalizer. The posterior movements of the maxillary first molars were evaluated using lateral cephalometric radiographs (group CP), photocopies of plaster models (group PH), and digitized 3D models (group TD). Additionally, distalization and expansion of the other teeth and the degrees of molar rotation were measured in group PH and group TD and compared between the two groups. Results No significant difference was observed regarding the amount of molar distalization among the three groups. A comparison of the aforementioned parameters between group PH and group TD did not reveal any significant difference. Conclusions 3D digital models are reliable to assess the results of upper molar distalization and can be considered a valid alternative to conventional measurement methods. PMID:25798414

  16. Evaluation of radius of gyration and intrinsic viscosity molar mass dependence and stiffness of hyaluronan.

    PubMed

    Mendichi, Raniero; Soltés, Ladislav; Giacometti Schieroni, Alberto

    2003-01-01

    Nine hyaluronan (HA) samples were fractionated by size-exclusion chromatography, and molar mass (M), radius of gyration (Rg), and intrinsic viscosity ([eta]) were measured in 0.15 M NaCl at 37 degrees C by on-line multiangle light scattering and viscometer detectors. Using such method, we investigated the Rg and [eta] molar mass dependence for HA over a very wide range of molar masses: M ranging from 4 x 10(4) to 5.5 x 10(6) g/mol. The Rg and the [eta] molar mass dependence found for HA showed a meaningful difference. The Rg = f(M) power law was substantially linear in the whole range of molar masses explored with a constant slope of 0.6. In contrast, the [eta] = f(M) power law (Mark-Houwink-Sakurada plot) showed a marked curve shape, and a linear regression over the whole range of molar masses does not make sense. Also the persistence length (stiffness) for HA was estimated. The persistence length derived by using both the Odijk's model (7.5 nm from Rg vs M data) and the Bohdanecky's plot (6.8 nm from [eta] vs M data) were quite similar. These persistence length values are congruent with a semistiff conformation of HA macromolecules. PMID:14606912

  17. An in vitro assessment of type, position and incidence of isthmus in human permanent molars

    PubMed Central

    de LIMA, Fernando José Camello; MONTAGNER, Francisco; JACINTO, Rogério Castilho; AMBROSANO, Glaucia Maria Bovi; GOMES, Brenda Paula Figueiredo de Almeida

    2014-01-01

    Root canal anatomical complexities, such as isthmus, may limit the action of the endodontic instruments, irrigant solutions and intracanal medications, leading to endodontic treatment failure. Objectives This in vitro study assessed the type, position and incidence of isthmus in human permanent molars. Material and Methods One hundred and twenty eight upper and lower first and second permanent molars were analyzed. The roots were embedded in transparent resin, and then split at different distances from the apex (1.0-2.5-4.0-5.5-7.0 mm). Following the sample examination in stereomicroscope, the data were submitted to chi-square statistical test at a 5% significance level. Results The highest isthmus incidence was at 7.0 mm from the root apex in all samples, except the distal root of lower molars (at 5.5 mm). In upper and lower molars, type V (complete isthmus with a continuous opening between the two main root canals) was the most common classification of isthmus (28.8%). In the mesial root of first and second mandibular molars, type IV had the highest incidence (36% and 23.9%, respectively). Conclusion It was concluded that isthmus was widely found in flat roots, with a low percentage in areas close to the apex. In upper and lower molars, these structures were most frequently found at 7 mm from the apex. PMID:25141198

  18. Sharp mandibular bone irregularities after lower third molar extraction: Incidence, clinical features and risk factors

    PubMed Central

    Alves-Pereira, Daniela; Valmaseda-Castellón, Eduard; Laskin, Daniel M.; Berini-Aytés, Leonardo; Gay-Escoda, Cosme

    2013-01-01

    Objectives: The purpose of this study was to determine the incidence and clinical symptoms associated with sharp mandibular bone irregularities (SMBI) after lower third molar extraction and to identify possible risk factors for this complication. Study Design: A mixed study design was used. A retrospective cohort study of 1432 lower third molar extractions was done to determine the incidence of SMBI and a retrospective case-control study was done to determine potential demographic and etiologic factors by comparing those patients with postoperative SMBI with controls. Results: Twelve SMBI were found (0.84%). Age was the most important risk factor for this complication. The operated side and the presence of an associated radiolucent image were also significantly related to the development of mandibular bone irregularities. The depth of impaction of the tooth might also be an important factor since erupted or nearly erupted third molars were more frequent in the SMBI group. Conclusions: SMBI are a rare postoperative complication after lower third molar removal. Older patients having left side lower third molars removed are more likely to develop this problem. The treatment should be the removal of the irregularity when the patient is symptomatic. Key words:Third molar, postoperative complication, bone irregularities, age. PMID:23524429

  19. Revolution vs status quo? Non-intervention strategy of asymptomatic third molars causes harm.

    PubMed

    Toedtling, V; Yates, J M

    2015-07-10

    The Faculty of Dental Surgery of the Royal College of Surgeons of England has prompted the National Institute for Health and Care Excellence to urgently re-assess the TA1 guidance on extractions of wisdom teeth and highlighted required amendments to the present version in light of published evidence concerning the harm caused by wisdom tooth retention. This article seeks to address the recent concerns relating the increasing frequency of distal-cervical caries in lower second molar teeth when associated with asymptomatic partially erupted mesial or horizontal impacted mandibular third molars. Such acute angle impactions are classified as partially erupted when one of the third molar cusps breached the epithelial attachment of the distal aspect of the second molar, thus prevents the formation of a gingival seal. At its earliest stage the wisdom tooth appears clinically absent or unerupted, yet histologically the architecture of the gingival epithelium has been disrupted allowing ingress of microbes, demineralisation and succeeding cavitation to take place on the distal aspect of the second molar. We hope to highlight the difficulties faced in addressing this growing clinical problem and encourage clinicians to re-evaluate their own caries risk assessment and caries prevention strategy in relation to mesial and horizontal third molar extractions. PMID:26159975

  20. A Novel Chitin Binding Crayfish Molar Tooth Protein with Elasticity Properties

    PubMed Central

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D.; Sagi, Amir

    2015-01-01

    The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties. PMID:26010981

  1. Morphologic and Demographic Predictors of Third Molar Agenesis: A Systematic Review and Meta-analysis.

    PubMed

    Carter, K; Worthington, S

    2015-07-01

    We aimed to consolidate all available data on worldwide third molar agenesis frequencies, with a particular emphasis on exploring the factors leading authors to find contradictory results for the demographic and morphologic predictors of this anomaly. A total of 12,376 studies were originally identified, then narrowed down to 1,312 for title/abstract screening. On the basis of our inclusion and exclusion criteria, we selected 92 studies, containing 100 effect sizes and 63,314 subjects, for systematic review and metaregression. The worldwide rate of agenesis was found to be 22.63% (95% confidence interval = 20.64% to 24.76%), although the estimates ranged from 5.32% to 56.0%. Our subgroup analyses revealed that women are 14% more likely than men to have agenesis of ?1 third molars and that maxillary agenesis was 36% more likely than mandibular agenesis in both sexes. Furthermore, we found that having agenesis of 1 or 2 molars was most common, while agenesis of 3 or 4 molars was least common. Finally, we found large differences among agenesis frequency depending on geographic region. This information is expected to be of use not only to clinicians and patients but also to policy makers, given the implications for third molar extraction protocols. PMID:25883107

  2. Gender Determination Using Diagonal Measurements of Maxillary Molar and Canine Teeth in Davangere Population

    PubMed Central

    Tarigoppula, Ratna Kumari V. N.; Kulkarni, Pavan G; BS, Anil

    2014-01-01

    Background: Mesiodistal and buccolingual measurements of the teeth have been the traditional means of determining gender which sometimes are difficult to measure. Aims and Objectives: To assess the degree of sexual dimorphism in upper permanent canines and first molars using diagonal diameters and to evaluate the applicability of diagonal measurements in sex determination. Materials and Methods: Mesiobuccal-distolingual (MBDL) and distobuccal-mesiolingual (DBML) measurements of the crown and cervix of maxillary canine and maxillary molar were taken using digital vernier callipers in 100 upper dental casts obtained from 50 males and 50 females of the age group of 17-25 y. Results: With step wise discriminant function analysis, results were statistically significant with males showing higher diagonal measurement values. The classification accuracy for males was 69% and in females was 73% with overall accuracy of 71%. Results showed that canines exhibited highest accuracy with cervical measurements being more dimorphic. MBDL measurements were found to be more reliable. Most dimorphicmeasurements included right molar cervical MBDL, left molar cervical MBDL followed by right and left molar crown MBDL. Conclusion: In cases of tooth rotations, crowding, certain fillings and attritions where traditional mesio-distal and bucco-lingual measurements are not applicable, diagonal measurements could be of help in predicting gender. PMID:25584308

  3. Cysts in Periradicular Region of Deciduous Molars in Mixed Dentition: Retrospective Study of Five Cases

    PubMed Central

    Chavan, Ankush; Wadde, Kavita; Dewalwar, Vishal

    2014-01-01

    ABSTRACT% The cyst in mixed dentition stage cause expansion of buccal cortex, displacement of teeth and may present as case of infection. The cyst in periradicular region of deciduous molar are of frequent occurrence. The differential diagnosis of this lesion is radicular cysts of deciduous molar: developmental or infammatory dentigerous cyst of corresponding unerupted premolar. After going through the available literature of radicular cyst of deciduous molars and dentigerous cysts of developing premolars in mixed dentition we studied the five cases of cyst in periradicular region of deciduous molars in mixed dentition retrospectively for the diagnostic dilemma of radicular cyst verses dentigerous cyst. In conclusion, we can set some criteria for the diagnosis which is particularly important for treatment and for conservation of developing premolar. How to cite this article: Manekar VS, Chavan A, Wadde K, Dewalwar V. Cysts in Periradicular Region of Deciduous Molars in Mixed Dentition: Retrospective Study of Five Cases. Int J Clin Pediatr Dent 2014;7(3):229-235. PMID:25709310

  4. Containing the cost of third-molar extractions: a dilemma for health insurance.

    PubMed Central

    Friedman, J W

    1983-01-01

    No known scientific studies support the extraction of third molars (wisdom teeth) to prevent future disease. Yet, third-molar surgery for this purpose has become so common that in at least one major U.S. health insurance plan, the cumulative cost exceeds that for every other kind of major surgery. Many third molars that are developing normally in adolescents are classified as impacted and removed before they erupt, a practice that results in large expenditures for unnecessary surgery. In addition, the difficulty of the extractions is frequently exaggerated, so that patients and insurance plans are overcharged. Third molar surgery is not without risk of iatrogenic injury. Fracture of the jaw, permanent numbness of the lip (paresthesia), and injury to other teeth may occur. This paper presents a mechanism for containing the cost of third-molar surgery by elimination of payment for nonessential extractions and of the related overcharges. Adoption of this policy by administrators of dental insurance plans would save millions of dollars each year, money that could be better used in providing care for more people with real dental disease. PMID:6611824

  5. Endodontic treatment of mandibular molars with atypical root canal anatomy: reports of 4 cases.

    PubMed

    Chauhan, Raju; Singh, Shweta

    2015-01-01

    The variations in root canal anatomy of multirooted teeth represent a continuous challenge to endodontic diagnosis and treatment. Although the most common configuration of mandibular molars is one containing 2 roots and 3 root canals, there are many different combinations. Very rarely, an additional third (supernumerary) root is seen. When it is located distolingually to the main distal root, this third root is called radix entomolaris (RE), and when it is located mesiobuccally to the mesial root, it is called radix paramolaris (RP). Variations of root canal systems need not always be in the form of extra roots or extra canals. Single roots with single canals can also occur. A general dentist should be aware of these unusual root canal morphologies in mandibular molars for the success of endodontic treatment. These case reports describe the root canal treatment of a case of RE in the mandibular first molar, 2 rare cases of RP (1 each in the mandibular first and second molars), and a mandibular second molar with a single root and root canal. PMID:25945768

  6. Studies of the chronological course of third molars eruption in a northern Chinese population.

    PubMed

    Guo, Yu-cheng; Yan, Chun-xia; Lin, Xing-wei; Zhou, Hong; Pan, Feng; Wei, Lai; Tang, Zheng; Liang, Feng; Chen, Teng

    2014-09-01

    Dental age estimation is of great importance for individual identification in forensic medicine and many other fields of study. Among them, tooth eruption is a parameter developmental morphology that can be determined by clinical examinations or by dental X-rays. The purpose of present research is to study the chronological course of third molars eruption in a Chinese population and compare that with other ethnic population for age estimation. A total of 1135 conventional orthopantomograms from 506 male and 629 female northern Chinese subjects aged between 11 and 26 years were analyzed. The eruption status of the third molars was assessed using the developmental stages described by Olze et al. Results showed that the third molars 18, 28, 38 and 48 in the stage A showed significant younger average age in males than in females. The Olze's stage A could be used as a reference stage to determine whether a male or female northern Chinese is likely to be equal or above age 16, with 99.6-100% and 97.4-98.1% of correct predictions, respectively. The stage D was found to be a useful marker for diagnosing age under 16 years, with 98.9-100% and 100% of correct predictions in males and females, respectively. There were some significant differences of the chronological course of the third molars eruption in different ethnic groups, which indicated that population-specific standards could enhance the accuracy of forensic age estimation based on third molar eruption. PMID:24907520

  7. Evc regulates a symmetrical response to Shh signaling in molar development.

    PubMed

    Nakatomi, M; Hovorakova, M; Gritli-Linde, A; Blair, H J; MacArthur, K; Peterka, M; Lesot, H; Peterkova, R; Ruiz-Perez, V L; Goodship, J A; Peters, H

    2013-03-01

    Tooth morphogenesis involves patterning through the activity of epithelial signaling centers that, among other molecules, secrete Sonic hedgehog (Shh). While it is known that Shh responding cells need intact primary cilia for signal transduction, the roles of individual cilia components for tooth morphogenesis are poorly understood. The clinical features of individuals with Ellis-van Creveld syndrome include various dental anomalies, and we show here that absence of the cilial protein Evc in mice causes various hypo- and hyperplasia defects during molar development. During first molar development, the response to Shh signaling is progressively lost in Evc-deficient embryos and, unexpectedly, the response consistently disappears in a buccal to lingual direction. The important role of Evc for establishing the buccal-lingual axis of the developing first molar is also supported by a displaced activity of the Wnt pathway in Evc mutants. The observed growth abnormalities eventually manifest in first molar microdontia, disruption of molar segmentation and symmetry, root fusions, and delayed differentiation. Analysis of our data indicates that both spatially and temporally disrupted activities of the Shh pathway are the primary cause for the variable dental anomalies seen in patients with Ellis-van Creveld syndrome or Weyers acrodental dysostosis. PMID:23315474

  8. The incidence of cysts and tumors associated with impacted third molars

    PubMed Central

    Vigneswaran, A. T.; Shilpa, S.

    2015-01-01

    Incidence of cysts and tumors associated with lower impacted third molars are very low prevalence, which might be because of the fact that most pathologies go unnoticed as many practitioners discard the erupted tissue after surgical removal of the impacted teeth rather than sending the tissue for histopathological examination. Our aim was to evaluate the patients who came for third molar surgical removal with due therapeutic prophylacis and an incidental finding. A proper study protocol both inclusion and exclusion criteria was strictly followed for all the cases, which were included in the study. The period of study was 6 years and the total number of cases assessed were 2778 patients out of which 70 cases reported pathology associated with the impacted third molars. Among 70 cases 61.4% were reported as cyst and tumors and 38.6% of the cases had chronic inflammatory reaction, including two cases with normal dental follicle. High incidence rate of pathology associated with third molar occurred between age group of 20 and 30 years older age groups showed very low incidence. Most common site of impaction was found to be left side of mandible and positions were vertical and distoangular impactions. Thus was male predominance in the younger groups. The examination is necessary whether the third molars impacted cases were symptomatic or asymptomatic PMID:26015725

  9. The chronological age estimation of third molar mineralization of Han population in southwestern China.

    PubMed

    Qing, Maofeng; Qiu, Lihua; Gao, Zhi; Bhandari, Kishor

    2014-05-01

    The purpose of the study was to estimate the chronology of third molar mineralization in Han population of southwestern China and find its unique characteristics so that it would provide a reference in several legal cases like forensic age estimation. The study used Demirjian's staging method to study 2192 orthopantomograms of 984 male and 1208 female subjects aged between 8 and 25 years. The statistical data was analyzed by Student's t test and ANOVA. The conclusions of the study are: (1) The chronological mineralization age of third molars of Han population in Southwestern China is similar to the Turkish and the Japanese, was earlier than the Austrian and Han of South China, but later than the Spanish. (2) The mineralization timing of the third molars between two sides in maxilla or mandible has no significant differences in the same gender group. (3) There is no significant difference in mineralization of third molars between male and female, except for tooth 48 in Demirjian's stage E. (4) The mineralization of third molar in maxilla is earlier than mandible. PMID:24794846

  10. Demirjian's method in the estimation of age: A study on human third molars

    PubMed Central

    Lewis, Amitha J.; Boaz, Karen; Nagesh, K. R; Srikant, N; Gupta, Neha; Nandita, K. P; Manaktala, Nidhi

    2015-01-01

    Aim: The primary aim of the following study is to estimate the chronological age based on the stages of third molar development following the eight stages (A to H) method of Demirjian et al. (along with two modifications-Orhan) and secondary aim is to compare third molar development with sex and age. Materials and Methods: The sample consisted of 115 orthopantomograms from South Indian subjects with known chronological age and gender. Multiple regression analysis was performed with chronological age as the dependable variable and third molar root development as independent variable. All the statistical analysis was performed using the SPSS 11.0 package (IBM ® Corporation). Results: Statistically no significant differences were found in third molar development between males and females. Depending on the available number of wisdom teeth in an individual, R2 varied for males from 0.21 to 0.48 and for females from 0.16 to 0.38. New equations were derived for estimating the chronological age. Conclusion: The chronological age of a South Indian individual between 14 and 22 years may be estimated based on the regression formulae. However, additional studies with a larger study population must be conducted to meet the need for population-based information on third molar development. PMID:26005306

  11. Tuning of magnetic properties in cobalt ferrite by varying Fe+2 and Co+2 molar ratios

    NASA Astrophysics Data System (ADS)

    Biswal, Dipti; Peeples, Brianna N.; Peeples, Caryn; Pradhan, Aswini K.

    2013-11-01

    Different grades of magnetic cobalt ferrite (CoFe2O4) nanoparticles were synthesized with various molar ratios of Fe+2 to Co+2 ions in the initial salt solutions by the co-precipitation method. The crystal structure and morphology of the nanoparticles are obtained from X-ray diffraction and transmission electron microscopy studies. Fourier transform infrared spectroscopy analysis exhibited the Fe-O stretching vibration ~540 cm-1, confirming the formation of metal oxide. The magnetic studies demonstrate that all of the nanoparticles are superparamagnetic at 300 K. The saturation magnetization and coercivity of the CoFe2O4 nanoparticles are affected by the molar ratios of Fe+2 to Co+2 ions. Among all the synthesized nanoparticles, the system with 75:25 molar ratio of Fe+2 to Co+2 ions with a particle size of 13 nm showed a high magnetization of 90 emu/g.

  12. Formation of polyelectrolyte complexes with diethylaminoethyl dextran: charge ratio and molar mass effect.

    PubMed

    Le Cerf, Didier; Pepin, Anne Sophie; Niang, Pape Momar; Cristea, Mariana; Karakasyan-Dia, Carole; Picton, Luc

    2014-11-26

    The formation of polyelectrolyte complexes (PECs) between carboxymethyl pullulan and DEAE Dextran, was investigated, in dilute solution, with emphasis on the effect of charge density (molar ratio or pH) and molar masses. Electrophoretic mobility measurements have evidenced that insoluble PECs (neutral electrophoretic mobility) occurs for charge ratio between 0.6 (excess of polycation) and 1 (stoichiometry usual value) according to the pH. This atypical result is explained by the inaccessibility of some permanent cationic charge when screened by pH dependant cationic ones (due to the Hoffman alkylation). Isothermal titration calorimetry (ITC) indicates an endothermic formation of PEC with a binding constant around 10(5) L mol(-1). Finally asymmetrical flow field flow fractionation coupled on line with static multi angle light scattering (AF4/MALS) evidences soluble PECs with very large average molar masses and size around 100 nm, in agreement with scrambled eggs multi-association between various polyelectrolyte chains. PMID:25256478

  13. Description, Nomenclature, and Mapping of a Novel Cerebello-Renal Syndrome with the Molar Tooth Malformation

    PubMed Central

    Valente, Enza Maria; Salpietro, Damiano Carmelo; Brancati, Francesco; Bertini, Enrico; Galluccio, Tiziana; Tortorella, Gaetano; Briuglia, Silvana; Dallapiccola, Bruno

    2003-01-01

    Cerebello-oculo-renal syndromes (CORSs) and Joubert syndrome (JS) are clinically and genetically heterogeneous autosomal recessive syndromes that share a complex neuroradiological malformation resembling a molar tooth on brain axial images, a condition referred to as “molar tooth on imaging” (MTI) or the “molar tooth sign.” The current literature on these syndromes is complex, with overlapping and incomplete phenotypes that complicate the selection of clinically homogeneous cases for genetic purposes. So far, only one locus (JBTS1 on 9q34) has been mapped, in two families with JS. Here, we describe a large consanguineous family with JS and nephronophthisis, representing a novel cerebello-renal phenotype. We have mapped this condition to the pericentromeric region of chromosome 11 and have named the locus “CORS2.” The acronym “CORS” is proposed for all loci associated with JS, CORSs, and related phenotypes sharing the MTI, because this neuroradiological sign seems to be the unifying feature of these clinically heterogeneous syndromes. PMID:12908130

  14. Iatrogenic mandibular fractures following removal of impacted third molars: an analysis of 130 cases.

    PubMed

    Ethunandan, M; Shanahan, D; Patel, M

    2012-02-01

    Immediate and late mandibular fractures are a rare complication of third molar removal. We analysed 130 cases of mandibular fractures following removal of impacted third molars reported in the literature, including four managed in the maxillofacial unit and identified potential risk factors. Its occurrence is likely to be multi-factorial, with age, gender, angulation, laterality, extent and degree of impaction and associated pathologies contributing to the risk of fracture. Postoperative fractures were more common than intra-operative fractures (2.7:1) and occurred most frequently in the second and third weeks (57%). A 'cracking' noise was the most frequent presentation (77%). Intra-operative fractures were more frequent among females (M:F - 1:1.3), and differed from postoperative fractures (M:F - 3.9:1). This study analyses the results, providing suggestions to minimise the risk and to manage a mandibular fracture following removal of a third molar. PMID:22361547

  15. Accessory Central Cusp in the Maxillary Second Primary Molars: A Rare Entity among the Rare

    PubMed Central

    Das, Monalisa

    2014-01-01

    ABSTRACT% Central accessory cusp in primary molars is an extremely rare condition which is due to abnormal proliferation and folding of inner enamel epithelium during morphodifferentiation stage of tooth development. The extension of the pulp in the cuspal area is often the reason for early involvement of pulp by the caries process. Therefore, early diagnosis and treatment planning is necessary to maintain the integrity of primary dental arch. This article reports such a case of central accessory cusps involving maxillary second primary molars. How to cite this article: Chandra B, Das M. Accessory Central Cusp in the Maxillary Second Primary Molars: A Rare Entity among the Rare. Int J Clin Pediatr Dent 2014;7(3):202-205. PMID:25709302

  16. An Evaluation of Pathologic Changes in the Follicle of Impacted Mandibular Third Molars

    PubMed Central

    Tambuwala, Aruna Azhar; Oswal, Rakesh Gulabchand; Desale, Rushikesh Suresh; Oswal, Nitin Prakash; Mall, Prashant Edwin; Sayed, Aatif Riyaz; Pujari, Aniket Tarachand

    2015-01-01

    Background: The purpose of this study was to evaluate the early pathologic changes in the follicular tissue of completely impacted mandibular third molar. Materials and Methods: 52 patients, between 18 and 52 years of age of which 25 were males and 27 were females, were selected. They had impacted mandibular third molars, which were indicated for extraction. After extraction, the follicle was sent for a histopathological evaluation to two different oral pathologists. Results: The results showed that 80.8% of the specimen had normal follicles. 11.5% specimen suggested cystic changes while 7.7% suggested infected follicle. Conclusion: It is desirable to consider prophylactic removal of impacted mandibular third molar presenting at a younger age, whereas their removal remains an enigma for the older age group and should only be considered appropriate in those cases where frank causes for its removal are established. PMID:25954073

  17. In vitro comparison of laser fluorescence performance with visual examination for detection of occlusal caries in permanent and primary molars

    Microsoft Academic Search

    Jonas A. Rodrigues; Michele B. Diniz; Érika B. Josgrilberg; Rita C. L. Cordeiro

    2009-01-01

    The aim of this study was to compare the performance of the DIAGNOdent 2095 with visual examination for occlusal caries detection\\u000a in permanent and primary molars. The sample comprised 148 permanent human molars and 179 primary human molars. The samples\\u000a were measured and visually examined three times by two examiners. After measurement, the teeth were histologically prepared\\u000a and assessed for

  18. Radiographic assessment of third molars development and it's relation to dental and chronological age in an Iranian population

    PubMed Central

    Monirifard, Mohamad; Yaraghi, Navid; Vali, Ava; Vali, Asana; Vali, Amrita

    2015-01-01

    Background: The aim of the present study was to estimate chronological age based on third molar development and to determine the association between dental age and third molar calcification stages. Materials and Methods: In this cross-sectional study, 505 digital panoramic radiographs of 223 males (44.2%) and 282 females (55.8%) between the age of 6 and 17 were selected from patients who were treated in Departments of Pediatrics and Orthodontics of Isfahan University of Medical Sciences between the years of 2009 and 2013. Correlation between chronological age and third molar development was analyzed with SPSS 21 using Spearman's Rank correlation coefficient, Chi-square test and multiple regression statistical tests (P < 0.05). Results: All third molars demonstrated a highly significant correlation with dental age (P < 0.001). The teeth showing the highest relationship with dental age were mandibular left third molar in males and mandibular right third molar in females (rs = 0.072). When multiple regression was used to predict dental age based on molar calcification stage, the only significant correlation was between maxillary left third molar in males (P < 0.05). There was no statistically significant correlation for any of third molars in females. Relationship between chronological age and molars development stage was significant in all age subgroups and in both gender (P < 0.001). Conclusion: Strong correlation was observed between left third molars and dental age in males. Results showed that third molar calcification stage can be used as an age predictor and in general mandibular teeth seems to be more reliable for this purpose in both genders and in all ages. PMID:25709677

  19. Classification of impacted mandibular third molars on cone-beam CT images

    PubMed Central

    Maglione, Michele; Bazzocchi, Gabriele

    2015-01-01

    Background Neurological involvement is a serious complication associated to the surgical removal of impacted mandibular third molars and the radiological investigation is the first mandatory step to assess the risk of a possible post-operative injury to the inferior alveolar nerve (IAN). The aim of this study was to introduce a new radiological classification that could be normally used in clinical practice to assess the relationship between an impacted third molar and mandibular canal on cone beam CT (CBCT) images. Material and Methods CBCT images of 80 patients (133 mandibular third molars) were independently studied by three members of the surgical team to draw a classification that could describe all the possible relationships between third molar and IAN on the cross-sectional images. Subsequently, the study population was subdivided according to this classification. The SPSS software, version 15.0 (SPSS® Inc., Chicago, Illinois, USA) was used for the statistical analysis. Results Eight different classes were proposed (classes 0-7) and six of them (classes 1-6) were subdivided in two subtypes (subtypes A-B). The distribution of classes showed a prevalence of buccal or apical course of the mandibular canal followed by lingual position and inter-radicular one. No differences have resulted in terms of anatomic relationship between males and females apart from a higher risk of real contact without corticalization of the canal when the IAN had a lingual course for female group. Younger patients showed an increased rate of direct contact with a reduced calibre of the canal and/or without corticalization. Conclusions The use of this classification could be a valid support in clinical practice to obtain a common language among operators in order to define the possible relationships between an impacted third molar and the mandibular canal on CBCT images. Key words:CBCT, classification, inferior alveolar nerve, third molars.

  20. The influence of impaction on the rate of third molar mineralisation in male black Africans.

    PubMed

    Olze, Andreas; van Niekerk, Piet; Schulz, Ronald; Ribbecke, Sebastian; Schmeling, Andreas

    2012-11-01

    One of the main criteria used in dental age diagnostics in living adolescents and young adults is assessment of the mineralisation stage of the third molars. In the case of Europid populations, it has been established that impaction status has an influence on the rate of mineralisation of the third molars. In view of this, a study was undertaken to determine whether the chronological process of wisdom tooth mineralisation is dependent upon impaction status in black Africans too. Orthopantomograms (553) of 437 male and 116 female black South Africans with verified birth dates in the age group between 10 and 26 years were studied. Mineralisation stage and impaction status were determined for all third molars. Statistical measures were calculated for the mandibular wisdom teeth at stages F, G and H and for the maxillary wisdom teeth at stage H in the male gender for both impacted and non-impacted third molars. It was ascertained that the minimum age in persons with impacted third molars, depending on the wisdom tooth observed, was 0.19-2.57 years higher than in those with non-impacted wisdom teeth. Test persons with impacted mandibular wisdom teeth at stage F or G were on average between 0.32 and 1.88 years older than those with non-impacted mandibular wisdom teeth. The 50 % probability values of impacted wisdom teeth at stage H were 1.85-3.31 years higher than those in non-impacted wisdom teeth. The conclusion was drawn that in male black Africans, impacted mandibular wisdom teeth mineralise more slowly than non-impacted lower third molars. The presence of impacted mandibular wisdom teeth in mineralisation stage H in male black Africans does not, however, furnish proof of completion of the 18(th) year of life beyond reasonable doubt. PMID:22885908

  1. Molar-Mass Characterization of Cationic Polymers for Gene Delivery by Aqueous Size-Exclusion Chromatography

    Microsoft Academic Search

    Xulin Jiang; Aschwin van der Horst; Mies J. van Steenbergen; Niels Akeroyd; Cornelus F. van Nostrum; Peter J. Schoenmakers; Wim E. Hennink

    2006-01-01

    \\u000a Purpose  This study was performed to develop a reliable aqueous size-exclusion chromatography (SEC) method to obtain the absolute molar\\u000a masses and distributions of various cationic polymers used in gene delivery.\\u000a \\u000a \\u000a \\u000a Methods  Water-soluble cationic [2-(dimethylamino) ethyl methacrylate] polymers (PDEs) with different molar masses and low polydispersities\\u000a were synthesized by living polymerization and these were used to optimize the SEC conditions. Online coupled multiangle

  2. The magnitude of a human bite measured exactly at the molar Intercuspidation using FBG

    NASA Astrophysics Data System (ADS)

    Marin, Gabriela Costa; Milczewski, Maura S.; Abe, Ilda; Lopes, Stephani C. P. S.; Camargo, Elisa S.; Kalinowski, Hypolito J.

    2014-05-01

    The aim of the study is to develop a new punctual method to determine the human bite force, between uppers and lowers first molars, at the moment of occlusion in maximum intercuspation. Fibre optic Bragg gratings are encapsulated in an acetate splint made by casting of a volunteer lower dentition. Splint sensor was positioned into the mouth to be pressured with minimal occlusal interference. The transversal pressure on the FBG was acquired at the moment of before occlusion (free), occlusion and biting. The measured forces were 12N during occlusion and 28N bite force, between right uppers and lowers first molars.

  3. Modified lingual split technique for extraction of impacted mandibular third molars.

    PubMed

    Lewis, J E

    1980-08-01

    Critical evaluation of existing chisel and bur techniques for removal of impacted mandibular third molars reveals a high incidence of complications. Both approaches require creation of a buccal defect immediately distal to the second molar for the insertion of an elevator, which may cause pocketing to occur postoperatively. The method described here minimizes periosteal reflection, almost completely avoids loss of bone, and effectively reduces the use of rotary instrumentation. The planning of the soft tissue flaps and bony cuts assists in primary wound closure, obliteration of dead space, and reduction of postoperative morbidity. PMID:6930459

  4. Upper molar distalization on palatal miniscrews: an easy to manage palatal appliance.

    PubMed

    Huanca Ghislanzoni, Luis Tomas; Piepoli, Claudio

    2012-05-01

    Upper molar distalization supported by miniscrews has become increasingly popular in the last years. A detailed clinical and lab procedure for the realization of a distalization appliance (fast back or distal jet) connected to miniscrews inserted in the anterior region of the palate is presented. A case report illustrates the use of a fast back appliance supported by miniscrews to correct the mesial shift of the molars and of the premolars as a consequence of an early loss of the maxillary deciduous canines. PMID:22583590

  5. Maxillary first molar with 8 root canals detected by CBCT scanning: a case report.

    PubMed

    Almeida, Gustavo; Machado, Ricardo; Sanches Cunha, Rodrigo; Vansan, Luiz Pascoal; Neelakantan, Prasanna

    2015-01-01

    Maxillary molars are prone to exhibit some of the most complex root canal configurations in endodontics. These complexities can result in diagnostic dilemmas, as well as management challenges. This case report illustrates how a cone beam computed tomography (CBCT) scan confirmed an unusual maxillary first molar with 3 root canals each in the mesiobuccal and distobuccal roots and 2 canals in the palatal root. This article illustrates how CBCT scanning and a dental operating microscope can facilitate a better understanding of complex root canal anatomies, ultimately allowing the dentist to clean, shape, and obturate root canal systems more efficiently. PMID:25734290

  6. The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of some ammonium salts

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2003-01-01

    Vapour pressures of water over saturated solutions of ammonium bromide, ammonium dihydrogen phosphate, ammonium thiosulfate, ammonium persulfate, ammonium acetate, ammonium oxalate and ammonium tartrate were determined as a function of temperature. These vapour pressures were used to evaluate the water activities, osmotic coefficients and molar enthalpies of vaporization. Molar enthalpies of solution of ammonium bromide ?solHm(NH4Br, T=293.97K, m=0.1030mol·kg?1)=(17.4±0.5)kJ·mol?1; ammonium hydrogen

  7. The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of some cesium salts

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2006-01-01

    Vapour pressures of water over saturated solutions of cesium chloride, cesium bromide, cesium nitrate, cesium sulfate, cesium formate, and cesium oxalate were determined as a function of temperature. These vapour pressures were used to evaluate the water activities, osmotic coefficients and molar enthalpies of vapourization. Molar enthalpies of solution of cesium chloride, ?solHm(T=295.73 K; m=0.0622 mol·kg?1)=(17.83±0.50) kJ·mol?1; cesium bromide, ?solHm(T=293.99

  8. Endodontic management of a mandibular second molar with radix entomolaris: a case report.

    PubMed

    Hannah, Rosaline; Kandaswamy, Deivanayagam; Jayaprakash, Nachimuthu

    2014-05-01

    The presence of radix entomolaris (RE) in a mandibular first molar is a common occurrence in certain ethnic groups, but the presence of RE in a mandibular second molar is a rare occurrence. In the present case, RE was identified from preoperative radiographs and confirmed using cone-beam computed tomography (CBCT). The access cavity was modified to locate the RE. Cleaning and shaping were performed with nickel-titanium rotary instruments. Obturation was completed with gutta-percha cones using AH Plus (Dentsply Detrey GmbH) as sealer. From the CBCT axial images, the RE was determined to have a Type III curvature by the De Moor classification, Type B separate RE by the Carlsen and Alexandersen classification, and radiographically, a Type i image by the Wang classification. The presence of RE in the mandibular second molar makes it essential to anticipate and treat the distolingual root canal. This case report highlights the usefulness of CBCT for assessing RE in the mandibular second molar, which can help the clinician in making a confirmatory diagnosis and assessing the morphology of the root canal. PMID:24790927

  9. A familial case of recurrent hydatidiform molar pregnancies with biparental genomic contribution

    Microsoft Academic Search

    Mazen N. Helwani; Muhieddine Seoud; Laila Zahed; Ghazi Zaatari; Ali Khalil; Rima Slim

    1999-01-01

    Hydatidiform mole is a benign trophoblastic neoplasia characterized by an abnormal development of the embryo and proliferation of placental villi. Using microsatellite markers amplified by the polymerase chain reaction, we have performed a genetic study on eight independent molar tissues occurring in two sisters. Karyotype and genotype data demonstrate a diploid and biparental constitution in seven of the analyzed moles

  10. Cemento-osseous dysplasia-like lesion and complex odontoma associated with an impacted third molar.

    PubMed

    Prodromidis, Georgios I; Tosios, Konstantinos I; Koutlas, Ioannis G

    2011-12-01

    We present a case of a 36-year-old female with a benign fibro-osseous lesion consistent with cemento-osseous dysplasia (COD) that was located coronally to the crown of an impacted mandibular third molar tooth and was associated with a complex odontoma. The pathogenesis of this unusual association is discussed and the odontogenic origin of COD is suggested. PMID:21505851

  11. Femto-Molar Sensitive Field Effect Transistor Biosensors Based on Silicon Nanowires and

    E-print Network

    Dalang, Robert C.

    (SiNW- FETs) for high sensitive detection of vascular endothelial growth factor (VEGF) molecules. Si with VEGF monoclonal antibodies in order to sense VEGF. Increasing concentrations of VEGF in the femto molar with antibodies has been developed and used to sense vascular endothelial growth factor (VEGF). VEGF is a promoter

  12. Corrosion of a zinc rotating disk in one molar hydrochloric acid

    Microsoft Academic Search

    Hauser

    1984-01-01

    The corrosion of a zinc rotating disk in one molar hydrochloric acid has been studied using a potentiodynamic polarization method. Experimental rotating-disk data at a rotation speed of 1600 rpm are presented. The polarization curves are analyzed to determine the transfer coefficients and rate constants for the anodic zinc dissolution and cathodic hydrogen evolution reactions. A modified Butler-Volmer equation is

  13. Evaluation of root canal morphology of maxillary molars using cone beam computed tomography

    PubMed Central

    Alrahabi, Mothanna; Sohail Zafar, Muhammad

    2015-01-01

    Objectives: The success of endodontic treatment is based on cleaning and shaping of the root canals. The root canals have complex morphology and wide individual variations. The objective of this study was to analyze root canals morphology and existence of extra canals in maxillary molars in Saudi subpopulation. Methods: Freshly extracted maxillary first molars (n=100) were included in this study. All teeth were examined for morphology of roots, root canals and apical foramen by Cone Beam Computed Tomography (CBCT). The root canals configuration was classified using Vertucci’s classification. Results: The majority of maxillary first molars (94%) were having three distinctly separated roots and 6% had four roots. Palatal and distobuccal roots were observed to contain one root canal (100%) and Vertucci’s type I configuration. The mesiobuccal root had one (29.4%; type I) or two canals (70.6%; type II, III or IV). Conclusions: The occurrence of second canal in the mesiobuccal root of upper first molar is very much likely (>70%). The mesiobuccal roots are more likely to have Vertucci’s type I or II configuration (>76%). The palatal and distobuccal roots always have a Vertucci’s type I canal configuration.

  14. Temporomandibular joint loading generated during bilateral static bites at molars and premolars

    Microsoft Academic Search

    Makoto Abe; Raul U. Medina-Martinez; Ken-ichi Itoh; Shoji Kohno

    2006-01-01

    The aim of this study was to investigate the features of the loading vectors of the temporomandibular joint (TMJ) generated during bilateral static bites at the molars and at the premolars, and to determine the major factors affecting the difference between the two loading vectors. We computed the subjects’ estimated and theoretical minimum TMJ loadings under the two different bite

  15. Estimation of legal age using calcification stages of third molars in living individuals.

    PubMed

    Streckbein, Philipp; Reichert, Isabelle; Verhoff, Marcel A; Bödeker, Rolf-Hasso; Kähling, Christopher; Wilbrand, Jan-Falco; Schaaf, Heidrun; Howaldt, Hans-Peter; May, Andreas

    2014-12-01

    The increased number of adolescents and young adults with unknown or inaccurately given date of birth is a current issue in justice and legal medicine. The objective of this study was to determine the extent to which third molar calcification stages assessed on panoramic X-rays could be useful as additional criteria for forensic age estimation in living individuals, focusing on the legally important ages 17 and 18. In a retrospective multi-center study, the developmental stage of each individual's third molar was analyzed using Demirjian's scale in 2360 cases. Additionally, sex, age and ancestry were assessed. Individuals with the lowest calcification stage of all present molars in stage H were ?18 years with a likelihood of ?99.05% in the female (n=388), and ?99.24% in the male (n=482) population. The lowest calcification stage of all present third molars proved to be useful as an additional reliable criterion for the determination of an age ?18 years. PMID:25498932

  16. Molar Functional Relations and Clinical Behavior Analysis: Implications for Assessment and Treatment

    ERIC Educational Resources Information Center

    Waltz, Thomas J.; Follette, William C.

    2009-01-01

    The experimental analysis of behavior has identified several molar functional relations that are highly relevant to clinical behavior analysis. These include matching, discounting, momentum, and variability. Matching provides a broader analysis of how multiple sources of reinforcement influence how individuals choose to allocate their time and…

  17. Materials and techniques for restoration of primary molars by pediatric dentists in Florida

    Microsoft Academic Search

    Marcio Guelmann; Ivar A. Mjör

    2002-01-01

    Purpose: The purpose of this study was to obtain an overview of materials and tech- niques used by pediatric dentistry clinicians for posterior restorations in primary molars and to compare the results to what is being taught in dental schools. Methods: A form with questions in different formats was mailed to all 180 members of the American Academy of Pediatric

  18. Postoperative Analgesia in Impacted Third Molar Surgery: The Role of Preoperative Diclofenac Sodium, Paracetamol and Lornoxicam

    Microsoft Academic Search

    Aysegul Mine Tuzuner Oncul; Duygu Yazicioglu; Zekeriyya Alanoglu; Samimi Demiralp; Adnan Ozturk; Cahit Ucok

    2011-01-01

    Objective: The aim of this study was to compare the postoperative analgesic effects of preoperative intravenous (i.v.) paracetamol, diclofenac sodium and lornoxicam (nonsteroidal anti-inflammatory drugs). Subjects and Methods: Sixty patients with impacted third molar who underwent surgical removal were randomly allocated into three groups: group P (n = 20), group D (n = 20) and group L (n = 20).

  19. Distal movement of mandibular molars in adult patients with the skeletal anchorage system

    Microsoft Academic Search

    Junji Sugawara; Takayoshi Daimaruya; Mikako Umemori; Hiroshi Nagasaka; Ichiro Takahashi; Hiroshi Kawamura; Hideo Mitani

    2004-01-01

    The skeletal anchorage system (SAS) consists of titanium anchor plates and monocortical screws that are temporarily placed in either the maxilla or the mandible, or in both, as absolute orthodontic anchorage units. Distalization of the molars has been one of the most difficult biomechanical problems in traditional orthodontics, particularly in adults and in the mandible. However, it has now become

  20. Differential Evolvability Along Lines of Least Resistance of Upper and Lower Molars in Island House Mice

    PubMed Central

    Renaud, Sabrina; Pantalacci, Sophie; Auffray, Jean-Christophe

    2011-01-01

    Variation within a population is a key feature in evolution, because it can increase or impede response to selection, depending on whether or not the intrapopulational variance is correlated to the change under selection. Hence, main directions of genetic variance have been proposed to constitute “lines of least resistance to evolution” along which evolution would be facilitated. Yet, the screening of selection occurs at the phenotypic level, and the phenotypic variance is not only the product of the underlying genetic variance, but also of developmental processes. It is thus a key issue for interpreting short and long term evolutionary patterns to identify whether main directions of phenotypic variance indeed constitute direction of facilitated evolution, and whether this is favored by developmental processes preferably generating certain phenotypes. We tackled these questions by a morphometric quantification of the directions of variance, compared to the direction of evolution of the first upper and lower molars of wild continental and insular house mice. The main phenotypic variance indeed appeared as channeling evolution between populations. The upper molar emerged as highly evolvable, because a strong allometric component contributed to its variance. This allometric relationship drove a repeated but independent evolution of a peculiar upper molar shape whenever size increased. This repeated evolution, together with knowledge about the molar development, suggest that the main direction of phenotypic variance correspond here to a “line of least developmental resistance” along which evolution between population is channeled. PMID:21589657

  1. Complication rates in patients using absorbable collagen sponges in third molar extraction sockets: a retrospective study

    PubMed Central

    Cho, Hoon; Jung, Hwi-Dong; Kim, Bok-Joo; Kim, Chul-Hoon

    2015-01-01

    Objectives The purpose of this study is to retrospectively evaluate the postoperative complication rates for absorbable type-I collagen sponge (Ateloplug; Bioland) use in third molar extraction. Materials and Methods From January to August 2013, 2,697 total patients undergoing third molar extraction and type-I collagen sponge application in the Department of Oral and Maxillofacial Surgery at Yonsei University Dental Hospital (1,163 patients) and Dong-A University Hospital (1,534 patients) were evaluated in a retrospective study using their operation and medical records. Results A total of 3,869 third molars in 2,697 patients were extracted and the extraction sockets packed with type-I collagen sponges to prevent postoperative complications. As a result, the overall complication rate was 4.52%, with 3.00% experiencing surgical site infection (SSI), 1.14% showing alveolar osteitis, and 0.39% experiencing hematoma. Of the total number of complications, SSI accounted for more than a half at 66.29%. Conclusion Compared to previous studies, this study showed a relatively low incidence of complications. The use of type-I collagen sponges is recommended for the prevention of complications after third molar extraction. PMID:25741465

  2. [Dental health of first molars among Westphalian immigrants and German students].

    PubMed

    Heinrich-Weltzien, R; Walther, M; Goddon, I; Kühnisch, J

    2014-01-01

    The aim of this study was to assess the health status of the occlusal surface on the first molars of Westphalian students, of whom 41.0% were immigrants. The prevalence and retention of fissure sealants (FS) and caries experience was scored for 161 students aged 8 and 10 years. Logistic regression analysis was used to predict the influence of sex, ethnicity, and retention of FS on the occlusal caries risk of the first molars. There was no difference in caries prevalence and experience in 8-year-old German students and immigrants (5.6%/10.5%; 0.07 DMFT/0.21 DMFT), both parameters were significantly higher in 10-year-old immigrants than in German students (25.5%/9.5%; 0.55 DMFT/0.11 DMFT). The prevalence and number of molars with FS was not different between German students and immigrants at 8 years (39.1%, 1.28 FS; 33.8%, 0.94 FS) and at 10 years of age (47.4%, 1.68 FS; 39.4%, 1.17 FS). The occlusal caries risk of first molars without FS was significantly higher in 8-year-old immigrants than in German students (OR 4.62). FS should be used more frequently in daily dental practice. To improve the quality of FS, stricter implementation of guideline-based standards is required. PMID:24297452

  3. Root Canal Morphology of Permanent Three-rooted Mandibular First Molars: Part II—Measurement of Root Canal Curvatures

    Microsoft Academic Search

    Yongchun Gu; Qun Lu; Ping Wang; Longxing Ni

    2010-01-01

    IntroductionThe distolingual (DL) roots of three-rooted mandibular molars often challenge clinicians during root canal therapy. This study investigated canal curvatures in permanent three-rooted mandibular first molars by using micro–computed tomography (micro-CT) scans.

  4. Analysis of stress in the periodontium of the maxillary first molar with a three-dimensional finite element model

    Microsoft Academic Search

    Peter D. Jeon; Patrick K. Turley; Hong B. Moon; Kang Ting

    1999-01-01

    The aim of this study was to simulate the stress response in the periodontium of the maxillary first molar to different moment to force ratios, and to determine the moment to force ratio for translational movement of the tooth by means of the finite element method. The three-dimensional finite element model of the maxillary first molar consisted of 3097 nodes

  5. Temperature dependence of partial molar heat capacities of binary critical mixtures: Study of the system isobutyric acid\\/water

    Microsoft Academic Search

    M. Pelger; H. Klein; D. Woermann

    1981-01-01

    Data of the temperature dependence of partial molar heat capacities of isobutyric acid and water near the critical point are reported. It is found that the singular part of the partial molar heat capacity of isobutyric acid in a critical mixture has a positive sign whereas that of water has a negative sign. A relationship between the critical amplitudes of

  6. Loss of molar occlusion and mandibular morphology in adults in an ancient human population consuming a coarse diet.

    PubMed

    Mays, Simon A

    2013-11-01

    The purpose of the study is to investigate the link between number of molar teeth retained in occlusion and mandibular morphology in adults in an ancient, high dental wear human population. The study material comprises skeletons from Mediaeval Wharram Percy, England (N = 50 female, 69 male adults). It was hypothesized that adults retaining fewer occluding molars would show reduction in mandibular dimensions, particularly in the ascending ramus and gonial regions where the main muscles of mastication have their insertions. Molar occlusal status is assessed using the concept of functional units. Mandibular morphology is assessed using a suite of ten linear measurements plus the mandibular angle. Results show no evidence for any association between number of molars retained in occlusion and mandibular angle. There was an association between mandibular size and number of molars retained in occlusion, with smaller mandibular dimensions in those retaining fewer occluding molars. Some measurements were affected more than others so that there was also some shape alteration. Alteration of mandibular dimensions was more clearly demonstrable in females than in males. Only in females could significant reduction in the ascending ramus and gonial regions be demonstrated. Reasons for the apparent difference in response to loss of molar occlusion between male and female mandibles are unclear, but sex differences in bony metabolism mediated by hormonal factors may be implicated. Results suggest that care should be exercised when including mandibles from individuals showing loss of molar occlusion in morphological studies. PMID:24104725

  7. Changes in the pattern of horseradish peroxidase diffusion into predentin and dentin after cavity preparation in rat molars

    Microsoft Academic Search

    Toshio Izumi; Hiroshi Inoue; Hiroshi Matsuura; Fumihiko Mukae; Hiromichi Osoegawa; Hirofumi Hirano; Naoharu Tamura

    2001-01-01

    Objective: The purpose of this study was to examine the process of reducing dentin permeability in adult rat molars after cavity preparation with horseradish peroxidase as a tracer. Study Design: Class V cavities were prepared on the upper first molars of 18 rats. Horseradish peroxidase was injected into the vascular system at intervals of 3 hours and 3, 5, 7,

  8. Furcation canals of the maxillary fourth premolar and the mandibular first molar teeth in cats.

    PubMed

    Negro, Viviana B; Hernández, Sabás Z; Maresca, Beatriz M; Lorenzo, Cesar E

    2004-03-01

    The furcation region morphology was evaluated in 103 mature feline carnassial teeth (54 maxillary fourth premolar and 49 mandibular first molar teeth). Patent furcation canals were present in 27.2% of teeth. No significant difference (p = 0.88) in distribution of this anatomical variation was found between maxillary fourth premolar and mandibular first molar teeth. The mean width of these furcation canals was 104.0 microns with two-thirds of the canals having a buccal orientation. The presence of furcation canals could be a factor in the etiopathogenesis of feline dental resorptive lesions, as well as a characteristic to be considered in the diagnosis, prognosis, and treatment of endodontic or periodontic-endodontic lesions in cat teeth. PMID:15108397

  9. Endodontic treatment of a mandibular first molar with 8 canals: a case report.

    PubMed

    Arora, Ankit; Acharya, Shashi Rashmi; Sharma, Padmaja

    2015-02-01

    Presented here is a case where 8 canals were located in a mandibular first molar. A patient with continuing pain in mandibular left first molar even after completion of biomechanical preparation was referred by a dentist. Following basic laws of the pulp chamber floor anatomy, 8 canals were located in three steps with 4 canals in each root. In both of the roots, 4 separate canals commenced which joined into two canals and exited as two separate foramina. At 6 mon follow-up visit, the tooth was found to be asymptomatic and revealed normal radiographic periapical area. The case stresses on the fact that understanding the laws of pulp chamber anatomy and complying with them while attempting to locate additional canals can prevent missing canals. PMID:25671216

  10. Antibiotic prophylaxis for third molar extraction in healthy patients: Current scientific evidence.

    PubMed

    Rodrigues, Willian Caetano; Okamoto, Roberta; Pellizzer, Eduardo Piza; dos Carrijo, Ana Cláudia Nazareno; de Almeida, Rafael Santiago; de Melo, Willian Morais

    2015-02-01

    Third molar extraction is one of the most frequently performed procedures in the dental clinic, and it is associated with innumerable trans- and postoperative complications, such as pain, trismus, edema, localized alveolar osteitis, and surgical site infection. Some authors advocate the use of local or systemic antibiotics to reduce the incidence of these postoperative complications. However, several studies have revealed an insignificant gain after using antibiotics. Despite the risks of allergic reactions, toxicity, and the development of resistant microorganisms, about 50% of dentists routinely prescribe the use of prophylactic antibiotics for this purpose. The goal of this paper is to evaluate the scientific evidence that justifies antibiotic prescription to healthy patients undergoing third molar extraction. PMID:25279397

  11. Degradation of high-molar-mass hyaluronan and characterization of fragments.

    PubMed

    Soltés, L; Kogan, G; Stankovska, M; Mendichi, R; Rychlý, J; Schiller, J; Gemeiner, P

    2007-09-01

    A sample of high-molar mass hyaluronan was oxidized by seven oxidative systems involving hydrogen peroxide, cupric chloride, ascorbic acid, and sodium hypochlorite in different concentrations and combinations. The process of the oxidative degradation of hyaluronan was monitored by rotational viscometry, while the fragments produced were investigated by size-exclusion chromatography, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, and non-isothermal chemiluminometry. The results obtained imply that the degradation of hyaluronan by these oxidative systems, some of which resemble the chemical combinations present in vivo in the inflamed joint, proceeds predominantly via hydroxyl radicals. The hyaluronan fragmentation occurred randomly and produced species with rather narrow and unimodal distribution of molar mass. Oxidative degradation not only reduces the molecular size of hyaluronan but also modifies its component monosaccharides, generating polymer fragments that may have properties substantially different from those of the original macromolecule. PMID:17691842

  12. Acute cervical artery dissection after a dental procedure due to a second inferior molar infection.

    PubMed

    Delgado, Montserrat G; Riesco, Nuria; Murias, Eduardo; Calleja, Sergio

    2015-01-01

    Periodontal infections might represent one of the causative factors for cervical artery dissection. We present a case of a 49-year-old woman admitted due to headache. The patient had been suffering from a right second inferior molar infection with a cervical phlegmon for 1?week prior to admission. On 2 October 2014, the patient went to the dentist and a molar extraction was performed in the morning. In the afternoon, the patient began to experience right hemifacial pain that progressed towards an intense and bilateral headache. Neurological status at the time of admission revealed right miosis, ptosis and conjuntival hyperaemia. A CT angiography showed a right internal carotid artery dissection provoking a high-degree stenosis. The relationship between periodontal infection and vascular disease has been previously presented. Microbial agents may directly, and inflammatory and immunological host response indirectly, influence inflammatory changes in cervical arteries favouring dissections with minor traumas. PMID:26038385

  13. Molar mass and temperature dependence of the thermodiffusion of polyethylene oxide in water/ethanol mixtures.

    PubMed

    Wang, Zilin; Afanasenkau, Dzmitry; Dong, Minjie; Huang, Danni; Wiegand, Simone

    2014-08-14

    In this work, we study the molar mass dependence of the thermodiffusion of polyethylene oxide at different temperatures in ethanol, water/ethanol mixture (c(water) = 0.7), and water in a molar mass range up to M(w) = 180,000 g/mol. Due to the low solubility of polyethylene oxide oligomers in ethanol the measurements are limited up to M(w) = 2200 g/mol. The specific water/ethanol concentration 0.7 has been chosen, because at this weight fraction the thermal diffusion coefficient, D(T), of water/ethanol vanishes so that the system can be treated as a pseudo binary mixture. The addition of ethanol will degrade the solvent quality, so that we expect a change of the interaction energies between polymer and solvent. The analysis of the experimental data within a theoretical model shows the need of a refined model, which takes specific interactions into account. PMID:25134596

  14. Mini-implant-borne Pendulum B appliance for maxillary molar distalisation: design and clinical procedure.

    PubMed

    Wilmes, Benedict; Katyal, Vandana; Drescher, Dieter

    2014-11-01

    A treatment objective of upper molar distalisation may often be required during the correction of a malocclusion. Distalisation is not only indicated for the management of Class II patients, but also for Class III surgery patients who require decompensation in the upper arch if upper incisor retrusion is needed. Unfortunately, most conventional intra-oral devices for non-compliance maxillary molar distalisation experience anchorage loss. A Pendulum type of appliance and a mini-implant-borne distalisation mechanism have been designed which can be inserted at chair-side, without a prior laboratory procedure and immediately after mini-implant placement. For re-activation purposes, a distal screw may be added to the Pendulum B appliance. PMID:25549527

  15. A quantitative investigation of irregular cuspules in human maxillary permanent molars.

    PubMed

    Kanazawa, E; Sekikawa, M; Ozaki, T

    1990-10-01

    The frequency of occurrence of anomalous cusps or tubercles on human upper first molars was investigated in seven racial populations using moiré contourography, which permits the three-dimensional measurement of minute cusps. Tubercles on the mesial marginal ridge were more frequently found in Mongoloid populations (Japanese and Eskimo) than in others. The frequency of the protoconule was high in Eskimos and Negroids (Bantu and San). The lingual paracone tubercle (mesial cusp) showed a particularly high frequency in Australian aborigines. The metaconule was rare or absent in all of the populations. Caucasoid groups (Dutch White and Asiatic Indian) showed generally low frequencies of all these abnormal tubercles, especially the distal accessory cusp (C5). Racial differences in the frequencies of occurrence may offer a key to understanding the adaptive significance of these traits and human microevolution. Confusion in nomenclature for upper molar tubercles is also discussed. PMID:2248376

  16. Endodontic Retreatment of a Mandibular Second Molar with four Separate Roots: A Case Report.

    PubMed

    Idris, Mohamed; Sakkir, Nasil; Kj, Nandakishore; Kini, Annapurna

    2014-03-01

    Aberrations in the root canal anatomy are a commonly occurring phenomenon. Although the mandibular second molar is commonly a bi-rooted tooth with an uncomplicated endodontic anatomy, variations have to be considered every time endodontic therapy is performed. This case report describes the non-surgical endodontic retreatment performed on a mandibular second molar with four seperate roots and canals. ProTaper Universal rotary nickel-titanium instruments (Dentsply Maillefer, Ballaigues, Switzerland) for treatment and retreatment were used to remove the old gutta percha and to clean and shape all root canals, followed by the complete obturation of root canal system. Post-operative CBCT scan was taken to confirm the quality of the performed treatment. PMID:24783160

  17. Severe impaction of the primary mandibular second molar accompanied by displacement of the permanent second premolar.

    PubMed

    Matsuyama, Junko; Kinoshita-Kawano, Shoko; Hayashi-Sakai, Sachiko; Mitomi, Tomoe; Sano-Asahito, Tomiko

    2015-01-01

    Tooth impaction is defined as any tooth that fails to erupt into a normal functional position and remains unerupted beyond the time at which it should normally erupt. Reports of impaction and eruption failure in primary teeth are relatively rare compared to permanent teeth. We report 2 rare cases where the second premolar was located on the occlusal side of the impacted mandibular second primary molar. In the first case, the succedaneous permanent tooth erupted after extraction of the primary tooth, fenestration, and traction. In the second case, the succedaneous permanent tooth erupted without fenestration or traction. Although the etiology of the tooth displacement was unknown in both cases, inhibition of the eruptive movement of the primary molar may have been associated with displacement of the succedaneous permanent premolar. PMID:25810929

  18. Entropy Estimates for Some Silicates at 298{degrees}K from Molar Volumes.

    PubMed

    Saxena, S K

    1976-09-24

    Third law entropies for silicates of Be, Mg, Ca, Zn, Na, and K containing the same anion group, for example, SiO(4) or SiO(3) or AlSi(3)O(8), are found to be linearly related to their molar volumes. The relationship between the molar volume and the entropy of silicates of Fe and Mn, atoms with unfilled d electron subshells, is different from that of other silicates. The linear correlations yield a useful method of estimating the entropies of ortho-, meta-, and framework silicates (feldspars and feld-spathoids). The estimated entropies of pyrope and almandine at 298 degrees K are 47.47 and 68.13 gibbs per mole, respectively. PMID:17837020

  19. Polymer Reference Materials: Round-Robin Tests for the Determination of Molar Masses

    Microsoft Academic Search

    U. Just; S. Weidner; P. Kilz; T. Hofe

    2005-01-01

    This article reports round-robin tests dealing with static light scattering (LS), size exclusion chromatography (SEC), and viscometry measurements of 10 reference materials of various polymer classes: poly(styrene)s (PS), poly(methyl methacrylate)s (PMMA), poly(ethylene oxide)s (PEO), and poly(lactide)s (PLA).In the certificates, molar masses and intrinsic viscosities as well as their uncertainties are specified. Additional values from nuclear magnetic resonance (NMR), infrared spectroscopy

  20. Near-UV molar absorptivities of alachlor, mecroprop-p, pendimethalin, propanil and trifluralin in methanol

    Microsoft Academic Search

    Eneida Reyes Perez; Stéphane Le Calvé; Philippe Mirabel

    2008-01-01

    An experimental set-up consisting of two parallel absorption cells coupled to a CCD detector was used to determine absolute values of molar absorptivity coefficients ? of five herbicides (alachlor, mecoprop-p, pendimethalin, propanil and trifluralin) in methanol. The absorption spectra were measured using a deuterium lamp at room temperature (298±2K) over the wavelength range 240–340nm, except for pendimethalin and trifluralin where

  1. Antibiotics in third molar extraction; are they really necessary: A non-inferiority randomized controlled trial

    PubMed Central

    Arora, Ankit; Roychoudhury, Ajoy; Bhutia, Ongkila; Pandey, Sandeep; Singh, Surender; Das, Bimal K.

    2014-01-01

    Introduction: Antibiotic resistance is now a serious problem, although it was not so only a few years ago. The need of the hour is to give clear evidence of the efficacy of antibiotic use, or lack thereof, to the surgeon for a procedure as common as mandibular third molar surgery. Aim: This study aimed to evaluate whether postoperative combined amoxicillin and clavulanic acid in mandibular third molar extraction is effective in preventing inflammatory complications. Study and Design: The study was structured as a prospective randomized double-blind placebo-controlled clinical trial. Materials and Methods: A study was designed wherein the 96 units (two bilaterally similar impacted mandibular third molars per head in 48 patients) were randomly assigned to two treatment groups (Group I and Group II). Each patient served as his/her own control. Each patient received 625 mg of combined amoxicillin and clavulanic acid 1 h before surgery. In the case of third molars belonging to Group I, 625 mg of combined amoxicillin and clavulanic acid TDS was continued for 3 days; in Group II, placebo in similar-looking packs was continued for 3 days. The patients were evaluated on the third and seventh postoperative days for signs of clinical infection and for microbial load evaluation. Statistical Analysis: The data between the two groups were statistically analyzed by the two-tailed Fisher's exact test, with a 95% confidence interval. Results: The difference was not statistically significant between the test group and the control group with regard to erythema, dehiscence, swelling, pain, trismus, and infection based on microbial load. The data were statistically significant for alveolar osteitis, with the occurrence of alveolar osteitis (14.58%) in the placebo group. Conclusion: Postoperative antibiotics are recommended only for patients undergoing contaminated, long-duration surgery. PMID:25937728

  2. Administration of bisphosphonate (ibandronate) impedes molar tooth movement in rabbits: A radiographic assessment

    PubMed Central

    Venkataramana, V.; Kumar, S. Sathesh; Reddy, B. Vishnuvardhan; Cherukuri, A. Sreekanth; Sigamani, K. Raja; Chandrasekhar, G.

    2014-01-01

    Introduction: Bisphosphonate (Bp)-ibandronate is a pharmacological agent, exhibits antiosteoclastic or antiresorptive activity and used to treat osteolytic or osteopenic disorders. BP-ibandronate may also interfere during orthodontic tooth movement. The aim of this study was to examine the influence of locally administered Bp-ibandronate on experimental tooth movement in rabbits. Materials and Methods: Twenty rabbits were divided into two groups- “10” served as Group-1 (control) and other “10” as Group-2 (experimental). Both groups received nickel-titanium closed coil springs with 100 g force between mandibular molar and incisors. Group-1 animals received 1 ml normal saline and Group-2 animals received ibandronate solution (0.3 mg/kg body weight) locally, mesial to the mandibular molar on the 1st, 7th, and 14th day of the experiment. A total of “40” lateral cephalograms were taken from both groups on the 1st and 21st day using a digital X-ray unit (Siemens X-ray systems, 300 mA Pleomophos analog, 2008, Germany). Individually, each animal's radiograph was traced manually and superimposed. The molar tooth movement was measured with the help of a standard metric scale. Results: The Student's t-test has been done to compare the mean values of Group-1 (4.650 ± 0.363) and Group-2 (2.030 ± 0.291) and the difference was statistically significant (P < 0.001). Conclusion: The retarded molar tooth movement was noticed in local drug administered rabbits, which could be beneficial in orthodontics to control the undesired tooth movement. PMID:25210364

  3. Morphology of the enamel-dentine junction in sections of anthropoid primate maxillary molars

    Microsoft Academic Search

    Anthony J. Olejniczak; Christopher C. Gilbert; Lawrence B. Martin; Tanya M. Smith; Lilian Ulhaas; Frederick E. Grine

    2007-01-01

    The shape of the enamel-dentine junction (EDJ) in primate molars is regarded as a potential indicator of phylogenetic relatedness because it may be morphologically more conservative than the outer enamel surface (OES), and it may preserve vestigial features (e.g., cuspules, accessory ridges, and remnants of cingula) that are not manifest at the OES. Qualitative accounts of dentine-horn morphology occasionally appear

  4. Proliferation of rat molar pulp cells after direct pulp capping with dentine adhesive and calcium hydroxide

    Microsoft Academic Search

    Till Dammaschke; Udo Stratmann; Rudolf-Josef Fischer; Darius Sagheri; Edgar Schäfer

    2011-01-01

    The aim was to evaluate the proliferation of pulp cells 1, 3 and 7 days after direct pulp capping with the dentine adhesive\\u000a Gluma Comfort Bond (GCB) and to compare it with calcium hydroxide (Ca(OH)2). An occlusal cavity was prepared in 72 molar teeth of 36 Wistar rats. Then GCB or Ca(OH)2 was placed on the exposed pulp. All cavities were

  5. Parvalbumin and calretinin-immunoreactive trigeminal neurons innervating the rat molar tooth pulp

    Microsoft Academic Search

    Hiroyuki Ichikawa; Toru Deguchi; Tadao Nakago; David M. Jacobowitz; Tomosada Sugimoto

    1995-01-01

    Calcium-binding proteins and neuropeptides were examined in trigeminal neuronal cell bodies retrogradely labeled with Fast blue (FB) from the maxillary molar tooth pulp of the rat. FB-labeled cells were located in the maxillary division of the trigeminal ganglion. ? 30 and 50% of the labeled cells were immunoreactive for parvalbumin and calcitonin gene-related peptide (CGRP), respectively. The coexpression of these

  6. Fracture Resistance of Non-Metallic Molar Crowns Manufactured with CEREC 3D

    Microsoft Academic Search

    Dalia A. Madani

    2010-01-01

    Objectives. To compare fracture strength and fatigue resistance of ceramic (ProCAD, Ivoclar-Vivadent) (C) and resin composite (Paradigm MZ100, 3M\\/ ESPE) (R) crowns made with CEREC-3D. Methods. A prepared ivorine molar tooth was duplicated to produce 40 identical prepared specimens made of epoxy resin (Viade). Twenty (C) crowns and 20 (R) were cemented to their dies using resin cement. Ten of

  7. Guided tissue regeneration in the treatment of degree III furcation defects in maxillary molars.

    PubMed

    Pontoriero, R; Lindhe, J

    1995-10-01

    11 subjects with generalized periodontitis and advanced lesions in the maxillary molar regions, including bilateral mesial-distal, but not buccal, degree III furcation defects in the 1st and/or 2nd molars, were recruited for the present clinical trial. The patients were given oral hygiene instruction and full-mouth scaling and root planing. A re-examination was performed after 3 months of healing, after which the furcation involved molars were randomly selected for a GTR or conservative treatment modality. An informed consent form was signed by each participating patient. The GTR procedure involved the elevation of mucoperiostal flaps, root surface debridement, and the placement of an e-PFTE membrane at the 2 entrances of the furcation defect. The flaps were repositioned and secured. The contralateral molar was treated in an identical manner but without the placement of the teflon membrane. The patients received amoxicillin (1g x 2/day for 8 days), were placed on chlorhexidine mouth rinsing and were recalled for prophylaxis 1x every 2 weeks. The teflon membranes were removed at a 2nd stage procedure after 6 weeks. All subjects were re-examined 6 months after the regenerative procedure, and in addition, all sites were evaluated following a reentry procedure. The final examination and measurements made during the reentry procedure documented that, although some reduction in probing pocket depth and some gain in probing attachment had occurred at both test and control sites, none of the furcation defects had closed, but retained the characteristics of a degree-III furcation involvement. PMID:8682929

  8. Excess molar enthalpies of binary mixtures containing mono- and polybromoalkanes at 298.15 K

    SciTech Connect

    Blanco, S.T.; Munoz, J.; Velasco, I.; Otin, S. [Univ. de Zaragoza (Spain). Dept. de Quimica Organica y Quimica Fisica

    1995-05-01

    An isobaric and quasi-isothermic calorimeter has been used to determine excess molar enthalpies, H{sub m}{sup E}, at 298.15 K and atmospheric pressure for 10 binary mixtures containing dibromomethane, tribromomethane, 1,2-dibromoethane, 1,1,2,2-tetrabromoethane, and 1-bromopropane. H{sub m}{sup E} values for these mixtures are negative except for 1,2-dibromoethane or dibromomethane + 1-bromopropane and 1,1,2,2-tetrabromoethane + tribromomethane.

  9. Electrical Conductance of Fissure Enamel in Recently Erupted Molar Teeth as Related to Caries Status

    Microsoft Academic Search

    Y. L. Ie; E. H. A. M. Verdonschot; M. J. M. Schaeken; M. A. van’t Hof

    1995-01-01

    Pit-and-fissure caries lesions contribute greatly to the caries incidence in permanent molar teeth in children. To date, the diagnosis of occlusal caries is still performed mainly by visual inspection, periodically aided by bite-wing radiography. However, in detecting small occlusal carious lesions, these methods perform inadequately, especially in low caries prevalence populations or individuals. The use of electrical conductance measurements (ECMs)

  10. Bone sialoprotein-induced reparative dentinogenesis in the pulp of rat’s molar

    Microsoft Academic Search

    F. Decup; B. Palmier; D. Buch; J. J. Lasfargues; E Salih; M. Goldberg

    2000-01-01

    Bone sialoprotein (BSP), an osteogenic protein (OP), mixed with a carrier, was implanted in the pulp of rat first upper molars\\u000a (OP group). Cavities were prepared with dental burs and pulp perforation was carried out by pressure with the tip of a steel\\u000a probe. After 8, 14, and 30 days, the rats were killed and the pulps of the OP

  11. A scanning electron microscope study of vascular development in the dental papilla of prenatal rat molars

    Microsoft Academic Search

    Shigemitsu Yoshida

    1991-01-01

    Prenatal development of the vascular supply to the dental papilla was studied in the maxillary first molar teeth of rats from 18.5 to 22.0 days gestation, using the vascular casting\\/scanning electron microscope method. Five pulp horns developed in order, central, distal, mesial, disto-lingual and mesio-lingual with the development of the dental papilla. The first vessels that invaded each pulp horn

  12. Replantation of Displaced Underlying Successor and Marsupialization of Radicular Cyst associated with a Primary Molar

    PubMed Central

    Ravi, GR

    2015-01-01

    ABSTRACT Radicular cysts are by far the most common cystic lesions of the jaw. However, those arising from primary teeth are comparatively rare, comprising only 0.5 to 3.3%. The aim of this paper is to present clinical, radiographic and histopathological characteristics of radicular cyst associated with a primary mandibular molar causing unusual displacement of the permanent successor. Extraction of primary tooth along with extirpation of cyst was done under local anesthesia. The displaced premolar was also extracted and then replanted in the socket after proper alignment. Healing was uneventful and the space of missing primary molar was maintained by band and loop space maintainer. The relationship between intracanal medicaments and rapid growth of cyst, as mentioned in literature was observed in our case too. Thus, pulpotomy treated primary teeth should receive periodic postoperative radiographic examination and absence of clinical symptoms does not mean that a pulpotomy treated tooth is healthy. How to cite this article: Lamba G, Ravi GR. Replantation of Displaced Underlying Successor and Marsupialization of Radicular Cyst associated with a Primary Molar. Int J Clin Pediatr Dent 2015;8(1):70-74.

  13. Histopathological and radiographic evaluation of rat molar teeth after traumatic injury-a pilot study

    PubMed Central

    Prasanth, T; Saraswathi, TR

    2012-01-01

    Objective: Radiographic and histopathological evaluation of mechanical trauma on the development of maxillary molars in rat. Materials and Methods: Experimental study with 7-day-old five new born Wistar rats. Trauma induced on 7th postnatal day with #55 K file. Right first molar region of the maxilla was the experimental side, and the left side as control. Each animal was sacrificed for histopathological observation on 8th day (immediately next day of injury), 10th day (after 3 days of injury), 13th day (Enamel completion), 19th day (Emergence into oral cavity) and 42nd day when all the teeth came into functional occlusion. Results: On the 42nd day experimental side of the study, the 1st molar tooth had not erupted and the radiographs taken revealed conglomerate mass suggestive of complex odontome. Reduced tooth size, altered enamel and dentin formation, abscess formation and complex odontome like structure were observed histopathologically. Conclusion: The diversity of morphlogical and histopathological changes to intrusive force implies intricate mechanism involved in tooth development. PMID:23248457

  14. A new 3-d approach to determine functional morphology of cercopithecoid molars.

    PubMed

    Ulhaas, Lilian; Kullmer, Ottmar; Schrenk, Friedemann; Henke, Winfried

    2004-12-01

    Functional relationships between diet and tooth morphology form an integral part of primatological and paleontological research. Previously, mostly two-dimensional parameters have been used to compare and interpret the complex crown morphology of cercopithecine and colobine molars. However, as teeth are three-dimensional objects, any dimensional reduction in describing their morphology must result in loss of information. In the current study we use a high resolution optical topometric system to record crown morphology in different wear stages in order to extract three-dimensional (3-d) parameters from virtual 3-d models. Structural parameters such as relief index, occlusal surface area, enamel area and strike and dip of cusp slopes as well as wear facets can be calculated, reflecting the changing occlusal topography of molars due to attrition and abrasion. By comparing mostly fruit-eating cercopithecines and leaf-eating colobines, functional implications of tooth wear, occlusal jaw movement and resulting relief can be inferred. Our analyses show that the main differences in occlusal relief between these genera do not change with wear. Colobines maintain higher occlusal relief, whereas in cercopithecines all cusps wear flat quite rapidly. Detailed models of wear for cercopithecoid molars will be used to reconstruct diet and will enhance our knowledge of the paleoecology of Cercopithecoidea. PMID:15646282

  15. Articaine versus lidocaine for third molar surgery: A randomized clinical study

    PubMed Central

    Santos, Thiago-de-S; Santos, Jadson-A.; Maia, Marcelo-C; Mendonça, Carla-G

    2012-01-01

    Objective: Pain reduction has been the subject of continuous research in the field of oral and maxillofacial surgery since postoperative pain with ranging of intensity and duration may affects the patient submitted in an oral surgical procedure. The aim of present study was to compare the analgesic effectiveness between two different anesthetic solutions (articaine and lidocaine) in third molar surgery. Study Design: A prospective, randomized and clinical study with patients submitted to third molar surgery at two distinct times. The visual analogue scale, the McGill Pain Questionnaire and the analgesic consumption record were used to measure the pain after each surgical time. Results: Duration of surgery, latency, the amount of anesthetic used and analgesic consumption showed clinical differences with highlights of articaine, though statistical significance was not observed (P<0.05). The pain scores indicated similar anesthetic efficacy with both solutions. Conclusion: In the present study no significant differences were observed between lidocaine and articaine in the control of postoperative pain. Key words: Articaine, lidocaine, pain control, lower third molar. PMID:22157664

  16. Randomized Split-Mouth Study on Postoperative Effects of Palmitoylethanolamide for Impacted Lower Third Molar Surgery

    PubMed Central

    Bacci, Christian; Cassetta, Giulia; Emanuele, Bruno; Berengo, Mario

    2011-01-01

    The aim of this study was to assess the efficacy of Normast 300?mg in reducing swelling and pain after the surgical extraction of impacted lower third molars. Materials and Methods. A randomized, split-mouth, single-blind study was conducted on 30 patients between 18 and 30 years of age requiring lower third molar extraction. Patients underwent bilateral extractions in a randomized sequence, one extraction being performed under Normast treatment. The Normast treatment involved 2 tablets a day for 15 days. The parameters assessed at each procedure were trismus, swelling, pain, NSAID consumption, postoperative complications, drug tolerability, and safety. The results obtained were processed using repeated measures analysis of variance. Results. Perceived postoperative pain was reportedly significantly milder on Normast treatment than control. The trend of the means differed over time (P < .0001) and between the two extraction groups (P < .0221). On the other hand, for edema and trismus, the trend differed over time for both groups but did not differ between the two groups. Discussion. Our analyses indicate that patients experienced significantly less postoperative pain when they were treated with Normast. Conclusions. Administering Normast improves the postoperative course—in terms of pain—after lower third molar extraction. PMID:22084787

  17. Classifying stages of third molar development: crown length as a predictor for the mature root length.

    PubMed

    Altalie, Salem; Thevissen, Patrick; Willems, Guy

    2015-01-01

    Multiple tooth development staging techniques were reported based on arbitrarily set borderlines between succeeding stages. Anatomic tooth features or predictions of future tooth part dimensions were described to identify the thresholds between the established stages. The need to predict mature tooth dimensions, while the tooth considered is still in development, is a drawback to use this staging technique for dental age estimations. Using the fully mature crown length as a predictor for the future root length could provide a tool for undisputable staging. The aim of this study was first to measure the crown and root length of fully mature third molars and second to investigate whether the crown length could be used as a predictor of the root length, in order to classify the observed root length as a proportion of the future mature root. The crown and root lengths of all present third molars were digitally measured on dental panoramic radiographs of 1,000 subjects. The included subjects were equally distributed in gender, and their age ranged between 22 and 40 years. Two occlusal borders, the cement enamel junction and the root apices, were defined as landmarks for standardized measurements. Regression models with root length as response and crown length as predictor were established and revealed low R (2) and high RMSE values. Due to the small explained variance by the prediction models and the high variation in prediction errors, the observed crown length cannot be used to predict the final root length of a developing third molar. PMID:24801360

  18. Incidence, Management, and Outcome of Molar Pregnancies at a Tertiary Care Hospital in Quetta, Pakistan

    PubMed Central

    Fatima, Mahrukh; Kasi, Pashtoon Murtaza; Baloch, Shahnaz Naseer; Kassi, Masoom; Marri, Shah Muhammad; Kassi, Mahwash

    2011-01-01

    Molar pregnancies represent a significant burden of disease on the spectrum of gestational trophoblastic diseases. The incidence appears to be higher in women from South Asia. The purpose of our prospective study was to determine the incidence, presentation, and outcomes of all molar pregnancies at our institution. During the study period, there were a total of 16,625 patients admitted to our department; out of whom 85 patients were diagnosed with a molar pregnancy. Vaginal bleeding was the commonest symptom (94.2%); theca lutein cysts were noted in 39% of the cases. Suction, dilatation, and curettage were noted to be the preferred method in almost all cases; hysterectomy was done in 12 (14.1%) patients. Single-agent chemotherapy was employed in high-risk patients and was well tolerated. Mean followup for these patients was 5.7?months (range 1–24 months). None of these patients developed persistent trophoblastic disease, invasive mole, or choriocarcinoma during the follow-up period. PMID:22028979

  19. Incidence, management, and outcome of molar pregnancies at a tertiary care hospital in quetta, pakistan.

    PubMed

    Fatima, Mahrukh; Kasi, Pashtoon Murtaza; Baloch, Shahnaz Naseer; Kassi, Masoom; Marri, Shah Muhammad; Kassi, Mahwash

    2011-01-01

    Molar pregnancies represent a significant burden of disease on the spectrum of gestational trophoblastic diseases. The incidence appears to be higher in women from South Asia. The purpose of our prospective study was to determine the incidence, presentation, and outcomes of all molar pregnancies at our institution. During the study period, there were a total of 16,625 patients admitted to our department; out of whom 85 patients were diagnosed with a molar pregnancy. Vaginal bleeding was the commonest symptom (94.2%); theca lutein cysts were noted in 39% of the cases. Suction, dilatation, and curettage were noted to be the preferred method in almost all cases; hysterectomy was done in 12 (14.1%) patients. Single-agent chemotherapy was employed in high-risk patients and was well tolerated. Mean followup for these patients was 5.7?months (range 1-24 months). None of these patients developed persistent trophoblastic disease, invasive mole, or choriocarcinoma during the follow-up period. PMID:22028979

  20. Molar ratio S/In effect on properties of sprayed In2S3 films

    NASA Astrophysics Data System (ADS)

    Bouguila, Nourredine; Timoumi, Abdelmajid; Bouzouita, Hassen; Lacaze, Emmanuelle; Bouchriha, Habib; Rezig, Bahri

    2013-08-01

    We have studied the structural, morphological and optical properties of In2S3 layers deposited on glass substrate by the spray pyrolysis method with the molar ratio S/In varies from 1 to 4. The substrate temperature was maintained at 613 K. The characteristics of these films have been determined by X-ray diffraction (XRD), optical absorption-transmission and atomic force microscopy (AFM). Their structure is strongly dependent on the molar ratio. The deposit is mainly constituted by the ? phase towards (4 0 0) direction. No characteristic peaks were observed for other impurities such as In2O3, S or In2(OH)3. The best crystallinity and surface morphology are obtained at molar ratio equal to 2.5. At this ratio, the crystallites coalesce and the local roughness is of the order of 1 nm. Optical transmission of 80% has been achieved in the visible spectrum. In2S3 band gap energy reached 2.63 eV from layers with x = 2 and deposited at Ts = 613 K.

  1. Highly Efficient Hyperbranched CNT Surfactants: Influence of Molar Mass and Functionalization

    E-print Network

    Ellen Bertels; Kevin Bruyninckx; Mert Kurttepeli; Mario Smet; Sara Bals; Bart Goderis

    2015-05-18

    End-group-functionalized hyperbranched polymers were synthesized to act as a carbon nanotube (CNT) surfactant in aqueous solutions. Variation of the percentage of triphenylmethyl (trityl) functionalization and of the molar mass of the hyperbranched polyglycerol (PG) core resulted in the highest measured surfactant efficiency for a 5000 g/mol PG with 5.6% of the available hydroxyl end-groups replaced by trityl functions, as shown by UV-vis measurements. Semiempirical model calculations suggest an even higher efficiency for PG5000 with 2.5% functionalization and maximal molecule specific efficiency in general at low degrees of functionalization. Addition of trityl groups increases the surfactant-nanotube interactions in comparison to unfunctionalized PG because of pi-pi stacking interactions. However, at higher functionalization degrees mutual interactions between trityl groups come into play, decreasing the surfactant efficiency, while lack of water solubility becomes an issue at very high functionalization degrees. Low molar mass surfactants are less efficient compared to higher molar mass species most likely because the higher bulkiness of the latter allows for a better CNT separation and stabilization. The most efficient surfactant studied allowed dispersing 2.85 mg of CNT in 20 mL with as little as 1 mg of surfactant. These dispersions, remaining stable for at least 2 months, were mainly composed of individual CNTs as revealed by electron microscopy.

  2. Diagnostic CBCT in Dentigerous Cyst with Ectopic Third Molar in the Maxillary Sinus–A Case Report

    PubMed Central

    Krishnamoorthy, Bhuvana; J K, Savitha; Bhai, Pankaja

    2014-01-01

    Dentigerous cyst is the second most common odontogenic cyst after radicular cyst. This report describes a case of a dentigerous cyst associated with an impacted maxillary third molar. Patient presented with foul smelling discharge through nose and oral cavity. Cone beam computed tomography revealed maxillary third molar displaced to lateral wall of the nose and a unilocular radiolucency obliterating the entire maxillary sinus. A provisional diagnosis of infected dentigerous cyst was made. The cyst was enucleated along with removal of third molar. Histopathological examination confirmed the diagnosis of dentigerous cyst. The patient recovery was uneventful. PMID:25121067

  3. [Epidemiology of third molar extractions: the experience of the S.G.C. Fatebenefratelli Hospital in Rome (Italy)].

    PubMed

    Gilardi, Francesco; Maurici, Massimo; Capozzi, Claudio; Di Dio, Marco; Ferrante, Maurizio; Arcuri, Claudio; Paulon, Luca

    2014-01-01

    The extraction of third molars (wisdom teeth) is one of the main surgical procedures performed in dentistry. The aim of this study was to describe the characteristics of patients undergoing the procedure in the SGC Fatebenefratelli Hospital, a large hospital in Rome (Italy), where about 20% of all third molar extractions in the Lazio Region are performed. Hospital discharge forms were analysed for patients discharged in the years 2010 and 2011 with a Diagnosis Related Group (DRG) code 169, used for the procedure. Study results indicate that the extraction of third molars is a relevant public health issue considering its frequency and associated yearly costs at the national level. The appropriateness of third molar extraction, especially when performed prophylactically in young persons, should be further explored. PMID:25715894

  4. Quantitative Three-Dimensional Analysis of Root Canal Curvature in Maxillary First Molars Using Micro-Computed Tomography

    Microsoft Academic Search

    Jong-Ki Lee; Byung-Hyun Ha; Jeong-Ho Choi; Seok-Mo Heo; Hiran Perinpanayagam

    2006-01-01

    In endodontic therapy, access and instrumentation are strongly affected by root canal curvature. However, the few studies that have actually measured curvature are mostly from two-dimensional radiographs. The purpose of this study was to measure the three-dimensional (3D) canal curvature in maxillary first molars using micro-computed tomography (microCT) and mathematical modeling. Extracted maxillary first molars (46) were scanned by microCT

  5. Quantitative Three-Dimensional Analysis of Root Canal Curvature in Maxillary First Molars Using Micro-Computed Tomography

    Microsoft Academic Search

    Jong-Ki Lee; Byung-Hyun Ha; Jeong-Ho Choi; Seok-Mo Heo; Hiran Perinpanayagam

    In endodontic therapy, access and instrumentation are strongly affected by root canal curvature. However, the few studies that have actually measured curvature are mostly from two-dimensional radiographs. The purpose of this study was to measure the three-dimensional (3D) canal curvature in maxillary first molars using micro-computed tomography (microCT) and mathemat- ical modeling. Extracted maxillary first molars (46) were scanned by

  6. Compositional dependence of molar absorptivities of near-infrared OH and H 2O bands in rhyolitic to basaltic glasses

    Microsoft Academic Search

    Susanne Ohlhorst; Harald Behrens; François Holtz

    2001-01-01

    Molar absorption coefficients (molar absorptivities) of the near infrared combination bands at 4500 and 5200 cm?1 assigned to OH groups and H2O molecules, respectively, were determined for glasses of dacitic, andesitic and basaltic compositions. Total water contents (range 1.5–6.3 wt.%) of the samples used in the calibration were determined by pyrolysis and subsequent Karl–Fischer Titration. Different combinations of baseline types

  7. Comparison of molar intrusion efficiency and bone density by CT in patients with different vertical facial morphology.

    PubMed

    Ding, W H; Li, W; Chen, F; Zhang, J F; Lv, Y; Chen, X Y; Lin, W W; Fu, Z; Shi, J J

    2015-05-01

    The purpose of this study is to examine the relationship between molar intrusion efficiency and bone density in patients with different vertical facial morphology. Thirty-six female patients, with overerupted upper first molars, were divided into two groups according to mandiblular plane angle (FH-MP): hyperdivergent, FH-MP>30° (G1), hypodivergent, FH-MP<22° (G2). Mini-screw implants with elastic chains were used to intrude upper first molars. Spiral CT was used to measure the intrusion degree of upper first molar and bone density, and molar intrusion efficiency was calculated as amount/duration (mm month(-1) ). In addition, each tooth was divided into three portions (cervical, furcation and apical) to measure the bone density. It was found in this study that treatment duration was 3·13 and 4·71 months in G1 and G2 and that the intrusion efficiency was 1·57 and 0·81 in G1 and G2 with significant difference (P < 0·05). There were significant differences in cervical, furcation and apical bone density between two groups (P < 0·05). The bone density was significantly reduced after molar intrusion. In addition, the bone density change was greater in G1 than in G2 (P < 0·05). It was concluded that molars were more easily to be intruded in hyperdivergent than in hypodivergent patients. The difference of bone density and bone density changes during intrusion may account for the variation of molar intrusion efficiency. PMID:25515652

  8. Simulated fatigue resistance of composite resin versus porcelain CAD\\/CAM overlay restorations on endodontically treated molars

    Microsoft Academic Search

    Pascal Magne; Alena Knezevic

    Objective: To assess the influence of material selection (porcelain versus composite resin) for overlay-type restoration of endodontically treated molars and its effect on the in vitro fatigue resistance and failure mode. Method and Materials: A standardized tooth prepara- tion was applied to 30 extracted molars, including root canal treatment, 3-mm coverage of all cusps, a mesial box 1.5 mm below

  9. State and trait related predictors of serum cortisol to DHEA(S) molar ratios and hormone concentrations in schizophrenia patients

    Microsoft Academic Search

    Michael Ritsner; Anatoly Gibel; Rachel Maayan; Yael Ratner; Eduard Ram; Ilan Modai; Abraham Weizman

    2007-01-01

    Objective:In previous studies we have demonstrated high serum molar ratios of cortisol to dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) [together abbreviated DHEA(S)], and the value of both cortisol\\/DHEA(S) molar ratios for prediction of responsivity to antipsychotic treatment in schizophrenia patients. The present study aimed to examine the contribution of anxiety, and severity of symptoms to the prediction of serum

  10. Influence of molar ratios of precursor, catalyst, solvent and water on monolithicity and physical properties of TMOS silica aerogels

    Microsoft Academic Search

    A. Venkateswara Rao; G. M. Pajonk; N. N. Parvathy

    1994-01-01

    In continuation to our earlier work on aerogels, the experimental results on the monolithicity and physical properties of silica aerogels as a function of the molar ratios of tetramethoxysilane (TMOS) precursor, catalyst (NH4OH), methanol (MeOH) solvent and water, are reported. The molar ratios of NH4OH\\/TMOS, MeOH\\/TMOS and H2O\\/TMOS were varied from 7.1 × 10-6 to 9.6 × 10-1, 1 to

  11. Fluctuation-based computer calculation of partial molar properties. I. Molecular dynamics simulation of constant volume fluctuations

    Microsoft Academic Search

    Pablo G. Debenedetti

    1987-01-01

    Partial molar volumes, energies, and enthalpies are calculated via the (N,U,V) molecular dynamics implementation of their corresponding operational definitions in terms of constant volume fluctuations. The method is exact for the former property but only approximate for the latter two. The partial molar volume operational definition satisfies Euler’s homogeneous function theorem identically. The corresponding energy definition is based upon a

  12. Unique inhibitory cascade pattern of molars in canids contributing to their potential to evolutionary plasticity of diet

    PubMed Central

    Asahara, Masakazu

    2013-01-01

    Developmental origins that guide the evolution of dental morphology and dental formulae are fundamental subjects in mammalian evolution. In a previous study, a developmental model termed the inhibitory cascade model was established. This model could explain variations in relative molar sizes and loss of the lower third molars, which sometimes reflect diet, in murine rodents and other mammals. Here, I investigated the pattern of relative molar sizes (inhibitory cascade pattern) in canids, a taxon exhibiting a wide range of dietary habits. I found that interspecific variation in canid molars suggests a unique inhibitory cascade pattern that differs from that in murine rodents and other previously reported mammals, and that this variation reflects dietary habits. This unique variability in molars was also observed in individual variation in canid species. According to these observations, canid species have greater variability in the relative sizes of first molars (carnassials), which are functionally important for dietary adaptation in the Carnivora. In conclusion, an inhibitory cascade that differs from that in murine rodents and other mammals may have contributed to diverse dietary patterns and to their parallel evolution in canids. PMID:23467478

  13. Construction of a cDNA library for miniature pig mandibular deciduous molars

    PubMed Central

    2014-01-01

    Background The miniature pig provides an excellent experimental model for tooth morphogenesis because its diphyodont and heterodont dentition resembles that of humans. However, little information is available on the process of tooth development or the exact molecular mechanisms controlling tooth development in miniature pigs or humans. Thus, the analysis of gene expression related to each stage of tooth development is very important. Results In our study, after serial sections were made, the development of the crown of the miniature pigs’ mandibular deciduous molar could be divided into five main phases: dental lamina stage (E33-E35), bud stage (E35-E40), cap stage (E40-E50), early bell stage (E50-E60), and late bell stage (E60-E65). Total RNA was isolated from the tooth germ of miniature pig embryos at E35, E45, E50, and E60, and a cDNA library was constructed. Then, we identified cDNA sequences on a large scale screen for cDNA profiles in the developing mandibular deciduous molars (E35, E45, E50, and E60) of miniature pigs using Illumina Solexa deep sequencing. Microarray assay was used to detect the expression of genes. Lastly, through Unigene sequence analysis and cDNA expression pattern analysis at E45 and E60, we found that 12 up-regulated and 15 down-regulated genes during the four periods are highly conserved genes homologous with known Homo sapiens genes. Furthermore, there were 6 down-regulated and 2 up-regulated genes in the miniature pig that were highly homologous to Homo sapiens genes compared with those in the mouse. Conclusion Our results not only identify the specific transcriptome and cDNA profile in developing mandibular deciduous molars of the miniature pig, but also provide useful information for investigating the molecular mechanism of tooth development in the miniature pig. PMID:24750690

  14. Radiographic Evaluation of Third Molar Development in 5- to 25 Year Olds in Tehran, Iran

    PubMed Central

    Jafari, A.; Mohebbi, SZ.; Khami, MR.; Shahabi, M. Shakur; Naseh, M.; Elhami, F.; Shamshiri, AR.

    2012-01-01

    Objective: Radiographic evaluation of the third molar tooth to determine its position and degree of development is an important part in diagnosis and treatment planning, as well as in forensic dentistry procedures. The objective was to investigate the developmental stages of third molars in relation to chronologic age, gender and location (maxillary/mandibular) in an Iranian population. Materials and Methods: The data were collected in departments of pediatric dentistry and orthodontics, Tehran Faculty of Dentistry and four private offices. Three calibrated observers visited the centers to examine panoramic radiographs and corresponded patients documents in each age cohort in the range of 5- to-25-years old. Data were analyzed by Generalized Estimating Equation (GEE) in the linear mode and exchangeable correlation structure. The significance level was defined as 0.05. Results: The mean age of emerging third molars’ follicle was 9.29±1.65 years. Early calcification was seen at the mean age of 10.28±1.66 years. The GEE model controlling for age, gender and tooth location (maxillary/mandibular) revealed that besides age (?=0.43, p<0.001), the tooth location had association with the developmental stage (?=0.11, p<0.001) so that maxillary teeth were prior in calcification stages, but no relationship between gender and developmental stages was seen (?=0.03, p=0.69). Conclusion: Maxillary teeth were ahead of mandibular teeth in calcification stages with no gender difference. The present study may provide a reference for oral surgeons, pediatric dentists and orthodontists practicing in Iran and may have implications for the neighboring countries especially those with Caucasian populations. PMID:23066475

  15. Molar mass characterization of sodium carboxymethyl cellulose by SEC-MALLS.

    PubMed

    Shakun, Maryia; Maier, Helena; Heinze, Thomas; Kilz, Peter; Radke, Wolfgang

    2013-06-01

    Two series of sodium carboxymethyl celluloses (NaCMCs) derived from microcrystalline cellulose (Avicel samples) and cotton linters (BWL samples) with average degrees of substitution (DS) ranging from DS=0.45 to DS=1.55 were characterized by size exclusion chromatography with multi-angle laser light scattering detection (SEC-MALLS) in 100 mmol/L aqueous ammonium acetate (NH4OAc) as vaporizable eluent system. The application of vaporizable NH4OAc allows future use of the eluent system in two-dimensional separations employing evaporative light scattering detection (ELSD). The losses of samples during filtration and during the chromatographic experiment were determined. The scaling exponent as of the relation [Formula: see text] was approx. 0.61, showing that NaCMCs exhibit an expanded coil conformation in solution. No systematic dependencies of as on DS were observed. The dependences of molar mass on SEC-elution volume for samples of different DS can be well described by a common calibration curve, which is of advantage, as it allows the determination of molar masses of unknown samples by using the same calibration curve, irrespective of the DS of the NaCMC sample. Since no commercial NaCMC standards are available, correction factors were determined allowing converting a pullulan based calibration curve into a NaCMC calibration using the broad calibration approach. The weight average molar masses derived using the so established calibration curve closely agree with the ones determined by light scattering, proving the accuracy of the correction factors determined. PMID:23618306

  16. Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals.

    PubMed

    Fornai, Cinzia; Benazzi, Stefano; Svoboda, Ji?í; Pap, Ildikó; Harvati, Katerina; Weber, Gerhard W

    2014-11-01

    Enamel thickness and dental tissue proportions have been recognized as effective taxonomic discriminators between Neanderthal and modern humans teeth. However, most of the research on this topic focused on permanent teeth, and little information is available for the deciduous dentition. Moreover, although worn teeth are more frequently found than unworn teeth, published data for worn teeth are scarce and methods for the assessment of their enamel thickness need to be developed. Here, we addressed this issue by studying the 2D average enamel thickness (AET) and 2D relative enamel thickness (RET) of Neanderthal and modern humans unworn to moderately worn upper first deciduous molars (dm(1)s) and upper second deciduous molars (dm(2)s). In particular, we used 3D ?CT data to investigate the mesial section for dm(1)s and both mesial and buccal sections for dm(2)s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm(1)s than dm(2)s in both Neanderthal and modern humans. We demonstrated that the Neanderthal 2D RET indices are significantly lower than those of modern humans at similar wear stages in both dm(1)s and dm(2)s (p < 0.05). The discriminant analysis showed that using 2D RET from dm(1) and dm(2) sections at different wear stages up to 93% of the individuals are correctly classified. Moreover, we showed that the dm(2) buccal sections, although non-conventionally used, might have an advantage on mesial sections since they distinguish as well as mesial sections but tend to be less worn. Therefore, the 2D analysis of enamel thickness is suggested as a means for taxonomic discrimination between modern humans and Neanderthal unworn to moderately worn upper deciduous molars. PMID:25282273

  17. Age estimation using lower permanent first molars on a panoramic radiograph: A digital image analysis

    PubMed Central

    Talabani, Ranjdar M.; Baban, Mohammed T.; Mahmood, Mohammed A.

    2015-01-01

    Objective: A study was carried out to analyze the efficacy and practical application for age estimation using digital panoramic radiograph to exploit image analysis to obtain metric measurement of morphological parameters of permanent mandibular first molar on Sulaimani population. Materials and Methods: In the present study a population of known age and sex was studied and subjected to digital panoramic radiographic examination. The correlation between the reduction of coronal pulp cavity and chronological age was examined in a sample of 96 individuals distributed into four age groups: 20-29 years (29 cases), 30-39 years (29 cases), 40-49 years (26 cases) and 50-59 years (12 cases). The height (mm) of the crown (CH = coronal height) and the height (mm) of coronal pulp cavity (CPCH = coronal pulp cavity height) of 96 of first molars from all subjects was measured. The tooth–coronal index (TCI) after Ikeda et al. was computed for each tooth and regressed on real age. Results: ANOVA was used to show the strength of relation between the age and TCI (P = 0.0000). The correlation coefficient (r2) was 0.49, which mean there is strong negative linear regression between age and TCI with the r2, regarding predicting age using TCI value, after the following equation calculated, Predicted age = 3.78 – (0.064 TCI) showed that there is no significant difference between real age and estimated age. Conclusion: There is a strong negative liner relationship between TCIs of mandibular first molars with chronological age of Sulaimani population, and age of individuals can therefore be estimated with a good degree of accuracy using regression equations. PMID:26005307

  18. Biometric study of the prefurcation area of human mandibular first molars.

    PubMed

    Barboza, Carlos Alberto; Rodrigues, Diogo Moreira; Petersen, Rodrigo; Trisão, Gilson Coutinho; Barboza, Eliane Porto

    2014-01-01

    This study analyzed the length of the root trunk (RT) as well as the width and depth of the prefurcation area (PFA) of human mandibular first molars. Ninety-six human mandibular first molars that were extracted after being observed to be in poor condition both clinically and radiographically were used in this study. A contour-measuring instrument was used, and profiles of the buccal and lingual root surfaces of these teeth were traced on a millimeter-scaled paper. The profiles were recorded from the cementoenamel junction, millimeter by millimeter, up to the entrance of the furcation of each tooth. The width and depth of the PFA as well as the length of the RT were studied. After statistical analysis it was concluded that the mean widths of the PFA on the buccal and lingual surfaces were 3.68 ± 0.66 and 3.48 ± 0.51 mm, respectively; mean depths of the PFA on the buccal and lingual surfaces were 0.89 ± 0.42 and 0.82 ± 0.28 mm, respectively; and mean lengths of the RT on the buccal and lingual surfaces were 3.07 ± 0.82 and 3.54 ± 0.73 mm. Of the samples, the lengths of the RT and the PFA were coincident in 39.58% on the buccal surface and in 46.87% on the lingual surface. There is a concavity (PFA) in the RT region of all mandibular first molars, showing larger width and depth on the buccal surface. The RT was longer on the lingual surface in comparison with the buccal surface. PMID:25411742

  19. Molar mass, surface tension, and droplet growth kinetics of marine organics from measurements of CCN activity

    NASA Astrophysics Data System (ADS)

    Moore, R. H.; Ingall, E. D.; Sorooshian, A.; Nenes, A.

    2008-04-01

    The CCN-relevant properties and droplet growth kinetics are determined for marine organic matter isolated from seawater collected near the Georgia coast. The organic matter is substantially less CCN active than (NH4)2SO4, but droplet growth kinetics are similar. Köhler Theory Analysis (KTA) is used to determine the average organic molar masses of two samples, which are 4370 +/- 24% and 4340 +/- 18% kg kmol-1. KTA is used to infer surface tension depression, which is in excellent agreement with direct measurements. For the first time it is shown that direct measurements of surface tension are relevant for CCN activation, and this study highlights the power of KTA.

  20. Clinical and radiographic diagnosis of underlying dark shadow from dentin (ICDAS 4) in permanent molars.

    PubMed

    Bertella, N; Moura, Dos S; Alves, L S; Damé-Teixeira, N; Fontanella, V; Maltz, M

    2013-01-01

    This study investigated the radiographic pattern of underlying dark shadow from dentin (ICDAS 4) in permanent molars and assessed the association between enamel breakdown and radiographic features. Ninety-five teeth (54 patients) were clinically and radiographically assessed. The majority of ICDAS 4 caries lesions presented enamel breakdown (n = 78, 82.1%) and no radiographic image (n = 64, 67.4%) or a radiolucent zone restricted to the enamel-dentin junction (n = 17, 17.9%). No association was found between enamel breakdown and radiographic features. This study suggests that a radiographic examination is needed prior to the decision making process for underlying dark shadows from dentin. PMID:23712062

  1. Prevalence of molar incisor hypomineralization in the city of Buenos Aires.

    PubMed

    Biondi, Ana M; Cortese, Silvina G; Martínez, Karina; Ortolani, Andrea M; Sebelli, Patricia M F; Ienco, Melisa; Paván, Verónica H; Mendel, Nancy; Bertolino, Mariana; Hecht, Pedro

    2011-01-01

    The prevalence of Molar Incisor Hypomineralization (MIH) still remains unknown in Argentina. The objectives of this work were to: estimate prevalence of MIH in a group of children seeking dental care in the city of Buenos Aires, analyze distribution according to year of birth and compare prevalence and severity of MIH in children with different access to health care services. A prospective, observational, transversal, descriptive study was designed, to be conducted on children seeking attention at Department of Comprehensive Children's Dentistry at the School of Dentistry of Buenos Aires University and at 3 pediatric dentistry offices attended by members of the team, located in Buenos Aires city (Kappa 0.933 0.911-0.952), from April to August 2010. The study included all children born between 1993 and 2003, whose 4 first molars and 8 permanent incisors had erupted. After prophylaxis and drying, the teeth were clinically evaluated and specially designed charts were used to record sex, year of birth, type of access to dental care, presence of MIH, number of affected incisors and molars, and maximum degree of severity for each tooth. The data obtained were analyzed using percentages, Fisher's Exact Test and Linear regression. 1098 children, mean age 11.3 years (11.08-11.39) were evaluated. Prevalence of MIH in this study was 15.9% (13.8-18.2). A highly significant positive correlation was obtained between MIH and year of birth (p<0.0001). Group A (private sector: prepaid medical insurance) was made up of 586 children (age: 10.92 6.22-15.62) while group B (public sector: university hospital) was made up of 512 children (age: 11.59 5.31-16.90). In Group A, MIH prevalence was 24.40% (20.9-27.9) while in Group B it was 6.44% (4.31-8.56) (p<0.0001). Of the affected molars, 37% (32.2-42) in A and 13.7% (6.7-23.8) in B had grade 3 lesions, with loss of enamel (p<0.0001). In this study, MIH was a frequent pathology (15.9%) and a significant increase was found according to year of birth during the study period. Patients with better access to health care had greater prevalence and degree of severity of MIH. PMID:22010411

  2. Sinus floor augmentation at the time of maxillary molar extraction: technique and report of preliminary results.

    PubMed

    Fugazzotto, P A

    1999-01-01

    A technique is described for accomplishing both localized sinus augmentation and guided bone regeneration at the time of maxillary molar extraction. One hundred nine sites were treated in 92 patients. Of these, 102 procedures (94.0%) were successful and 7 (6.0%) were partially successful. Success was defined as the ability to ideally position an implant at least 10 mm in length and 4.8 mm in width without perforating the floor of the sinus or generating an implant fenestration or dehiscence. Partially successful procedures required an additional osteotome sinus lift at the time of implant placement. PMID:10453669

  3. Brief communication: Comparative patterns of enamel thickness topography and oblique molar wear in two Early Neolithic and medieval population samples.

    PubMed

    Le Luyer, Mona; Rottier, Stéphane; Bayle, Priscilla

    2014-09-01

    Enamel thickness has been linked to functional aspects of masticatory biomechanics and has been demonstrated to be an evolutionary plastic trait, selectively responsive to dietary changes, wear and tooth fracture. European Late Paleolithic and Mesolithic hunter-gatherers mainly show a flat wear pattern, while oblique molar wear has been reported as characteristic of Neolithic agriculturalists. We investigate the relationships between enamel thickness distribution and molar wear pattern in two Neolithic and medieval populations. Under the assumption that dietary and/or non-dietary constraints result in directional selective pressure leading to variations in enamel thickness, we test the hypothesis that these two populations will exhibit significant differences in wear and enamel thickness patterns. Occlusal wear patterns were scored in upper permanent second molars (UM2) of 64 Neolithic and 311 medieval subadult and adult individuals. Enamel thickness was evaluated by microtomography in subsamples of 17 Neolithic and 25 medieval individuals. Eight variables describing enamel thickness were assessed. The results show that oblique molar wear is dominant in the Neolithic sample (87%), while oblique wear affects only a minority (42%) of the medieval sample. Moreover, in the Neolithic molars, where buccolingually directed oblique wear is dominant and greatest enamel lost occurs in the distolingual quadrant, thickest enamel is found where occlusal stresses are the most important-on the distolingual cusp. These results reveal a correlation between molar wear pattern and enamel thickness that has been associated to dietary changes. In particular, relatively thicker molar enamel may have evolved as a plastic response to resist wear. PMID:24961878

  4. The Component Slope Linear Model for Calculating Intensive Partial Molar Properties: Application to Waste Glasses and Aluminate Solutions - 13099

    SciTech Connect

    Reynolds, Jacob G. [Washington River Protection Solutions, LLC, P.O. Box 850, Richland, WA 99352 (United States)] [Washington River Protection Solutions, LLC, P.O. Box 850, Richland, WA 99352 (United States)

    2013-07-01

    Partial molar properties are the changes occurring when the fraction of one component is varied while the fractions of all other component mole fractions change proportionally. They have many practical and theoretical applications in chemical thermodynamics. Partial molar properties of chemical mixtures are difficult to measure because the component mole fractions must sum to one, so a change in fraction of one component must be offset with a change in one or more other components. Given that more than one component fraction is changing at a time, it is difficult to assign a change in measured response to a change in a single component. In this study, the Component Slope Linear Model (CSLM), a model previously published in the statistics literature, is shown to have coefficients that correspond to the intensive partial molar properties. If a measured property is plotted against the mole fraction of a component while keeping the proportions of all other components constant, the slope at any given point on a graph of this curve is the partial molar property for that constituent. Actually plotting this graph has been used to determine partial molar properties for many years. The CSLM directly includes this slope in a model that predicts properties as a function of the component mole fractions. This model is demonstrated by applying it to the constant pressure heat capacity data from the NaOHNaAl(OH){sub 4}-H{sub 2}O system, a system that simplifies Hanford nuclear waste. The partial molar properties of H{sub 2}O, NaOH, and NaAl(OH){sub 4} are determined. The equivalence of the CSLM and the graphical method is verified by comparing results determined by the two methods. The CSLM model has been previously used to predict the liquidus temperature of spinel crystals precipitated from Hanford waste glass. Those model coefficients are re-interpreted here as the partial molar spinel liquidus temperature of the glass components. (authors)

  5. NLRP7, Involved in Hydatidiform Molar Pregnancy (HYDM1), Interacts with the Transcriptional Repressor ZBTB16

    PubMed Central

    Singer, Heike; Biswas, Arijit; Nuesgen, Nicole; Oldenburg, Johannes; El-Maarri, Osman

    2015-01-01

    Mutations in the maternal effect gene NLRP7 cause biparental hydatidiform mole (HYDM1). HYDM1 is characterized by abnormal growth of placenta and lack of proper embryonic development. The molar tissues are characterized by abnormal methylation patterns at differentially methylated regions (DMRs) of imprinted genes. It is not known whether this occurs before or after fertilization, but the high specificity of this defect to the maternal allele indicates a possible maternal germ line-specific effect. To better understand the unknown molecular mechanism leading to HYDM1, we performed a yeast two-hybrid screen against an ovarian library using NLRP7 as bait. We identified the transcriptional repressor ZBTB16 as an interacting protein of NLRP7 and verified this interaction in mammalian cells by immunoprecipitation and confocal microscopy. Native protein analysis detected NLRP7 and ZBTB16 in a 480kD protein complex and both proteins co-localize in the cytoplasm in juxtanuclear aggregates. HYDM1-causing mutations in NLRP7 did not show altered patterns of interaction with ZBTB16. Hence, the biological significance of the NLRP7-ZBTB16 interaction remains to be revealed. However, a clear effect of harvesting ZBTB16 to the cytoplasm when the NLRP7 protein is overexpressed may be linked to the pathology of the molar pregnancy disease. PMID:26121690

  6. Growth-Associated Changes in the Periodontal Bone and Molar Teeth of Male Rats

    PubMed Central

    García, María F; Moreno, Hilda; Rigalli, Alfredo; Puche, Rodolfo C

    2009-01-01

    Here we report quantitative data associating periodontal bone variables of young conventional rats with the growth process. The hemimandibles of male rats (IIM/Fm stock, 2 to 15 wk of age.) were excised and submitted to conventional morphologic, radiologic, and histologic evaluation. The length, area, or X-ray absorbance of various regions or structures was measured on digital images of radiographs by using an image-analysis program. The sum of periodontal bone areas undergoing resorption (interproximal + intraradicular) increased until 9 or 10 wk of age and decreased thereafter. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The mineral density of resorption areas in alveolar bone fitted sinusoidal kinetics, indicative of the ‘instability’ of the tissue due to its high metabolic activity. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The proportion of root length within alveolar bone exhibited a biphasic curve (minimum at 5 wk of age), due to differences in the growth rates of variables involved in its calculation (distance between the cementoenamel junction to the apex and height of the resorption areas). The distance between the cementoenamel junction and alveolar bone crest over time fitted a sigmoidal function with a point of inflection that did not differ significantly from that of body or mandible dry weight. In summary, the growth process appears to affect periodontal bone support and the distance between the cementoenamel junction and alveolar bone crest in male rats. PMID:19807966

  7. Evaluation of intra-alveolar chlorhexidine dressings after removal of impacted mandibular third molars.

    PubMed

    Fotos, P G; Koorbusch, G F; Sarasin, D S; Kist, R J

    1992-03-01

    Chlorhexidine gluconate (CHX) has been investigated for its possible benefit in the prevention of alveolar osteitis complicating third molar removal. In a double-blind, placebo-controlled clinical study, 70 randomly selected healthy patients were subjected to uncomplicated mandibular third molar removal followed by CHX-gelatin sponge and saline solution-gelatin sponge intra-alveolar dressings. Each patient was followed for 6 days for postoperative discomfort and complications, and scored accordingly. The results demonstrated that patients receiving 0.2% CHX intra-alveolar dressings exhibited a significant reduction in postoperative discomfort and complications when compared with saline solution-treated control sites (p less than 0.005). Further, this phenomenon was not found to be related to patient factors including age, sex, and race, nor did any correlation exist between treated or control sites, and surgical factors including performing surgeon, surgeon's dominant hand, time of surgery, surgical site, and difficulty of the removal. These findings warrant further studies concerning the apparent clinical benefit of postextraction intra-alveolar CHX dressings for the reduction of postoperative alveolar osteitis. PMID:1545974

  8. Accuracy of Cameriere's cut-off value for third molar in assessing 18 years of age.

    PubMed

    De Luca, S; Biagi, R; Begnoni, G; Farronato, G; Cingolani, M; Merelli, V; Ferrante, L; Cameriere, R

    2014-02-01

    Due to increasingly numerous international migrations, estimating the age of unaccompanied minors is becoming of enormous significance for forensic professionals who are required to deliver expert opinions. The third molar tooth is one of the few anatomical sites available for estimating the age of individuals in late adolescence. This study verifies the accuracy of Cameriere's cut-off value of the third molar index (I3M) in assessing 18 years of age. For this purpose, a sample of orthopantomographs (OPTs) of 397 living subjects aged between 13 and 22 years (192 female and 205 male) was analyzed. Age distribution gradually decreases as I3M increases in both males and females. The results show that the sensitivity of the test was 86.6%, with a 95% confidence interval of (80.8%, 91.1%), and its specificity was 95.7%, with a 95% confidence interval of (92.1%, 98%). The proportion of correctly classified individuals was 91.4%. Estimated post-test probability, p was 95.6%, with a 95% confidence interval of (92%, 98%). Hence, the probability that a subject positive on the test (i.e., I3M<0.08) was 18 years of age or older was 95.6%. PMID:24365729

  9. Evaluation of formocresol, calcium hydroxide, ferric sulfate, and MTA primary molar pulpotomies

    PubMed Central

    Yildiz, Esma; Tosun, Gul

    2014-01-01

    Objective: The aim of this study is to evaluate four different pulpotomy medicaments in primary molars. Materials and Methods: A total of 147 primary molars with deep caries were treated with four different pulpotomy medicaments (FC: formocresol, FS: ferric sulfate, CH: calcium hydroxide, and MTA: mineral trioxide aggregate) in this study. The criteria for tooth selection for inclusion were no clinical and radiographic evidence of pulp pathology. During 30 months of follow-up at 6-month intervals, clinical and radiographic success and failures were recorded. The differences between the groups were statistically analyzed using the Chi-square test and Kaplan-Meier analysis. Results: At 30 months, clinical success rates were 100%, 95.2%, 96.4%, and 85% in the FC, FS, MTA, and CH groups, respectively. In radiographic analysis, the MTA group had the highest (96.4%), and the CH group had the lowest success rate (85%). There were no clinical and radiographic differences between materials (P > 0.05). Conclusions: Although there were no differences between materials, only in the CH group did three teeth require extraction due to further clinical symptoms of radiographic failures during the 30-month follow-up period. None of the failed teeth in the other groups required extraction during the 30-month follow-up period. PMID:24966776

  10. Primary and secondary closure technique following removal of impacted mandibular third molars: A comparative study

    PubMed Central

    Chaudhary, Manoj; Singh, Manpreet; Singh, Sanjay; Singh, S. P.; Kaur, Gagandeep

    2012-01-01

    Aim: The purpose of this study was to evaluate and compare the post operative healing, using primary versus second closure techniques after impacted mandibular third molar removal. Materials and Methods: The study consisted of twelve patients, Seven males and five females under 30 years of age were divided into two groups as Group A and Group B in the randomized fashion. In the Group A, closure was done by primary intention and in the Group B, by secondary closure. A comparison between both groups was done with a follow-up period of 6 h to 6 days with regards to postoperative pain and swelling. Results: The statistical analysis (analysis of variance for repeated measures, P < 0.05) showed that pain was greater in Group A, although it decreased over time similarly in the two groups. Pain and swelling was less severe with secondary healing than with primary healing. Conclusion: The outcome of this study suggested that secondary closure technique is better than primary closure technique for removal of impacted mandibular third molar with regards to postoperative pain and swelling. PMID:23251051

  11. Sealing versus partial caries removal in primary molars: a randomized clinical trial

    PubMed Central

    2014-01-01

    Background The resin-based pit and fissure sealant is considered a successful tool in caries prevention, however there is a growing evidence of its use in controlling already established caries in posterior teeth. The aim of this clinical trial is to verify the efficacy of pit and fissure sealants in arresting dentinal caries lesions compared to partial excavation and restorative treatment in primary molar teeth. Methods Thirty six patients with occlusal cavitated primary molar reaching outer half of dentin were selected. The patients were randomly allocated into two groups: sealant application (experimental group – n?=?17) and restoration with composite resin (control group – n?=?19). Clinical and radiograph evaluation were performed after 6, 12 and 18 months. The chi-square test was used to verify the distribution of characteristics variables of the sample among the groups. The survival rate of treatments was evaluated using Kaplan–Meier survival and log-rank test. Fisher’s Exact and logistic regression tests were calculated in each evaluation period (??=?5%). Results The control group showed significantly better clinical survival after 18 months (p?=?0.0025). In both groups, no caries progression was registered on the radiographic evaluations. Conclusions Sealing had similar efficacy in the arrestment of caries progression of cavitated occlusal lesions compared to partial excavation of the lesions, even though the frequency of re-treatments was significantly higher in sealed lesions. Trial registration Registro Brasileiro de Ensaios Clínicos (ReBEC): RBR-9kkv53 PMID:24884684

  12. The Effect of Prism Orientation in the Indentation Testing of Human Molar Enamel

    PubMed Central

    Braly, A.; Darnell, L.A.; Mann, A.B.; Teaford, M.F.; Weihs, T.P.

    2007-01-01

    Recent nanoindentation studies have demonstrated that the hardness and Young's modulus of human molar enamel decreases by more than 50% on moving from the occlusal surface to the dentin-enamel junction on cross-sectional samples. Possible sources of these variations are changes in local chemistry, microstructure, and prism orientation. This study investigates the latter source by performing nanoindentation tests at two different orientations relative to the hydroxyapatite prisms: parallel and perpendicular. A single sample volume was tested in order to maintain a constant chemistry and microstructure. The resulting data show very small differences between the two orientations for both hardness and Young's modulus. The 1.5 to 3.0% difference is significantly less than the standard deviations found within the data set. Thus, the variations in hardness and Young's modulus on cross-sectional samples of human molar are attributed to changes in local chemistry (varying levels of mineralization, organic matter, and water content) and changes in microstructure (varying volume fractions of inorganic crystals and organic matrix). The impact of prism orientation on mechanical properties measured by nanoindentation appears to be minimal. PMID:17449008

  13. Morphological and clinical considerations of first and second permanent molar eruption disorders.

    PubMed

    Proff, Peter; Bayerlein, Thomas; Fanghänel, Jochen; Allegrini, Sergio; Gedrange, Tomas

    2006-07-01

    Tooth eruption is a complex biological process which starts from the site of development in the jaw bone until the teeth reach their final functional position in the chewing plane. Various factors can disturb this process. Besides mechanical obstacles on the eruption path, a pathological position or axial orientation of the tooth germ, morphological aberrations of the tooth or pathological alterations of the periodontium, primary disorders of the eruption mechanism may lead to complete or partial retention of the tooth in the jaw bone. These morphological features bear upon the prognosis of orthodontic correction which is dependent upon the underlying cause. First and second molars are rarely affected by eruption disorders, with a prevalence of 0.01 to 0.08 per cent, however, marked consequences for function such as posterior open bite or elongation of the antagonists may result. Following an overview of pathogenetic factors of tooth eruption disorders, selected cases of impacted first and second permanent molars are presented with respect to their morphological causes. PMID:16856600

  14. Identification of possible factors impacting dental students' ability to locate MB2 canals in maxillary molars.

    PubMed

    Park, Ellen; Chehroudi, Babak; Coil, Jeffrey M

    2014-05-01

    This study examined the effect of the access size and straight-line path of access on third-year dental students' ability to locate a second mesiobuccal (MB2) canal in maxillary first and second molars. One hundred and six third-year dental students at one Faculty of Dentistry performed simulated root canal treatment with the aid of 2x magnification loupes on extracted teeth. A postgraduate endodontic student subsequently made a reasonable search for an untreated MB2 canal with the aid of a dental operating microscope. The mesiobuccal roots were then sectioned horizontally for determination of the canal configuration. The dental students were able to treat an MB2 canal in 15.8 percent of the teeth, but this was not associated with satisfactory access criteria. The postgraduate endodontic student identified an MB2 canal in 54.7 percent of the remaining tooth samples excluding those where the MB2 canal was found by the dental students; this represented 94.3 percent of those teeth confirmed by horizontal sectioning of the root to have an MB2 canal. The postgraduate student troughed, on average, 2.6 mm before negotiating the MB2 canal. As satisfactory access criteria and straight-line path of access did not correlate with the dental students' ability to find a second mesiobuccal canal, this result has important implications for educational goals with respect to endodontic treatment of maxillary molar teeth. PMID:24789839

  15. Refractive index, molar refraction and comparative refractive index study of propylene carbonate binary liquid mixtures.

    PubMed

    Wankhede, Dnyaneshwar Shamrao

    2012-06-01

    Refractive indices (n) have been experimentally determined for the binary liquid-liquid mixtures of Propylene carbonate (PC) (1) with benzene, ethylbenzene, o-xylene and p-xylene (2) at 298.15, 303.15 and 308.15 K over the entire mole fraction range. The experimental values of n are utilised to calculate deviation in refractive index (?n), molar refraction (R) and deviation in molar refraction (?R). A comparative study of Arago-Biot (A-B), Newton (NW), Eyring and John (E-J) equations for determining refractive index of a liquid has been carried out to test their validity for all the binary mixtures over the entire composition range at 298.15 K. Comparison of various mixing relations is represented in terms of average deviation (AVD). The ?n and ?R values have been fitted to Redlich-Kister equation at 298.15 K and standard deviations have been calculated. The results are discussed in terms of intermolecular interactions present amongst the components. PMID:24061238

  16. Molar tooth sign of the midbrain-hindbrain junction: occurrence in multiple distinct syndromes.

    PubMed

    Gleeson, Joseph G; Keeler, Lesley C; Parisi, Melissa A; Marsh, Sarah E; Chance, Phillip F; Glass, Ian A; Graham Jr, John M; Maria, Bernard L; Barkovich, A James; Dobyns, William B

    2004-03-01

    The Molar Tooth Sign (MTS) is defined by an abnormally deep interpeduncular fossa; elongated, thick, and mal-oriented superior cerebellar peduncles; and absent or hypoplastic cerebellar vermis that together give the appearance of a "molar tooth" on axial brain MRI through the junction of the midbrain and hindbrain (isthmus region). It was first described in Joubert syndrome (JS) where it is present in the vast majority of patients with this diagnosis. We previously showed that the MTS is a component of several other syndromes, including Dekaban-Arima (DAS), Senior-Löken, and COACH (cerebellar vermis hypoplasia (CVH), oligophrenia, ataxia, coloboma, and hepatic fibrosis). Here we present evidence that the MTS is seen together with polymicrogyria, Váradi-Papp syndrome (Orofaciodigital VI (OFD VI)), and a new syndrome with encephalocele and cortical renal cysts. We also present a new patient with COACH syndrome plus the MTS. We propose that the MTS is found in multiple distinct clinical syndromes that may share common developmental mechanisms. Proper classification of patients with these variants of the MTS will be essential for localization and identification of mutant genes. PMID:14981712

  17. Morphometric study of the root anatomy in furcation area of mandibular first molars

    PubMed Central

    MARCACCINI, Andréa Marcia; PAVANELO, Ângela; NOGUEIRA, Andressa Vilas Boas; de SOUZA, João Antonio Chaves; PORCIÚNCULA, Hélio Ferraz; CIRELLI, Joni Augusto

    2012-01-01

    Furcation involvement in periodontal disease has been a challenge for the dentist. Objective The aim of this study was to investigate root dimensions in the furcation area of 233 mandibular first molars. Material and Methods Digital photomicrographs were used to obtain the following measurements on the buccal and lingual surfaces of each tooth: root trunk height (RT), horizontal interadicular distance obtained 1 mm (D1) and 2 mm (D2) below the fornix and interadicular angle (IA). Results Mean± standard deviation of buccal and lingual furcation measurements were, respectively, 1.37±0.78 mm and 2.04±0.89 mm for RT; 0.86±0.39 mm and 0.71±0.42 mm for D1; 1.50±0.48 mm and 1.38±0.48 mm for D2; 41.68±13.20º and 37.78±13.18º for IA. Statistically significant differences were found between all measured parameters for buccal and lingual sides (p<0.05, paired t test). Conclusions In conclusion, the lingual furcation of mandibular first molars presented narrower entrance and longer root trunk than the buccal furcation, suggesting more limitation for instrumentation and worse prognosis to lingual furcation involvements in comparison to buccal lesions. PMID:22437682

  18. Hemisection: A Treatment Option for an Endodontically treated Molar with Vertical Root Fracture.

    PubMed

    Anitha, S; Rao, Deepika Sc

    2015-01-01

    Vertical root fractures (VRF) in endodontically treated teeth have long been reported and pose diagnostic difficulties. A hemisection/root resection procedures removes the fractured fragments completely, and retains a portion of the compromized tooth offers a predictable treatment option. The key to this rests in ideal case selection involving balancing all indications and contraindications. The success of the treatment depends on careful case selection based on a firm set of guidelines. This article presents a case with VRF in an endodontic treated molar. This article describes the case of a 65-year-old man with a VRF on the mesial root and a healthy periodontium supporting the distal root making it ideal for retention as well as restoration and support of the final prosthesis. Also, the patient was motivated to try and save as much of the tooth as possible. Postoperatively no untoward complication was reported making it an alternative treatment option in patients with VRF in a molar, willing to retain the remaining tooth portion. With all other factors balanced, it allows for retaining the remaining intact portion of the tooth structure. PMID:25906809

  19. The effects of informed consent format on preoperative anxiety in patients undergoing inferior third molar surgery

    PubMed Central

    Heras-Meseguer, Marisa; Azcárate-Velázquez, Francisco; Hita-Iglesias, Pilar; Ruiz-de-León-Hernández, Gonzalo; Hernández-Pacheco, Esther; Gutiérrez-Pérez, José L.

    2014-01-01

    Objectives: To evaluate the effect of informed consent format on preoperative anxiety of patients. Material and Methods: We performed a prospective study (91 patients) undergoing lower third molar extraction. Patients were distributed into three groups. Informed consent for surgery was obtained through a written document, an oral interview or a video recording. Afterwards, patients were asked about their anxiety level and the effect the informed consent had had on it. Results: Whereas the information conveyed both in oral and written formats relieved the patient to some extent (in a scale of -3 to +3) 0.97±1.21 and 0.29±0.97, respectively), the video recording increased patient’s anxiety in a statistically significant way (in a scale of -3 to +3, -0.57±1.43). The difference obtained between the values obtained in oral and written information was not statistically significant. Discussion: The most adequate format, according to our study, would be the oral format. Key words:Anxiety, satisfaction, third molar surgery, Spielberger State-Trait Anxiety Inventory. PMID:24316709

  20. Computer-assisted intraosseous anaesthesia for molar and incisor hypomineralisation teeth. A preliminary study.

    PubMed

    Cabasse, C; Marie-Cousin, A; Huet, A; Sixou, J L

    2015-03-01

    Anesthetizing MIH (Molar and Incisor Hypomineralisation) teeth is one of the major challenges in paediatric dentistry. Computer-assisted IO injection (CAIO) of 4% articaine with 1:200,000 epinephrine (Alphacaine, Septodont) has been shown to be an efficient way to anesthetize teeth in children. The aim of this study was to assess the efficacy of this method with MIH teeth. This preliminary study was performed using the Quick Sleeper system (Dental Hi Tec, Cholet, France) that allows computer-controlled rotation of the needle to penetrate the bone and computer-controlled injection of the anaesthetic solution. Patients (39) of the department of Paediatric Dentistry were included allowing 46 sessions (including 32 mandibular first permanent molars) to be assessed. CAIO showed efficacy in 93.5% (43/46) of cases. Failures (3) were due to impossibility to reach the spongy bone (1) and to achieve anaesthesia (2). This prospective study confirms that CAIO anaesthesia is a promising method to anesthetize teeth with MIH that could therefore be routinely used by trained practitioners. PMID:26058304

  1. Molar Incisor Hypomineralization: A Study of Prevalence and Etiology in a Group of Iranian Children

    PubMed Central

    Ahmadi, Rahil; Ramazani, Nahid; Nourinasab, Rahmatollah

    2012-01-01

    Objective The aim of this study was to investigate the prevalence of molar incisor hypomineralization (MIH) and its relationship with systemic conditions in a group of Iranian children. Methods The study population comprised of 433 7-9 year olds, from four schools in Zahedan, Iran. Subjects were evaluated clinically by one examiner, and at a separate session, their mothers completed a coded medical history questionnaire. Hypo-mineralized molars and incisors were recorded based on DDE (developmental defects of enamel) index and DMFT (number of decayed, filled and missing teeth) was determined. Statistical analyses were performed using Chi-square and independent sample t-tests. Findings Fifty-five (12.7%) children showed MIH. The overall mean number of affected teeth was 0.2. The mean value of DMFT in MIH children was greater than in normal children. Demarcated opacities were the most frequent (76%) enamel defect. Mother's and child's medical problems during prenatal, perinatal and post natal period were significantly remarkable in MIH children. Conclusion The prevalence of MIH in a group of Iranian children was 12.7%. Prenatal, perinatal and post natal medical conditions were more prevalent in children affected by MIH. PMID:23056894

  2. Determination of sexual dimorphism via maxillary first molar teeth in Himachali population

    PubMed Central

    Singla, Swati; Gupta, Rakhi; Puri, Abhiney; Bansal, Sucheta; Singla, Smita; Nangia, Rajat

    2015-01-01

    Context: Sex determination of skeletal remains forms part of archaeological and medicolegal examinations. It is an aspect of forensic odontology. Forensic odontology primarily deals with identification, based on recognition of unique features present in an individual's dental structures. Correct sex determination limits the pool of missing persons to just one half of the population. Aim of Study: Purpose of this study is to evaluate the existence of sexual dimorphism and variation in left and right maxillary first molars using bucco-lingual and mesio-distal dimensions in population of Sirmour District, H.P. Materials and Methods: Base sample comprised 100 subjects (50 males and 50 females) of an age group ranging from 17 to 25 years. Statistical Analysis Used: Unpaired t-test. Results: It was observed that the comparison of mean values of bucco-lingual and mesio-distal parameters showed highly statistically significant differences between males and females, measured both intraorally and on study casts. There were no significant differences between the mean values of both the parameters on the left side as compared to right side. Conclusion: The study concludes that sexual dimorphism is population specific. Among Himachali people, mesio-distal dimensions and bucco-lingual dimensions of first molar can aid in sex determination. PMID:26005295

  3. Approach for determination of ATP:ADP molar ratio in mixed solution by surface-enhanced Raman scattering.

    PubMed

    Fang, Hui; Yin, Hong Jun; Lv, Ming Yang; Xu, Hai Jun; Zhao, Yong Mei; Zhang, Xin; Wu, Zheng Long; Liu, Luo; Tan, Tian Wei

    2015-07-15

    The ATP:ADP molar ratio is an important physiological factor. However, in previous literatures, ATP and ADP could not be distinguished by Raman spectroscopy due to the high similarity of molecular structure. To challenge this problem, also considering that the ? phosphate group may interact with adenine group and cause a different variation of the Raman spectrum than that of ADP, a highly sensitive, low-cost, environment protecting, flexible and super-hydrophobic Au nanoparticles/cicada wing (Au/CW) substrate with three-dimension structure was fabricated and employed as an active surface-enhanced Raman scattering (SERS) substrate to detect the ATP:ADP molar ratios. The concentration as low as 10(-8)M for ATP and ADP was analyzed to determine the limit of detection. This SERS study on various ATP:ADP molar ratios demonstrates that ATP:ADP could be distinguished and the quantitative determination of ATP content was achieved. Moreover, a principle was speculated based on the molecular structures of ATP and ADP of the Raman peaks centered at ~685 and ~731cm(-1) to explain the linear relationship between the area ratio and the molar ratio. A new method has been developed for quantitative determination of ATP:ADP molar ratio based on Au/CW substrate by the SERS method. PMID:25703730

  4. Accuracy of identifying juvenile/adult status from third molar development using prediction probabilities derived from logistic regression analysis.

    PubMed

    Acharya, Ashith B; Bhowmik, Biyas; Naikmasur, Venkatesh G

    2014-05-01

    The use of third molars in predicting juvenile/adult status (molar development was assessed using Köhler's grading on 268 orthopantomograms of Indian subjects. Logistic regression analysis was applied to determine allocation accuracy of juvenile/adult status and the level of probability that is "reliable" in predicting juvenile/adult status. Allocation accuracies ranged between 75.8% and 78.2% for the sexes combined, with minimal male-female differences. Adults were categorized more accurately than juveniles, suggesting that Köhler's grading puts Indian juveniles at greater risk of unwarranted punishment. In both sexes, juvenile/adult status was "reliably" predicted when the probability was >80% using individual third molars (excepting the lower right third molar in males); combining upper and lower third molars on the left/right sides, "reliable" predictions were possible when the probability was >80% and >90% for females and males, respectively. Overall, "reliable" juvenile/adult status prediction was achieved in c. 36% of subjects. PMID:24313875

  5. Guided tissue regeneration in the treatment of degree II furcations in maxillary molars.

    PubMed

    Pontoriero, R; Lindhe, J

    1995-10-01

    he present clinical trial was designed to evaluate the clinical effect of GTR in the treatment of degree II furcation defects in maxillary molars. 28 patients, 21 to 59 years of age, referred for treatment of advanced periodontal disease were included. They presented with similar periodontal lesions in the right and the left maxillary molar regions, but had only one surface which exhibited furcation involvement. A total of 28 pairs of contralateral furcation defects of degree II including 18 interproximal pairs (10 mesial, 8 distal) and 10 buccal pairs, were available for the study. After the completion of basic therapy, the furcation involved molars in the right and left quadrants in each patient were randomly assigned to either a test or a control treatment procedure. Following flap elevation, scaling, root planing and granulation tissue removal, an e-PTFE membrane at the test site was adjusted to cover the entrance to the furcation defect and adjacent bone and was retained in this position with sling sutures. The mucoperiostal flaps were subsequently adjusted and positioned to cover the entire surface of the membrane and were secured in this position. An identical surgical procedure was performed in the control tooth regions with the exception of the placement of a teflon membrane. No periodontal dressing was used. Starting the day before surgery and continuing for 7 days, the patients received 1 + 1 g of Amoxicillin per day; morning and evening. The sutures were removed after 10 days. At the test sites, the membranes were removed after 6 weeks of healing. The treated sites were examined and re-entry procedures performed 6 months after reconstructive surgery. Open flap debridement at maxillary furcations of degree II resulted in some gingival recession and probing depth reduction, but no change occurred in parameters describing probing attachment or bone levels. The addition of GTR at buccal furcations enhanced the treatment result by promoting probing attachment and bone gain and reduced the amount of soft tissue recession above what was accomplished by flap debridement alone. No such benefit of membrane therapy was observed at mesial and distal furcations. PMID:8682922

  6. Economic modeling of sealing primary molars using a "value of information" approach.

    PubMed

    Ney, J P; van der Goes, D N; Chi, D L

    2014-09-01

    The objective was to evaluate 2 primary molar sealant strategies for publicly insured children using an "expected value of perfect information" (EVPI) approach. We converted a 10,000-observation tooth-level cost-effectiveness simulation model comparing 2 primary molar sealant strategies - always seal (AS) and standard care (SC) - with a 1,250-observation child-level model. Costs per child per restoration or extraction averted were estimated. Opportunity losses under the AS strategy were determined for children for whom SC was the optimal choice. We determined the EVPI by multiplying mean opportunity losses by the projected incident population of publicly insured 3-year-olds in the US over 10 years with costs discounted at 2%. All analyses were conducted under assumptions of high and low intrachild correlations between at-risk teeth. The AS strategy cost $43.68 over SC (95% CI: -$5.50, $92.86) per child per restoration or extraction averted under the high intrachild correlation assumption and $15.54 (95% CI $7.86, $23.20) under the low intrachild correlation. Under high intrachild correlation, mean opportunity losses were $80.28 (95% CI: $76.39, $84.17) per child, and AS was the optimal strategy in 31% of children. Under low correlation, mean opportunity losses were $14.61 (95% CI: $12.20, $17.68) and AS was the optimal strategy in 87% of children. The EVPI was calculated at $530,813,740 and $96,578,389 (for high and low intrachild correlation, respectively), for a projected total incident population of 8,059,712 children. On average, always sealing primary molars is more effective than standard care, but widespread implementation of this preventive approach among publicly insured children would result in large opportunity losses. Additional research is needed to identify the subgroups of publicly insured children who would benefit the most from this effective and potentially cost-saving public health intervention. PMID:25056993

  7. A Novel Approach for Restoration of Hemisectioned Mandibular Second Molar with Modified Tunnel Restoration: A Case Report

    PubMed Central

    Varma K, Madhu; Satish R, Kalyan; Kumar M, Sita Rama; Sajjan, Girija S

    2014-01-01

    Hemisection refers to sectioning of a mandibular molar into two halves followed by removal of the diseased root and its coronal portion. Hemisection of a mandibular molar may be a suitable treatment option when the decay is restricted to one root and the other root is healthy. The retained root is endodontically treated and the furcation area is made self-cleansable. Retained tooth structure is restored as premolar which helps to reduce the masticatory load. Hemisection of mandibular molar was often referred to as premolarization. Studies showed that the remaining coronal structure influenced the fracture resistance of endodontically treated maxillary first premolars. Clinical experience showed the viability of tunnel restoration as an alternative to class II conventional cavity preparation in initial proximal lesion. This article discusses a case that presents the novel technique involved in restoration of the remaining hemisected tooth using modified tunnel restoration. PMID:25478460

  8. Dental age estimation utilizing third molar development: A review of principles, methods, and population studies used in the United States.

    PubMed

    Lewis, James M; Senn, David R

    2010-09-10

    When an individual reaches the age of legal majority, their treatment within the criminal and civil legal systems is changed dramatically in the United States. Forensic odontologists are often asked to assist government agencies in estimating the ages of persons who may or may not have reached that legally important age. The third molars are the only teeth useful as forensic estimators of chronological age in the target age group. This study reviews the principles, methodology, and population data of the most commonly used technique in the United States, the analysis of the third molar development based on modified Demirjian staging. The method analyzes the developing third molar to estimate mean age, age intervals and the empirical probability that an individual has reached the anniversary of her or his eighteenth birthday. PMID:20493649

  9. Molar-mass measurement of a 28Si-enriched silicon crystal for determination of the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Narukawa, Tomohiro; Hioki, Akiharu; Kuramoto, Naoki; Fujii, Kenichi

    2014-06-01

    The molar mass of a 28Si-enriched crystal was measured at the National Metrology Institute of Japan to determine the Avogadro constant by the x-ray crystal density method as part of the International Avogadro Coordination project. The molar mass was determined by isotope ratio measurements using a multicollector inductively coupled plasma mass spectrometer combined with an isotope dilution technique. The 28Si-enriched crystal was dissolved in tetramethylammonium hydroxide and three different blended solutions were used to correct for mass bias in the measurement. The molar mass of the 28Si-enriched crystal was determined to be 27.976?970 09 g mol-1 with a standard uncertainty of 0.000?000 14 g mol-1. This corresponds to a relative standard uncertainty of 5.2 × 10-9. This result is consistent with measurements reported by the Physikalisch-Technische Bundesanstalt, Germany.

  10. Studies of Partial Molar Volumes of Some Narcotic-Analgesic Drugs in Aqueous-Alcoholic Mixtures at 25°C

    NASA Astrophysics Data System (ADS)

    Sharma, Poonam; Chauhan, S.; Syal, V. K.; Chauhan, M. S.

    2008-04-01

    Partial molar volumes of the drugs Parvon Spas, Parvon Forte, Tramacip, and Parvodex in aqueous mixtures of methanol (MeOH), ethanol (EtOH), and propan-1-ol (1-PrOH) have been determined. The data have been evaluated using the Masson equation. The parameters, apparent molar volumes {(?_v)}, partial molar volumes {(?_v0)}, and S v values (experimental slopes) have been interpreted in terms of solute solvent interactions. In addition, these studies have also been extended to determine the effect of these drugs on the solvation behavior of an electrolyte (sodium chloride), a surfactant (sodium dodecyl sulfate), and a non-electrolyte (sucrose). It can be inferred from these studies that all drug cations can be regarded as structure makers/promoters due to hydrophobic hydration. Furthermore, the results are correlated to understand the solution behavior of drugs in aqueous-alcoholic systems, as a function of the nature of the alcohol and solutes.

  11. Accuracy of predicting 18 years of age from mandibular third molar development in an Indian sample using Demirjian’s ten-stage criteria

    Microsoft Academic Search

    Ashith B. Acharya

    2011-01-01

    Predicting 18 years of age can be crucial in forensic contexts. The third molar is the only tooth developing during this chronological\\u000a period and has been used to estimate minority\\/majority status (<\\/?18 years). Conventionally, Demirjian’s grading has been\\u000a used to assess third molar development although the method was not originally intended for evaluating this tooth. Demirjian\\u000a incorporated third molar assessment in a

  12. Biogeography and molar morphology of Pleistocene African elephants: new evidence from Elandsfontein, Western Cape Province, South Africa

    NASA Astrophysics Data System (ADS)

    Smith, Kathlyn M.; Stynder, Deano D.

    2015-05-01

    Elandsfontein (EFT) is a Middle Pleistocene archaeological/paleontological site located in the Western Cape Province of South Africa. The largest herbivore in the assemblage is Loxodonta atlantica zulu, an extinct member of the genus that includes modern African elephants. No Elephas recki specimens were recovered at EFT, despite their common occurrence in other regions of Africa at the same time. Because E. recki and L. atlantica molars are similar in appearance, but the two species are traditionally viewed as dominating different regions of Africa during the Pleistocene, isolated molars may on occasions have been assessed to species level on the basis of geography rather than morphology. The last morphologic evaluation of EFT elephants was conducted in the 1970s, and revisiting this issue with new specimens provides added insight into the evolution of elephants in Africa. Reevaluating morphological characteristics of EFT elephant molars, through qualitative and quantitative description and comparison with Middle Pleistocene E. recki recki, L. atlantica atlantica, and L. atlantica zulu molar morphology, corroborates assessment of EFT elephants as L. a. zulu. Two recently discovered, previously undescribed molars from EFT show that molars of L. a. zulu exhibit greater variation in enamel thickness, lamellar frequency, and occlusal surface morphology than previously reported. An update of the Pleistocene biogeography of Loxodonta and Elephas indicates that fossil remains of both are often found at the same localities in eastern Africa. Their rare co-occurrences in the north and south, however, suggest geographic separation of the two genera in at least some regions of Africa, which may have been based on habitat preference.

  13. Comparative evaluation of Ferric Sulfate, Electrosurgical and Diode Laser on human primary molars pulpotomy: an “in-vivo” study

    PubMed Central

    Yadav, P; Indushekar, KR; Saraf, BG; Sheoran, N; Sardana, D

    2014-01-01

    Background and aims: Despite modern advances in the prevention of dental caries and increased understanding of the importance of maintaining the natural primary dentition, many teeth are still lost prematurely. This can lead to malocclusion with aesthetic, phonetic and functional problems that may be transient or permanent. Therefore, maintaining the integrity and health of the oral tissues is the primary objective of pulp treatment. Pulpotomy has remained an acceptable and mainstay treatment in preserving the vitality of primary tooth and prolonging its life till the permanent successor erupts. Various materials and techniques are available for pulpotomy on primary molars; all with some advantages and disadvantages. The present study was carried out on 45 primary molars to evaluate and compare the clinical and radiographic success of diode laser, electrosurgical and ferric sulfate pulpotomy over a period of 9 months. Materials (Subjects) and Methods: The forty five primary molars were randomly and equally divided into three treatment groups which were as follows: Group A: 15 primary molars treated with 15.5% Ferric sulfate Group B: 15 primary molars treated with electrosurgical unit and Group C: 15 primary molars treated with diode laser. All teeth in three categories were followed up clinically and radiographically at 1, 3, 6 and 9 months post treatment and the findings were recorded on the prepared proforma Results: Clinically, 86.6% success rate was found in ferric sulfate group whereas 100% success rate was found in electrosurgical and diode laser groups. Radiographically, 80% success rate was found in all the three groups at the end of 9 months with internal resorption being the most common cause of failure after pulpotomy. Conclusions: Thus, electrosurgery and diode lasers appear to be acceptable alternative to pharmacotherapeutic pulpotomy agents. PMID:24771970

  14. Infected dentigerous cyst of maxillary sinus arising from an ectopic third molar.

    PubMed

    Guruprasad, Yadavalli; Chauhan, Dinesh Singh; Kura, Umashankar

    2013-01-01

    A dentigerous cyst or follicular cyst is a form of odontogenic cyst. It is believed that it forms during the development of the tooth and is associated with pressure exerted by the crown of an unerupted (or partially erupted) tooth on the fluid within the follicular space. Typically, dentigerous cysts are painless and discovered during routine radiographic examination. However, they may be large and result in a palpable mass. Additionally, as they grow they displace adjacent teeth. They almost exclusively occur in permanent dentition. The cyst is lined by stratified squamous non-keratinizing epithelium. About 70% of dentigerous cysts occur in the mandible and 30% in the maxilla. Dentigerous cysts associated with ectopic teeth within the maxillary sinus are very rare. We report radiologic and pathologic features in a rare case of infected dentigerous cyst of maxillary sinus arising from an ectopic third molar in a 21-year-old female patient. PMID:24516770

  15. Immunohistochemical demonstration of exocytosis-regulating proteins within rat molar dentinal tubules.

    PubMed

    Norlin, T; Hilliges, M; Brodin, L

    1999-03-01

    No morphologically defined synaptic structures have so far been detected between nerve terminals and the dentine-producing odontoblasts. Recent studies of the molecular mechanisms in neuronal exocytosis have identified several proteins that participate in synaptic-vesicle exocytosis. By localizing these proteins with immunohistochemical methods, information about the capacity for synaptic exocytosis should be obtained. Here, antibodies directed against some of the exocytosis-related proteins were used to investigate whether they are present in nerve fibers within the dentinal tubules in rat molars. Antibodies against synaptosome-associated protein of 25 kDa, Rab 3, synaptotagmin and synapsin all produced a punctuate staining pattern, suggesting that the proteins are accumulated in bouton-like elements. The results demonstrate that a set of exocytosis-related proteins is accumulated in the dentinal tubules, most probably within the intradentinal nerves. This finding is consistent with the hypothesis that intradentinal nerves can mediate efferent signals. PMID:10217513

  16. How big is the hydrated electron? Thermodynamics of electron solvation and its partial molar volume

    NASA Astrophysics Data System (ADS)

    Bartels, David

    2015-03-01

    Several models for the hydrated electron solvation structure have been proposed, which all can do a reasonable job of reproducing the room temperature optical spectrum. As Larsen, Glover and Schwartz demonstrated, tweaking the electron-water pseudopotential can completely change the structure from a cavity to a non-cavity geometry. Deciding between the competing models then requires comparison with other observables. The resonance Raman spectrum and the temperature dependence of the optical spectrum can be cited as evidence in favor of a non-cavity structure. In the present work we will re-examine the thermodynamics of hydration. In particular, we will present new experimental and simulation results for the partial molar volume, which can bear directly on the cavity vs. non-cavity controversy. DMB is supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences under Award Number DE- FC02-04ER1553.

  17. Solution properties of high-molar-mass hyaluronans: the biopolymer degradation by ascorbate.

    PubMed

    Soltés, Ladislav; Valachová, Katarína; Mendichi, Raniero; Kogan, Grigorij; Arnhold, Juergen; Gemeiner, Peter

    2007-06-11

    An accurate molecular characterization, molar mass and size distributions, of 10 hyaluronan (HA) samples was performed by using a multi-angle light scattering detector connected on-line to a size exclusion chromatographic system. The dynamic viscosity eta of the HA solutions was investigated using a rotational viscometer. On monitoring the sample dynamic viscosity for up to 5h, a small however constant increase of the eta value was observed, indicating rheopectic behavior of all 10 HA solutions. Addition of ascorbic acid to the HA solutions caused significant changes in the rheological properties of the samples investigated. The change of eta values in the course of time was explained by the redox reactions (caused by the added ascorbate) that occur during the dynamic viscosity monitoring. PMID:17362893

  18. Coumarin-bearing triarylamine sensitizers with high molar extinction coefficient for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhong, Changjian; Gao, Jianrong; Cui, Yanhong; Li, Ting; Han, Liang

    2015-01-01

    Coumarin unit is introduced into triarylamine and three organic sensitizers are designed and synthesized with triarylamine bearing coumarin moiety as the electron donor, conjugated system containing thiophene unit as the ?-bridge, and cyanoacetic acid moiety as the electron acceptor. The light-harvesting capabilities and photovoltaic performance of these dyes are investigated systematically with the comparison of different ?-bridges. High molar extinction coefficients are observed in these triarylamine dyes and the photocurrent and photovoltage are increased with the introduction of another thiophene or benzene. Optimal photovoltaic performance (? = 6.24%, Voc = 690 mV, Jsc = 14.33 mA cm-2, and ff = 0.63) is observed in the DSSC based on dye with thiophene-phenyl unit as the ?-conjugated bridge under 100 mW cm-2 simulated AM 1.5 G solar irradiation.

  19. Fracture Resistance of Non-Metallic Molar Crowns Manufactured with CEREC 3D

    NASA Astrophysics Data System (ADS)

    Madani, Dalia A.

    Objectives. To compare fracture strength and fatigue resistance of ceramic (ProCAD, Ivoclar-Vivadent) (C) and resin composite (Paradigm MZ100, 3M/ ESPE) (R) crowns made with CEREC-3D. Methods. A prepared ivorine molar tooth was duplicated to produce 40 identical prepared specimens made of epoxy resin (Viade). Twenty (C) crowns and 20 (R) were cemented to their dies using resin cement. Ten of each group were subjected to compressive loading to fracture. The remaining 10 of each group were subjected to mechanical cyclic loading for 500,000 cycles. The survivors were subjected to compressive loading to fracture. Results. No significant difference in mean fracture load was found between the two materials. However, only 30% of the (C) crowns vs. 100% of the (R) crowns survived the cyclic loading test. Conclusions. (R) crowns demonstrated higher fatigue Resistance than (C) crowns in-vitro and might better resist cracking in-vivo.

  20. Joubert Syndrome: The Molar Tooth Sign of the Mid-Brain

    PubMed Central

    Nag, C; Ghosh, M; Das, K; Ghosh, TN

    2013-01-01

    Joubert syndrome (JS) is a very rare, autosomal-recessive condition. It is characterized by agenesis of cerebellar vermis, abnormal eye movements with nystagmus, episodes of hyperpnea and apnea, delayed generalized motor development, retinal coloboma and dystrophy and, sometimes, multicystic kidney disease. The importance of recognizing JS is related to the outcome and its potential complications. Prenatal diagnosis by ultarsonography and antenatal magnetic resonance imaging (MRI) is also possible. We have diagnosed a case of JS in a male infant with history of delayed mental and motor milestone development, history of abnormal breathing pattern, abnormal limb movement, generalized hypotonia and abnormal head movements with nystagmus. MRI showed hypoplastic cerebellar vermis with hypoplasia of the superior cerebellar peduncle resembling the “Molar Tooth Sign” in the mid-brain. PMID:23919210

  1. Characterization of cellulose acetates according to DS and molar mass using two-dimensional chromatography.

    PubMed

    Ghareeb, Hewa Othman; Radke, Wolfgang

    2013-11-01

    A two-dimensional liquid chromatographic method (2D LC) was developed to analyze the heterogeneities of cellulose acetates (CA) in the DS-range DS=1.5-2.9 with respect to both, molar mass and degree of substitution (DS). The method uses gradient liquid chromatography (HPLC) as the first dimension in order to separate by DS followed by separation of the different fractions by size (SEC) in the second dimension. The 2D experiments revealed different correlations between gradient and SEC elution volume. These correlations might arise from differences in the synthetic conditions. The newly developed 2D LC separation therefore provides new insights into the heterogeneity of CAs. PMID:24053824

  2. Maxillary first molar with seven root canals diagnosed with cone-beam computed tomography scanning.

    PubMed

    Munavalli, Anil; Kambale, Sharnappa; Bandekar, Siddhesh; Ajgaonkar, Nishant

    2015-01-01

    Nonsurgical endodontic therapy of a right maxillary first molar with three roots and seven root canals. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images. CBCT axial images showed that both the palatal and distobuccal root have a Vertucci type II canal pattern, whereas the mesiobuccal root showed a Sert and Bayirli type XVIII canal configuration. The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently. PMID:25961622

  3. Comparative study of the upper molar occlusal table morphology among seven human populations.

    PubMed

    Kanazawa, E; Morris, D H; Sekikawa, M; Ozaki, T

    1988-10-01

    Three-dimensional morphology of the occlusal table of the upper first molars was compared in seven racial populations. Materials were moiré contourograms collected by ourselves over 5 years. Intercuspal distances and cuspal heights were comparatively studied in this analysis. When the populations were arranged in the order of these sizes, their arrangements based on intercuspal distances and cuspal heights were quite different from each other. When intercuspal distances were scaled by protocone-paracone distance, the distances connecting distal cusps were significantly smaller in Mongoloids (Japanese and Eskimo) than in Caucasoids (Dutch and Asiatic Indian), which suggests a reduction tendency of distal cusps in Mongoloids. This tendency was intermediate in Negroids and Australoid. Principal coordinate analysis was carried out on the basis of a similarity matrix including both intercuspal distances and cuspal heights. The result suggested that the three-dimensional shape of the occlusal table was distinguishable in four representative racial populations. PMID:3207172

  4. Correction of the occlusal and functional sequelae of mandibular condyle fractures using orthodontic mini-implant molar intrusion.

    PubMed

    Cousley, Richard R J; Gibbons, Andrew J

    2014-09-01

    We report on the non-surgical management of an adult female whose bilateral mandibular condylar fractures had resulted in a clockwise (posterior) mandibular rotation, limitation of mandibular movements and increased occlusal loading on the molar teeth. She refused maxillary surgery and was treated with a minimally-invasive approach, involving orthodontic fixed appliances and mini-implant intrusion of the maxillary molar teeth. This provided both occlusal and functional improvements, including a significant increase in the inter-incisal distance, which were stable after one year of retention. PMID:24521751

  5. Molar Distalization with Different Pendulum Appliances: In Vitro Registration of Orthodontic Forces and Moments in the Initial Phase

    Microsoft Academic Search

    Gero Kinzinger; Christian Syrée; Ulrike Fritz; Peter Diedrich

    2004-01-01

    \\u000a Abstract.\\u000a \\u000a Aim:\\u000a   Registration of the orthodontic forces and moments acting with different types of pendulum appliance for non-compliance upper molar distalization in an in vitro study.\\u000a Material and Methods:\\u000a   The purpose-designed test set-up comprised the following components: artificial maxilla with anchorage unit and two electrothermodynamic (ETD) molars, electronic measuring unit for temperature control and regulation, and a sensor unit with

  6. Mandibular first molars with disto-lingual roots: review and clinical management.

    PubMed

    Abella, F; Patel, S; Durán-Sindreu, F; Mercadé, M; Roig, M

    2012-11-01

    The purpose of this review was (i) to conduct a literature review on the prevalence and morphologic classification of mandibular first molars with disto-lingual (DL) roots, and (ii) to discuss the clinical approach to diagnosis and root canal treatment of these teeth. A search was carried out on electronic (MEDLINE, PubMed and Cochrane) and hand databases, which covered all publications from 1970 to December 2011. Two reviewers independently assessed the studies and recorded type of study, origin and sample sizes, number of teeth with three roots and type of root canal configuration. Forty-five studies were identified with a total of 19,056 mandibular first molar teeth. The frequency of DL roots was 14.4% and was associated with certain ethnic populations. The most common canal configuration of mesial and distal roots was Vertucci types IV and I, respectively. No significant differences were observed in the prevalence of DL roots according to gender. Variable results related to side were observed as well as a trend in bilateral occurrence. The root length of the DL roots was in general shorter than that of the disto-buccal roots (DB). Most DL roots had a greater angle of curvature and a smaller radius of curvature in a bucco-lingual orientation. The best methods to identify DL roots are a 25° mesial parallax periapical radiograph or cone-beam computed tomography (CBCT). A trapezoidal shape access cavity is desirable to locate the orifice of the DL canal. Clinicians should be aware of the variable furcation levels during coronal pre-flaring or post-space preparation to avoid furcal/strip perforations and a weakening of DL roots. PMID:22681628

  7. Reliability of CBCT as an assessment tool for mandibular molars furcation defects

    NASA Astrophysics Data System (ADS)

    Marinescu, Adrian George; Boariu, Marius; Rusu, Darian; Stratul, Stefan-Ioan; Ogodescu, Alexandru

    2014-01-01

    Introduction. In numerous clinical situations it is not possible to have an exact clinical evaluation of the furcation defects. Recently the use of CBCT in periodontology has led to an increased precision in diagnostic. Aim. To determine the accuracy of CBCT as diagnostic tool of the furcation defects. Material and method. 19 patients with generalised advanced chronic periodontitis were included in this study, presenting a total of 25 lower molars with different degrees of furcation defects. Clinical and digital measurements (in mm) were performed on all the molars involved. The data obtained has been compared and statistically analysed. Results. The analysis of primary data has demonstrated that all the furcation grade II and III defects were revealed using the CBCT technique. Regarding the incipient defects (grade I Hamp < 3mm), the dimensions measured on CBCT images were slightly bigger. The results have shown that 84% of the defects detected by CBCT have been confirmed by clinical measurements. These data are similar to those revealed by other studies1. Conclusions. The use of CBCT technique in evaluation and diagnosis of human mandibular furcation defects can provide many important information regarding the size and aspect of the interradicular defect, efficiently and noninvasively. CBCT technique is used more effectively in detection of advanced furcation degree compared to incipient ones. However, the CBCT examination cannot replace, at least in this stage of development, the clinical measurements, especially the intraoperative ones, which are considered to represent the „golden standard" in this domain.

  8. Volume analysis of heat-induced cracks in human molars: A preliminary study

    PubMed Central

    Sandholzer, Michael A.; Baron, Katharina; Heimel, Patrick; Metscher, Brian D.

    2014-01-01

    Context: Only a few methods have been published dealing with the visualization of heat-induced cracks inside bones and teeth. Aims: As a novel approach this study used nondestructive X-ray microtomography (micro-CT) for volume analysis of heat-induced cracks to observe the reaction of human molars to various levels of thermal stress. Materials and Methods: Eighteen clinically extracted third molars were rehydrated and burned under controlled temperatures (400, 650, and 800°C) using an electric furnace adjusted with a 25°C increase/min. The subsequent high-resolution scans (voxel-size 17.7 ?m) were made with a compact micro-CT scanner (SkyScan 1174). In total, 14 scans were automatically segmented with Definiens XD Developer 1.2 and three-dimensional (3D) models were computed with Visage Imaging Amira 5.2.2. The results of the automated segmentation were analyzed with an analysis of variance (ANOVA) and uncorrected post hoc least significant difference (LSD) tests using Statistical Package for Social Sciences (SPSS) 17. A probability level of P < 0.05 was used as an index of statistical significance. Results: A temperature-dependent increase of heat-induced cracks was observed between the three temperature groups (P < 0.05, ANOVA post hoc LSD). In addition, the distributions and shape of the heat-induced changes could be classified using the computed 3D models. Conclusion: The macroscopic heat-induced changes observed in this preliminary study correspond with previous observations of unrestored human teeth, yet the current observations also take into account the entire microscopic 3D expansions of heat-induced cracks within the dental hard tissues. Using the same experimental conditions proposed in the literature, this study confirms previous results, adds new observations, and offers new perspectives in the investigation of forensic evidence. PMID:25125923

  9. Lipid concentration and molar ratio boundaries for the use of isotropic bicelles.

    PubMed

    Beaugrand, Maïwenn; Arnold, Alexandre A; Hénin, Jérôme; Warschawski, Dror E; Williamson, Philip T F; Marcotte, Isabelle

    2014-06-01

    Bicelles are model membranes generally made of long-chain dimyristoylphosphatidylcholine (DMPC) and short-chain dihexanoyl-PC (DHPC). They are extensively used in the study of membrane interactions and structure determination of membrane-associated peptides, since their composition and morphology mimic the widespread PC-rich natural eukaryotic membranes. At low DMPC/DHPC (q) molar ratios, fast-tumbling bicelles are formed in which the DMPC bilayer is stabilized by DHPC molecules in the high-curvature rim region. Experimental constraints imposed by techniques such as circular dichroism, dynamic light scattering, or microscopy may require the use of bicelles at high dilutions. Studies have shown that such conditions induce the formation of small aggregates and alter the lipid-to-detergent ratio of the bicelle assemblies. The objectives of this work were to determine the exact composition of those DMPC/DHPC isotropic bicelles and study the lipid miscibility. This was done using (31)P nuclear magnetic resonance (NMR) and exploring a wide range of lipid concentrations (2-400 mM) and q ratios (0.15-2). Our data demonstrate how dilution modifies the actual DMPC/DHPC molar ratio in the bicelles. Care must be taken for samples with a total lipid concentration ?250 mM and especially at q ? 1.5-2, since moderate dilutions could lead to the formation of large and slow-tumbling lipid structures that could hinder the use of solution NMR methods, circular dichroism or dynamic light scattering studies. Our results, supported by infrared spectroscopy and molecular dynamics simulations, also show that phospholipids in bicelles are largely segregated only when q > 1. Boundaries are presented within which control of the bicelles' q ratio is possible. This work, thus, intends to guide the choice of q ratio and total phospholipid concentration when using isotropic bicelles. PMID:24797658

  10. Manual and rotary instrumentation ability to reduce Enterococcus faecalis associated with photodynamic therapy in deciduous molars.

    PubMed

    Pinheiro, Sérgio Luiz; Silva, Josianne Neres da; Gonçalves, Rafael Orro; Villalpando, Karina Teixeira

    2014-12-01

    This aim of this study was to assess the ability of manual or rotary instrumentation associated with photodynamic therapy (PDT) to reduce Enterococcus faecalis using three combinations of light/photosensitizers: toluidine blue O/laser, fuchsin/halogen light and fuchsin/LED. Twenty deciduous molars were selected and contaminated with Enterococcus faecalis (McFarland 0.5 scale). Working length determination was performed by visual method. The teeth were randomly divided into two groups: G1 (n=10): manual instrumentation (Kerr-type files) and G2 (n=10): rotary instrumentation (ProTaper system). The bacteria were collected three times using sterile paper cones compatible with the anatomic diameter of the root canal for 30 s before and after instrumentation and after PDT. The samples were diluted in peptone water, seeded on blood agar plates and incubated in an oven at 37 °C for colony-forming units counting. The decrease of E. faecalis counts after instrumentation and after PDT was compared using the Wilcoxon test, t-test and Kruskal Wallis test. A significant reduction of E. faecalis occurred after manual and rotary instrumentation and after PDT using the three combinations of light/photosensitizer (p<0.05). It may be concluded that both rotary and manual instrumentation reduced E. faecalis. Fuchsin with halogen light or LED irradiation and toluidine blue O with laser irradiation can be used to reduce E. faecalis in root canals of primary molars. PDT can be used as an adjuvant to conventional endodontic treatment. PMID:25590196

  11. A Review on Prediction Methods for Molar Enthalpies of Vaporization of Hydrocarbons: The ELBA Method as the Best Answer

    NASA Astrophysics Data System (ADS)

    Santos, Rui C.; Leal, João P.

    2012-12-01

    A review on prediction methods for molar enthalpies of vaporization at T = 298.15 K of hydrocarbons is presented. A new method is proposed and compared with six of the most common used ones from the literature. This new method, the extended Laidler bond additivity (ELBA), was applied to the prediction of standard molar enthalpies of vaporization of hydrocarbons (alkanes, alkenes, alkynes, polyenes, poly-ynes, cycloalkanes, cycloalkenes, benzene compounds, biphenyl compounds, and polyphenyl compounds) at T = 298.15 K. A total of 260 experimental standard molar enthalpies of vaporization at T = 298.15 K were used for the parameters optimization. Comparison between the experimental values and those calculated using ELBA led to an average absolute difference of 0.35 kJ mol-1, corresponding to an average relative error of 0.92%. In addition, this new method proves to be better than the ones used for comparison with an independent set of 83 experimental standard molar enthalpies of vaporization at T = 298.15 K.

  12. Panoramic radiographs do not accurately detect curvature of or close association with the mandibular canal of mandibular third molar roots

    Microsoft Academic Search

    S. Thomas Deahl

    2003-01-01

    Original ArticleBell GW, Rodgers JM, Grime RJ, Edwards KL, Hahn MR, Dorman ML, et al. The accuracy of dental panoramic tomographs in determining the root morphology of mandibular third molar teeth before surgery. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;95(1):119–25.

  13. Lost and found: The third molars of Callimico goeldii and the evolution of the callitrichine postcanine dentition.

    PubMed

    Scott, Jeremiah E

    2015-06-01

    This study tests the hypothesis that the third molars of Callimico goeldii represent a reversal in evolutionary tooth loss within the Callitrichinae. Loss of third molars is part of a suite of unusual characters that has been used to unite marmosets and tamarins in a clade to the exclusion of Callimico. However, molecular phylogenetic studies provide consistent support for the hypothesis that marmosets are more closely related to Callimico than to tamarins, raising the possibility that some or all of the features shared by marmosets and tamarins are homoplastic. Here, I use the binary-state speciation and extinction (BiSSE) model and a sample of 249 extant primate species to demonstrate that, given the shape of the primate phylogenetic tree and the distribution of character states in extant taxa, models in which M3 loss is constrained to be irreversible are much less likely than models in which reversals are allowed to occur. This result provides support for the idea that the last common ancestor of Callimico and marmosets was characterized by the two-molared phenotype. The M3s of Callimico therefore appear to be secondarily derived rather than plesiomorphic. This conclusion may also apply to the other apparently plesiomorphic traits found in Callimico. Hypotheses regarding the re-evolution of M3 in the callitrichine clade and the origin and maintenance of the two-molared phenotype are discussed. PMID:25887279

  14. Endodontic Treatment of the Mandibular First Molar with Six Roots Canals – Two Case Reports and Literature Review

    PubMed Central

    Anderson, Craig

    2015-01-01

    The most common configuration of the mandibular first molar is the presence of two roots and three root canals. The objective of this work is to present two rare anatomic configurations with six root canals on two mandibular left first molars diagnosed during endodontic therapy. Root canal therapy was performed using a dental operating microscope. Ultrasonic troughing in the grooves in between the mesial root canals and in between the distal root canals was able to show the middle root canals. Large samples population characterization researches and systematic reviews were unable to detect a single case of six root canals configuration in a mandibular first molar in their investigations. Although it is a rare configuration, a six root canal configuration is possible to be found in the mandibular first molar. Three different pulp chamber configurations are possible to be found. Two or three roots may be present and the root configuration more common in the mesial root is the Type 8 and Type 12 for the distal root. Some concepts about the required technique to approach these cases are also debated. PMID:26023651

  15. Excess molar volumes of mixtures of hexane + natural oils from 298.15 to 313.15 K

    SciTech Connect

    Gonzalez, C.; Resa, J.M.; Ruiz, A.; Gutierrez, J.I. [Univ. del Pais Vasco, Vitoria (Spain). Dept. of Chemical Engineering] [Univ. del Pais Vasco, Vitoria (Spain). Dept. of Chemical Engineering

    1997-03-01

    Excess molar volume data for mixtures containing hexane with three edible oils: olive, corn, and pip of grape have been determined from density measurements at various temperatures between 298.15 and 313.15 K using a vibrating tube densimeter. Results have been correlated by the Redlich-Kister equation. Systems showed negative deviations from ideality in the whole composition range.

  16. Treatment of a maxillary molar in a patient presenting with florid cemento-osseous dysplasia: a case report.

    PubMed

    Tonioli, Matthew B; Schindler, William G

    2004-09-01

    A case report of a 49-year-old black woman with florid cemento-osseous dysplasia is presented. Endodontic treatment of a maxillary first molar and a general review of florid cemento-osseous dysplasia are presented. Treatment considerations including diagnosis, difficulty in radiographic interpretation, working length determination, and postoperative concerns are discussed. PMID:15329574

  17. Age at first molar emergence in early Miocene Afropithecus turkanensis and life-history evolution in the Hominoidea

    E-print Network

    Smith, Tanya M.

    Age at first molar emergence in early Miocene Afropithecus turkanensis and life-history evolution by Sivapithecus parvada (Function, Phylogeny, and Fossils: Miocene Hominoid Evolution and Adaptations, 1997, 173. 2003 Elsevier Science Ltd. All rights reserved. Keywords: Miocene hominoid; dentition; dental eruption

  18. The Presence of Mandibular Third Molars During Sagittal Split Osteotomies Does not Increase the Risk of Complications

    Microsoft Academic Search

    Jean-Charles Doucet; Archibald D. Morrison; Benjamin R. Davis; Curtis E. Gregoire; Reginald Goodday; David S. Precious

    PurposeThe purpose of this study was to prospectively investigate the effects of the presence or absence of third molars during sagittal split osteotomies (SSOs) on the frequency of unfavorable fractures, degree of entrapment and manipulation of the inferior alveolar nerve (IAN), and procedural time.

  19. Molar concentration on k2so4 and soil ph estimation of extractable c with chloroform fumigation-extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods of determining soil microbial biomass need to be reliable and produce consistent results across soils with a wide range of properties. We investigated the effect of extractant molarity (distilled water and 0.001, 0.01, 0.1, and 0.5 M K2SO4) on the flush of C (i.e., the difference between fum...

  20. Effect of traumatic occlusion on CGRP and SP immunoreactive nerve fibre morphology in rat molar pulp and periodontium

    Microsoft Academic Search

    I. Kvinnsland; K. J. Heyeraas

    1992-01-01

    Traumatic occlusion provides a trauma that affects the whole tooth and its supporting tissues. To study the effect of this trauma on CGRP and SP immunoreactive nerve morphology in pulp and periodontium, traumatic occlusion was induced in 2-months-old rats. The occlusal surface of the first maxillary molar in 30 rats were unilaterally raised 1 mm with a composite material. At

  1. Clinical performance of a new laser fluorescence device for detection of occlusal caries lesions in permanent molars

    Microsoft Academic Search

    K. C. Huth; K. W. Neuhaus; M. Gygax; K. Bücher; A. Crispin; E. Paschos; R. Hickel; A. Lussi

    2008-01-01

    ObjectivesTo determine the clinical performance of a laser fluorescence device (DIAGNOdent pen, KaVo) to discriminate between different occlusal caries depths (D0–D1–4; D0–2–D3,4) in permanent molars.

  2. Inferior alveolar nerve damage after lower third molar surgical extraction: A prospective study of 1117 surgical extractions

    Microsoft Academic Search

    Eduard Valmaseda-Castellón; Leonardo Berini-Aytés; Cosme Gay-Escoda

    2001-01-01

    Purpose: The purpose of this study was to determine the incidence of inferior alveolar nerve (IAN) damage after surgical removal of lower third molars, to identify the causes, and to construct a predictive model to assess the risk of IAN injury. Study Design: We performed a nonrandomized forward prospective study of 946 consecutive outpatients subjected to surgical extraction of 1117

  3. Efficacy of platelet-rich plasma applied to post-extraction retained lower third molar alveoli. A systematic review

    PubMed Central

    Barona-Dorado, Cristina; González-Regueiro, Iria; Martín-Ares, María; Arias-Irimia, Oscar; Martínez-González, José M.

    2014-01-01

    Dental retentions have a high prevalence among the general population and their removal can involve multiple complications. The use of platelet rich plasma has been proposed in an attempt to avoid these complications, as it contains high growth factors and stimulates diverse biological functions that facilitate the healing of soft and hard tissues. Objectives: To evaluate the available scientific evidence related to the application of platelet-rich plasma in the post-extraction alveoli of a retained lower third molars. Material and Methods: A systematic review of published literature registered in the Medline, EMBASE, Cochrane and NIH databases. The following categories were included: human randomized clinical studies. Key search words were: platelet rich plasma; platelet rich plasma and oral surgery; platelet rich in growth factors and third molar. Results: Of 101 potentially valid articles, seven were selected, of which four were rejected as they failed to meet quality criteria. Three studies fulfilled all selection and quality criteria: Ogundipe et al.; Rutkowski et al.; Haraji et al. The studies all measured osteoblast activity by means of sintigraphy, and also registered pain, bleeding, inflammation, temperature, numbness as perceived by the patients, radiological bone density and the incidence of alveolar osteitis. Conclusions: Scientific evidence for the use of PRP in retained third molar surgery is poor. For this reason randomized clinical trials are needed before recommendations for the clinical application of PRP can be made. Key words:Platelet rich plasma, lower third molar surgery, postoperative. PMID:24316707

  4. Effect of Tooth Preparation on Microleakage of Stainless Steel Crowns Placed on Primary Mandibular First Molars with Reduced Mesiodistal Dimension

    PubMed Central

    Ramazani, Nahid; Ranjbar, Mina

    2015-01-01

    Objectives: Incomplete adaptation of stainless steel crown margins leads to microleakage. The aim of this study was to evaluate the effect of tooth preparation on microleakage of stainless steel crowns (SSCs) placed on mesiodistally reduced primary mandibular first molars. Materials and Methods: In this In vitro study, 60 primary mandibular first molars with reduced mesiodistal dimension were selected. Pulp cavities were filled with amalgam and occlusal surfaces were reduced. The samples were randomly divided into two groups (groups P and BLP). Standard preparation was done in group P with only proximal reduction. In group BLP, after reducing the proximal undercuts, buccal and lingual surfaces were slightly reduced. Occlusal one-third of the buccal surfaces was beveled in both groups. Then, the SSCs of the primary maxillary and mandibular first molars were fitted and cemented in P and BLP groups, respectively. After immersing the samples into deionized water, thermo-cycling, and immersion in 2% basic fuchsin, the samples were sectioned buccolingually. The mesial halves were evaluated microscopically for microleakage in both buccal and lingual margins. Data were analyzed using Mann-Whitney U test in SPSS 19 at the significant level of 0.05. Results: There was a significant difference in microleakage of the buccal margin (P=0.003); whereas, the difference observed in the lingual margin was not significant (P=0.54). Conclusion: We suggest reduction of buccal and lingual surfaces of mesiodistally reduced primary mandibular first molars and placing lower (mandibular) crowns. PMID:26005450

  5. Providing an environment for reparative dentine induction in amputated rat molar pulp by high molecular-weight hyaluronic acid

    Microsoft Academic Search

    Takahisa Sasaki; Hidemi Kawamata-Kido

    1995-01-01

    To study provision of this environment, wound healing was examined by light and electron microscopy following pulp amputation and direct capping with hyaluronic acid. Molar pulps of female Sprague-Dawley rats were mechanically exposed and directly capped; the cavities were then restored with glass-ionomer cement. As an experimental control, Calvital (a commercial preparation of calcium hydroxide paste) was used as the

  6. Efficacy of methylprednisolone injected into the masseter muscle following the surgical extraction of impacted lower third molars

    Microsoft Academic Search

    E. Vegas-Bustamante; J. Micó-Llorens; J. Gargallo-Albiol; M. Satorres-Nieto; L. Berini-Aytés; C. Gay-Escoda

    2008-01-01

    The aim of this study was to demonstrate the efficacy of methylprednisolone, as a single 40-mg dose, injected into the masseter muscle upon completion of extraction of impacted lower third molars. A prospective, randomized cross-over study was made of 35 healthy patients. The difficulty of extraction was similar in all cases. The study group received 40mg of methylprednisolone injected into

  7. Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population

    PubMed Central

    Sequeira, Catarina-Dourado; Teixeira, Alexandra; Afonso, Américo; Pérez-Mongiovi, Daniel

    2014-01-01

    Objectives: The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Study Design: Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. Results: The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. Conclusions: This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament. PMID:25674324

  8. Evaluation of skeletal and dental age using third molar calcification, condylar height and length of the mandibular body

    PubMed Central

    Kedarisetty, Sunil Gupta; Rao, Guttikonda Venkateswara; Rayapudi, Naveen; Korlepara, Rajani

    2015-01-01

    Aim: To identify the most reliable method for age estimation among three variables, that is, condylar height, length of mandibular body and third molar calcification by Demirjian's method. Materials and Methods: Orthopantomograms and lateral cephalograms of 60 patients with equal gender ratio were included in the study, among each gender 15 subjects were below 18 years and 15 subjects were above 18 years. Lateral cephalograms were traced, height of condyle and mandibular body are measured manually on the tracing paper, OPG's were observed on radiographic illuminator and maturity score of third molar calcification was noted according to Demirjian's method. All the measurements were subjected to statistical analysis. Results: The results obtained are of no significant difference between estimated age and actual age with all three parameters (P > 0.9780 condylar height, P > 0.9515 length of mandibular body, P > 0.8611 third molar calcification). Among these three, length of mandibular body shows least standard error test (i.e. 0.188). Conclusion: Although all three parameters can be used for age estimation, length of mandibular body is more reliable followed by height of condyle and third molar calcification. PMID:26005300

  9. Endodontic treatment of the mandibular first molar with six roots canals - two case reports and literature review.

    PubMed

    Martins, Jorge N R; Anderson, Craig

    2015-04-01

    The most common configuration of the mandibular first molar is the presence of two roots and three root canals. The objective of this work is to present two rare anatomic configurations with six root canals on two mandibular left first molars diagnosed during endodontic therapy. Root canal therapy was performed using a dental operating microscope. Ultrasonic troughing in the grooves in between the mesial root canals and in between the distal root canals was able to show the middle root canals. Large samples population characterization researches and systematic reviews were unable to detect a single case of six root canals configuration in a mandibular first molar in their investigations. Although it is a rare configuration, a six root canal configuration is possible to be found in the mandibular first molar. Three different pulp chamber configurations are possible to be found. Two or three roots may be present and the root configuration more common in the mesial root is the Type 8 and Type 12 for the distal root. Some concepts about the required technique to approach these cases are also debated. PMID:26023651

  10. Comparison of the efficacy of two anesthetic techniques of mandibular primary first molar: A randomized clinical trial

    PubMed Central

    Tudeshchoie, Davood Ghasemi; Rozbahany, Neda Ahmadi; Hajiahmadi, Maryam; Jabarifar, Ebrahim

    2013-01-01

    Background: The most common technique to anesthetize mandibular primary teeth is inferior alveolar (I.A) nerve block injection which induces a relatively sustained anesthesia and in turn may potentially traumatize soft-tissues. Therefore, the need of having an alternative technique of anesthesia with a shorter term but the same efficacy is reasonable. The aim of this study was a comparison of the efficacy of two anesthetic techniques of mandibular primary first molar. Materials and Methods: In this randomized crossover clinical trial, 40 children with ages ranged from 5 years to 8 years whose mandibular primary first molars were eligible for pulpotomy, were selected and divided randomly into two groups. The right and left mandibular first molars of group A were anesthetized with infiltration and I. A nerve block techniques in the first and second sessions respectively. The left and right mandibular first molars of group B were anesthetized with I.A nerve block and infiltration techniques in the first and second sessions respectively. The severity of pain were measured and recorded according to sound-eye-motor scale by a certain person. Data was analyzed using Wilcoxon Signed Rank and Mann-Whitney U tests (P > 0.05). Results: The severity of pain was lower in infiltration technique versus I.A nerve block. There were no significant differences between the severities of pain on pulpal exposure of two techniques. Conclusion: It seems that infiltration technique is more favorable to anesthetize the mandibular primary first molar compared to I.A nerve block. PMID:24348619

  11. Comparison of clinical efficacy of methylprednisolone and serratiopeptidase for reduction of postoperative sequelae after lower third molar surgery

    PubMed Central

    Chappi D., Mouneshkumar; Patil, Manisha R.; Desai, Rajendra; Tauro, David P.; Bharani K.N.S., Shiva; Parkar, Mushtaq I.; Babaji, Harsha V.

    2015-01-01

    Background Surgical removal of mandibular third molars results in some degree of post-operative pain, swelling and trismus. These can be controlled by proper administration of local anesthesia, careful bone removal, minimal trauma to adjacent soft tissues and administration of methylprednisolone and serratiopeptidase drugs. The aim of the present study was to compare the efficacy of methylprednisolone and serratiopeptidase in controlling post-operative pain, swelling and trismus after surgical removal of impacted mandibular third molars. Material and Methods The subjects were divided into two groups of 50 patients each undergoing surgical removal of mandibular third molars. Group A was given methylprednisolone 4mg orally every 8th hourly and Group B was given serratiopeptidase 10 mg every 12th hourly orally. Post-operatively pain, swelling and trismus were evaluated at the end of 1st, 3rd and 5thday. Results The results of this study showed that methylprednisolone is an effective analgesic, while serratiopeptidase has moderate analgesic activity. Serratiopeptidase is more effective than methylprednisolone in controlling post surgical swelling and trismus. Hence combination of these two drugs would be very effective than individual drug when widespread post-operative sequelae are expected after surgical removal of impacted lower third molars. Conclusions We conclude that methylprednisolone affords better pain relief while serratiopeptidase exerts better anti-inflammatory and anti-swelling effects in the post-operative period. Synergistic combinations of these two drugs would however prove to be more effective when extensive post-operative sequelae are expected. Key words:Methylprednisolone, serratiopeptidase, pain, swelling, trismus, third molar.

  12. Corneal Stromal Cell Growth on Gelatin/Chondroitin Sulfate Scaffolds Modified at Different NHS/EDC Molar Ratios

    PubMed Central

    Lai, Jui-Yang

    2013-01-01

    A nanoscale modification strategy that can incorporate chondroitin sulfate (CS) into the cross-linked porous gelatin materials has previously been proposed to give superior performance for designed corneal keratocyte scaffolds. The purpose of this work was to further investigate the influence of carbodiimide chemistry on the characteristics and biofunctionalities of gelatin/CS scaffolds treated with varying N-hydroxysuccinimide (NHS)/1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) molar ratios (0–1) at a constant EDC concentration of 10 mM. Results of Fourier transform infrared spectroscopy and dimethylmethylene blue assays consistently indicated that when the NHS to EDC molar ratio exceeds a critical level (i.e., 0.5), the efficiency of carbodiimide-mediated biomaterial modification is significantly reduced. With the optimum NHS/EDC molar ratio of 0.5, chemical treatment could achieve relatively high CS content in the gelatin scaffolds, thereby enhancing the water content, glucose permeation, and fibronectin adsorption. Live/Dead assays and interleukin-6 mRNA expression analyses demonstrated that all the test samples have good cytocompatibility without causing toxicity and inflammation. In the molar ratio range of NHS to EDC from 0 to 0.5, the cell adhesion ratio and proliferation activity on the chemically modified samples significantly increased, which is attributed to the increasing CS content. Additionally, the materials with highest CS content (0.143 ± 0.007 nmol/10 mg scaffold) showed the greatest stimulatory effect on the biosynthetic activity of cultivated keratocytes. These findings suggest that a positive correlation is noticed between the NHS to EDC molar ratio and the CS content in the biopolymer matrices, thereby greatly affecting the corneal stromal cell growth. PMID:23337203

  13. Characterization of mandibular molar root and canal morphology using cone beam computed tomography and its variability in Belgian and Chilean population samples

    PubMed Central

    Jacobs, Reinhilde; Lambrechts, Paul; Brizuela, Claudia; Cabrera, Carolina; Concha, Guillermo; Pedemonte, María Eugenia

    2015-01-01

    Purpose This study used cone-beam computed tomography (CBCT) to characterize mandibular molar root and canal morphology and its variability in Belgian and Chilean population samples. Materials and Methods We analyzed the CBCT images of 515 mandibular molars (257 from Belgium and 258 from Chile). Molars meeting the inclusion criteria were analyzed to determine (1) the number of roots; (2) the root canal configuration; (3) the presence of a curved canal in the cross-sectional image of the distal root in the mandibular first molar and (4) the presence of a C-shaped canal in the second mandibular molar. A descriptive analysis was performed. The association between national origin and the presence of a curved or C-shaped canal was evaluated using the chi-squared test. Results The most common configurations in the mesial root of both molars were type V and type III. In the distal root, type I canal configuration was the most common. Curvature in the cross-sectional image was found in 25% of the distal canals of the mandibular first molars in the Belgian population, compared to 11% in the Chilean population. The prevalence of C-shaped canals was 10% or less in both populations. Conclusion In cases of unclear or complex root and canal morphology in the mandibular molars, CBCT imaging might assist endodontic specialists in making an accurate diagnosis and in treatment planning.

  14. Estimation of band broadening in size-exclusion chromatography. I. A method based on analyzing narrow standards with a molar mass-sensitive detector

    Microsoft Academic Search

    Mariana M. Yossen; Jorge R. Vega; Gregorio R. Meira

    2006-01-01

    A method is proposed for estimating the (asymmetrical and non-uniform) band broadening function (BBF) in size-exclusion chromatography (SEC). The following data are required: the molar mass calibration and the concentration- and molar mass chromatograms of a set of narrow standards. In the narrow range of each standard, the BBF is uniform but skewed. Each uniform BBF is estimated through a

  15. Isolation and characterization of stem cells derived from human third molar tooth germs of young adults: implications in neo-vascularization, osteo-, adipo- and neurogenesis

    Microsoft Academic Search

    M E Yalvac; M Ramazanoglu; A A Rizvanov; F Sahin; O F Bayrak; U Salli; A Palotás; G T Kose

    2010-01-01

    A number of studies have reported in the last decade that human tooth germs contain multipotent cells that give rise to dental and peri-odontal structures. The dental pulp, third molars in particular, have been shown to be a significant stem cell source. In this study, we isolated and characterized human tooth germ stem cells (hTGSCs) from third molars and assessed

  16. The Ti/Al molar ratio as a new proxy for tracing sediment transportation processes and its application in aeolian events and sea level change in East Asia

    NASA Astrophysics Data System (ADS)

    Chen, Huei-Fen; Yeh, Po-Yi; Song, Sheng-Rong; Hsu, Shih-Chieh; Yang, Tien-Nan; Wang, Yong; Chi, Zhenqing; Lee, Teh-Quei; Chen, Min-Te; Cheng, Chien-Liang; Zou, Jianjun; Chang, Yuan-Pin

    2013-09-01

    Ti/Al molar ratios of sediments in various sedimentary environments are used to explain sediment transportation from source regions to sink areas. Samples were collected from outcrops, soils, fluvial, lake, and marine sediment environments. Initial Ti/Al molar ratios of sediments are controlled by those of parent soils or rocks. These ratios tend to decline gradually as a result of heavy-mineral gravity fractionation during transportation. Sedimentary Ti/Al molar ratios in sink areas such as lakes and pelagic environments are lower than those in source regions. In this study, for the Changjiang River, Huanghe River, and Kaoping River, Ti/Al molar ratios decline considerably from downstream to estuary environments. Additionally, well sorted aeolian sands have extremely low Ti/Al molar ratios in northern China. The Ti/Al molar ratios of aerosol particles found in Taiwan and the East China Sea show reduced ratios as a result of Asia Dust Storm episodes. Furthermore, lower Ti/Al molar ratios in deep ocean sediments were discovered by tracing the distribution of sedimentary Ti/Al molar ratios in the South China Sea. When sea levels dropped during glacial periods, the river estuary was closer to deep marine areas and carried more terrestrial sediments into deep marine environments. The closer estuary with relatively higher Ti/Al ratio would lead increase of Ti/Al molar ratios in deep sea sediments. In this study, Ti/Al molar ratio is promoted as a new proxy to help with understanding changes in sedimentary environments.

  17. Endodontic treatment of mandibular molar with root dilaceration using Reciproc single-file system.

    PubMed

    Meireles, Daniely Amorin; Bastos, Mariana Mena Barreto; Marques, André Augusto Franco; Garcia, Lucas da Fonseca Roberti; Sponchiado, Emílio Carlos

    2013-08-01

    Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods. PMID:24010084

  18. Single C-shaped canal in mandibular first molar: A case report

    PubMed Central

    Raghavendra, Srinidhi Surya; Napte, Bandu D.; Desai, Niranjan N.; Hindlekar, Ajit N.

    2015-01-01

    The variability of root canal system morphology presents a continuous challenge to endodontic diagnosis and therapeutics. There have been reports of teeth with multiple roots and canals as also those with lesser number of root and root canals. Variations of root canal systems need not always be in the form of extra canals. Clinicians should be aware that there is a possibility of existence of fewer numbers of roots and root canals than normal, which presents varied canal anatomy and poses a challenge to the clinician's expertise. This case report deals with the management of an unusual case of C-shaped canal in mandibular molar with two buccally fused roots. Cone-beam computed tomography (CBCT) was employed to confirm the extension of the unusual anatomy. The Self Adjusting File (SAF) system was used to ensure complete cleaning of the canal system. One-year follow-up of the case showed good healing. The clinician should expect to encounter unusual features when performing endodontic treatment. Use of diagnostic aids like CBCT, improved magnification with dental operating microscope, and the use of novel file systems like SAF ensure success. PMID:25829700

  19. A rare case of impacted supernumerary premolar causing resorption of mandibular first molar

    PubMed Central

    Murali, R. V.; Gnanashanmugam, K.; Rajasekar, L.; Kularashmi, B. S.; Saravanan, B.

    2015-01-01

    The management of patients with pain in today's general practice has become a major concern and sometimes this pain is related to some rare causes. A male patient aged 26 years reported with pain in the lower left molar region (36) and then an intra-oral periapical radiograph (IOPA), and orthopantomograph was taken. IOPA revealed the presence of supernumerary premolar causing pressure and root resorption of 36. Also, there was missing 21 and proximal decay in 11. Eleven was treated endodontically, and then bridge was done in relation to 11, 21 and 22. Lower anterior crowding was also present. The treatment plan was to extract 36 followed by orthodontic extrusion of the supernumerary premolar and also the correction of lower anterior crowding. Hidden approach (lingual orthodontics) was used as the patient was insisting upon the braces not being seen outside during the course of the treatment. Later all ceramic bridge was done in relation to 11, 21 and 22. Orthodontic tooth extrusion techniques offer excellent treatment options for Partially Impacted tooth. It is a well-documented clinical method for extruding sound tooth material from within the alveolar socket by light forces. The use of lingual technique for forced eruption enhance acceptance of orthodontic treatment by adults. The treatment of a young adult patient illustrates the importance of treatment planning from one discipline to another, communication among team members and the benefits of working together in an interdisciplinary approach PMID:26015740

  20. Radiographic Estimation of Chronological Age using Mineralization of Third Molars in Coastal Andhra, India

    PubMed Central

    Babburi, Suresh; Nelakurthi, Hasini; Aparna, V; Soujanya, P; Kotti, Ajay Benarji; Ganipineni, Kiranmai

    2015-01-01

    Background: Age estimation is an important factor in establishing the identity of a person. Among various techniques, dental age estimation is helpful in estimating the age in children above 16 years of age. Determination of age using developmental stages of teeth is more useful than using tooth eruption. Materials and Methods: A total of 550 orthopantomographs of 248 males and 302 females aged between 15 and 22 years were taken and evaluated by Demirjian’s tooth mineralization stages. Statistical assessment was done using logistic regression analysis. Results: Complete apical closure of third molars was observed at the age of 20.4 years in 50% of males. Gender is also thought to influence mineralization and males showed early apical closure than females. Mean value testing is also done but showed influence of high and lower end age groups on age estimation. Conclusion: Finally, we conclude that, though the exact age of a person cannot be determined, the Demirjian’s stage at which 18 years of age is attained can be found out. PMID:26028903

  1. Hertwig’s Epithelial Root Sheath Fate during Initial Cellular Cementogenesis in Rat Molars

    PubMed Central

    Yamamoto, Tsuneyuki; Yamada, Tamaki; Yamamoto, Tomomaya; Hasegawa, Tomoka; Hongo, Hiromi; Oda, Kimimitsu; Amizuka, Norio

    2015-01-01

    To elucidate the fate of the epithelial root sheath during initial cellular cementogenesis, we examined developing maxillary first molars of rats by immunohistochemistry for keratin, vimentin, and tissue non-specific alkaline phosphatase (TNALP) and by TdT-mediated dUTP nick end labeling (TUNEL). The advancing root end was divided into three sections, which follow three distinct stages of initial cellular cementogenesis: section 1, where the epithelial sheath is intact; section 2, where the epithelial sheath becomes fragmented; and section 3, where initial cellular cementogenesis begins. After fragmentation of the epithelial sheath, many keratin-positive epithelial sheath cells were embedded in the rapidly growing cellular cementum. A few unembedded epithelial cells located on the cementum surface. Dental follicle cells, precementoblasts, and cementoblasts showed immunoreactivity for vimentin and TNALP. In all three sections, there were virtually no cells possessing double immunoreactivity for vimentin-keratin or TNALP-keratin and only embedded epithelial cells showed TUNEL reactivity. Taken together, these findings suggest that: (1) epithelial sheath cells divide into two groups; one group is embedded in the cementum and thereafter dies by apoptosis, and the other survives on the cementum surface as epithelial cell rests of Malassez; and (2) epithelial sheath cells do not undergo epithelial-mesenchymal transition during initial cellular cementogenesis.

  2. Dental radiographic features of impacted third molars and some management implications.

    PubMed

    Owotade, F J; Fatusi, O A; Ibitoye, B; Otuyemi, O D

    2003-09-01

    The objective of the study was to determine the principal dental radiographic features of impacted third molars and to highlight some management implications, 255 periapical radiographs belonging to 197 patients with the clinical records were examined. The age of the subjects, sex, and degree of impaction, inclination, depth, mesiodistal space and associated pathology were documented as well as the number of roots and their relationship to the neurovascular bundle. The mean age was 23.4 years with more female teeth (152, 59.6%) than male (103, 40.4%). Majority were partially erupted (223, 91.4%) with vertical impaction most commonly seen in 80 teeth (31.4%). Over half of the teeth (135, 52.9%) had no obvious relationship with the inferior alveolar neuro-vascular bundle and where this existed, darkening of the root was the most common radiographic indicator (55 teeth, 21.6%). Most of the teeth (54.9%) had no obvious pathologic changes associated. In those with pathologic changes, periodontal bone loss and a wide follicle were most commonly observed (44 teeth or 17.3% in both cases). Older subjects had significantly more periodontal bone loss (p = 0.001). Periapical radiographic examination can reveal vital information for treatment planning of impacted teeth and the monitoring of asymptomatic teeth. PMID:14705372

  3. Clinical evaluation of guided tissue regeneration in the treatment of maxillary class II molar furcation invasions.

    PubMed

    Metzler, D G; Seamons, B C; Mellonig, J T; Gher, M E; Gray, J L

    1991-06-01

    This investigation assessed and compared the clinical efficacy of combined open flap debridement/occlusive membrane therapy versus open flap debridement therapy alone, in the treatment of maxillary periodontal furcation defects. Seventeen patients presenting with advanced adult periodontitis, including at least one pair of Class II maxillary furcal defects, comprised the study group. Following completion of a hygienic phase of treatment, measurements were made with calibrated periodontal probes to determine soft tissue recession, probing pocket depths, and attachment levels. Each pair of furcation defects was surgically exposed and hard tissue measurements obtained. Defects were treated with either open flap debridement and a polytetrafluoroethylene periodontal membrane or open flap debridement alone. Membranes were removed at 4 to 6 weeks. Six months postsurgery, soft tissue measurements were repeated and all sites were surgically re-entered to obtain hard tissue measurements. No statistically significant differences were found in recession, probing depth reductions, clinical attachment gains, or resorption of alveolar crest height between test and control groups. Results for these parameters were inconsistent and unpredictable. Statistically significant improvements were found, however, in horizontal open probing attachment (HOPA) and vertical open probing attachment (VOPA) between experimental and control sites. The GTR procedure as used in this study likely has limited application as a therapeutic modality for Class II furcations of maxillary molars. Modifications or improvements in the procedure may result in more predictable healing of these lesions. PMID:1870064

  4. CBCT evaluation of multiple idiopathic internal resorptions in permanent molars: case report

    PubMed Central

    2014-01-01

    Background Internal inflammatory root resorption is a rare condition in permanent teeth, which requires the presence of necrotic and infected pulp tissue within the coronal portion of the root canal system as well as inflamed pulp tissue apical to the resorptive defect. The aetiology of internal root resorption is not completely understandable, trauma and chronic pulpitis are considered the main risk factors. Case presentation We report a rare case of the multiple idiopathic resorption in the permanent maxillary and mandibular molars in a healthy 33-year-old female patient. In addition to clinical examination the patient was imaged using conventional radiography techniques and cone beam computed tomography (CBCT).The patient had recurrent throbbing pain in her # 46. The radiographic examination including “panoramic radiography and CBCT” revealed that radiographic evidence of internal resorption in #37 #36 #35 #34 #33 #47 #46 #45 #44 #43 #16 #15 #14 #13 and also including in unerupted #17, #26, #27, #28 teeth. The definitive diagnosis was made with the histopathological examination of the extracted tooth. Conclusions Internal root resorption is a rare clinical process that should be examined using different radiographic modalities. CBCT seems to be useful in evaluation of the lesions with superior diagnostic performance. PMID:24739085

  5. Localization and density of myeloid leucocytes in the periodontal ligament of normal rat molars.

    PubMed

    Kan, L; Okiji, T; Kaneko, T; Suda, H

    2001-06-01

    The phenotypic distribution and density of macrophage-associated antigen-expressing cells in the periodontal ligament (PDL) of normal rat mandibular first molars was evaluated by immunohistochemistry, and an attempt made to identify dendritic cells (DCs) by immunoelectron microscopy. Cells immunopositive to ED1 (a general macrophage marker) were widely distributed throughout the PDL and were most common around blood vessels. A small number of T lymphocytes and OX62 (anti-veiled cells and gammadelta T cells)-positive DC-like cells were also found. The relative density of cells immunopositive to ED9 (CD14), OX42 (CD11b), OX6 (anti-class II MHC molecules), ED2 (anti-tissue-resident macrophages), 8A2 (CD11c) and WT.1 (CD11a) varied in the mesial, distal and periapical regions of the distal root and the furcal region. This finding suggests that there are several subpopulations of ED1-positive cells which express various combinations of these markers. Immunoelectron microscopy revealed that a small, but distinct, subpopulation of ED1- and OX6-positive cells did have a DC-like ultrastructure, although the majority of these cells were identified as macrophages. The DC-like cells were characterized by poorly developed lysosomal structures and an absence of phagocytic vesicles. It was concluded that the normal rat PDL is equipped with heterogeneous populations of macrophages with regional variations in density. The DC-like cells may function as antigen-presenting cells. PMID:11311198

  6. Management of a massive resorptive lesion with multiple perforations in a molar: case report.

    PubMed

    Borkar, Swati; de Noronha de Ataide, Ida

    2015-05-01

    Internal resorption is usually asymptomatic. Large resorption defects may result in penetration of the root dentin leading to perforation. In this case report, we describe the diagnosis and nonsurgical repair of a large resorptive lesion with multiple perforations in a mandibular first molar using cone-beam computed tomographic technology. The 3 different root perforations were located in the mesial root and repaired using Biodentine (Septodont, Saint-Maur des Fossés, France). The mesial root weakened from resorption was reinforced by replacing the lost root dentin with calcium silicate-based cement and placement of a glass fiber post. The 18-month follow-up confirmed remineralization of the osseous defect and asymptomatic function of the tooth. A further follow-up at 43 months revealed retention of the tooth and absence of root fracture. Usually, a tooth with multiple perforations and such a severe tooth material loss would have been destined for extraction. However, with contemporary diagnostic techniques such as cone-beam computed tomography and use of advanced biomaterials and root reinforcement methods, such teeth can be salvaged. PMID:25728818

  7. A rare case of impacted supernumerary premolar causing resorption of mandibular first molar.

    PubMed

    Murali, R V; Gnanashanmugam, K; Rajasekar, L; Kularashmi, B S; Saravanan, B

    2015-04-01

    The management of patients with pain in today's general practice has become a major concern and sometimes this pain is related to some rare causes. A male patient aged 26 years reported with pain in the lower left molar region (36) and then an intra-oral periapical radiograph (IOPA), and orthopantomograph was taken. IOPA revealed the presence of supernumerary premolar causing pressure and root resorption of 36. Also, there was missing 21 and proximal decay in 11. Eleven was treated endodontically, and then bridge was done in relation to 11, 21 and 22. Lower anterior crowding was also present. The treatment plan was to extract 36 followed by orthodontic extrusion of the supernumerary premolar and also the correction of lower anterior crowding. Hidden approach (lingual orthodontics) was used as the patient was insisting upon the braces not being seen outside during the course of the treatment. Later all ceramic bridge was done in relation to 11, 21 and 22. Orthodontic tooth extrusion techniques offer excellent treatment options for Partially Impacted tooth. It is a well-documented clinical method for extruding sound tooth material from within the alveolar socket by light forces. The use of lingual technique for forced eruption enhance acceptance of orthodontic treatment by adults. The treatment of a young adult patient illustrates the importance of treatment planning from one discipline to another, communication among team members and the benefits of working together in an interdisciplinary approach. PMID:26015740

  8. Single C-shaped canal in mandibular first molar: A case report.

    PubMed

    Raghavendra, Srinidhi Surya; Napte, Bandu D; Desai, Niranjan N; Hindlekar, Ajit N

    2015-01-01

    The variability of root canal system morphology presents a continuous challenge to endodontic diagnosis and therapeutics. There have been reports of teeth with multiple roots and canals as also those with lesser number of root and root canals. Variations of root canal systems need not always be in the form of extra canals. Clinicians should be aware that there is a possibility of existence of fewer numbers of roots and root canals than normal, which presents varied canal anatomy and poses a challenge to the clinician's expertise. This case report deals with the management of an unusual case of C-shaped canal in mandibular molar with two buccally fused roots. Cone-beam computed tomography (CBCT) was employed to confirm the extension of the unusual anatomy. The Self Adjusting File (SAF) system was used to ensure complete cleaning of the canal system. One-year follow-up of the case showed good healing. The clinician should expect to encounter unusual features when performing endodontic treatment. Use of diagnostic aids like CBCT, improved magnification with dental operating microscope, and the use of novel file systems like SAF ensure success. PMID:25829700

  9. Walk the line: 600000 years of molar evolution constrained by allometry in the fossil rodent Mimomys savini.

    PubMed

    Firmat, Cyril; Lozano-Fernández, Iván; Agustí, Jordi; Bolstad, Geir H; Cuenca-Bescós, Gloria; Hansen, Thomas F; Pélabon, Christophe

    2014-08-19

    The allometric-constraint hypothesis states that evolutionary divergence of morphological traits is restricted by integrated growth regulation. In this study, we test this hypothesis on a time-calibrated and well-documented palaeontological sequence of dental measurements on the Pleistocene arvicoline rodent species Mimomys savini from the Iberian Peninsula. Based on 507 specimens representing nine populations regularly spaced over 600 000 years, we compare static (within-population) and evolutionary (among-population) allometric slopes between the width and the length of the first lower molar. We find that the static allometric slope remains evolutionary stable and predicts the evolutionary allometry quite well. These results support the hypothesis that the macroevolutionary divergence of molar traits is constrained by static allometric relationships. PMID:25002706

  10. Dandy-Walker malformation masking the molar tooth sign: an illustrative case with magnetic resonance imaging follow-up.

    PubMed

    Sartori, Stefano; Ludwig, Kathrin; Fortuna, Manuela; Marzocchi, Cinzia; Calderone, Milena; Toldo, Irene; Salviati, Leonardo; Laverda, Anna Maria; Tenconi, Romano

    2010-11-01

    Joubert syndrome is a disorder characterized by ataxia, developmental delay, oculomotor anomalies, and breathing irregularities, with cerebellar vermian and midbrain dysgenesis. The molar tooth sign, reflecting the midbrain dysgenesis of Joubert syndrome, is the neuroradiological hallmark and is an essential sign in the identification of this condition. Variable vermian agenesis, an expanded fourth ventricle, and a large posterior cranial fossa with a normal brainstem are typical of Dandy-Walker malformation. The authors report a case in which a Dandy-Walker malformation coexisted with Joubert syndrome, but initially prevented the ''molar tooth sign'' from being recognized because of an important cystic dilatation of the fourth ventricle. In this article, they discuss the importance of the re-examination of brain magnetic resonance features after decompression of the posterior cranial fossa in a patient with Dandy-Walker malformation and additional clinical neurological or systemic abnormalities typical of Joubert syndrome, to not miss the correct diagnosis. PMID:20823032

  11. The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of aluminium chloride, aluminium nitrate and aluminium sulphate

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2002-01-01

    Vapour pressures of water over saturated solutions of aluminium chloride, aluminium nitrate and aluminium sulphate were determined as a function of temperature. The vapour pressures served to evaluate the water activities, osmotic coefficients and molar enthalpies of vaporization. Molar enthalpies of solution of aluminium chloride hexahydrate, ?solHm(AlCl3·6H2O, T=295.02K, m=0.02084mol·kg?1)=?(54.6±2.1)kJ·mol?1, aluminium nitrate nonahydrate, ?solHm(Al(NO3)3·9H2O; T=296.62K, m=0.01342mol·kg?1)=(30.7±1.0)kJ·mol?1 and aluminium sulphate octadecahydrate, ?solHm(Al2(SO4)3·18H2O,

  12. Molar mass, entanglement, and associations of the biofilm polysaccharide of Staphylococcus epidermidis.

    PubMed

    Ganesan, Mahesh; Stewart, Elizabeth J; Szafranski, Jacob; Satorius, Ashley E; Younger, John G; Solomon, Michael J

    2013-05-13

    Biofilms are microbial communities that are characterized by the presence of a viscoelastic extracellular polymeric substance (EPS). Studies have shown that polysaccharides, along with proteins and DNA, are a major constituent of the EPS and play a dominant role in mediating its microstructure and rheological properties. Here, we investigate the possibility of entanglements and associative complexes in solutions of extracellular polysaccharide intercellular adhesin (PIA) extracted from Staphylococcus epidermidis biofilms. We report that the weight average molar mass and radius of gyration of PIA isolates are 2.01×10(5)±1200 g/mol and 29.2±1.2 nm, respectively. The coil overlap concentration, c*, was thus determined to be (32±4)×10(-4) g/mL. Measurements of the in situ concentration of PIA (cPIA,biofilm) was found to be (10±2)×10(-4) g/mL.Thus, cPIA,biofilm

  13. How to measure and predict the molar absorption coefficient of a protein.

    PubMed Central

    Pace, C. N.; Vajdos, F.; Fee, L.; Grimsley, G.; Gray, T.

    1995-01-01

    The molar absorption coefficient, epsilon, of a protein is usually based on concentrations measured by dry weight, nitrogen, or amino acid analysis. The studies reported here suggest that the Edelhoch method is the best method for measuring epsilon for a protein. (This method is described by Gill and von Hippel [1989, Anal Biochem 182:319-326] and is based on data from Edelhoch [1967, Biochemistry 6:1948-1954]). The absorbance of a protein at 280 nm depends on the content of Trp, Tyr, and cystine (disulfide bonds). The average epsilon values for these chromophores in a sample of 18 well-characterized proteins have been estimated, and the epsilon values in water, propanol, 6 M guanidine hydrochloride (GdnHCl), and 8 M urea have been measured. For Trp, the average epsilon values for the proteins are less than the epsilon values measured in any of the solvents. For Tyr, the average epsilon values for the proteins are intermediate between those measured in 6 M GdnHCl and those measured in propanol. Based on a sample of 116 measured epsilon values for 80 proteins, the epsilon at 280 nm of a folded protein in water, epsilon (280), can best be predicted with this equation: epsilon (280) (M-1 cm-1) = (#Trp)(5,500) + (#Tyr)(1,490) + (#cystine)(125) These epsilon (280) values are quite reliable for proteins containing Trp residues, and less reliable for proteins that do not. However, the Edelhoch method is convenient and accurate, and the best approach is to measure rather than predict epsilon. PMID:8563639

  14. Antimicrobial effect of ozonated water, sodium hypochlorite and chlorhexidine gluconate in primary molar root canals

    PubMed Central

    Goztas, Zeynep; Onat, Halenur; Tosun, Gul; Sener, Yagmur; Hadimli, Hasan Huseyin

    2014-01-01

    Objective: The aim was to determine the antimicrobial effect of ozonated water, ozonated water with ultrasonication, sodium hypochloride and chlorhexidine (CHX) in human primary root canals contaminated by Enterococcus faecalis (E. faecalis). Materials and Methods: Fifty-eight extracted human primary molar teeth were used. Crowns were cut off using a diamond saw under water-cooling. One hundred roots were obtained and mechanically prepared. The roots were then sterilized by autoclaving in water for 15 min at 121°C. All samples were contaminated with E. faecalis for 24 h and the root canals were randomly divided into five groups (n = 20). Group I: 25 mg/L of Ozonated water (O3aq), Group II: 25 mg/L of O3aq with ultrasonication, Group III: 2.5% Sodium hypochloride (NaOCl), Group IV: 2% CHX and Group V: Positive control. The canal of each specimen was irrigated for 4 min and positive control was untreated. All root canals were agitated with sterile saline solution. The saline solution was collected from canals with sterile paper points. For each specimen, the paper points were transposed to eppendorf vials containing 2 ml of brain heart infusion. According to bacterial proliferation, the mean values of optical density were achieved by EL?SA (Biotek EL ×800, Absorbance Microplate Reader, ABD) and the data were analyzed. Results: NaOCI, CHX and two types of O3aq were found statistically different than positive control group. NaOCI irrigation was found significantly most effective. Conclusions: NaOCl, CHX and O3aq applications provide antibacterial effect in vitro conditions in primary root canals. PMID:25512726

  15. Silica-alumina molar ratio and some factors effect on the synthesis of zeolites from fly ash

    Microsoft Academic Search

    Yue-zhi Sun; Ke-ming Fu; Hong Zhu; Tian-lin Zhu

    2009-01-01

    In order to improve the activity and eliminate some impurities, pretreatment was used before hydrothermal synthesis. The fly\\u000a ash was mixed with an aqueous NaOH solution, the alkali melted fly ash was also adopted, which is hydrothermally treated at\\u000a about 104 °C, and the liquid\\/solid ratio was controlled at 6:1. In order to control Si\\/Al molar ratio, SiO2 or Al2O3

  16. Comparison of Conventional, Rotary, and Ultrasonic Preparation, Different Final Irrigation Regimens, and 2 Sealers in Primary Molar Root Canal Therapy

    Microsoft Academic Search

    Harun Canoglu; Meryem U. Tekcicek; Zafer C. Cehreli

    2006-01-01

    Purpose: The aim of this study was to compare the shaping effectiveness rotary nickel- titanium (Profi le .04 ISO), ultrasonic (K-Type\\/Satelec), and stainless-steel hand fi le (K-fi le\\/Maillefer) instrumentation and to assess tubular penetration of 2 gutta percha seal- ers (AH Plus and Sealite-Ultra) following 4 different fi nal irrigation regimens in primary molar roots. Methods: Distal roots of extracted

  17. Consecutive condylectomy and molar intrusion using temporary anchorage devices as an alternative for correcting facial asymmetry with condylar hyperplasia.

    PubMed

    Choi, Yoon Jeong; Lee, Sang-Hwy; Baek, Man-Suk; Kim, Jae-Young; Park, Young-Chel

    2015-04-01

    This case report demonstrates the successful treatment of facial asymmetry with condylar hyperplasia with limited surgical and orthodontic treatment. A high condylectomy was performed to shorten the elongated condyle and to remove its active growth site. The maxillary molars on the affected side were then orthodontically intruded using temporary anchorage devices to improve the occlusal cant and posterior open bite of the unaffected side. This combined surgical-orthodontic treatment provided a satisfactory outcome without additional orthognathic surgery. PMID:25836342

  18. Investigation of Adsorption and Inhibitive Effect of Calixarene Derivative Newly Synthesized Towards C38 Steel in Molar HCl

    Microsoft Academic Search

    R. Souane; M. Kaddouri; M. Bouklah; N. Cheriaa; B. Hammouti; J. Vicens

    2009-01-01

    The focus of this study is to synthesize a new calixarene derivative namely calix[6]arene (C21) and to test its performance as corrosion inhibitor of C38 steel in molar HCl at 308 K. Polarization and weight loss measurements were used. Weight loss tests show that C21 retards until to stop corrosion phenomenon at 5 × 10-5 M. C21 is an excellent

  19. Temporal and spatial distribution of Fos protein in the parabrachial nucleus neurons during experimental tooth movement of the rat molar

    Microsoft Academic Search

    Kuniyasu Hiroshima; Takeyasu Maeda; Kooji Hanada; Satoshi Wakisaka

    2001-01-01

    The present study was undertaken to reveal spatio-temporal changes in the distribution of Fos-like immunoreactive (-IR) neurons in the parabrachial nucleus (PBN), one of the important relay nuclei for processing autonomic and somatosensory information from the oro-facial regions, following the induction of experimental tooth movement in rat upper molars. The experimental tooth movement was induced by the insertion of elastic

  20. Evolution of the Tribosphenic Molar Pattern in Early Mammals, with Comments on the “Dual-Origin” Hypothesis

    Microsoft Academic Search

    Brian M. Davis

    Development of the tribosphenic molar was a fundamental event that likely influenced the rise of modern mammals. This multi-functional\\u000a complex combined shearing and grinding in a single chewing stroke, and provided the base morphology for the later evolution\\u000a of the myriad dental morphologies employed by mammals today. Here a series of morphotypes are presented that represent stepwise\\u000a acquisition of characters

  1. Stability of silver clusters in mordenites with different SiO 2\\/Al 2O 3 molar ratio

    Microsoft Academic Search

    Nina E Bogdanchikova; Vitalii P. Petranovskii; Roberto Machorro M; Yoshihiro Sugi; Victor M Soto G; Sergio Fuentes M

    1999-01-01

    The stability and decay of silver clusters characterized by absorption bands 320 and 285 nm incorporated in mordenites with different SiO2\\/Al2O3 molar ratios were studied under ambient conditions. Significantly different rates of disappearance of these two bands were the basis for assigning them to different silver species. Oxidation converts the clusters peaking at 320 and 285 nm into other silver

  2. Evaluation of isthmus prevalence, location, and types in mesial roots of mandibular molars in the Iranian Population

    PubMed Central

    Mehrvarzfar, Payman; Akhlagi, Nahid Mohammadzade; Khodaei, Fatemeh; Shojaee, Golnaz; Shirazi, Sara

    2014-01-01

    Background: Management of canal isthmus is considered as an important factor for successful endodontic treatment. Accordingly, this study was designed to determine the prevalence, location, and types of isthmus in mesial root canals of extracted mandibular molars in a sample of Iranian population. Materials and Methods: In this cross-sectional descriptive study, 60 extracted molars with two mesial canals were included. The samples were initially decoronated and then, roots were sectioned horizontally at 2, 4, and 6 mm levels from the apex via a low-speed handpiece with a thin metallic disk and finally prepared and stained with Indian ink. All sections were examined using a stereomicroscope at a magnification of ×30. Prevalence, location, and types of isthmus were evaluated based on the classifications by Kim and Teixeira and all data were statistically analyzed by the chi-squared test. The statistical significance level was established at 0.05. Results: Eighty-three percent of extracted mandibular molars had an isthmus at the mesial root. This prevalence increased with distance from the apex, that is, 92% at 6 mm from the apex and 70% at 2 mm from the apex. A statistically significant difference was found between the sections at 2 and 6 mm from the apex (P < 0.05), but no other significant differences between other levels (P > 0.05). Conclusion: Isthmus is very common in the mesial roots of the mandibular permanent molars in the Iranian population, with the highest prevalence in the 6 mm distance from the root apex. Therefore, detection, cleaning, and filling of these apical 6 mm isthmuses are of great benefit in modern endodontics. PMID:24932198

  3. Three-dimensional quantitative analysis of adhesive remnants and enamel loss resulting from debonding orthodontic molar tubes

    PubMed Central

    2014-01-01

    Aims Presenting a new method for direct, quantitative analysis of enamel surface. Measurement of adhesive remnants and enamel loss resulting from debonding molar tubes. Material and methods Buccal surfaces of fifteen extracted human molars were directly scanned with an optic blue-light 3D scanner to the nearest 2 ?m. After 20 s etching molar tubes were bonded and after 24 h storing in 0.9% saline - debonded. Then 3D scanning was repeated. Superimposition and comparison were proceeded and shape alterations of the entire objects were analyzed using specialized computer software. Residual adhesive heights as well as enamel loss depths have been obtained for the entire buccal surfaces. Residual adhesive volume and enamel loss volume have been calculated for every tooth. Results The maximum height of adhesive remaining on enamel surface was 0.76 mm and the volume on particular teeth ranged from 0.047 mm3 to 4.16 mm3. The median adhesive remnant volume was 0.988 mm3. Mean depths of enamel loss for particular teeth ranged from 0.0076 mm to 0.0416 mm. Highest maximum depth of enamel loss was 0.207 mm. Median volume of enamel loss was 0.104 mm3 and maximum volume was 1.484 mm3. Conclusions Blue-light 3D scanning is able to provide direct precise scans of the enamel surface, which can be superimposed in order to calculate shape alterations. Debonding molar tubes leaves a certain amount of adhesive remnants on the enamel, however the interface fracture pattern varies for particular teeth and areas of enamel loss are present as well. PMID:25208969

  4. Influence of the molar concentration and substrate temperature on fluorine-doped zinc oxide thin films chemically sprayed

    Microsoft Academic Search

    J. Rodríguez-Báez; A. Maldonado; G. Torres-Delgado; R. Castanedo-Pérez; M. de la L. Olvera

    2006-01-01

    The effect of both the molar concentration of the starting solution and the substrate temperature on the electrical, morphological, structural and optical properties of chemically sprayed fluorine-doped zinc oxide (ZnO:F) thin films deposited on glass substrates is analyzed in this work. All the starting solutions employed were aged for 10 days before the deposition. The results show that as the

  5. Influence of extended operation time and of occlusal force on determination of pulpal healing pattern in replanted mouse molars

    Microsoft Academic Search

    Tomoko Hasegawa; Hironobu Suzuki; Hiromasa Yoshie; Hayato Ohshima

    2007-01-01

    The mechanism regulating the divergent healing processes following tooth replantation is unclear. This study clarifies the\\u000a relationship between the healing pattern, the time taken for tooth replantation, and the influence of occlusal force. We investigated\\u000a the pulpal healing process after tooth replantation by immunohistochemistry for 5-bromo-2?-deoxyuridine and nestin and by\\u000a histochemistry for tartrate-resistant acid phosphatase. The upper right first molar

  6. Pulp-capping with Recombinant Human Insulin like Growth Factor I (rhIGF-I) in Rat Molars

    Microsoft Academic Search

    H. Lovschall; O. Fejerskov; A. Flyvbjerg

    2001-01-01

    The aim of this study was to explore pulp healing and reparative dentinogenesis following pulp-capping by using recombinant human insulin-like growth factor I (rhIGF-I). Exposures were made through the mesial pulp horn in first upper molars in two-month-old Wistar rats. The pulp was covered with one dose of sterile 4% methylcellulose gel containing either 400 ng rhIGF-I or saline in

  7. Responses of immunocompetent cells in the dental pulp to replantation during the regeneration process in rat molars

    Microsoft Academic Search

    Aya Shimizu; Kuniko Nakakura-Ohshima; Tadashi Noda; Takeyasu Maeda; Hayato Ohshima

    2000-01-01

    Responses of immunocompetent cells to tooth replantation during the regeneration process of the dental pulp in rat molars were investigated by immunocytochemistry using antibodies to class II major histocompatibility complex (MHC) molecules (OX6 antibody), monocyte\\/macrophage lineage cells (ED1 antibody) and protein gene product 9.5 (PGP 9.5), as well as by histochemical reaction for periodic acid-Schiff (PAS). Tooth replantation caused an

  8. Responses of macrophage-associated antigen-expressing cells in the dental pulp of rat molars to experimental tooth replantation

    Microsoft Academic Search

    Seree Rungvechvuttivittaya; Takashi Okiji; Hideaki Suda

    1998-01-01

    Bacterial infection of the dental pulp is a major hindrance to successful pulp regeneration after tooth replantation. This study examined how macrophages and class II molecule-expressing cells of the pulp respond to tooth replantation, on the hypothesis that they contribute to the defence and repair of the traumatized pulp. Upper right first molars of 5-week-old male Wistar rats were replanted

  9. Aqueous leachability of metakaolin-based geopolymers with molar ratios of Si\\/Al = 1.5–4

    Microsoft Academic Search

    Z. Aly; E. R. Vance; D. S. Perera; J. V. Hanna; C. S. Griffith; J. Davis; D. Durce

    2008-01-01

    The leachability in water of metakaolin based geopolymers with molar ratios of Na\\/Al=1 and Si\\/Al=1.5–4.0 has been investigated in order to optimise the composition for the immobilisation of nuclear waste. Formulations with Si\\/Al of around 2 are the most suitable using the ASTM\\/PCT leach test method. The variability of the leach results is discussed with reference to the microstructure, compressive

  10. Inhibition of secondary cartilage of the intermaxillary suture in Sprague-Dawley rats following the enucleation of maxillary molars

    SciTech Connect

    Forbes, D.P.; Al-Bareedi, S.

    1986-01-01

    A single craniofacial suture can undergo several morphologic transformations during its development. From 3 to 7 weeks of age, the intermaxillary suture of the rat is synchondrotic in character, featuring secondary cartilage; at later times, this suture is syndesmotic in character, featuring a fibrous tissue interface. Since intermittent mechanical stimulation has been reported to initiate secondary cartilage formation, a study was done to determine if the functioning dentition were responsible for secondary cartilage formation in the intermaxillary suture of the rat. Twenty-two female Sprague-Dawley rats were used. At 3 weeks of age, prior to eruption, the maxillary molars were enucleated from nine animals. Body weights were recorded weekly. Animals were sacrificed weekly from 4 to 7 weeks of age. One hour prior to sacrifice, each rat was injected with (/sup 35/S)sulfate at a dosage of 2 microCi/g body weight. The tissues were evaluated by light microscopy and autoradiography. In the experimental group, the midpalatal suture did not undergo the normal synchondrotic transformation. Instead, this suture remained fibrous with negligible metachromatic staining. In the control animals, the peak period of (/sup 35/S)sulfate incorporation was 4 weeks of age and was five times greater than in the experimental group. The primary stimulus for the initiation of secondary cartilage formation in the midpalatal suture of the rat was molar function. Also, functioning molars were found to be important in the maintenance of the palatal bone.

  11. Can the Follicle-Crown Ratio of the Impacted Third Molars be a Reliable Indicator of Pathologic Problem?

    PubMed Central

    Haghanifar, Sina; Moudi, Ehsan; Seyedmajidi, Maryam; Mehdizadeh, Mohammad; Nosrati, Kamran; Abbaszadeh, Naghi; Bijani, Ali; Ghorbani, Hakimeh

    2014-01-01

    Statement of the Problem: The presence of impacted third molars in the jaws is a common finding in the routine dental examination of patients. Concerning the odontogenic components of the dental follicle, it can be the origin of different types of odontogenic cysts and tumors. Purpose: The aim of this study was to find feasible radiographic criteria to help differentiate between normal and pathological dental follicles. Materials and Method: 134 asymptomatic impacted third molars were recruited in this study. Then, based on the radiographic measurements, the ratio between the diameter of the dental follicle and the mesiodistal width of the tooth crown was calculated. After surgical removal of impacted third molars, the related dental follicles were evaluated histopathologically. Statistical analyses were performed by adopting chi-square test, t-test, receiver oprating characteristic (ROC) curve, and logistic regression using SPSS-19 software. Results: The mean ratio of the dental follicle’s diameter to the mesiodistal width, in the normal and cystic follicle group was 1.18 ± 0.07 and 1.18 ± 0.08, respectively. There was no statistically significant difference between this ratio and the histopathological evaluation. Based on the logistic regression analysis, only the age >20 years and inflammation had predictive value in identifying cystic changes in dental follicle. Conclusion: According to the findings of the current study, the ratio of dental follicle diameter to the mesiodistal width of the teeth cannot not be employed as a diagnostic index to differentiate between normal and pathological dental follicle. PMID:25469358

  12. Combined validity of DIAGNOdent™ and visual examination for in vitro detection of occlusal caries in primary molars.

    PubMed

    Kavvadia, Katerina; Lagouvardos, Panagiotis; Apostolopoulou, Daphne

    2012-03-01

    The purpose of this in vitro investigation was to compare in primary molars, the validity of DIAGNOdent™ 2095 on occlusal caries diagnosis used either separately or in combination with direct and/or indirect visual examinations, based on histological examination as the reference method. In 24 extracted primary molars, 111 occlusal pits were examined for caries by one trained operator (intra-examiner reliability k > 0.80), using the following examination methods: direct visual (DV), indirect visual (IDV), radiographic (XR), and fluorescence (DD) with the DIAGNOdent™. The extent of caries was then determined histologically. Sensitivity, specificity, accuracy, and the area under the ROC curve (AUC) were calculated for each method separately as well as for the combination of DD with DV and/or IDV. The DD accuracy was found both for lesions into enamel and into dentin to be 0.70 while the accuracy of the DD combination with DV and IDV was found to be 0.89. The DD AUC for lesions into enamel and into dentin, 0.68, were not statistically significant different from the other methods (p > 0.5), however the AUC of the combination of DD with DV and IDV, found to be 0.82, was higher than all the other methods, and this was statistically significant for enamel lesions. The validity of DIAGNOdent™ for occlusal caries diagnosis in primary molars was much higher when the DD was used in combination with direct and indirect visual examination, than when used by itself. PMID:21243511

  13. Guided tissue regeneration in Class II furcation involved maxillary molars: a controlled study of 8 split-mouth cases.

    PubMed

    Avera, J B; Camargo, P M; Klokkevold, P R; Kenney, E B; Lekovic, V

    1998-09-01

    The purpose of this study was to clinically evaluate the effectiveness of polytetrafluoroethylene membranes in the healing of interproximal Class II furcation defects in maxillary molars using a surgical treatment technique based on the principles of guided tissue regeneration. Eight subjects with similar bilateral Class II furcation lesions on the mesial aspect of maxillary first molars participated in this study. Patients received initial therapy consisting of oral hygiene instructions, scaling and root planing, and occlusal adjustment if necessary. Clinical parameters evaluated included plaque index, sulcular bleeding index, probing depth, attachment level, gingival recession, and open horizontal and vertical furcation fill. An acrylic occlusal stent was used to assure reproducibility of measurements. Experimental sites received a polytetrafluoroethylene membrane following surgical exposure of the furcation. Control sites were treated in the exact same manner but without a membrane. Membranes were removed at 6 weeks after the first surgery. Reentry surgeries were performed at 9 months. Postsurgical results showed a significant improvement in probing depth, attachment level, and open horizontal furcation fill for both groups when compared to baseline values, with experimental sites performing significantly better than controls. Control sites showed a slight loss in open vertical furcation fill while experimental sites remained unchanged. This study suggests that guided tissue regeneration using polytetrafluoroethylene membranes is of some but limited value in the treatment of maxillary molar interpoximal Class II furcation lesions. PMID:9776030

  14. Maintenance of class III trifurcated molars versus implant placement in regenerated extraction sockets: long-term results of 2 cases.

    PubMed

    Zafiropoulos, Gregory-George K; di Prisco, Manuela Occipite; Deli, Giorgio; Hoffmann, Oliver

    2011-03-01

    Studies to date have reached differing conclusions regarding the long-term prognosis of teeth with class III furcation involvement. Replacement of such teeth with implants could be an alternative. This report compares the treatment outcomes of 2 cases with similar disease progression: 1 treated by implant therapy and 1 maintained with nonsurgical periodontal treatment. Two patients with advanced chronic periodontitis and class III furcation involvement of all molars were treated. Case 1 received a conservative periodontal and antibiotic treatment, followed by 15 years of maintenance. In case 2, the molars were extracted and replaced with implants, and the implants were observed for 7 years. Clinical attachment level (CAL), probing attachment level (PAL), bleeding on probing, plaque index, and periodontal pathogens were recorded. Despite good compliance of case 1, periodontal pathogens were not eliminated and tissue destruction was not halted. The PAL outcomes of case 2 improved over time; mean PAL loss reached 0.35 mm/y in the first 3 years and then decreased to 0.01 mm/y. While CAL outcomes did not change in case 2, case 1 showed increased CAL loss after 8 years. Based on the limited findings of this case report, extraction of molars with class III furcation involvement and subsequent implant placement may render a better predictability of treatment outcomes than nonsurgical periodontal therapy in the cases of infection with periodontal pathogens. PMID:20553166

  15. Prospective double-blind clinical trial evaluating the effectiveness of Bromelain in the third molar extraction postoperative period

    PubMed Central

    de la Barrera-Núñez, María C.; Yáñez-Vico, Rosa M.; Batista-Cruzado, Antonio; Heurtebise-Saavedra, Jean M.; Castillo-de Oyagüe, Raquel

    2014-01-01

    Objectives: To evaluate the anti-inflammatory and analgesic effect of Bromelain (pineapple extract) administered orally in the postoperative after extraction of impacted lower molars. Study Design: This is a prospective, placebo-controlled, unicentric, double-blind study; the sample size was 34 patients. The pre and postoperative outcomes, evaluated on the third (D3) and eighth day (D8), included inflamtion, pain and oral aperture, as well as the need for analgesics. One group received bromelain 150mg per day for three days and 100mg on days 4 to 7. The other group received placebo in the same dosage. All outcomes werrecorded quantitatively and analyzed with the Mann-Whitney U test for independent samples. Results: Although there were no statistically significant differences between the treatment groups, a trend towards less inflammation and improved oral aperture was observed in the group that received bromelain, compared to the group that received placebo. This trend can be attributed completely to random reasons, since there is no statistical difference in the results. Conclusions: Further studies are necessary to analyze different administration patterns and doses of bromelain for the use in the postoperative of impacted third molars. Key words:Tooth extraction, third molar, postoperative period, bromeline, clinical study. PMID:24316697

  16. Fracture resistance of computer-aided design/computer-aided manufacturing-generated composite resin-based molar crowns.

    PubMed

    Harada, Akio; Nakamura, Keisuke; Kanno, Taro; Inagaki, Ryoichi; Örtengren, Ulf; Niwano, Yoshimi; Sasaki, Keiichi; Egusa, Hiroshi

    2015-04-01

    The aim of this study was to investigate whether different fabrication processes, such as the computer-aided design/computer-aided manufacturing (CAD/CAM) system or the manual build-up technique, affect the fracture resistance of composite resin-based crowns. Lava Ultimate (LU), Estenia C&B (EC&B), and lithium disilicate glass-ceramic IPS e.max press (EMP) were used. Four types of molar crowns were fabricated: CAD/CAM-generated composite resin-based crowns (LU crowns); manually built-up monolayer composite resin-based crowns (EC&B-monolayer crowns); manually built-up layered composite resin-based crowns (EC&B-layered crowns); and EMP crowns. Each type of crown was cemented to dies and the fracture resistance was tested. EC&B-layered crowns showed significantly lower fracture resistance compared with LU and EMP crowns, although there was no significant difference in flexural strength or fracture toughness between LU and EC&B materials. Micro-computed tomography and fractographic analysis showed that decreased strength probably resulted from internal voids in the EC&B-layered crowns introduced by the layering process. There was no significant difference in fracture resistance among LU, EC&B-monolayer, and EMP crowns. Both types of composite resin-based crowns showed fracture loads of >2000 N, which is higher than the molar bite force. Therefore, CAD/CAM-generated crowns, without internal defects, may be applied to molar regions with sufficient fracture resistance. PMID:25683749

  17. Self-assembly of myristic acid in the presence of choline hydroxide: effect of molar ratio and temperature.

    PubMed

    Arnould, Audrey; Perez, Adrian A; Gaillard, Cédric; Douliez, Jean-Paul; Cousin, Fabrice; Santiago, Liliana G; Zemb, Thomas; Anton, Marc; Fameau, Anne-Laure

    2015-05-01

    Salt-free catanionic systems based on fatty acids exhibit a broad polymorphism by simply tuning the molar ratio between the two components. For fatty acid combined with organic amino counter-ions, very few data are available on the phase behavior obtained as a function of the molar ratio between the counter-ion and the fatty acid. We investigated the choline hydroxide/myristic acid system by varying the molar ratio, R=n(choline hydroxide)/n(myristic acid), and the temperature. Myristic acid ionization state was determined by coupling pH, conductivity and infra-red spectroscopy measurements. Self-assemblies were characterized by small angle neutron scattering and microscopy experiments. Self-assembly thermal behavior was investigated by differential scanning calorimetry, wide angle X-ray scattering and nuclear magnetic resonance. For R<1, ionized and protonated myristic acid molecules coexisted leading to the formation of facetted self-assemblies and lamellar phases. The melting process between the gel and the fluid state of these bilayers induced a structural change from facetted or lamellar objects to spherical vesicles. For R>1, myristic acid molecules were ionized and formed spherical micelles. Our study highlights that both R and temperature are two key parameters to finely control the self-assembly structure formed by myristic acid in the presence of choline hydroxide. PMID:25626134

  18. Nano-Molar Deltamethrin Sensor Based on Electrical Impedance of PAH/PAZO Layer-by-Layer Sensing Films

    PubMed Central

    Abegão, Luís Miguel Gomes; Ribeiro, Jorge Humberto Fernandes; Ribeiro, Paulo António; Raposo, Maria

    2013-01-01

    This work reports a novel deltamethrin (DM) sensor able to detect nano-molar concentrations in ethanol solutions. The sensing layer consists of a thin film, obtained via a layer-by-layer technique, from alternate adsorption of poly(allylamine chloride) (PAH) and poly[1-[4-(3-carboxy-4-hydroxyphenylazo)-benzenesulfonamide)-1,2-ethanediyl]sodium salt] (PAZO) onto a solid support with interdigitaded gold electrodes. The sensor response, obtained from impedance spectroscopy measurements, was revealed to be linear with respect to the real part of impedance, taken at 100 Hz, when plotted as a function of the logarithm of deltamethrin molar concentrations in the micro- to nano-molar range. Sensor sensitivity was of 41.1 ± 0.7 k? per decade of concentration for an immersion time above 2 min and the reproducibility is approximately 2% in a binary solution of ethanol and deltamethrin. The main insight of this work concerns to DM detection limits as the sensor revealed to be able to detect concentrations below 0.1 nM, a value which is significantly lower than any reported in the literature and close what is appropriate for in situ environmental contaminant detection. PMID:23966185

  19. Bupivacaine 0.5 % versus articaine 4 % for the removal of lower third molars. A crossover randomized controlled trial

    PubMed Central

    Sancho-Puchades, Manuel; Vílchez-Pérez, Miguel A.; Paredes-García, Jordi; Berini-Aytés, Leonardo; Gay-Escoda, Cosme

    2012-01-01

    Objective: To compare the anesthetic action of 0.5% bupivacaine in relation to 4% articaine, both with 1:200,000 epinephrine, in the surgical removal of lower third molars. As a secondary objective hemodynamic changes using both anesthetics were analyzed. Study Design: Triple-blind crossover randomized clinical trial. Eighteen patients underwent bilateral removal of impacted lower third molars using 0.5% bupivacaine or 4% articaine in two different appointments. Preoperative, intraoperative and postoperative variables were recorded. Differences were assessed with McNemar tests and repeated measures ANOVA tests. Results: Both solutions exhibited similar latency times and intraoperative efficacy. Statistical significant lower pain levels were observed with bupivacaine between the fifth (p=0.011) and the ninth (p=0.007) postoperative hours. Bupivacaine provided significantly longer lasting soft tissue anesthesia (p<0.05). Systolic blood pressure and heart rate values were significantly higher with articaine. Conclusions: Bupivacaine could be a valid alternative to articaine especially due to its early postoperative pain prevention ability. Key words:Bupivacaine, articaine, third molar, anesthesia, postoperative pain. PMID:22143739

  20. A specific molar ratio of stabilizer to protein is required for storage stability of a lyophilized monoclonal antibody.

    PubMed

    Cleland, J L; Lam, X; Kendrick, B; Yang, J; Yang, T H; Overcashier, D; Brooks, D; Hsu, C; Carpenter, J F

    2001-03-01

    The selection of the appropriate excipient and the amount of excipient required to achieve a 2-year shelf-life is often done by using iso-osmotic concentrations of excipients such as sugars (e.g., 275 mM sucrose or trehalose) and salts. Excipients used for freeze-dried protein formulations are selected for their ability to prevent protein denaturation during the freeze-drying process as well as during storage. Using a model recombinant humanized monoclonal antibody (rhuMAb HER2), we assessed the impact of lyoprotectants, sucrose, and trehalose, alone or in combination with mannitol, on the storage stability at 40 degrees C. Molar ratios of sugar to protein were used, and the stability of the resulting lyophilized formulations was determined by measuring aggregation, deamidation, and oxidation of the reconstituted protein and by infrared (IR) spectroscopy (secondary structure) of the dried protein. A 360:1 molar ratio of lyoprotectant to protein was required for storage stability of the protein, and the sugar concentration was 3-4-fold below the iso-osmotic concentration typically used in formulations. Formulations with combinations of sucrose (20 mM) or trehalose (20 mM) and mannitol (40 mM) had comparable stability to those with sucrose or trehalose alone at 60 mM concentration. A formulation with 60 mM mannitol alone provided slightly less protection during storage than 60 mM sucrose or trehalose. The disaccharide/mannitol formulations also inhibited deamidation during storage to a greater extent than the lyoprotectant formulations alone. The reduction in aggregation and deamidation during storage correlated directly with inhibition of unfolding during lyophilization, as assessed by IR spectroscopy. Thus, it appears that the protein must be retained in its native-like state during freeze-drying to assure storage stability in the dried solid. Long-term studies (23-54 months) performed at 40 degrees C revealed that the appropriate molar ratio of sugar to protein stabilized against aggregation and deamidation for up to 33 months. Therefore, long-term storage at room temperature or above may be achieved by proper selection of the molar ratio and sugar mixture. Overall, a specific sugar/protein molar ratio was sufficient to provide storage stability of rhuMAb HER2. PMID:11170024

  1. The threshold strength of laminar ceramics utilizing molar volume changes and porosity

    NASA Astrophysics Data System (ADS)

    Pontin, Michael Gene

    It has been shown that uniformly spaced thin compressive layers within a ceramic body can arrest the propagation of an otherwise catastrophic crack, producing a threshold strength: a strength below which the probability of failure is zero. Previous work has shown that the threshold strength increases with both the magnitude of the compressive stress and the fracture toughness of the thin layer material, and finite element analysis predicts that the threshold strength can be further increased when the elastic modulus of the compressive layer is much smaller than the thicker layer. The current work describes several new approaches to increase the threshold strength of a laminar ceramic system. The initial method utilized a molar volume expansion within the thin layers, produced by the tetragonal-to-monoclinic phase transformation of unstabilized zirconia during cooling, in order to produce large compressive stresses within the thin layers. High threshold strengths were measured for this system, but they remained relatively constant as the zirconia content was increased. It was determined that microcracking produced during the transformation reduced the magnitude of the compressive stresses, but may also have served to reduce the modulus of the thin compressive layer, providing an additional strengthening mechanism. The second approach studied the addition of porosity to reduce the elastic modulus of the thin compressive layers. A new processing method was created and analyzed, in which thick layers of the laminate were fabricated by tape-casting, and then dip-coated into a slurry, containing rice starch, to create thin porous compressive layers upon densification. The effects of porosity on the residual compressive stress, elastic modulus, and fracture toughness of the thin layers were measured and calculated, and it was found that the elastic modulus mismatch between the thin and thick layers produced a large strengthening effect for volume fractions of porosity below a critical level. Specimens with greater volume fractions of porosity exhibited complete crack arrest, typically followed by non-catastrophic failure, as cracks initiating in adjacent thick layers coalesced by cracking or delamination along the thin porous layers.

  2. Late postoperative hemorrhage in a patient with undiagnosed COX-1 deficiency after third molar extractions.

    PubMed

    Doscher, Jesse C; Volpe, Fedele N

    2014-04-01

    Oral maxillofacial surgeons direct invasive procedures that often cause significant bleeding. Uncontrolled hemorrhage is a rare, yet serious, complication that can be seen in patients with thrombocytopathy. Platelets have 3 distinct roles in coagulation: initial adhesion, phospholipid externalization, and platelet aggregation.(1) Several types of platelet deficiencies, including defects of adhesion (Bernard-Soulier syndrome), defects of aggregation (Glanzmann thrombasthenia), and disorders of platelet secretion due to a deficiency of adenosine diphosphate (ADP) or cyclooxygenase-1 (COX-1).(2-4) COX has 2 isoforms: COX-1 and COX-2.(5,6) COX-1 is expressed constitutively in most tissues, and COX-2 is induced primarily by inflammatory mediators.(7,8) Although both isoforms are present in platelets, COX-1 is the major isoform that contributes to coagulation, because it is critically important in the formation of thromboxane A2 (TXA2) by way of the arachidonic acid (AA) pathway.(9) AA is a potent inducer of platelet aggregation.(1,3,4) When AA is exposed to an activating agent, such as ADP, it undergoes a series of enzymatic reactions that culminates in the production of TXA2.(10) TXA2 is the predominant product of the COX-1 pathway and is a major metabolite of AA in platelets. TXA2 is necessary for normal platelet function. Therefore, the inhibition of, or a deficiency in, COX-1 will compromise the AA pathway, thereby reducing platelet secretion and altering normal platelet aggregatory function.(1,3) COX-1 deficiencies are usually caused by drug interactions with the enzyme itself. In addition, studies have identified genetic mutations that can result in COX-1 deficiency.(2) We present the hospital course, management, and diagnosis of a patient with an undiagnosed COX-1 deficiency who had had third molars removed in a private office. To our knowledge, this is the first case of COX-1 deficiency diagnosed after exodontia documented in English studies. In addition, we reviewed the published data of this rare disorder that has significant clinical implications. PMID:24480756

  3. A comparison of two anesthesia methods for the surgical removal of maxillary third molars: PSA nerve block technique vs. local infiltration technique

    PubMed Central

    2014-01-01

    Objectives: The purpose of this study was to compare the effect of PSA block injection with infiltration technique regarding local anesthesia for surgical extraction of upper third molar. Material and Methods: A prospective, intra individual, single-blind randomized controlled trial was designed to study the severity of pain during injection and after surgical extraction of the bilaterally and symmetrically similar upper third molar in a total of 53 patients, in addition to evaluating the need to repeat the injection and requirement of post operative anti-inflammatory tablets. Result: Although the average pain score for all studied times in PSA side was lower than the average pain score in infiltration technique, repeated statistical measures demonstrated that no significant pain reduction occurred in the two techniques. Conclusion: The both tested methods have the same statistic equivalence for the surgical extraction of maxillary third molars. Key words:Surgical extraction, maxillary third molars, PSA block, infiltration. PMID:24596629

  4. The vapour pressures of saturated aqueous solutions of magnesium, calcium, nickel and zinc acetates and molar enthalpies of solution of magnesium, calcium, zinc and lead acetates

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2001-01-01

    Vapour pressures of water over saturated solutions of magnesium, calcium, nickel and zinc acetates were determined as a function of temperature. The vapour pressures served to evaluate the water activities, osmotic coefficients and molar enthalpies of vaporization. Molar enthalpies of solution of magnesium acetate tetrahydrate,?solHm (T= 294.71K ;m= 0.01 mol · kg?1) =?(15.65 ± 0.97)kJ · mol?1; calcium acetate,?solHm (T=

  5. Comparison of Maxillary Molar Distalization with an Implant-Supported Distal Jet and a Traditional Tooth-Supported Distal Jet Appliance

    PubMed Central

    Cozzani, Mauro; Pasini, Marco; Zallio, Francesco; Ritucci, Robert; Mutinelli, Sabrina; Mazzotta, Laura; Giuca, Maria Rita; Piras, Vincenzo

    2014-01-01

    Aim. To investigate and compare the efficiency of two appliances for molar distalization: the bone-anchored distal screw (DS) and the traditional tooth-supported distal jet (DJ) for molar distalization and anchorage loss. Methods. Tests (18 subjects) were treated with a DS and controls (18 subjects) were treated with a DJ. Lateral cephalograms were obtained before and at the end of molar distalization and were analysed. Shapiro Wilk test, unpaired t-test, and Wilcoxon rank-sum test were applied according to values distribution. The ? level was fixed at 0.05. Results. Maxillary first molars were successfully distalized into a Class I relationship in all patients. The mean molar distalization and treatment time were similar in both groups. The DS group exhibited a spontaneous distalization (2.1 ± 0.9?mm) of the first premolar with control of anchorage loss, distal tipping, extrusion, and skeletal changes. Conclusions. The DS is an adequate compliance-free distalizing appliance that can be used safely for the correction of Class II malocclusions. In comparison to the traditional DJ, the DS enables not only a good rate of molar distalization, but also a spontaneous distalization of the first premolars. PMID:25018770

  6. A Retrospective Radiographic Survey of Pathology Associated with Impacted Third Molars among Patients Seen in Oral & Maxillofacial Surgery Clinic of College of Dentistry, Riyadh

    PubMed Central

    Khawaja, Naveed Ahmad; Khalil, Hesham; Parveen, Kauser; Al-Mutiri, Abdulmajeed; Al-Mutiri, Saif; Al-Saawi, Abdullah

    2015-01-01

    Background: The purpose of this study is to determine the type and frequency of pathological conditions around third molar teeth among randomly selected patient’s records in Oral and Maxillofacial Surgery, College of Dentistry, King Saud University, Riyadh. Materials and Methods: Totally, 281 patient panoramic radiographs were selected with detectable pathology among 570 files of patients seen in oral and maxillofacial surgery clinics 2 years retrospectively. Almost 17-55 years age (mean age 25.43) was selected. The following radiographs were analyzed for all pathology associated impacted teeth; dental caries, bone resorption, periodontitis, and apical pathology. Results: The study found caries, external bone resorption and periodontitis are highly frequent to mesioangular and horizontal in mandibular impacted third molar compared to maxillary impacted third molar. Overall result evaluated that tooth #28 related periodontitis is significant (P = 0.021), and tooth #38 related bone resorption, tooth #48 related root caries, bone resorption and apical pathology are highly significant (P = 0.000) comparing to others. This study also concluded the high frequency of root caries, bone resorption and apical pathology reported in relation to mandibular impacted third teeth. Significant results were also achieved with periodontitis in relation to mesiangular and vertical angulation of left impacted maxillary third molars. Conclusion: Prophylactic removal of impacted third molars is recommended in many studies to avoid future risk of associated pathology. Retained asymptomatic impacted third molars imply pathology that could be difficult in later ages as less morbidity in younger ages. PMID:25954064

  7. In Vivo Evaluation of the Treatment Outcome of Pulpotomy in Primary Molars Using Diode Laser, Formocresol, and Ferric Sulphate

    PubMed Central

    Tanboga, Ilknur

    2014-01-01

    Abstract Objective: The purpose of this study was to assess whether the diode laser (DL) pulpotomy method is a suitable alternative to formocresol (FC) and ferric sulphate (FS) pulpotomies in human primary teeth. Background data: Pulpotomy is the amputation of infected coronal pulp to maintain radicular pulp vitality and function. Although FC is regarded as the gold standard for pulpotomy in primary teeth, concerns about its safety have been reported. Lasers are an effective nonpharmacological alternative for treating pulp in children. Methods: This study included 120 primary molars in 58 children 5–9 years of age who underwent an identical conventional pulpotomy technique; the molars were allocated to FC, FS, and DL groups. After removal of the coronal tissue, complete hemostasis of the remaining pulp in the DL group was achieved by DL at 1.5 W, 30?Hz, and 50?mJ, with a 10?sec exposure time. For the FC group, diluted FC (1:5 Buckley's formocresol) was used for 5?min., and for the FS group, a 15.5% FS solution was used for 15?sec. Treatments in all groups were completed with stainless steel crowns and monitored clinically and radiographically at 1, 3, 6, 9, and 12 months. Results: The clinical success rates at 12 months were 97%, 95%, and 100%, whereas the radiographic success rates were 87%, 79%, and 75%, for the FC, FS and DL groups, respectively. The differences in the results were not statistically significant according to the ?2 test (p>0.05). Conclusions: DL pulpotomy offers a high clinical success rate, however considering radiographic success rate, it may not replace traditional FC and FS pulpotomies in primary molars. PMID:24717147

  8. Cone-beam computed tomography analysis of the vestibular surgical pathway to the palatine root of the maxillary first molar

    PubMed Central

    Kalender, Atakan; Aksoy, Umut; Basmaci, Fatma; Orhan, Kaan; Orhan, Ayse Isil

    2013-01-01

    Objective: The aim of this study was to evaluate the anatomical distance between apices of the palatine root of the maxillary first molars to the buccal bone plate to identify the vestibular surgical pathway in a Turkish adult population using cone-beam computed tomography (CBCT) images. Methods: CBCT scans of 107 (48 male and 59 female) patients were retrospectively analyzed. The overall mean age was 38.6 years. The distance between the vestibular cortex and vestibular side of the palatine root was measured for 192 maxillary first molars both on axial images parallel to the palatal plane and on reformatted cross-sectional images. A Pearson’s chi square test and Mann-Whitney U-test were performed to evaluate differences among age, localization, and measurements. Differences were considered statistically significant at P<.05. Results: The mean distance between the buccal cortex and the buccal side of the palatine root of the superior first molar in both male and female patients was 10.13 and 9.70 mm, respectively. The incidence of interposition of the lateral recess of the maxillary sinus between the roots was 42.2% and 49% in men and women, respectively. Statistically significant sex-related differences were found in the vestibular surgical pathway (P<.05). Conclusions: For precise planning of endodontic surgery, it is crucial to determine the exact dimensions and location of the periapical lesion, as well as its relationship with the roots and other neighboring anatomical structures. CBCT can be a powerful tool for the evaluation of surgical cases in three dimensions with less ionizing radiation and better avoidance of complications during surgery. PMID:23408714

  9. Effect of occlusal rehabilitation on spatial memory and hippocampal neurons after long-term loss of molars in rats.

    PubMed

    Sakamoto, S; Hara, T; Kurozumi, A; Oka, M; Kuroda-Ishimine, C; Araki, D; Iida, S; Minagi, S

    2014-10-01

    Experimental loss of occlusal support caused by the extraction or grinding of molar teeth has been reported to foment the impairment of learning and memory in laboratory animals. The purpose of this study was to examine the effect of occlusal reconstruction after long-term loss of molars on spatial memory by using 8-arm radial maze and by assessing histopathological changes of neuron density in the hippocampus. Experimental dentures were inserted into the oral cavities of molarless rats to recover the occlusal support. Age-matched groups of control, molarless and denture-wearing rats were trained to perform the maze tasks. The difference of the error incidence in the maze task was evaluated between three groups. The difference of neuron density between three groups was also evaluated at the end of the maze task. Serum corticosterone levels were also measured to estimate the chronic stress, which could be caused by extraction, insertion of the experimental denture or any experimental procedure. The error incidence in the denture-wearing group was significantly higher than that of the control group, but significantly lower than that of the molarless group. Significant differences of neuron density were observed between three groups in each of the hippocampal CA1, CA3 and DG subfields. No significant difference of the serum corticosterone levels between three groups could be observed. From the results of this study, it was suggested that the recovery of occlusal support would bring amelioration of cognitive impairment concomitant with long period loss of molars in rats. PMID:24909970

  10. Taxonomic differences in deciduous upper second molar crown outlines of Homo sapiens, Homo neanderthalensis and Homo erectus.

    PubMed

    Bailey, Shara E; Benazzi, Stefano; Souday, Caroline; Astorino, Claudia; Paul, Kathleen; Hublin, Jean-Jacques

    2014-07-01

    A significant number of Middle to Late Pleistocene sites contain primarily (and sometimes only) deciduous teeth (e.g., Grotta del Cavallo, Mezmaiskaya, Blombos). Not surprisingly, there has been a recent renewed interest in deciduous dental variation, especially in the context of distinguishing Homo neanderthalensis and Homo sapiens. Most studies of the deciduous dentition of fossil hominins have focused on standard metrical variation but morphological (non-metric and morphometric) variation also promises to shed light on long standing taxonomic questions. This study examines the taxonomic significance of the crown outline of the deciduous upper second molar through principal components analysis and linear discriminant analysis. We examine whether or not the crown shape of the upper deciduous second molar separates H. neanderthalensis from H. sapiens and explore whether it can be used to correctly assign individuals to taxa. It builds on previous studies by focusing on crown rather than cervical outline and by including a large sample of geographically diverse recent human populations. Our samples include 17 H. neanderthalensis, five early H. sapiens, and 12 Upper Paleolithic H. sapiens. In addition, we include two Homo erectus specimens in order to evaluate the polarity of crown shape differences observed between H. neanderthalensis and H. sapiens. Our results show that crown outline shape discriminates H. sapiens and H. neanderthalensis quite well, but does not do well at distinguishing H. erectus from H. sapiens. We conclude that the crown outline shape observed in H. sapiens is a primitive retention and that the skewed shape observed in H. neanderthalensis is a derived condition. Finally, we explore the phylogenetic implications of the results for the H. erectus molars. PMID:24703186

  11. Cryotherapy and Topical Minocycline as Adjunctive Measures to Control Pain After Third Molar Surgery: An Exploratory Study

    PubMed Central

    Gelesko, Savannah; Long, Leann; Faulk, Jan; Phillips, Ceib; Dicus, Carolyn; White, Raymond P.

    2013-01-01

    Purpose To assess the impact of cryotherapy or topical minocycline on patients’ perceptions of recovery from pain after third molar surgery in an exploratory comparative-effectiveness study. Patients and Methods Subjects aged at least 14 years who were having all 4 third molars removed were enrolled in 3 separate institutional review board–approved studies. Study groups included subjects treated with a passively applied cold wrap for 24 hours postoperatively, subjects treated with topical minocycline during surgery, and subjects enrolled in a nonconcurrent comparison group who had received neither topical minocycline nor directed cryotherapy. Third molar surgery was performed in all cases by trained surgeons using the same protocol. An exact Kruskal-Wallis test was used to compare the distributions of the worst and average pain scores and a Fisher exact test to compare verbal responses from Gracely pain scales among the 3 groups for postsurgical days (PSDs) 1 to 3. Results This study comprised 51 cryotherapy subjects (2005–2009), 63 minocycline subjects (2003–2004), and 92 comparison-group subjects (2002–2006) who were treated at academic centers and in community practices across the United States (N = 206). Demographic descriptors were similar among all groups. For PSDs 1 through 3 (unadjusted), the highest scores for worst pain (6–7 [out of 7] on Likert-type scale) were reported less frequently in each of the study groups than in subjects in the comparison group, although the numbers of subjects reporting the highest scores were few. The distribution of pain outcomes was significantly different among the 3 groups for worst pain and affective words on PSD 1 (P = .04 for both). However, the small number of subjects who reported the highest pain scores precluded adequate multivariate statistical analyses for all outcomes on PSD 1 to 3. Conclusions Data from this exploratory study suggest that adjunctive therapy to decrease postoperative pain—cryotherapy or topical minocycline—might be effective at moderating the patient’s highest pain levels after third molar surgery. The topic should be studied further in a multicenter, prospective, randomized trial. PMID:21802812

  12. Diffusion coefficients and molar conductivities in aqueous solutions of 1-ethyl-3-methylimidazolium-based ionic liquids

    Microsoft Academic Search

    Chun-Li Wong; Allan N. Soriano; Meng-Hui Li

    2008-01-01

    Here, we presented new experimental data of diffusion coefficients of five [Emim, (1-ethyl-3-methylimidazolium)]-based ionic liquids in water at infinite dilution for temperatures ranging from 303.2 to 323.2K using Taylor dispersion method. The investigated ILs were [Emim][C2N3 (dicyanamide)], [Emim][BF4 (tetrafluoroborate)], [Emim][C2H5SO4 (ethylsulfate)], [Emim][CF3SO3 (trifluoromethanesulfonate)], and [Emim][MDEGSO4 (2-(2-methoxyethoxy) ethylsulfate)]. The molar conductivities of these ionic liquids were also measured and the infinite

  13. [Facial pain- a rare cause. Impacted lower third molars causing primarily "unclear" facial pain: a case report].

    PubMed

    Gander, Thomas; Dagassan-Berndt, Dorothea; Mascolo, Luana; Kruse, Astrid L; Grätz, Klaus W; Lübbers, Heinz-Theo

    2013-01-01

    Orofacial pain often causes special difficulties to patients and dentists. Numerous differential diagnoses require the utilization of a coordinated diagnostic concept. Often, multiple causes lead to the need for a complex treatment plan. Impacted third molars are a potential cause of a variety of complications. Caries, pulp necrosis, and periapical infection are some of the infrequent causes of such pain. The presented case shows just such a constellation, resulting in primarily "unclear" orofacial pain. A diagnostic sequence generally leads to the correct diagnosis and thereby allows for fast and effective therapy. This shows how important structured diagnostics are, especially in cases of "unclear" pain. PMID:24114596

  14. Efficacy of ibuprofen versus lornoxicam after third molar surgery: a randomized, double-blind, crossover pilot study

    Microsoft Academic Search

    Francine D. Lustenberger; Klaus W. Grätz; Till S. Mutzbauer

    2011-01-01

    Purpose  The aim of this study is to compare the analgesic efficacy and tolerability of a pre-emptive\\/post-surgery 4-day regimen of\\u000a oral ibuprofen 400 mg with that of lornoxicam 8 mg.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Sixteen patients received ibuprofen or lornoxicam, respectively, before and after surgery of impacted third molars in two\\u000a separate appointments, in a double-blind, randomized, and crossover design. The postoperative analgesic and rescue medication\\u000a consumption

  15. Limiting Partial Molar Volumes of Electrolytes in 2Methyl2Butanol + Water Mixtures at 298.15 K

    Microsoft Academic Search

    Eugenio Garcia-Pañeda; Pilar Guardado; Alfredo Maestre

    2004-01-01

    Partial molar volumes at infinite dilution, V02, of alkali–metal halides (LiCl, NaCl KCl RbCl CsCl, NaBr, KBr, KI), tetra-n-alkylammonium bromides, R4NBr (R=Me, Et, n-Pr, n-Bu, n-Pen), NaBPh4, and Ph4PCl have been determined in binary solvent mixtures of water with 2-methyl-2-butanol covering the water-rich region and the alcohol-rich region at 298.15 K. V02 for alkali–metal halides show relatively little dependence on

  16. Excess molar volumes of the systems m-xylene?+?1-propanol, +2-propanol, +1-butanol,?+2-methyl-2-propanol

    Microsoft Academic Search

    M. A. Saleh; M. Habibullah; M. Shamsuddin Ahmed; M. Ashraf Uddin; S. M. H. Uddin; M. Afsar Uddin; F. M. Khan

    2005-01-01

    Densities, ?, of the systems m-xylene?+?1-propanol,?+?2-propanol,?+?1-butanol and?+?2-methyl-2-propanol have been determined from 303.15 to 323.15?K with an interval of 5?K. Excess molar volumes, , have been calculated from density data.???and have been fitted to appropriate polynomial equations and plotted against mole fraction of alkanols. For the systems, m-xylene?+?1-propanol and m-xylene?+?1-butanol, sigmoid type of curves have been observed, but for the systems,

  17. Mechanical properties of metakaolin-based geopolymers with molar ratios of Si\\/Al ? 2 and Na\\/Al ? 1

    Microsoft Academic Search

    B. A. Latella; D. S. Perera; D. Durce; E. G. Mehrtens; J. Davis

    2008-01-01

    The mechanical properties of four different types of geopolymers, but of the same composition (Na\\/Al ? 1, Si\\/Al ? 2 molar\\u000a ratio), made using a combination of precursors, were determined. The four types were: (i) sodium aluminate (NaAlO2\\/NaOH solution), Ludox (colloidal SiO2 solution) and metakaolin (MK), (SAGP), (ii) NaOH, fumed silica and MK (FSGP), (iii) Ludox, NaOH and MK (LGP) and (iv) commercial\\u000a sodium silicate

  18. Effect of molarity of TiO2 seeded-template to the growth of ZnO nanostructures

    NASA Astrophysics Data System (ADS)

    Asib, N. A. M.; Afaah, A. N.; Aadila, A.; Mahmud, M. R.; Lim, Y. C.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.; Khusaimi, Z.

    2015-05-01

    ZnO nanostructures were deposited by solution-immersion method on TiO2 layers by sol-gel spin-coating technique. Seven layers of TiO2 were coated on glass substrates at different molarities, followed by annealing treatment and solution-immersion process in aqueous solution containing 1:1 ratio of 0.05 M of zinc nitrate hexahydrate (Zn(NO3)2.6H2O) and hexamethylenetetramine (HMTA) (C6H12N4). FESEM images confirmed that ZnO nanostructures grown on TiO2 seeded-template are in needle-like shape with smaller tip can be observed. Photoluminescence (PL) spectroscopy showed that as the molarity of TiO2 seeded- template increase, the intensity of PL emission at UV region decrease. UV emission peak for 0.10 M and 0.25 M are higher compared to UV emission peak film of 0.50 M and 1.00 M, which are too low. Meanwhile, the UV absorption properties of the nanostructured thin film for 0.25 M of TiO2 seeded-template was higher compared to other thin films.

  19. Densities and excess molar volumes of binary mixtures containing propylene carbonate + chlorohydrocarbons at 298.15 K and atmospheric pressure

    SciTech Connect

    Comelli, F. [Centro di Studio per la Fisica delle Macromolecule del CNR, Bologna (Italy); Francesconi, R. [Univ. degli Studi, Bologna (Italy). Dipt. di Chemica

    1995-11-01

    Densities and excess molar volumes, V{sub m}{sup E}, for binary mixtures containing propylene carbonate + 10 chlorohydrocarbons (dichloromethane, 1,2-dichloroethane, 1,3-dichloropropane, 1,4-dichlorobuthane, 1,6-dichlorohexane, 1,10-dichlorodecane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trans-1,2-dichloroethene, and trichloroethene) have been measured at 298.15 K and at atmospheric pressure using an Anton Paar digital vibrating tube density meter. The results are fitted to the Redlich-Kister equation. The values of V{sub m}{sup E} for the mixtures containing dichloroalkanes show an increasing trend with the increase of the chain length and vary from a minimum of {minus}0.24 cm{sup 3}/mol for dichloromethane up to a maximum of +0.31 cm{sup 3}/mol for 1,10-dichlorodecane. The excess molar volumes for the other mixtures are negative over the entire range of composition. Results are qualitatively discussed in terms of molecular interactions.

  20. Compliance of postoperative instructions following the surgical extraction of impacted lower third molars: A randomized clinical trial

    PubMed Central

    Alvira-González, Joaquín

    2015-01-01

    Objectives: The understanding and adherence to postoperative care instructions are factors that influence the recuperation process after any surgical procedure. The aim of this study was to determine the percentage of patients who strictly follow the postoperative instructions after the extraction of an impacted lower third molar in relation to sociocultural level, preoperative anxiety scores and how postoperative information is provided to the patient. Study Design: Patients were randomly assigned to one of three different test groups according to how the postoperative instructions were presented: verbal, written and a group that received additional information. Before surgery, patients were required to complete the Corah Dental Anxiety Scale and personal information (age, gender and educational level) was also collected. P<0.05 was considered significant. Patients were surveyed a week after surgery regarding their adherence to postoperative instructions. Results: 84 patients (45 women and 39 men with an average of 28.23 ± 7.41 years) completed the study. There were no statistically significant differences regarding adherence of postoperative care instructions depending on the manner of instruction presentation, preoperative anxiety level and sociocultural level (p> 0.05). Quitting smoking or drinking of alcoholic/carbonated beverages were the main influential factors for the lack of adherence to postoperative care instructions during the week after surgery. Conclusions: Presentation of postoperative instructions, preoperative anxiety scores and sociocultural level do not appear to be key factors that promote the adherence to postoperative instructions. Key words:Compliance, postoperative instructions, treatment, third molar. PMID:25475774

  1. Histological evaluation of experimentally induced subluxation in rat molars and its implications on the management of orthodontic treatment.

    PubMed

    Pereira, Alex Luiz Pozzobon; de Mendonça, Marcos Rogério; Sonoda, Celso Koogi; Cuoghi, Osmar Aparecido; Poi, Wilson Roberto

    2010-02-01

    The purpose of this study was to evaluate the histological alterations occurred in the periradicular region of rat molars after intentional subluxation using an experimental method to induce dentoalveolar trauma. Eighteen adult male Wistar rats (Rattus norvegicus albinus) were selected for the study. The dentoalveolar trauma was experimentally induced by the application of an occlusogingival force on the occlusal surface of the maxillary right first molar using a tensiometer secured on a fully articulated support with adjustable steel shafts. The animals were assigned to six groups (n = 3), according to the intensity of the force applied to induce trauma: Group I (GI, control) - no force application; Groups II-VI (GII-GVI) - the animals were subjected to 600, 700, 800, 900 and 1000 cN force, respectively. After experimental induction of trauma, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy. In the animals of GII, GIII and GIV, the histological alterations were similar to those described for GI. GVI (1000 cN) presented the most severe alterations, with the occurrence of buccal bone plate fracture, alveolar fracture and root fracture, which are not present in mild traumatic injuries like subluxation. The 900 cN force (GV) was capable to produce clinical and histological alterations in the gingival and periodontal tissues compatible with those observed in subluxation. PMID:20089060

  2. Collagen proteins in electrorefining: Rate constants for glue hydrolysis and effects of molar mass on glue activity

    NASA Astrophysics Data System (ADS)

    Saban, M. D.; Scott, J. D.; Cassidy, R. M.

    1992-03-01

    Animal glue (collagen proteins) degradation was studied in water and in a simulated copper electrolyte (150 g/L H2SO4, 46 g/L Cu2+ as CuSO4) by size-exclusion chromatography. The rate of degradation was relatively slow in pure aqueous solutions, and depending on the temperature and glue concentration, some association to larger molar mass species was observed. For simulated electrolyte in a temperature range of 42 °C to 70 °C and a glue concentration range of 100 to 3000 mg/L, the degradation rate constant was described with the following relation: k' = 1.5· 107exp (-9951 /T), min-1 The degradation rate was zero order with respect to initial concentration of the protein and first order with respect to acid concentration. The results show that glue degradation under normal tankhouse operation should be rapid, with degradation to number-average molar mass (M n ) < 10,000 units occurring in about 40 to 80 minutes depending on the mass transfer rate (or mixing) of the electrolyte solution. Samples of glue from three different sources showed almost no difference in degradation rates. Results calculated from the rate equation for glue degradation have been correlated with cathode polarization data from the literature, and the results suggest that critical glue M n below which the glue loses most of its activity is 3700.

  3. Effect of the route of administration of methylprednisolone on oedema and trismus in impacted lower third molar surgery.

    PubMed

    Koçer, G; Yuce, E; Tuzuner Oncul, A; Dereci, O; Koskan, O

    2014-05-01

    Due to their anatomical position, the surgical removal of impacted third molars results in oedema, pain, and trismus. The purpose of this study was to evaluate the efficacy of supraperiosteal injection of methylprednisolone compared with an oral tablet form and intravenous (i.v.) injection in the prevention of postoperative pain and oedema associated with inflammation. This randomized, prospective, and controlled study included 44 patients. The patients were randomly divided into four groups: group 1 (control; no steroids), group 2 (local injection), group 3 (oral tablets), and group 4 (i.v. injection). On days 2 and 7 following surgery, linear oedema was determined using facial landmarks, and maximal mouth opening was measured. Postoperative mouth opening and swelling were evaluated for each route of methylprednisolone administration and compared. The female (59%) to male (41%) ratio was 1.44; the mean age of the patients was 29.6 years. The level of significance was set at P<0.01 for mouth opening and P<0.05 for oedema. With regard to trismus, all three routes of administration demonstrated better efficacy in comparison to the control. While oral administration and i.v. injection of methylprednisolone achieved similar results, masseter injection provided better results in reducing oedema and trismus when compared to the control following lower third molar surgery. PMID:24332587

  4. Dental caries in primary and permanent molars in 7-8-year-old schoolchildren evaluated with Caries Assessment Spectrum and Treatment (CAST) index

    PubMed Central

    2014-01-01

    Background No reports on a caries pattern covering the full spectrum of the disease could be found in the literature. The aim of this study was to evaluate caries in primary and first permanent molars of 7-8-year-old Polish children by the Caries Assessment Spectrum and Treatment (CAST) index and to find whether there was any correlation between the caries stages in such teeth. Methods The study covered 284 7-8-year-old children from randomly selected schools in the Bialystok District, Poland. The prevalence of CAST categories was evaluated with regard to the first and second primary, and first permanent, molars. The Spearman’s rank correlation coefficient was used to explore the correlation of the distribution of CAST codes among the evaluated teeth. The level of statistical significance was established at p?molars, caries was observed in 14.8% to 17.3% of the molar and most lesions were scored at the non-cavitation level. Caries in primary molars was most often recorded at the stage of cavitated dentine lesion. Teeth with pulpal involvement, sepsis and extracted due to caries were found to be more prevalent in first, and then in second primary molars. A strong correlation was found between the status of teeth from the right and left sides of the oral cavity. The correlation of the status of first and second primary teeth was stronger for the left than for the right side of the mouth, r was 0.627 and 0.472 in maxilla and 0.513 and 0.483 in mandible (p?molars the correlation was assessed to be weak. With regard to the teeth situated in opposite jaws the study revealed that the correlations were moderate - r between 0.33 and 0.49. The intra-examiner reliability was established at 0.96 for the primary dentition and at 0.878 for permanent molars. Conclusion The strongest correlation found in the evaluated population concerned the distribution of caries in primary molars on the left side of the mouth. The study proved the usefulness of the CAST index in epidemiological surveys. PMID:24952612

  5. Does the Preemptive Use of Oral Nonsteroidal Anti-inflammatory Drugs Reduce Postoperative Pain in Surgical Removal of Third Molars? A Meta-analysis of Randomized Clinical Trials.

    PubMed

    Costa, Fábio Wildson Gurgel; Esses, Diego Felipe Silveira; de Barros Silva, Paulo Goberlânio; Carvalho, Francisco Samuel Rodrigues; Sá, Carlos Diego Lopes; Albuquerque, Assis Filipe Medeiros; Bezerra, Tácio Pinheiro; Ribeiro, Thyciana Rodrigues; Fonteles, Cristiane Sá Roriz; Soares, Eduardo Costa Studart

    2015-01-01

    The purpose of this study was to investigate the effectiveness of preemptive analgesia with nonsteroidal anti-inflammatory drugs (NSAIDs) in third-molar surgery. A PubMed literature search was conducted for articles restricted to the English language using the following terms (DeCS/MeSH) or combinations: analgesia, third molar, and preemptive. From a total of 704 articles, 6 (n = 420 subjects) were selected. All studies presented a low risk of bias (Cochrane criteria) but exhibited high heterogeneity of methods. Two studies were excluded from the meta-analysis because they did not have adequate numeric values (dichotomous data) for the calculations. Preemptive analgesia showed no significant benefit (n = 298, P = .2227, odds ratio: 2.30, 0.60-8.73) in reducing postoperative pain after removal of lower impacted third molars. However, there was a probable direct relationship between the effectiveness of NSAIDs in preemptive analgesia for removal of third molars and its selectivity for the cyclooxygenase-2 (COX-2). Preemptive analgesia did not have a significant effect in reducing postoperative pain after removal of lower impacted third molars. More homogeneous and well-delineated clinical studies are necessary to determine a possible association between NSAIDs' selectivity for COX-2 and treatment effectiveness. PMID:26061574

  6. Molar Absorptivity and Concentration-Dependent Quantum Yield of Fe(II) Photo-Formation for the Aqueous Solutions of Fe(III)-Dicarboxylate Complexes

    NASA Astrophysics Data System (ADS)

    Hitomi, Y.; Arakaki, T.

    2009-12-01

    Redox cycles of iron in the aquatic environment affect formation of reactive oxygen species such as hydrogen peroxide and hydroxyl radicals, which in turn determines lifetimes of many organic compounds. Although aqueous Fe(III)-dicarboxylate complexes are considered to be important sources of photo-formed Fe(II), molar absorptivity and quantum yield of Fe(II) formation for individual species are not well understood. We initiated a study to characterize Fe(II) photo-formation from Fe(III)-dicarboxylates with the concentration ranges that are relevant to the natural aquatic environment. The Visual MINTEQ computer program was used to calculate the equilibrium concentrations of individual Fe(III)-dicarboxylate species. The molar absorptivity of Fe(III)-dicarboxylate species was obtained by UV-VIS spectrophotometer, and the product of the quantum yield and the molar absorptivity of Fe(III)-dicarboxylate species were obtained from photochemical experiments. These experimental data were combined with the calculated equilibrium Fe(III)-dicarboxylate concentrations to determine individual molar absorptivity and quantum yield of Fe(II) photo-formation for a specific Fe(III)-dicarboxylate species. We used initial concentrations of less than 10 micromolar Fe(III) to study the photochemical formation of Fe(II). Dicarboxylate compounds studied include oxalate, malonate, succinate, malate, and phthalate. We report molar absorptivity and concentration-dependent quantum yields of Fe(II) photo-formation of individual Fe(III)-dicarboxylates.

  7. Selenium and mercury molar ratios in commercial fish from New Jersey and Illinois: Variation within species and relevance to risk communication

    PubMed Central

    Burger, Joanna; Gochfeld, Michael

    2015-01-01

    There is an emerging consensus that people consuming large amounts of fish with selenium:mercury ratios below 1 may be at higher risk from mercury toxicity. As the relative amount of selenium increases compared to mercury, risk may be lowered, but it is unclear how much excess selenium is required. It would be useful if the selenium:mercury ratio was relatively consistent within a species, but this has not been the case in our studies of wild-caught fish. Since most people in developed countries and urban areas obtain their fish and other seafood commercially, we examined selenium:mercury molar ratios in commercial fish purchased in stores and fish markets in central New Jersey and Chicago. There was substantial interspecific and intraspecific variation in molar ratios. Across species the selenium:mercury molar ratio decreased with increasing mean mercury levels, but selenium variation also contributed to the ratio. Few samples had selenium:mercury molar ratios below 1, but there was a wide range in ratios, complicating the interpretation for use in risk management and communication. Before ratios can be used in risk management, more information is needed on mercury:selenium interactions and mutual bioavailability, and on the relationship between molar ratios and health outcomes. Further, people who are selenium deficient may be more at risk from mercury toxicity than others. PMID:23541437

  8. Effect of fuel to oxidant molar ratio on particle size and LPG sensing properties of ZnO nanoparticles prepared by simple solution combustion method.

    NASA Astrophysics Data System (ADS)

    Naveen, C. S.; Rajeeva, M. P.; Lamani, Ashok R.; Deshmukh, P. R.; Lokhande, C. D.; Jayanna, H. S.

    2013-06-01

    ZnO nanoparticles of different size were prepared by varying the molar ratio of glycine and zinc nitrate hexahydrate as fuel and oxidizer (F/O molar ratio = 0.8, 1.11, 1.7) by simple solution combustion method. Powder samples were characterized by UV-Visible spectrophotometer, X-ray diffractometer (XRD), Scanning electron microscope (SEM). LPG sensing measurements were carried out in the temperature range 523-673K. It was found that, ZnO nanoparticle thick film prepared from F/O molar ratio 1.7 has maximum sensitivity of 5.20% for 520ppm of LPG at 623K compared to other thick films.

  9. Degradation of high-molar-mass hyaluronan by ascorbate plus cupric ions: effects of D-penicillamine addition.

    PubMed

    Valachová, Katarína; Rapta, Peter; Kogan, Grigorij; Hrabárová, Eva; Gemeiner, Peter; Soltés, Ladislav

    2009-03-01

    Pro- and anti-oxidative effects of an anti-rheumatoid drug, D-penicillamine (D-PN), on the kinetics of high-molar-mass hyaluronan (HA) degradation were monitored using the method of rotational viscometry. The degradation of the dissolved HA macromolecules was attained by applying the Weissberger's system comprising ascorbic acid plus cupric ions. Electron paramagnetic resonance (EPR) spectroscopy was used to identify the generated free radicals. The results obtained indicate that the initial anti-oxidative action of D-PN is followed by induction of pro-oxidative conditions due to the generation of reactive free radicals. It is speculated, however, that the latter situation may be considered as an advantageous property of D-PN. Hydroxyl radicals formed in this way may participate in decomposition of proteinases, which are believed to be responsible for the destruction of joint cartilage under rheumatoid arthritic conditions. PMID:19319875

  10. Changes of structure and property of alkali soluble hydroxyethyl celluloses (HECs) and their regenerated films with the molar substitution.

    PubMed

    Li, Faxue; Wang, Wencong; Wang, Xueli; Yu, Jianyong

    2014-12-19

    Hydroxyethyl celluloses (HECs) with low molar substitutions (MS) were prepared by reaction of alkali cellulose with ethylene oxide (EO) in a heterogeneous process. NMR, FTIR, WAXD, TG, solubility and tensile tests were adopted to investigate the changes of structures and properties of HECs with their MS values. NMR results showed that the hydroxyethyl groups were introduced into the cellulose chains as expected, causing the destruction in ordered structure and a loss in crystallinity. Crystal transformation from cellulose I of raw cellulose to cellulose II of HECs was proved by different methods. The crystalline structure of HEC seriously deteriorated with the rising MS value, accompanying lower thermal stability and improvements on its solubility in 8 wt% NaOH solvent and moisture related properties such as water retention. These different properties depending on the MS values endowed HECs with various potential applications in the form of regenerated cellulose fibers or other absorbent materials. PMID:25263883

  11. Studies on the molar conductivity behavior of PMMA-co-MA electrolyte solution at different polymer concentrations

    NASA Astrophysics Data System (ADS)

    Hanibah, Hussein; Ahmad, Azizan; Hassan, Nur Hasyareeda

    2014-09-01

    Polymer is an important constituent of liquid polymer electrolyte along with salt and solvent. The limiting molar conductivity (?0) and equilibrium constant (Keq) for LiClO4 in PMMA-co-MA solution was studied at 25.0 °C. Both ?0 and Keq were determined after Oswald's dilution law for a range of PMMA-co-MA concentrations (0.0010 - 0.0030 g cm-3). It was noticed that, as PMMA-co-MA concentration increased the ?0 value showed a decreasing trend. However, this decreasing trend did not cause any significant improvement in total LiClO4 dissociation for the electrolyte. This is supported by almost constant Keq values for the range of PMMA-co-MA concentration was at the same order of magnitude. The constant Keq with a decreasing ?0 might due to the formation of ions aggregation in the electrolyte.

  12. Partial Molar Volumes of Some of ?-Amino Acids in Binary Aqueous Solutions of MgSO 4 ·7H 2 O at 298.15 K

    Microsoft Academic Search

    Bairagi C. Mallick; Nand Kishore

    2006-01-01

    The apparent molar volume, V\\u000a o\\u000a ?, 2, of glycine, alanine, ?-amino-n-butyric acid, valine and leucine have been determined in aqueous solutions of 0.25, 0.5 and 1.0 mol?dm?3 magnesium sulfate, and the partial specific volume from density measurements at 298.15 K. These data have been used to calculate the infinite dilution apparent molar volume, V\\u000a o\\u000a 2,m\\u000a , group contribution

  13. Repetitive Complete Molar Pregnancy in a 54-Year-Old Patient in a Time Distance of Eighteen Years from the First Incident: Case Report and Mini Review

    PubMed Central

    Oikonomidis, Polychronis; Pergialiotis, Basileios; Pitsouni, Elina; Natsis, Stavros; Lagkadas, Antonios; Giannakopoulos, Konstantinos

    2011-01-01

    We report a case of complete hydatidiform mole in a 54-year-old patient referred to Gynecology department of General Hospital of Athens “Laiko”, with history of previous molar pregnancy at the age of thirty-six. Our purpose was to indicate the advanced maternal age beside the long recurrence distance of the disease, which was eighteen years after the first molar pregnancy. Our diagnostic approach was through measurement of serum beta-human chorionic gonadotropin (?-HCG) and pelvic ultrasound evaluation, and the chosen therapeutic approach was abdominal hysterectomy and bilateral salpingoophorectomy. PMID:22110509

  14. Mandibular first molar with Vertucci type I canal confguration diagnosed with the help of cone beam computed tomography: a rare case report.

    PubMed

    Gaur, Ankit; Trivedi, H P; Gupta, Manju; Sharma, Anuradha; Likhyani, Lalit; Agarwal, Manoj

    2014-01-01

    The knowledge of root canal morphology and the existing anatomical variations is essential for successful endodontic therapy. This report presents an extraordinary case of unusual tooth morphology involving the mandibular first molar with a single root and a single canal in a patient. Endodontic treatment of the affected tooth 36 was performed. Cone beam computed tomography (CBCT) images confirmed our diagnostic and therapeutic measures after endodontic management of the teeth. This morphologic variation has been reported once in the literature. The availability of three-dimensional images further provided the opportunity for the precise description of the anatomy of mandibular first molar with single roots and single canals. PMID:25825109

  15. Application of third molar development and eruption models in estimating dental age in Malay sub-adults.

    PubMed

    Mohd Yusof, Mohd Yusmiaidil Putera; Cauwels, Rita; Deschepper, Ellen; Martens, Luc

    2015-08-01

    The third molar development (TMD) has been widely utilized as one of the radiographic method for dental age estimation. By using the same radiograph of the same individual, third molar eruption (TME) information can be incorporated to the TMD regression model. This study aims to evaluate the performance of dental age estimation in individual method models and the combined model (TMD and TME) based on the classic regressions of multiple linear and principal component analysis. A sample of 705 digital panoramic radiographs of Malay sub-adults aged between 14.1 and 23.8 years was collected. The techniques described by Gleiser and Hunt (modified by Kohler) and Olze were employed to stage the TMD and TME, respectively. The data was divided to develop three respective models based on the two regressions of multiple linear and principal component analysis. The trained models were then validated on the test sample and the accuracy of age prediction was compared between each model. The coefficient of determination (R²) and root mean square error (RMSE) were calculated. In both genders, adjusted R² yielded an increment in the linear regressions of combined model as compared to the individual models. The overall decrease in RMSE was detected in combined model as compared to TMD (0.03-0.06) and TME (0.2-0.8). In principal component regression, low value of adjusted R(2) and high RMSE except in male were exhibited in combined model. Dental age estimation is better predicted using combined model in multiple linear regression models. PMID:26165657

  16. Effects of co-administered dexamethasone and diclofenac potassium on pain, swelling and trismus following third molar surgery

    PubMed Central

    Bamgbose, Babatunde Olamide; Akinwande, Jelili Adisa; Adeyemo, Wasiu Lanre; Ladeinde, Akinola Ladipo; Arotiba, Godwin Toyin; Ogunlewe, Mobolanle Olugbemiga

    2005-01-01

    Background The apparent interactions between the mechanisms of action of non-steroidal anti-inflammatory drugs (NSAIDS) and steroids suggest that co-therapy may provide beneficial inflammatory and pain relief in the absence of side effects. The aim of the study was to compare the effect of co-administered dexamethasone and diclofenac potassium (diclofenac K) with diclofenac K alone on the postoperative pain, swelling and trismus after surgical removal of third molars. Patients and Methods A prospective randomized double-blind study was conducted at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Nigeria. A total of 100 patients were randomly allocated to two treatment groups of dexamethasone (prophylactic 8 mg and postoperative 4 mg IV) and diclofenac K (50 mg Oral before and after surgery), and diclofenac K alone (as with first group). The overall analgesic efficacy of the drug combinations was assessed postoperatively by determination of pain intensity using a category rating scale. Facial swelling was measured using a tape measure placed from tragus to gonion to tragus, while interincisal mouth-opening of patients was measured using a vernier calibrated caliper pre-operatively and post-operatively. Results Co-administration of dexamethasone and diclofenac K was significantly superior to diclofenac alone for the relief of pain (P < 0.05), and facial swelling up to post-operative 48 hour (P < 0.05). However, there was no significant difference for trismus relief between the two medication protocols (P > 0.05). Conclusion This study illustrates enhanced effects of co-administered dexamethasone and diclofenac K on short-term post-operative pain and swelling, compared to diclofenac potassium alone in third molar surgery. PMID:16274480

  17. Corticosteroids or cyclooxygenase 2-selective inhibitor medication for the management of pain and swelling after third-molar surgery.

    PubMed

    Sotto-Maior, Bruno Salles; Senna, Plínio Mendes; de Souza Picorelli Assis, Neuza Maria

    2011-03-01

    The dental-impaction pain model is the most commonly used and widely accepted acute pain model for assessing the analgesic effect of drugs in humans. The aim of this randomized crossover clinical trial was to observe and compare the anti-inflammatory effects of corticosteroid and nonsteroidal cyclooxygenase 2-selective inhibitor medication on pain, swelling, and trismus after third-molar surgery. For this, 50 adult subjects, 25 male and 25 female, with ages ranging between 18 and 29 years (mean, 22.5 years) and no local or systemic problems, presenting bilateral impacted lower third molars in similar position with surgical extraction indicated were selected. The subjects were submitted to 1 surgical procedure for each side with interval of 3 weeks between each procedure, in which they were given 120 mg etoricoxib, nonsteroidal anti-inflammatory (group 1), or 4 mg dexamethasone, corticosteroid anti-inflammatory (group 2), 1 hour before the procedures. Data were registered at preoperative baseline and 24 and 48 hours postoperatively. Postoperative pain was evaluated using a visual analog scale, and the degree of swelling was evaluated through facial reference points' variation. The presence of trismus was analyzed through measurement of the interincisal distance. These assessments were obtained before the operation and at 24 and 48 hours after the surgeries. There was no statistically significant difference between anti-inflammatory treatments. However, at 48 hours, the facial swelling increased in both groups despite trismus reduction. The effects of nonsteroidal and steroidal anti-inflammatory drugs were similar for pain, swelling, and trismus. PMID:21415660

  18. Molar Absorptivity and Quantum Yield of Fe(II) Photo-formation for the Aqueous Solutions of Fe(III)-Dicarboxylate Comlexes

    NASA Astrophysics Data System (ADS)

    Hitomi, Y.; Arakaki, T.

    2009-04-01

    Fe(III)/Fe(II) cycle in the environment affects formation of active oxygen species such as hydrogen peroxide and hydroxyl radicals, which in turn determines lifetimes of many organic compounds. Although aqueous Fe(III)-dicarboxylate complexes are considered to be an important source of photo-chemically formed Fe(II), molar absorptivity and quantum yield of Fe(II) formation for individual species are not well understood. The Visual MINTEQ computer program was used to calculate the equilibrium concentrations of individual Fe(III)-dicarboxylate species in the aqueous solutions of Fe(III)-dicarboxylate complexes. The molar absorptivity and the product of the quantum yield and the molar absorptivity of Fe(III)-dicarboxylate species were obtained by UV-VIS spectrophotometer and photochemical experiments, and these experimental data were combined with the calculated equilibrium Fe(III)-dicarboxylate concentrations to determine individual molar absorptivity and quantum yield of Fe(II) photo-formation for a specific Fe(III)-dicarboxylate species. Dicarboxylate compounds studied were oxalate, malonate, succinate, malate, and phthalate.

  19. A primary isotopic gas standard for krypton with values for isotopic composition and molar mass traceable to the Système International d’Unités

    Microsoft Academic Search

    Y Aregbe; S Valkiers; J Poths; J Nørgaard; H Kipphardt; P De Bièvre; P. D. P Taylor

    2001-01-01

    Isotope amount ratios of krypton were measured on subsamples from one large batch of high purity krypton separated from the atmosphere. Synthetic mixtures of enriched krypton isotopes were used to “calibrate” the measurements with small uncertainties. The result is a primary isotopic gas standard (PIGS) IRMM-2030 with certified values for isotope ratios, isotopic composition, and molar mass of krypton with

  20. The CPA Equation of State and an Activity Coefficient Model for Accurate Molar Enthalpy Calculations of Mixtures with Carbon Dioxide and Water/Brine

    E-print Network

    P. C. Myint; Y. Hao; A. Firoozabadi

    2015-04-20

    Thermodynamic property calculations of mixtures containing carbon dioxide (CO$_2$) and water, including brines, are essential in theoretical models of many natural and industrial processes. The properties of greatest practical interest are density, solubility, and enthalpy. Many models for density and solubility calculations have been presented in the literature, but there exists only one study, by Spycher and Pruess, that has compared theoretical molar enthalpy predictions with experimental data. In this report, we recommend two different models for enthalpy calculations: the CPA equation of state by Li and Firoozabadi, and the CO$_2$ activity coefficient model by Duan and Sun. We show that the CPA equation of state, which has been demonstrated to provide good agreement with density and solubility data, also accurately calculates molar enthalpies of pure CO$_2$, pure water, and both CO$_2$-rich and aqueous (H$_2$O-rich) mixtures of the two species. It is applicable to a wider range of conditions than the Spycher and Pruess model. In aqueous sodium chloride (NaCl) mixtures, we show that Duan and Sun's model yields accurate results for the partial molar enthalpy of CO$_2$. It can be combined with another model for the brine enthalpy to calculate the molar enthalpy of H$_2$O-CO$_2$-NaCl mixtures. We conclude by explaining how the CPA equation of state may be modified to further improve agreement with experiments. This generalized CPA is the basis of our future work on this topic.

  1. Comparison of occlusal contact areas of class I and class II molar relationships at finishing using three-dimensional digital models

    PubMed Central

    Lee, Hyejoon; Kim, Minji

    2015-01-01

    Objective This study compared occlusal contact areas of ideally planned set-up and accomplished final models against the initial in class I and II molar relationships at finishing. Methods Evaluations were performed for 41 post-orthodontic treatment cases, of which 22 were clinically diagnosed as class I and the remainder were diagnosed as full cusp class II. Class I cases had four first premolars extracted, while class II cases had maxillary first premolars extracted. Occlusal contact areas were measured using a three-dimensional scanner and RapidForm 2004. Independent t-tests were used to validate comparison values between class I and II finishings. Repeated measures analysis of variance was used to compare initial, set up, and final models. Results Molars from cases in the class I finishing for the set-up model showed significantly greater contact areas than those from class II finishing (p < 0.05). The final model class I finishing showed significantly larger contact areas for the second molars (p < 0.05). The first molars of the class I finishing for the final model showed a tendency to have larger contact areas than those of class II finishing, although the difference was not statistically significant (p = 0.078). Conclusions In set-up models, posterior occlusal contact was better in class I than in class II finishing. In final models, class I finishing tended to have larger occlusal contact areas than class II finishing.

  2. The effect of Cu/Zn molar ratio on CO2 hydrogenation over Cu/ZnO/ZrO2/Al2O3 catalyst

    NASA Astrophysics Data System (ADS)

    Shaharun, Salina; Shaharun, Maizatul S.; Mohamad, Dasmawati; Taha, Mohd F.

    2014-10-01

    Catalytic hydrogenation of carbon dioxide (CO2) to methanol is an attractive way to recycle and utilize CO2. A series of Cu / ZnO / Al2O3/ZrO2 catalysts (CZAZ) containing different molar ratios of Cu/Zn were prepared by the co-precipitation method and investigated in a stirred slurry autoclave system. The catalysts were characterized by temperature-programmed reduction (TPR), field emission scanning electron microscopy-energy dispersive analysis (FESEM-EDX), X-ray diffraction (XRD) and N2 adsorption-desorption. Higher surface area, SABET values (42.6-59.9 m2/g) are recorded at low (1) and high (5) Cu/Zn ratios with the minimum value of 35.71 m2/g found for a Cu/Zn of 3. The reducibility of the metal oxides formed after calcination of catalyst samples was also affected due to change in metal-support interaction. At a low reaction temperature of 443 K, total gas pressure of 3.0 MPa and 0.1 g/mL of the CZAZ catalyst, the selectivity to methanol decreased as the Cu/Zn molar ratio increased, and the maximum selectivity of 67.73 was achieved at Cu/Zn molar ratio of 1. With a reaction time of 3h, the best performing catalyst was CZAZ75 with Cu/Zn molar ratio of 5 giving methanol yield of 79.30%.

  3. Third canal in the mesial root of permanent mandibular first molars: Review of the literature and presentation of 3 clinical reports and 2 in vitro studies

    Microsoft Academic Search

    Leopoldo Forner Navarro; Arlinda Luzi; Amelia Almenar García; Adela Hervás García

    Introduction. Systematic anatomical studies corroborate the anatomical complexity of the root canal system. Deviations from the norm such as multiple orifices, apical deltas, accessory canals and other variations are frequent. Objectives. To present clinical reports of mandibular molars with three canals in the mesial root and two in vitro studies of the morphology of these canals, together with a review

  4. Uso de la clorhexidina al 0,12% como prevención de la osteítis alveolar en la extracción indicada del tercer molar inferior incluído

    Microsoft Academic Search

    TRABAJO DE INVESTIGACIÓN

    2006-01-01

    Alveolar osteitis or alveolítis is a very common complication found after the extraction of permanent te- eth, especially in the extraction of impacted mandibular third molars. There are effective treatments for this complication but it is convenient to take measures to avoid its development. The purpose of this study was to evaluate the use of the chlorhexidine at 0,12% as

  5. Apparent molar heat capacity of aqueous hydrolyzed and non-hydrolyzed AlCl[sub 3] between 50 and 150[degree]C

    SciTech Connect

    Conti, G.; Gianni, P. (Dipartimento di Chimica e Chimica Industriale, Pisa (Italy)); Matteoli, E. (Istituto di Chimica Quantistica ed Energetica Molecolare, Pisa (Italy))

    1992-12-01

    By means of a flow calorimeter, the specific heats of aqueous solutions containing AlCl[sub 3] with and without added HCl have been measured at 50, 100, and 150[degree]C. The apparent molar heat capacity C[sub p,[phi

  6. Protoplasts Surviving Freezing to ?196 C and Osmotic Dehydration in 5 Molar Salt Solutions Prepared from the Bark of Winter Black Locust Trees 1

    PubMed Central

    Siminovitch, David

    1979-01-01

    Free protoplasts were prepared from the living bark tissue of the trunk of summer and winter black locust trees by enzymic digestion of thin slices of the tissue for 3 hours in a medium containing 2% Onozuka cellulase, 2% Rhozyme pectinase, and 2% Driselase in mannitol solutions using 0.4 molar mannitol for summer tissue and 1.0 molar mannitol for winter tissues. Cleaned suspensions of protoplasts and also thin slices of tissue with cells intact were frozen to temperatures of ?10 C, ?20 C, ?30 C, ?40 C and liquid nitrogen in sucrose and balanced salt solutions. Similar suspensions of protoplasts were also subjected to strong osmotic dehydration (plasmorrhysis) in a series of balanced salt solutions of increasing molarity. Tests for survival showed that protoplasts retain the same properties of either extreme susceptibility or extreme resistance to injury by freezing or osmotic dehydration as the cells from which they are prepared. Winter protoplasts showed capability for tolerating freezing to ?196 C and plasmorrhysis in 5 molar salt solutions. These results indicate that protoplasts are a valid and useful system for investigating the properties of the protoplasm and surface membranes associated with the seasonal development of extreme hardiness in the cells of woody plants. Images PMID:16660800

  7. Protoplasts surviving freezing to -196 C and osmotic dehydration in 5 molar salt solutions prepared from the bark of winter black locust trees.

    PubMed

    Siminovitch, D

    1979-04-01

    Free protoplasts were prepared from the living bark tissue of the trunk of summer and winter black locust trees by enzymic digestion of thin slices of the tissue for 3 hours in a medium containing 2% Onozuka cellulase, 2% Rhozyme pectinase, and 2% Driselase in mannitol solutions using 0.4 molar mannitol for summer tissue and 1.0 molar mannitol for winter tissues. Cleaned suspensions of protoplasts and also thin slices of tissue with cells intact were frozen to temperatures of -10 C, -20 C, -30 C, -40 C and liquid nitrogen in sucrose and balanced salt solutions. Similar suspensions of protoplasts were also subjected to strong osmotic dehydration (plasmorrhysis) in a series of balanced salt solutions of increasing molarity. Tests for survival showed that protoplasts retain the same properties of either extreme susceptibility or extreme resistance to injury by freezing or osmotic dehydration as the cells from which they are prepared. Winter protoplasts showed capability for tolerating freezing to -196 C and plasmorrhysis in 5 molar salt solutions. These results indicate that protoplasts are a valid and useful system for investigating the properties of the protoplasm and surface membranes associated with the seasonal development of extreme hardiness in the cells of woody plants. PMID:16660800

  8. Partial molar volumes of NiO and CoO liquids: implications for the pressure dependence of metal-silicate partitioning

    NASA Astrophysics Data System (ADS)

    Courtial, Philippe; Gottsmann, Joachim; Holzheid, Astrid; Dingwell, Donald B.

    1999-08-01

    Volumetric measurements have been conducted on 7 Ni- and Co-containing sodium disilicate liquids within a compositional range varying from 0 to 9 mol% of NiO and from 0 to 23 mol% of CoO and over a large temperature interval (i.e., above their respective glass transition temperature and up to at least 1473 K). Their molar volumes and thermal expansivities have been determined by combining high-temperature measurements using the Pt-based double-bob Archimedean method and low-temperature measurements using the method described by Webb et al. [S.L. Webb, R. Knoche, D.B. Dingwell, Determination of silicate liquid thermal expansivity using dilatometry and calorimetry, Eur. J. Mineral. 4 (1992) 95-104] based on an assumed equivalence of the relaxation of volume and enthalpy at the glass transition. The molar volume of the present liquids decreases with increasing NiO and CoO contents and the Co-containing liquids exhibit a greater molar volume than the Ni-containing liquids at equivalent molar concentrations. The present results were analysed using a regression equation from which the partial molar volume of NiO and CoO liquids was obtained by the least squares method. This procedure yields partial molar volumes valid over the entire temperature range of 11.506 ± 0.687 and 14.884 ± 0.149 cm 3/mol and temperature derivatives of 2.684 ± 1.6 × 10 -3 and 1.441 ± 0.4 × 10 -3 cm 3/mol K, respectively for NiO and CoO at 800 K. The behavior of M-Fe metal-silicate exchange partition coefficient (M = Ni, Co), based on present molar volume determinations, has been estimated as a function of pressure over a wide temperature range. The metal-silicate exchange partition coefficients of both Ni and Co decrease with increasing pressure within the entire temperature range considered in this study (i.e., 800-3000 K).

  9. Digital radiographic evaluation of mandibular third molar for age estimation in young adults and adolescents of South Indian population using modified Demirjian's method

    PubMed Central

    Mohammed, Rezwana Begum; Koganti, Ravichandra; Kalyan, Siva V.; Tircouveluri, Saritha; Singh, Johar Rajvinder; Srinivasulu, Enganti

    2014-01-01

    In recent years, it has become increasingly important to determine the age of living people for a variety of reasons, including identifying criminal and legal responsibility and for many other social events such as birth certificate, marriage, beginning a job, joining the army and retirement Objectives: The aim of this study was to assess the developmental stages of mandibular third molar for estimation of dental age (DA) in different age groups and to evaluate the possible correlation between DA and chronological age (CA) in South Indian population. Materials and Methods: Digital orthopantomography of 330 subjects (165 males, 165 females) who fit the study and the criteria were obtained. Assessment of mandibular third molar development was performed using Demirjian et al., modified method and DA was assessed using tooth specific stages. Results and Discussion: The present study showed a significant correlation between DA and CA in both males and females. Third molar development commenced around 9 years and root completion takes place around 18.9 years in males and in females 9 years and 18.6 years respectively. Demirjian modified method underestimated the mean age of males by 0.8 years and females by 0.5 years and also showed that females mature earlier than males in selected population. Conclusion: Digital radiographic assessment of mandibular third molar development can be used to generate mean DA using Demirjian modified method and also the estimated age range for an individual of unknown CA. Since the Demirjian method is based on French-Canadian population, to enhance the accuracy of forensic age estimates based on third molar development, the use of population-specific standards is recommended. PMID:25177143

  10. Interspecific and intraspecific variation in selenium:mercury molar ratios in saltwater fish from the Aleutians: potential protection on mercury toxicity by selenium.

    PubMed

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

    2012-08-01

    A number of factors affect the consumption risk from mercury in fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for saltwater fish. We examine levels of mercury and selenium in several species of fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant interspecific and intraspecific variation in selenium:mercury molar ratios for fish, and for birds. The mean selenium:mercury molar ratios for all fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios. PMID:22664537

  11. Mercury and selenium in European catfish (Silurus glanis) from Northern Italian Rivers: can molar ratio be a predictive factor for mercury toxicity in a top predator?

    PubMed

    Squadrone, S; Benedetto, A; Brizio, P; Prearo, M; Abete, M C

    2015-01-01

    The study of mercury and selenium bioaccumulation in fish is crucially important for evaluating the extent of contamination in freshwater environments, and the possible health risk posed for humans when the antagonistic interactions of these two elements are considered. Several factors affect the risk of mercury intake from fish consumption, including mercury levels, human consumption patterns, and sensitive populations (e.g., pregnant women, foetuses, young children and unknown genetic factors). The protective effects of selenium on mercury toxicity have been extensively publicised in recent years, particularly targeting fish consumers. In this study, mercury (Hg) and selenium (Se) concentrations were determined in the muscle of European catfish (Silurus glanis) collected from North Italian Rivers. Differences in mercury and selenium levels, as a function of size, gender and location were investigated. Hg was strongly related to length, gender and location, while Se levels are not dependent on fish size or location. The mean Se/Hg molar ratio was strongly affected by location, and significantly related to length and age. Selenium was in molar excess of mercury in all sites, with a rank order of mean Se/Hg molar ratio of the Parma River (2.55)>Po River (1.71)>Tanaro River (1.66)>Bormida River (1.36). However, in 37% of analyzed samples, Hg exceeded the maximum level set by 1881/2006/EC and 629/2008/EC in fish muscle. The molar ratio of Se/Hg was <1 only in the presence of significantly high Hg levels (>0.5mg/kg), and therefore the mean molar ratio cannot be considered as a safety criterion in top predator fish. PMID:25460744

  12. PROPERTIES OF THE SYSTEM URANYL NITRATE-ALUMINUM NITRATE-NITRIC ACID (OR SODIUM HYDROXIDE)SODIUM NITRATE-WATER-HEXONE. PART 2. DENSITY, APPARENT MOLAR VOLUME AND VISCOSITY

    Microsoft Academic Search

    L. L. Burger; I. M. Rehn; H. R. Schmidt; C. M. Slansky

    1949-01-01

    The viscosity and density of various Redox Process solutions were ; determined at 15, 25. and 40 ction prod- C. Apparent molar volumes for UO\\/sub ; 2\\/(NOâ)â and HNOâ in hexone and in aqueou s solutions were ; calculated from the density data as a function of concentration. The molar ; volumes of Al(NOâ)â in water and of hexone in

  13. Method for determining molar concentrations of metabolites in complex solutions from two-dimensional 1H-13C NMR spectra.

    PubMed

    Lewis, Ian A; Schommer, Seth C; Hodis, Brendan; Robb, Kate A; Tonelli, Marco; Westler, William M; Sussman, Michael R; Markley, John L

    2007-12-15

    One-dimensional (1D) (1)H nuclear magnetic resonance (NMR) spectroscopy is used extensively for high-throughput analysis of metabolites in biological fluids and tissue extracts. Typically, such spectra are treated as multivariate statistical objects rather than as collections of quantifiable metabolites. We report here a two-dimensional (2D) (1)H-(13)C NMR strategy (fast metabolite quantification, FMQ, by NMR) for identifying and quantifying the approximately 40 most abundant metabolites in biological samples. To validate this technique, we prepared mixtures of synthetic compounds and extracts from Arabidopsis thaliana, Saccharomyces cerevisiae, and Medicago sativa. We show that accurate (technical error 2.7%) molar concentrations can be determined in 12 min using our quantitative 2D (1)H-(13)C NMR strategy. In contrast, traditional 1D (1)H NMR analysis resulted in 16.2% technical error under nearly ideal conditions. We propose FMQ by NMR as a practical alternative to 1D (1)H NMR for metabolomics studies in which 50-mg (extract dry weight) samples can be obtained. PMID:17985927

  14. Spectrophotometric determination of pico-molar level of hydrazine by using Alizarin red in water and urine samples.

    PubMed

    Arulraj, Abraham Daniel; Vijayan, Muthunanthevar; Vasantha, Vairathevar Sivasamy

    2015-09-01

    In this paper, very simple and rapid sensor has been developed for the spectrophotometric determination of pico-molar level of hydrazine using Alizarin red. There was a decrease of optical intensity of the probe in the presence of hydrazine. The LOD is calculated from the linear graph between 5-100pM as 0.66pM of hydrazine which is well below the risk level proposed by Agency for Toxic Substance and Disease Registry. The probe selectivity for the detection of hydrazine was tested in the presence of commonly encountered metal ions and anions. The calibration curves showed good linearity for working ranges from 5-100pM and 0.5-40mM respectively, with R(2)=0.9911 and 0.9744, indicate the validity of the Beer-Lambert law. The binding constant and the free energy change values are determined by the Benesi-Hildebrand method. Determination of hydrazine in environmental water and human urine samples are successfully performed by the proposed method with the recovery of 100%. PMID:25911160

  15. Octanol-Water Partition Coefficient from 3D-RISM-KH Molecular Theory of Solvation with Partial Molar Volume Correction.

    PubMed

    Huang, WenJuan; Blinov, Nikolay; Kovalenko, Andriy

    2015-04-30

    The octanol-water partition coefficient is an important physical-chemical characteristic widely used to describe hydrophobic/hydrophilic properties of chemical compounds. The partition coefficient is related to the transfer free energy of a compound from water to octanol. Here, we introduce a new protocol for prediction of the partition coefficient based on the statistical-mechanical, 3D-RISM-KH molecular theory of solvation. It was shown recently that with the compound-solvent correlation functions obtained from the 3D-RISM-KH molecular theory of solvation, the free energy functional supplemented with the correction linearly related to the partial molar volume obtained from the Kirkwood-Buff/3D-RISM theory, also called the "universal correction" (UC), provides accurate prediction of the hydration free energy of small compounds, compared to explicit solvent molecular dynamics [ Palmer , D. S. ; J. Phys.: Condens. Matter 2010 , 22 , 492101 ]. Here we report that with the UC reparametrized accordingly this theory also provides an excellent agreement with the experimental data for the solvation free energy in nonpolar solvent (1-octanol) and so accurately predicts the octanol-water partition coefficient. The performance of the Kovalenko-Hirata (KH) and Gaussian fluctuation (GF) functionals of the solvation free energy, with and without UC, is tested on a large library of small compounds with diverse functional groups. The best agreement with the experimental data for octanol-water partition coefficients is obtained with the KH-UC solvation free energy functional. PMID:25844645

  16. Aurothiomalate as preventive and chain-breaking antioxidant in radical degradation of high-molar-mass hyaluronan.

    PubMed

    Valachová, Katarína; Vargová, Andrea; Rapta, Peter; Hrabárová, Eva; Dráfi, František; Bauerová, Katarína; Juránek, Ivo; Soltés, Ladislav

    2011-07-01

    The potential anti- or pro-oxidative effects of a disease-modifying antirheumatic drug, aurothiomalate, to protect high-molar-mass hyaluronan against radical degradation were investigated along with L-glutathione - tested in similar functions. Hyaluronan degradation was induced by the oxidative system Cu(II) plus ascorbate known as the Weissberger's oxidative system. The time- and dose-dependent changes of the dynamic viscosity of the hyaluronan solutions were studied by the method of rotational viscometry. Additionally, the antioxidative activity of aurothiomalate expressed as a radical-scavenging capacity based on a decolorization 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay was inspected. At the higher concentrations tested, L-glutathione showed excellent scavenging of (.) OH and peroxyl-type radicals, however, at the lowest concentration applied, its pro-oxidative effect was revealed. The effects of aurothiomalate on hyaluronan degradation were similar to that of L-glutathione, however, at the lowest concentration tested, no significant pro-oxidant effect was observed. PMID:21766448

  17. Evolutionary Patterns in the Dentition of Duplicidentata (Mammalia) and a Novel Trend in the Molarization of Premolars

    PubMed Central

    Kraatz, Brian P.; Meng, Jin; Weksler, Marcelo; Li, Chuankui

    2010-01-01

    Background The cusp homology of Lagomorpha has long been problematic largely because their teeth are highly derived relative to their more typically tribosphenic ancestors. Within this context, the lagomorph central cusp has been particularly difficult to homologize with other tribosphenic cusps; authors have previously considered it the paracone, protocone, metacone, amphicone, or an entirely new cusp. Methodology/Principal Findings Here we present newly described fossil duplicidentates (Lagomorpha and Mimotonidae) in the context of a well-constrained phylogeny to establish a nomenclatural system for cusps based on the tribosphenic pattern. We show that the central cusp of lagomorphs is homologous with the metaconule of other mammals. We also show that the buccal acquisition of a second cusp on the premolars (molarization) within duplicidentates is atypical with respect to other mammalian lineages; within the earliest lagomorphs, a second buccal cusp is added mesially to an isolated buccal cusp. Conclusions/Significance The distal shift of the ‘ancestral’ paracone within early duplicidentates amounts to the changing of a paracone into a metacone in these lineages. For this reason, we support a strictly topological approach to cusp names, and suggest a discontinuity in nomenclature to capture the complexity of the interplay between evolutionary history and the developmental process that have produced cusp patterns in duplicidentates. PMID:20877465

  18. Finite element analysis of adhesive endo-crowns of molars at different height levels of buccally applied load

    PubMed Central

    Frentzen, Matthias; Utz, Karl-Heinz; Hoyer, Daniel; Langenbach, Alexander; Bourauel, Christoph

    2012-01-01

    This study aimed to evaluate the biomechanical behaviour of adhesive endo-crowns and the influence of their design on the restoration prognosis when four loading positions are applied from the restoration–tooth junction. Two three-dimensional finite element models for the lower first molar were developed: endo-crown as a monobloc and endo-crown of a primary abutment and a full crown. Four crown loading positions were considered: 5, 6, 7 and 8 mm. A force of 1400 N was applied buccally on the middle of the mesiodistal width. No differences were observed for the two endo-crowns concerning restoration displacement and the distribution of equivalent von Mises stress and total equivalent strain. Shifting the position of the applied load to 8 mm resulted in an increase in the displacement from 25 to 42 µm and an increase of equivalent von Mises stress concentration at the tooth. The height of load application on the restoration has a significant role in the prognosis of endo-crowns. PMID:22924064

  19. Differential expression of E-cadherin, ?-catenin, and Lewis x between invasive hydatidiform moles and post-molar choriocarcinomas.

    PubMed

    Candelier, Jean-Jacques; Frappart, Lucien; Diatta, Ange Lucien; Yadaden, Tarik; Cissé, Mamadou-Lamine; Afoutou, Jean-Marie; Picard, Jean-Yves; Mennesson, Benoît; Slim, Rima; Si-Tayeb, Karim; Coullin, Philippe

    2013-06-01

    Trophoblast cell adhesion and migration are carefully coordinated during normal placental development. We have compared the expression of three adhesion molecules, E-cadherin, ?-catenin, and Lewis x, by immunohistochemistry during normal trophoblast differentiation, and in hydatidiform moles and choriocarcinomas. Both E-cadherin and ?-catenin were expressed in normal placenta cytotrophoblast, and this expression decreased with trophoblast maturation. E-cadherin was mainly localized along the contact between cytotrophoblast and syncytiotrophoblast, which indicates its role in the differentiation of the syncytial layer. Lewis x disappeared progressively during differentiation of normal villous vessels, and was expressed in molar pregnancies. Interestingly, whereas choriocarcinomas were not, or poorly, stained, invasive hydatidiform moles (invHMs) strongly expressed Lewis x in vascular structures. This observation correlated well with E-cadherin and ?-catenin expression and suggests that these three markers are associated with the invasive transformation. The presence of robust endothelial structures in invHMs could also explain their ability to maintain organized villous architecture (contrary to metastatic choriocarcinomas) during their invasion of extrauterine tissues such as the lung or the brain after dissemination through the blood flow. In our hands, Lewis x appeared to be a new, reliable marker that can be used to clearly distinguish invHMs from choriocarcinomas. PMID:23681114

  20. Improved prediction of octanol-water partition coefficients from liquid-solute water solubilities and molar volumes

    USGS Publications Warehouse

    Chiou, C.T.; Schmedding, D.W.; Manes, M.

    2005-01-01

    A volume-fraction-based solvent-water partition model for dilute solutes, in which the partition coefficient shows a dependence on solute molar volume (V??), is adapted to predict the octanol-water partition coefficient (K ow) from the liquid or supercooled-liquid solute water solubility (Sw), or vice versa. The established correlation is tested for a wide range of industrial compounds and pesticides (e.g., halogenated aliphatic hydrocarbons, alkylbenzenes, halogenated benzenes, ethers, esters, PAHs, PCBs, organochlorines, organophosphates, carbamates, and amidesureas-triazines), which comprise a total of 215 test compounds spanning about 10 orders of magnitude in Sw and 8.5 orders of magnitude in Kow. Except for phenols and alcohols, which require special considerations of the Kow data, the correlation predicts the Kow within 0.1 log units for most compounds, much independent of the compound type or the magnitude in K ow. With reliable Sw and V data for compounds of interest, the correlation provides an effective means for either predicting the unavailable log Kow values or verifying the reliability of the reported log Kow data. ?? 2005 American Chemical Society.

  1. Age-related changes in the immunoreactivity of the monocyte/macrophage system in rat molar pulp.

    PubMed

    Okiji, T; Kosaka, T; Kamal, A M; Kawashima, N; Suda, H

    1996-05-01

    Defence reactions of the dental pulp potentially involve a variety of immunocompetent cells, particularly class II major histocompatibility complex (MHC)-expressing cells and macrophages. In order to examine how the immunodefence potential of the pulp changes as a function of age, phenotypic distribution of pulpal cells expressing immunoreactivity to monoclonal antibody ED1 (reactive with nearly all macrophages and dendritic cells) was examined immunohistochemically in the lower first molars of developing (new-born to 10-week-old), adult (14-24-week-old) and aged (1-1.5-yr-old) Wistar rats. During tooth development, increasing numbers of ED1+ cells in the pulp also expressed immunoreactivity to ED2 (reactive with a differentiation-related antigen present on resident macrophages). ED1+ and ED2+ cells were distributed throughout the pulp before the tooth formation was completed. OX6+ (class II MHC-expressing) cells started to increase in number shortly after the eruption of the tooth and the increase continued even after the tooth formation had been completed. In aged rats, the density of the pulpal ED1+ cells was maintained at a relatively high level, whereas a significant decrease in the density of OX6+ cells was observed. These results indicate that the density and composition of pulpal cells expressing macrophage-associated antigens vary with increasing age, which most probably is related to changes in the immunological defence potential of the pulp against infection. PMID:8809308

  2. Density of some titanium-bearing silicate liquids and the compositional dependence of the partial molar volume of TiO 2

    NASA Astrophysics Data System (ADS)

    Dingwell, Donald B.

    1992-09-01

    The densities of thirteen silicate liquids along the Na 2SiO 3-TiO 2 and CaSiO 3-TiO 2 joins and six other titanium-bearing silicate liquids of the general formula X 2/nn+TiSiO 5 (where X = Li, Na, K, Rb, Cs, Ca, Sr, Ba) have been measured in equilibrium with air using the double Pt bob Archimedean method. The Na 2SiO 3-TiO 2 join was investigated from 10-50 mole% TiO 2 in the temperature range 1000-1150°C whereas the CaSiO 3-TiO 2 join was investigated from 10-80 mole% TiO 2 in the temperature range of 1400-1625°C. Density increases with TiO 2 content along both joins. Partial molar volumes of the binary endmembers, Na 2SiO 3 and CaSiO 3, and of TiO 2 have been computed. The partial molar volume of Na 2SiO 3 agrees well with that determined by BOCKRIS et al. (1955). The partial molar volume of CaSiO 3 is in disagreement with that of TOMLINSON et al. (1958). The partial molar volume of TiO 2 derived from a linear fit to the Na 2SiO 3-TiO 2 join is 27.6(3) cm 3/mole at 1150°C. The partial molar volume of TiO 2 derived from linear extrapolation of the CaSiO 3-TiO 2 data to TiO 2 at 1600°C is 24.3(4) cm 3/mole. Comparison of the partial molar volume data from these binary joins with TiO 2 liquid density data ( DINGWELL, 1991) requires the existence of a large positive excess volume in the Na 2SiO 3-TiO 2 system at 1150°C.

  3. The CPA Equation of State and an Activity Coefficient Model for Accurate Molar Enthalpy Calculations of Mixtures with Carbon Dioxide and Water/Brine

    E-print Network

    Myint, P C; Firoozabadi, A

    2015-01-01

    Thermodynamic property calculations of mixtures containing carbon dioxide (CO$_2$) and water, including brines, are essential in theoretical models of many natural and industrial processes. The properties of greatest practical interest are density, solubility, and enthalpy. Many models for density and solubility calculations have been presented in the literature, but there exists only one study, by Spycher and Pruess, that has compared theoretical molar enthalpy predictions with experimental data. In this report, we recommend two different models for enthalpy calculations: the CPA equation of state by Li and Firoozabadi, and the CO$_2$ activity coefficient model by Duan and Sun. We show that the CPA equation of state, which has been demonstrated to provide good agreement with density and solubility data, also accurately calculates molar enthalpies of pure CO$_2$, pure water, and both CO$_2$-rich and aqueous (H$_2$O-rich) mixtures of the two species. It is applicable to a wider range of conditions than the Spy...

  4. Evaluation of Micromovements and Stresses around Single Wide-Diameter and Double Implants for Replacing Mandibular Molar: A Three-Dimensional FEA

    PubMed Central

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

    2012-01-01

    Purpose. The purpose of this finite element study was to compare stresses, strains, and displacements of double versus single implant, in immediate loading for replacing mandibular molar. Materials and Methods. Two 3D FEM models were made to simulate implant designs. The first model used 6?mm wide-diameter implant to support a single molar crown. The second model used 3.75-3.75 double implant design. Each model was analyzed with a single force magnitude of 70?N in oblique axis in three locations. Results. This FEM study suggested that micromotion can be well controlled by both double implants and 6?mm single wide-diameter implant. The Von Mises stress for double implant had 31%–43% stress reduction compared to the 6?mm implant. Conclusion. Within the limitations of the paper, when the mesiodistal space for artificial tooth is more than 12.5?mm, under immediate loading, the double implant support should be considered. PMID:22461992

  5. Responses of pulpal nerves to cavity preparation in rat molars: an immunohistochemical study using neurofilament protein (NFP) antiserum.

    PubMed

    Sato, O

    1989-10-01

    The response of neural elements to a dentin injury was morphologically investigated in rat molars by use of immunostaining for neurofilament protein (NFP). An artificially formed cavity in dentin by drilling rapidly caused the displacement of some odontoblasts into the exposed dentinal tubules, while others were detached from the predentin. The subodontoblastic nerve plexus consisting of NFP-immunoreactive nerves shifted inward together with the separated odontoblasts, while a movement of the nerves into the exposed dentinal tubules was not recognized. The odontoblasts separated from the predentin degenerated and disappeared one day after the cavity preparation; at this time, the subodontoblastic nerve plexus underlying the drilled dentin was remarkably disrupted, presumably losing dentinal sensation of the drilled area. Three days after the cavity preparation, the destroyed odontoblastic layer began to be repaired by newly differentiating odontoblasts; the reparative dentin was produced from 5 to 7 days onward. Numerous NFP-positive nerves, beaded in type, gathered in the odontoblastic layer in accordance with the differentiation of the new odontoblasts. The increased beaded nerve fibers were suggested to represent peptide-containing nerves. In 10-15 days, the reparative dentin accumulated quite remarkably under the cavity area. The NFP-positive subodontoblastic nerve plexus was entirely reconstituted and also regained continuity to its surrounding plexus. The nerve fibers in the reconstituted plexus were mostly non-beaded in type as seen in the control teeth. Since dentinal tubules in the reparative dentin are not normally continuous to the primary dentinal tubules, dentinal sensation may not have been restored. PMID:2513855

  6. Panoramic radiography and cone-beam computed tomography findings in preoperative examination of impacted mandibular third molars

    PubMed Central

    2014-01-01

    Background Preoperative radiographic examination of impacted mandibular third molars (IMTM) is essential to prevent inferior alveolar nerve injury during extraction. The purpose of this study was to evaluate the correlation between cone-beam computed tomography (CBCT) and digital panoramic radiography (DPR) findings in preoperative examination of IMTM. Methods This retrospective study included 298 teeth in 191 individuals. The relationship between the inferior alveolar canal (IAC) and the IMTM (buccal, lingual, interradicular or inferior), the position of the IMTM with respect to the IAC (contact, no contact), the morphologic shape of the mandible in the IMTM region (round, lingual extended, lingual concave), the type of IMTM (vertical, horizontal or angular) and the number of roots of the IMTM were evaluated on CBCT images. DPR images were evaluated for the number of roots of the IMTM and for the most common radiographic findings indicating a relationship between the IAC and the IMTM (darkening of the roots, diversion of the IAC, narrowing of the IAC and interruption of the white line). Data were statistically analyzed with Cramer V coefficient, Kappa statistic, chi-square and Fisher’s exact test. Results There was a significant difference in number of roots detected on DPR versus CBCT images. There was a significant association between the type of IMTM and the morphologic shape of the mandible on CBCT images. Darkening of the roots and interruption of the white line on DPR images were significantly associated with the presence of contact between the IMTM and the IAC on CBCT images. Conclusions Panoramic radiography is inadequate, whereas CBCT is useful to detect multiple roots of IMTM. When darkening of the roots and interruption of the white line are observed on panoramic images, there is increased likelihood of contact between the IMTM and the IAC. CBCT is required in these cases. PMID:24928108

  7. Occlusal caries detection in permanent molars according to WHO basic methods, ICDAS II and laser fluorescence measurements.

    PubMed

    Kühnisch, Jan; Berger, Susanne; Goddon, Inka; Senkel, Helga; Pitts, Nigel; Heinrich-Weltzien, Roswitha

    2008-12-01

    This epidemiological study aimed to compare the diagnostic outcome of the WHO criteria, ICDAS II criteria, laser fluorescence measurements, presence of plaque and roughness as activity scores on occlusal fissures and buccal/palatal pits of the first permanent molars. The study involved 311 children between 8 and 12 years of age from the Ennepe-Ruhr District in North Rhine-Westphalia, Germany. The surface-related caries status was registered according to the WHO basic method criteria (1997). Additionally, pit and fissure sealants, the ICDAS II visual criteria, the DIAGNOdent reading, plaque retention and surface roughness were documented. Caries experience was 1.0 (+/-2.5) DMFS. About 70% of the examined students had no obvious dentin caries in the permanent dentition (DMFS = 0). Sealants were registered on 1.4 (+/-1.7) occlusal fissures and 0.4 (+/-0.9) palatal/buccal pits. Noncavitated caries lesions were recorded as ICDAS II score 1-4 on 1.8 (+/-1.6) fissures and 1.5 (+/-1.4) pits. The comparison of the diagnostic methods suggests a relationship between higher ICDAS II scores/DIAGNOdent values and a proportional increase in the occurrence of plaque as well as in the number of rough surfaces. In conclusion, this study showed the diagnostic potential of the ICDAS II criteria in comparison to the traditional WHO criteria by means of the noncavitated caries lesions additionally detected. The DIAGNOdent use in field studies that already apply detailed visual criteria seems to bring limited additional information. While the presence of plaque provides information for the caries activity assessment more work is required to provide information about the contribution of surface roughness. PMID:18422704

  8. A comparison of mesial molar root canal preparations using two engine-driven instruments and the balanced-force technique.

    PubMed

    Imura, N; Kato, A S; Novo, N F; Hata, G; Uemura, M; Toda, T

    2001-10-01

    The purpose of this study was to compare the effects of two engine-driven, nickel-titanium instrument systems with hand files in the final shape of slight and moderately curved canals. A total of 72 mesial roots of extracted human mandibular molars were divided into three groups: ProFile .04 taper, Pow-R rotary systems, and Flex-R hand-filing technique. The roots were mounted and cross-sectioned at two different horizontal levels using a modified Bramante technique. Pre- and postinstrumented cross-sectional roots were imaged, recorded, and computer analyzed. Results showed that, at the middle third, in almost all groups, there was a tendency of cutting more toward the mesial side with only one exception: Pow-R cut more to the distal side (danger zone) (p < 0.02). At the apical third, Flex-R (p < 0.03) and ProFile (0.001) transported to the mesial side (danger zone) when the curvature increased. When the three techniques were compared analyzing each side and considering the two groups of curvature, at the middle third in the moderately curved-canal group, Flex-R cut statistically more than Pow-R toward the lingual side. The other comparisons showed no statistically significant difference. When the techniques were compared in relation with the degree of curvature, in the apical third, ProFile .04 cut statistically more toward the mesial side in the moderately curved canal group than in the slightly curved canal group. The other comparisons showed no statistically significant difference. Canal preparation time was shorter with hand instrumentation (p < .05) in a few instances. PMID:11592493

  9. C:N:P Molar Ratios, Sources and 14C Dating of Surficial Sediments from the NW Slope of Cuba

    PubMed Central

    de la Lanza Espino, Guadalupe; Soto, Luis A.

    2015-01-01

    The surficial sediments recovered from 12 sites located near the channel axis of the Florida Straits and the lower slope off NW Cuba were analyzed for total organic carbon (TOC), nitrogen (TN), phosphorus (TP), elemental C:N:P ratios, C and N isotopic values, and 14C dating. The depth profiles of TOC, TN, and TP (0-18 cm) displayed a downcore trend and a significant variation. The TOC values were low (0.15 to 0.62%; 66 to 516 µmol g-1). Sites near the island’s lower slope had lower TOC average concentrations (158-333 µmol g-1) than those closer to the channel axis (averaging 341-516 µmol g-1; p <0.05). The TN concentrations near the lower slope attained 0.11% (80 µmol g-1), whereas, towards the channel axis, they decreased to 0.07% (55 µmol g-1; p<0.05). The C:N ratios ranged from 1.9 to 10.2. The mean molar C:N ratio (5.4) indicated a marine hemipelagic deposition. The TP was lower at sites near the lower slope (38.4 to 50.0 µmol g-1; 0.12% to 0.16%) than those near the channel axis (50.0 to 66 µmol g-1; 0.15 to 0.21%). C:P fluctuated from 7.7 to 14.1 in the surficial sediment layer. The bulk organic ?13Corg and ?15N values confirmed pelagic organic sources, and the 14C dating revealed that the sediments were deposited during the Holocene (1000-5000 yr BP). We suggest that the hydrodynamic conditions in the Straits influence vertical and advective fluxes of particulate organic material trapped in the mixed-layer, which reduces the particulate matter flux to the seabed. PMID:26110791

  10. A novel whole tooth-in-jaw-bone culture of rat molars: morphological, immunohistochemical, and laser capture microdissection analysis.

    PubMed

    Chokechanachaisakul, Uraiwan; Kaneko, Tomoatsu; Yamanaka, Yusuke; Okiji, Takashi; Suda, Hideaki

    2012-10-01

    In conventional whole-tooth culture systems, limitation exists regarding maintenance of the vitality of the dental pulp, because this tissue is encased in rigid dentin walls that hinder nutrition supply. We here report a whole tooth-in-jaw-bone culture system of rat mandibular first molars, where transcardiac perfusion with culture medium was carried out before placement of the jaw bone into culture medium, aiming to facilitate longer time preservation of the dental pulp tissue. Following 7 days of culture, the pulp tissues were analyzed by histology and immunohistochemistry to ED2 (antiresident macrophage). ED2-positive macrophages were also analyzed for their Class II MHC, interleukin-6 (IL-6), and p53 mRNA expression levels by means of immune-laser capture microdissection (immune-LCM). Dentin sialophosphoprotein (DSPP) mRNA expression in odontobalstic layer was also examined by LCM. Teeth cultured following saline-perfusion and nonperfusion served as cultured controls. Normal teeth also served as noncultured controls. Histological examination demonstrated that the structure of the pulp tissue was well preserved in the medium-perfused explants in contrast to the cultured control groups. The Class II MHC, IL-6, and p53 mRNA expression levels of ED2-positive cells and DSPP expression levels of odontoblastic layer tissues in the pulp of medium-perfused explants were not significantly different from those in the noncultured normal teeth. In conclusion, the structural integrity and mRNA expression in the pulp were maintained at the in vivo level in the ex vivo whole tooth-in-jaw-bone culture system. The system may lay the foundation for studies aiming at defining further histological and molecular mechanism of the pulp. PMID:22623030

  11. Enhanced expression of activation-associated molecules on macrophages of heterogeneous populations in expanding periapical lesions in rat molars.

    PubMed

    Suzuki, N; Okiji, T; Suda, H

    1999-01-01

    Exudative macrophages are the most prevalent inflammatory cells during the entire pathogenetic process in experimentally induced rat periapical lesions. To clarify the significance of macrophages in the pathogenesis of periapical lesions, the way in which the phenotype of ED1 (a general marker for mononuclear phagocytes)-positive cells is modulated in actively expanding lesions was investigated, by immunoperoxidase staining with a panel of antibodies that recognize several activation-associated molecules on macrophages. Periapical lesions were induced experimentally by exposing the pulp in the lower first molars of Wistar rats. Active lesion expansion with morphological diversification of ED1-positive cells occurred between 14 and 28 days after the injury. Double immunoperoxidase staining revealed that ED1-positive cells coexpressing class II molecules of the major histocompatibility complex (MHC) molecules, inducible nitric oxide synthase (iNOS) and/or CD11a increased during the period of active lesion expansion. Increases of endothelial cells expressing intracellular adhesion molecule-1 and CD25 (interleukin-2 receptor)-expressing lymphocytes were also seen during the same period. Moreover, there existed two particular subpopulations of ED1 + cells in the established lesion at 28 days: (1) ED1++/class II MHC - /iNOS+ cells, located around the periapical abscess, and (2) ED1+/class II MHC+/ iNOS- cells with slender or dendritic morphology, distributed predominantly in the outer portion of the lesion where T lymphocytes were abundant. The first cell type could be a macrophage with potent phagocytic and antimicrobial actions, and the second might possess sufficient antigen-presenting capacity to cause the activation of T lymphocytes. It was concluded that macrophages, when activated, may participate in triggering lesion expansion. Functionally distinct subpopulations of macrophages may occupy different sites within the lesion where they can most effectively exert their specific functions. PMID:10075152

  12. C:N:P Molar Ratios, Sources and 14C Dating of Surficial Sediments from the NW Slope of Cuba.

    PubMed

    de la Lanza Espino, Guadalupe; Soto, Luis A

    2015-01-01

    The surficial sediments recovered from 12 sites located near the channel axis of the Florida Straits and the lower slope off NW Cuba were analyzed for total organic carbon (TOC), nitrogen (TN), phosphorus (TP), elemental C:N:P ratios, C and N isotopic values, and 14C dating. The depth profiles of TOC, TN, and TP (0-18 cm) displayed a downcore trend and a significant variation. The TOC values were low (0.15 to 0.62%; 66 to 516 µmol g-1). Sites near the island's lower slope had lower TOC average concentrations (158-333 µmol g-1) than those closer to the channel axis (averaging 341-516 µmol g-1; p <0.05). The TN concentrations near the lower slope attained 0.11% (80 µmol g-1), whereas, towards the channel axis, they decreased to 0.07% (55 µmol g-1; p<0.05). The C:N ratios ranged from 1.9 to 10.2. The mean molar C:N ratio (5.4) indicated a marine hemipelagic deposition. The TP was lower at sites near the lower slope (38.4 to 50.0 µmol g-1; 0.12% to 0.16%) than those near the channel axis (50.0 to 66 µmol g-1; 0.15 to 0.21%). C:P fluctuated from 7.7 to 14.1 in the surficial sediment layer. The bulk organic ?13Corg and ?15N values confirmed pelagic organic sources, and the 14C dating revealed that the sediments were deposited during the Holocene (1000-5000 yr BP). We suggest that the hydrodynamic conditions in the Straits influence vertical and advective fluxes of particulate organic material trapped in the mixed-layer, which reduces the particulate matter flux to the seabed. PMID:26110791

  13. Low temperature nanostructured zinc titanate by an aqueous particulate sol–gel route: Optimisation of heat treatment condition based on Zn:Ti molar ratio

    Microsoft Academic Search

    M. R. Mohammadi; D. J. Fray

    2010-01-01

    Nanocrystalline zinc titanate (ZnTiO3) thin films and powders with purity of 94% were produced at the low sintering temperature of 500°C and the short sintering time of 1h by a straightforward aqueous particulate sol–gel route. The effect of Zn:Ti molar ratio was studied on the crystallisation behaviour of zinc titanates. The prepared sols showed a narrow particle size distribution in

  14. Influence of the Metal Nitrates to Citric Acid Molar Ratio on the Processing of Nickel Zinc Ferrite Nanocrystalline Powders Synthesized by a Sol-Gel Auto Combustion Method

    Microsoft Academic Search

    M. R. Barati; S. A. Seyyed Ebrahimi; A. Badiei

    2009-01-01

    Nanocrystalline powder of the single phase nickel-zinc ferrite have been prepared by a sol-gel auto-combustion process. The nitrate-citrate gels were prepared from metal nitrates and citric acid solutions with various molar ratios of the metal nitrates to citric acid. The results showed that the nitrate citrate gels exhibit a self-propagating behavior after ignition in air. The thermal decomposition of nitrate-citrate

  15. Influence of the metal nitrates to citric acid molar ratio on the combustion process and phase constitution of barium hexaferrite particles prepared by sol–gel combustion method

    Microsoft Academic Search

    A. Mali; A. Ataie

    2004-01-01

    A novel sol–gel combustion process was used to synthesize the ultrafine particles of barium hexaferrite. The nitrate–citrate gels were prepared from metal nitrates and citric acid solutions under various molar ratios of the metal nitrates to citric acid of 0.5, 1, 1.5 and 3 by sol–gel process. The results showed that the nitrate citrate gels exhibit a self-propagating behavior after

  16. The effect of citric acid to metal nitrates molar ratio on sol–gel combustion synthesis of nanocrystalline LaMnO 3 powders

    Microsoft Academic Search

    Yuanyuan Li; Lihong Xue; Lingfang Fan; Youwei Yan

    2009-01-01

    Nanocrystalline LaMnO3 powders were synthesized by sol–gel combustion method. The effect of citric acid (CA) to metal nitrates (MN) molar ratio of the precursor solution on the structure of gels and as-synthesized powders, combustion behavior, and microstructure of as-synthesized powders was investigated with the help of thermal analysis, infrared spectra, X-ray diffraction technique and scanning electron microscopy. The results show

  17. Two years survival rate of class II composite resin restorations prepared by ART with and without a chemomechanical caries removal gel in primary molars

    Microsoft Academic Search

    Asli Topaloglu-Ak; Ece Eden; J. E. F. M. Frencken; Ozant Oncag

    2009-01-01

    The aim was to test the null hypotheses that there is no difference: (1) in carious lesion development at the restoration\\u000a margin between class II composite resin restorations in primary molars produced through the atraumatic restorative treatment\\u000a (ART) with and without a chemomechanical caries removal gel and (2) in the survival rate of class II composite resin restorations\\u000a between two

  18. Comparison of the effects of growth hormone, insulin-like growth factor-I and fetal calf serum on mouse molar odontogenesis in vitro

    Microsoft Academic Search

    W. G. Young; J. V. Ruch; M. R. Stevens; C. Bègue-Kirn; C. Z. Zhang; H. Lesot; M. J. Waters

    1995-01-01

    The effects of growth hormone, its mediator insulin-like growth factor-I (IGF-I), and fetal calf serum on odontogenesis were compared to those of serum-free medium. Explanted, 16-day, fetal mouse first molar tooth germs in early bell stage were grown on semisolid, serum-free medium supplemented with ascorbic and retinoic acids. Recombinant human growth hormone at 50 or 100 ng\\/ml, IGF-I at 100

  19. Quantitative Assessment of Enamel Hypomineralization by KaVo DIAGNOdent at Different Sites on First Permanent Molars of Children in China

    Microsoft Academic Search

    Shao-Min Li; Zhengyan Wang; J. Tim Wright

    2003-01-01

    Purpose: The purpose of this study was to identify the most caries-susceptible site of pits and fissures on first permanent molars by quantitative evaluation of the mineraliza- tion in both caries-active and caries-free children, and to provide helpful information for cost-effective, targeted prevention. Methods: Eighty-four caries-free and 85 caries-active children were selected from 800 6- to 7-year-old children with fully

  20. Changes in the incidence of molar pregnancies. A population-based study in Chiba Prefecture and Japan between 1974 and 2000

    Microsoft Academic Search

    Hideo Matsui; Yoshinori Iitsuka; Koji Yamazawa; Naotake Tanaka; Katsuyoshi Seki; Souei Sekiya

    2003-01-01

    BACKGROUND: The aim of this population-based retrospective study was to evaluate the trend in the incidence of molar pregnancy. METHODS: Questionnaires about the occurrence of hydatidiform mole were mailed to all clinics and hospitals in Chiba Prefecture between 1974 and 2000. The diagnosis of hydatidiform mole was based on the post-operative morphological and\\/or pathological findings. Data of live births were

  1. Pre-emptive effect of dexamethasone injection and consumption on post-operative swelling, pain, and trismus after third molar surgery. A prospective, double blind and randomized study

    PubMed Central

    Chaudhary, Pradeep D.; Rastogi, Sanjay; Gupta, Prashant; Niranjanaprasad Indra, B.; Thomas, Roy; Choudhury, Rupshikha

    2015-01-01

    Aim To evaluate the preventative effect of intravenous 4 mg of dexamethasone and 8 mg oral dexamethasone on post-operative pain, swelling and trismus after the surgical extraction of mandibular third molars. Materials and methods A randomized clinical trial comprised of 200 patients (control group I intravenous and experimental group II orally) with impacted lower third molars, average age 20.8 years with no local or systemic problems, with bilateral impacted lower third molars, were operated under local anesthesia. Group I was given 4 mg IV and group II was given 8 mg orally of dexamethasone 1 h before procedure. The choice of which side to operate first and the amount of concentration of medication to use was made randomly and double-blindly. Post-operative pain was evaluated using a visual analog scale (VAS) and the degree of swelling was evaluated through facial reference points' variation. The presence of trismus was analyzed through measurement of the interincisal distance (IID). These assessments were obtained before the operation and 24 h, 48 h and 7th POD. Results No significant difference was found in facial swelling and trismus between IV 4 mg injection and oral 8 mg consumption after lower third molar surgery (student t test P > 0.05). The visual analogue scale scores for pain assessment showed no significant difference between IV injection and oral route of dexamethasone (student t test P > 0.05). Conclusion Patients can be administered 8 mg oral dexamethasone is as effective as 4 mg intra venous route without much difference in final outcome at any given point of time. PMID:25853044

  2. Randomized, double-blind study on effectiveness of intra-alveolar chlorhexidine gel in reducing the incidence of alveolar osteitis in mandibular third molar surgery

    Microsoft Academic Search

    D. Torres-Lagares; J. L. Gutierrez-Perez; P. Infante-Cossio; M. Garcia-Calderon; M. M. Romero-Ruiz; M. A. Serrera-Figallo

    2006-01-01

    Chlorhexidine (CHX) mouthwash is a good prophylactic agent for postextraction alveolar osteitis (AO), a very common complication. Recently, a bio-adhesive gel to deliver the active substance, CHX, has been introduced. The intra-alveolar positioning of the bio-adhesive gel allows more direct and prolonged action of CHX, which could be useful in the prevention of AO following extraction of impacted third molars.

  3. Effect of the suture technique on postoperative pain, swelling and trismus after removal of lower third molars: A randomized clinical trial

    PubMed Central

    Gómez-Santos, Laila; Sánchez-Torres, Alba; Herráez-Vilas, José-María

    2015-01-01

    Background To evaluate the intensity of pain, swelling and trismus after the removal of impacted lower third molars comparing two different suture techniques of the triangular flap: the complete suture of the distal incision and relieving incision and the partial suture with only one suture knot for closure of the corner of the flap and the closure of the distal incision, without suturing the relieving incision. Material and Methods A prospective, randomized, crossover clinical trial was conducted in 40 patients aged from 18 to 45 years who underwent surgical extraction of impacted lower third molars at the Department of Oral Surgery in the Odontological Hospital of the University of Barcelona during the year 2011. Patients were randomly divided in 2 groups. Two different techniques (hermetical closure and partial closure of the wound) were performed separated by a one month washout period in each patient. Postoperative pain, swelling and trismus were evaluated prior to the surgical procedure and also at 2 and 7 days post operatively. Results No statistically significant differences were observed for pain (p<0.06), trismus (p<0.71) and swelling (p<0.05) between the test and the control group. However, the values of the three parameters related to the test group were lower than those for the control group. Conclusions Partial closure of the flap without suturing the relieving incision after surgical extraction of lower third molars reduces operating time and it does not produce any postoperative complications compared with complete closure of the wound. Key words: Third molar, surgical flaps, suture techniques, postoperative pain, swelling, trismus. PMID:25662551

  4. The effect of [Fe 3+ ]\\/[Fe 2+ ] molar ratio and iron salts concentration on the properties of superparamagnetic iron oxide nanoparticles in the water\\/ethanol\\/toluene system

    Microsoft Academic Search

    Wen JiangKui-Lin; Kui-Lin Lai; Hao Hu; Xiao-Bo Zeng; Fang Lan; Ke-Xia Liu; Yao Wu; Zhong-Wei Gu

    In this study, we developed a convenient one-pot method with sodium oleate as both the surfactant and precipitant to synthesize\\u000a pure magnetite nanoparticles in the water\\/ethanol\\/toluene system. The initial molar ratio of [Fe3+]\\/[Fe2+] and the concentration of iron salts were changed in order to systematically investigate their influences on the chemical\\u000a and physical properties of nanoparticles, such as the crystal

  5. Improved selective cholesterol adsorption by molecularly imprinted poly(methacrylic acid)/silica (PMAA-SiO?) hybrid material synthesized with different molar ratios.

    PubMed

    Clausen, Débora Nobile; Pires, Igor Matheus Ruiz; Tarley, César Ricardo Teixeira

    2014-11-01

    The present paper describes the synthesis of molecularly imprinted polymer - poly(methacrylic acid)/silica and reports its performance feasibility with desired adsorption capacity and selectivity for cholesterol extraction. Two imprinted hybrid materials were synthesized at different methacrylic acid (MAA)/tetraethoxysilane (TEOS) molar ratios (6:1 and 1:5) and characterized by FT-IR, TGA, SEM and textural data. Cholesterol adsorption on hybrid materials took place preferably in apolar solvent medium, especially in chloroform. From the kinetic data, the equilibrium time was reached quickly, being 12 and 20 min for the polymers synthesized at MAA/TEOS molar ratio of 6:1 and 1:5, respectively. The pseudo-second-order model provided the best fit for cholesterol adsorption on polymers, confirming the chemical nature of the adsorption process, while the dual-site Langmuir-Freundlich equation presented the best fit to the experimental data, suggesting the existence of two kinds of adsorption sites on both polymers. The maximum adsorption capacities obtained for the polymers synthesized at MAA/TEOS molar ratios of 6:1 and 1:5 were found to be 214.8 and 166.4 mg g(-1), respectively. The results from isotherm data also indicated higher adsorption capacity for both imprinted polymers regarding to corresponding non-imprinted polymers. Nevertheless, taking into account the retention parameters and selectivity of cholesterol in the presence of structurally analogue compounds (5-?-cholestane and 7-dehydrocholesterol), it was observed that the polymer synthesized at the MAA/TEOS molar ratio of 6:1 was much more selective for cholesterol than the one prepared at the ratio of 1:5, thus suggesting that selective binding sites ascribed to the carboxyl group from MAA play a central role in the imprinting effect created on MIP. PMID:25280685

  6. Influence of Cd2+/S2- molar ratio and of different capping environments in the optical properties of CdS nanoparticles incorporated within a hybrid diureasil matrix

    NASA Astrophysics Data System (ADS)

    Gonçalves, Luis F. F. F.; Silva, Carlos J. R.; Kanodarwala, Fehmida K.; Stride, John A.; Pereira, Mario R.; Gomes, Maria J. M.

    2014-09-01

    The incorporation of CdS nanoparticles (NPs), as prepared through colloidal methods using reverse micelles, within diureasil hybrid organic-inorganic sol-gel matrices was investigated. Several experimental conditions, namely the influence of capping agent 3-mercaptopropyltrimethoxysilane (MPTMS) or the use of tetraethoxysilane (TEOS), were studied in order to assure the preservation of the original optical properties of colloidal CdS NPs after the incorporation of the NPs within the solid diureasil hybrid matrix. The diureasil matrix is based on a siliceous network cross linked through urea bonds to poly(oxyethylene)/poly(oxypropylene) (PEO/PPO) chains. The influence of the Cd2+/S2- molar ratio of the NPs in the stability and dispersion of the NPs within the diureasil matrix was also investigated. The obtained CdS doped hybrid matrix was characterized by absorption, steady-state and time-resolved photoluminescence (PL) spectroscopy and by transmission electron microscopy (TEM). The stability of the CdS NPs within the hybrid matrix showed to be dependent on the Cd2+/S2- molar ratio used in the synthesis of the NPs. The use of MPTMS proved to be crucial in the preservation of the original optical properties of the colloidal CdS NPs after the incorporation of the NPs within the hybrid matrix. The effect of MPTMS was in turn influenced by the Cd2+/S2- molar ratio employed in the synthesis of the CdS NPs. The use of MPTMS was less effective when Cd2+/S2- molar ratio equal to 0.5 was used. In the absence of MPTMS or TEOS larger NPs size distribution and clustering of the CdS NPs were obtained after the transfer of the NPs into the hybrid matrix.

  7. Influence of the initial formaldehyde to phenol molar ratio (F\\/P) on the formation of a phenolic resol resin catalyzed with amine

    Microsoft Academic Search

    G Astarloa Aierbe; J. M Echeverr??a; M. D Martin; A. M Etxeberria; I Mondragon

    2000-01-01

    The influence of the initial formaldehyde\\/phenol molar ratio (F\\/P) on the formation kinetics of five resol type phenolic resin prepolymers has been studied. Initial formaldehyde\\/phenol mixtures were fixed to pH=8.0 by adding triethylamine as alkaline catalyst. The evolution of reactants and first formed addition products were followed by liquid chromatography (HPLC). 13C NMR spectroscopy was applied to final prepolymers. The

  8. Differential repair responses in the coronal and radicular areas of the exposed rat molar pulp induced by recombinant human bone morphogenetic protein 7 (osteogenic protein 1)

    Microsoft Academic Search

    Jean-Jacques Lasfargues; Michel Goldberg

    2002-01-01

    Bone morphogenetic protein 7 (BMP 7), also termed osteogenic protein 1, a member of the transforming growth-factor superfamily, was examined for its efficacy in inducing reparative dentinogenesis in the exposed pulps of rat molars. To determine if the reaction was dose-dependent, collagen pellets containing 1, 3 or 10?g of recombinant BMP 7 were inserted in intentionally perforated pulps (10–12 pulps

  9. An In vitro Comparison of Furcal Perforation Repaired with Pro-root MTA and New Endodontic Cement in Primary Molar Teeth- A Microleakage Study

    PubMed Central

    Haghgoo, R.; Niyakan, M.; Nazari Moghaddam, K.; Asgary, S.; Mostafaloo, N.

    2014-01-01

    Statement of Problem: One of the most challenging procedural accidents during pulpotomy of primary molars is furcal perforation. To prevent bacterial invasion, the perforation site should be sealed as soon as possible. Purpose: The aim of the current study is to investigate the ability of the pro-root MTA and new endodontic cement (NEC) in repairing the furcation perforations of primary molar teeth. Materials and Method: In this in vitro study, 42 extracted primary molars were selected. Their roots were sectioned horizontally and standard access cavity was prepared. The orifices and the root apices were sealed with two layers of resin composite.The samples were randomly assigned into 2 groups. 6 teeth were considered as the positive and the negative controls. In the experimental groups; perforation was made. In group 1 and 2, perforation site received pro-root MTA and NEC respectively. The teeth were covered by two layers of nail polish except for the external surface of the perforation site. The negative control group received no repairing material. All teeth were mounted and sterilized for 24 hours. Lower chambers were filled with sterilized Muller Hinton broth. Bacterial suspension of Enterococcus faecalis in 0.5 McFarland was prepared. The repaired site was then exposed to the bacterial suspension of Enterococcus faecalis every 3 days. All samples were inserted in an incubator at 37oC and 100% humidity. The turbidity of the samples was detected for a period of 30 days. Data were analyzed by Chi- square test. Results: 44% of samples in Pro- root group, 50% of the samples in the NEC group showed contaminations during 30 days. There was no significant difference between these two groups (p= 0.799). Conclusion: With limitations of this study, Pro- root MTA and NEC showed similar capability in sealing the furcal perforations of the primary molars. PMID:24738087

  10. Effects of hygrothermal aging on the molar mass and thermal properties of recycled poly(ethylene terephthalate) and its short glass fibre composites

    Microsoft Academic Search

    Alessandro Pegoretti; Amabile Penati

    2004-01-01

    This paper reports on the effects of hygrothermal aging at 70°C in water, and at 80% relative humidity, on the molar mass and thermal properties of recycled poly(ethylene terephthalate) and its short glass fibre composites.During the initial period of exposure, water uptake increases linearly with the square root of time and apparent diffusivity decreases as fibre content increases and as

  11. Shaping Abilities of Two Different Engine-Driven Rotary Nickel Titanium Systems or Stainless Steel Balanced-Force Technique in Mandibular Molars

    Microsoft Academic Search

    Michael J. Matwychuk; Walter R. Bowles; Scott B. McClanahan; Jim S. Hodges; Igor J. Pesun

    2007-01-01

    The purpose of this study was to compare apical transportation, working-length changes, and instrumentation time by using nickel-titanium (Ni-Ti) rotary file systems (crown-down method) or stainless steel hand files (balanced-force technique) in mesiobuccal canals of extracted mandibular molars. The curvature of each canal was determined and teeth placed into three equivalent groups. Group 1 was instrumented with Sequence (Brasseler USA,

  12. Confocal laser scanning and microscopic study of tartrate-resistant acid phosphatase-positive cells in the dental follicle during early morphogenesis of mouse embryonic molar teeth

    Microsoft Academic Search

    Yasunori Sakakura; Toshihiko Yajima; Eichi Tsuruga

    1998-01-01

    Tartrate-resistant acid phosphatase (TRAPase)-positive cells were examined during the early morphogenesis of mouse mandibular first molar teeth, using a simultaneous azo dye-coupling technique and confocal laser scanning microscopy (CLSM). CLSM of paraffin-embedded sections revealed that cells exhibiting TRAPase fluorescence appeared along the marginal region of the condensed dental mesenchyme, not yet the dental follicle, at embryonic day 12 (E12). The

  13. Comparative efficacy of nimesulide and ketoprofen on inflammatory events in third molar surgery: a split-mouth, prospective, randomized, double-blind study.

    PubMed

    Pouchain, E C; Costa, F W G; Bezerra, T P; Soares, E C S

    2015-07-01

    This study aimed to compare the effect of nimesulide and ketoprofen on inflammatory parameters related to the surgical removal of third molars. A split-mouth, prospective, randomized, double-blind study was conducted in patients undergoing removal of four third molars. Eighteen eligible patients were allocated to one of two groups to receive treatment two times a day with either ketoprofen 100mg or nimesulide 100mg for a period of 3 days. The rescue medication intake (number) and pain intensity were evaluated at 6, 12, 24, and 48h, and at 7 days postoperatively. Swelling and maximum mouth opening were evaluated at 24h, 72h, and 7 days postoperatively. The peak pain score occurred at 6h after surgery in the nimesulide group and at 12h in the ketoprofen group. There was no statistically significant difference between the groups, although pain relief was observed after 48h in the nimesulide group and after 7 days in the ketoprofen group. For each group, there was a statically significant difference in pain scores among the studied periods (P<0.0001). None of the patients required rescue medication. There was a statistically significant difference in maximum mouth opening between the preoperative and postoperative periods (P<0.0001). Ketoprofen and nimesulide were effective at controlling pain, swelling, and trismus after the surgical removal of third molars. PMID:25847016

  14. The effect of horizontal X-ray beam angulation on the detection of furcation defects of mandibular first molars in intraoral radiography

    PubMed Central

    Hishikawa, T; Izumi, M; Naitoh, M; Furukawa, M; Yoshinari, N; Kawase, H; Matsuoka, M; Noguchi, T; Ariji, E

    2010-01-01

    Objectives The aim was to investigate the effect of changes in horizontal X-ray beam angulation in intraoral radiography on the detection accuracy of furcation defects in the mandibular first molar, and to examine the anatomical relationship between the roots and furcation area as a possible cause of changes in detectability. Methods Simulated furcation defects with various depths were created in five mandibular first molars. Intraoral radiographs were taken at various horizontal angulations of the projection beams. The diagnostic accuracies were determined based on receiver operating characteristic analysis. The geometric relationship that might influence the accuracy was investigated through use of a compact cone beam CT in 59 first molar areas. Results Although the horizontal angulations showing the highest accuracies were shifted mesially, no differences were found between the angles of ?10° and 20°. The relationship between the roots and the furcation area was relevant to the range of angulations showing high detectabilities. Conclusions The angulations traditionally used for detecting proximal caries are also suitable for detecting furcation defects. PMID:20100919

  15. Assessment of the radiographic visibility of the periodontal ligament in the lower third molars for the purpose of forensic age estimation in living individuals.

    PubMed

    Olze, Andreas; Solheim, Tore; Schulz, Ronald; Kupfer, Michael; Pfeiffer, Heidi; Schmeling, Andreas

    2010-09-01

    The main criterion for dental age estimation in living individuals is the mineralisation of third molars. However, the mineralisation of third molars can be completed before the forensically relevant age of 18 years has been attained. In a material of 1,198 orthopantomograms from 629 females and 569 males aged between 15 and 40 years, the radiographic visibility of the periodontal membrane of fully mineralised third molars was assessed according to stages 0, 1, 2 and 3. Stage 0 first appeared at the age of 17.2 years in females and at the age of 17.6 years in males. Stage 1 was first achieved by females between 18.9 and 20.0 years and by males between 20.1 and 20.2 years. The earliest appearance of stage 2 was between 22.5 and 23.1 years in females and at 22.3 years in males. The occurrence of stage 3 was first found between 24.6 and 25.2 years in females and between 25.4 and 26.2 years in males. If stage 1 is determined, it is, therefore, possible to prove that an individual has already attained the legally relevant age of 18 years. For stages 2 and 3, it can be stated beyond reasonable doubt that a person is over 21 years of age. PMID:20623296

  16. Biodegradable in situ gelling delivery systems containing pilocarpine as new antiglaucoma formulations: effect of a mercaptoacetic acid/N-isopropylacrylamide molar ratio

    PubMed Central

    Lai, Jui-Yang

    2013-01-01

    Ocular drug delivery is one of the most commonly used treatment modalities in the management of glaucoma. We have recently proposed the use of gelatin and poly(N-isopropylacrylamide) (PNIPAAm) graft copolymers as biodegradable in situ forming delivery systems for the intracameral administration of antiglaucoma medications. In this study, we further investigated the influence of carrier characteristics on drug delivery performance. The carboxyl-terminated PNIPAAm samples with different molecular weights were synthesized by varying the molar ratio of mercaptoacetic acid (MAA)/N-isopropylacrylamide (NIPAAm) from 0.05 to 1.25, and were determined by end-group titration. The preparation of gelatin-g-PNIPAAm (GN) copolymers from these thermoresponsive polymers was achieved using carbodiimide chemistry. Our results showed that the carboxylic end-capped PNIPAAm of high molecular weight may lead to the lower thermal phase transition temperature and slower degradation rate of GN vehicles than its low molecular weight counterparts. With a decreasing MAA/NIPAAm molar ratio, the drug encapsulation efficiency of copolymers was increased due to fast temperature-triggered capture of pilocarpine nitrate. The degradation of the gelatin network could greatly affect the drug release profiles. All of the GN copolymeric carriers demonstrated good corneal endothelial cell and tissue compatibility. It is concluded that different types of GN-based delivery systems exhibit noticeably distinct intraocular pressure-lowering effect and miosis action, thereby reflecting the potential value of a MAA/NIPAAm molar ratio in the development of new antiglaucoma formulations. PMID:24187486

  17. The Molar Volume of FeO-MgO-Fe2O3-Cr2O3-Al2O3-TiO2 Spinels

    NASA Astrophysics Data System (ADS)

    Hamecher, E. A.; Antoshechkina, P. M.; Ghiorso, M. S.; Asimow, P. D.

    2011-12-01

    A new model of molar volume has been calibrated in the spinel supersystem (Mg,Fe2+)(Al,Cr,Fe3+)2O4 - (Mg,Fe2+)2TiO4. A total of 832 X-ray and neutron diffraction experiments performed on spinels at ambient and in situ high-P, T conditions (from the American Mineralogist Crystal Structure Database (Downs and Hall-Wallace, 2003) and other sources) were used to calibrate end-member equations of state and an excess volume model for this system. The effect on molar volume of cation ordering over the octahedral and tetrahedral sites is captured with linear dependence on Mg2+, Al3+, and Fe3+ site occupancy terms. We allowed standard state volumes and coefficients of thermal expansion of the end members to vary within their uncertainties during extraction of the mixing properties, in order to achieve the best fit. Published equations of states of the various spinel end members were analyzed to obtain optimal values of the bulk modulus and its pressure derivative, for each explicit end member. For any spinel composition in the supersystem, the model molar volume is obtained by adding excess volume and cation order-dependent terms to a linear combination of the five end member volumes, estimated at pressure and temperature using the high-T Vinet equation of state. The model has a total of 31 parameters and fits nearly all experiments to within 0.02 J/bar/mol, or better than 0.5% in volume. The model is compared to the current MELTS (Ghiorso and Sack, 1995; Ghiorso et al., 2002) spinel model with a demonstration of the impact of the model difference on the estimated spinel-garnet lherzolite transition pressure. Our primary motivation in this work is the development of a comprehensive spinel molar volume model for use in calibration of activity-composition models of garnet and pyroxene solid solutions. The thermodynamic models, along with a new silicate liquid equation of state, will be incorporated into the next generation MELTS model, xMELTS. The new solid solution models will include some minor components, including Ti4+ and Cr3+. Because most constraints on the activity of garnet and pyroxene at high-P are derived from experiments with coexisting spinel, we must be confident in the ability of our spinel model to realistically reproduce thermodynamic behavior over all applicable compositions. Additionally, producing a spinel molar volume model calibrated with recent in situ high-P, T diffraction data is crucial to our ability to accurately model the spinel-garnet transition in Earth's upper mantle. For example, we recently calibrated Cr-Al exchange equilibria for garnet and spinel. When this new calibration is used with the current MELTS model, a region of garnet-spinel coexistence in lherzolites is predicted with width in pressure comparable to experimental constraints. The transition occurs, however, at the unexpectedly low pressure of ~1.7 GPa. The improved model of spinel molar volume presented here, along with a new garnet molar volume model in the system FeO-MgO-CaO-Fe2O3-Cr2O3-Al2O3-TiO2-Na2O-SiO2 currently being calibrated, will enable coupled recalibration of the garnet and pyroxene models to match both the absolute pressure and width of this key transition in mantle lithology.

  18. Manganese-mitigation of cadmium toxicity to seedling growth of Phytolacca acinosa Roxb. is controlled by the manganese/cadmium molar ratio under hydroponic conditions.

    PubMed

    Liu, Huimin; Zhang, Yuxiu; Chai, Tuanyao; Tan, Jinjuan; Wang, Jianwu; Feng, Shanshan; Liu, Geyu

    2013-12-01

    Manganese (Mn) can interact with cadmium (Cd) in environments and influence the toxic effect of Cd on plants. However, few studies have investigated the relationship between the Mn/Cd ratio and plant Cd-toxicity along Cd concentrations. In this paper, we studied the effects of external Mn/Cd molar ratios (0, 10, 30, 50 and 60) on Cd toxicity in the Mn hyperaccumulator and Cd tolerant plant, Phytolacca acinosa Roxb., at three Cd levels (50, 100 and 200 ?M) under hydroponic conditions. Our result showed that seedling growth (y) under Cd stress was strongly positively related to the solution Mn/Cd molar ratio (SMCR). The relationship between the two variables under solution Cd concentrations was well explained by the linear regression model y=a+b1 (SMCR)+b2 (Solution-Cd). Increasing SMCR significantly reduced the Cd concentration and increased the Mn concentration in plant tissues. However, seedling growth was consistent with the shoot Mn/Cd molar ratio rather than with the Mn or Cd concentrations in plant tissues. At low levels of SMCR (e.g. 0 and 10), elevation of Mn distribution in shoot tissues might be a mechanism in P. acinosa seedlings to defend against Cd-toxicity. In comparison with low levels of SMCR, high levels of SMCR (e.g. 50 and 60) greatly alleviated lipid peroxidation and plant water-loss, and enhanced photosynthesis. However, the alleviated lipid peroxidation in the Mn-mitigation of Cd toxicity was likely to be the secondary effect resulting from the antagonism between Mn and Cd in the plant. PMID:24095921

  19. The Efficacy and Clinical Safety of Various Analgesic Combinations for Post-Operative Pain after Third Molar Surgery: A Systematic Review and Meta-Analysis

    PubMed Central

    Au, Alvin Ho Yeung; Choi, Siu Wai; Cheung, Chi Wai; Leung, Yiu Yan

    2015-01-01

    Objectives To run a systematic review and meta-analysis of randomized clinical trials aiming to answer the clinical question “which analgesic combination and dosage is potentially the most effective and safe for acute post-operative pain control after third molar surgery?”. Materials and Methods A systematic search of computer databases and journals was performed. The search and the evaluations of articles were performed by 2 independent reviewers in 3 rounds. Randomized clinical trials related to analgesic combinations for acute post-operative pain control after lower third molar surgery that matched the selection criteria were evaluated to enter in the final review. Results Fourteen studies with 3521 subjects, with 10 groups (17 dosages) of analgesic combinations were included in the final review. The analgesic efficacy were presented by the objective pain measurements including sum of pain intensity at 6 hours (SPID6) and total pain relief at 6 hours (TOTPAR6). The SPID6 scores and TOTPAR6 scores of the reported analgesic combinations were ranged from 1.46 to 6.44 and 3.24 – 10.3, respectively. Ibuprofen 400mg with oxycodone HCL 5mg had superior efficacy (SPID6: 6.44, TOTPAR6: 9.31). Nausea was the most common adverse effect, with prevalence ranging from 0-55%. Ibuprofen 200mg with caffeine 100mg or 200mg had a reasonable analgesic effect with fewer side effects. Conclusion This systematic review and meta-analysis may help clinicians in their choices of prescribing an analgesic combination for acute post-operative pain control after lower third molar surgery. It was found in this systematic review Ibuprofen 400mg combined with oxycodone HCL 5mg has superior analgesic efficacy when compared to the other analgesic combinations included in this study. PMID:26053953

  20. Structures and standard molar enthalpies of formation of a series of Ln(III)–Cu(II) heteronuclear compounds with pyrazine-2,3-dicarboxylic acid

    SciTech Connect

    Yang, Qi; Xie, Gang; Wei, Qing; Chen, Sanping, E-mail: sanpingchen312@gmail.com; Gao, Shengli

    2014-07-01

    Fifteen lanthanide–copper heteronuclear compounds, formulated as [CuLn{sub 2}(pzdc){sub 4}(H{sub 2}O){sub 6}]·xH{sub 2}O (1–6(x=2), 8(x=3), 9–10(x=4)); [CuLn{sub 2}(pzdc){sub 4}(H{sub 2}O){sub 4}]·xH{sub 2}O (7, 12–13, 15(x=4), 14(x=5), 11(x=8)) (Ln(III)=La(1); Ce(2); Pr(3); Nd(4); Sm(5); Eu(6); Gd(7); Tb(8); Dy(9); Ho(10); Er(11); Tm(12); Yb(13); Lu(14); Y(15); H{sub 2}pzdc (C{sub 6}H{sub 4}N{sub 2}O{sub 4})=pyrazine-2,3-dicarboxylic acid) have been hydrothermally synthesized. All compounds were characterized by element analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analyses confirm that all compounds are isostructural and feature a 3D brick-like framework structure with (4.6{sup 2}){sub 2}(4{sup 2}.6{sup 2}.8{sup 2})(6{sup 3}){sup 2}(6{sup 5}.8){sub 2} topology. Using 1 mol cm{sup ?3} HCl(aq) as calorimetric solvent, with an isoperibol solution–reaction calorimeter, the standard molar enthalpies of formation of all compounds were determined by a designed thermochemical cycle. In addition, solid state luminescence properties of compounds 5, 6, 8 and 9 were studied in the solid state. - Graphical abstract: According to Hess' rule, the standard molar enthalpies of formation of Ln–Cu heterometallic coordination compounds were determined by a designed thermochemical cycle. - Highlights: • Fifteen lanthanide–copper heteronuclear isostructural compounds. • Structurally characterization by IR, X-ray diffraction and thermal analysis. • The standard molar enthalpy of formation. • Isoperibol solution–reaction calorimetry.

  1. The distribution and ultrastructure of the forming blood capillaries and the effect of apoptosis on vascularization in mouse embryonic molar mesenchyme

    PubMed Central

    Yuan, Guohua; Zhang, Li; Yang, Guobin; Yang, Jingwen; Wan, Chunyan; Zhang, Lu; Song, Guangtai

    2014-01-01

    Vascularization is essential for organ and tissue development. Teeth develop through interactions between epithelium and mesenchyme. The developing capillaries in the enamel organ, the dental epithelial structure, occur simultaneously by mechanisms of vasculogenesis and angiogenesis at the onset of dentinogenesis. The vascular neoformation in the dental mesenchyme has been reported to start from the cap stage. However, the mechanisms of vascularization in the dental mesenchyme remain unknown. In the hope of understanding the mechanisms of the formation of dental mesenchymal vasculature, mouse lower molar germs from embryonic day (E) 13.5 to E16.5 were processed for immunostaining of CD31 and CD34, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and transmission electron microscopy (TEM). In addition, the role of apoptosis for the vascularization in dental mesenchyme was examined by in vitro culture of E14.0 lower molars in the presence of the apoptosis inhibitor (z-VAD-fmk) and a subsequent subrenal culture. Our results showed that CD31- and CD34-positive cells progressively entered the central part of the dental papilla from the peridental mesenchyme. For TEM, angioblasts, young capillaries with thick endothelium and endothelial cells containing vacuoles were observed in peripheral dental mesenchyme, suggesting vasculogenesis was taking place. The presence of lateral sprouting, cytoplasmic filopodia and transluminal bridges in the dental papilla suggested angiogenesis was also occurring. Inhibition of apoptosis delayed the angiogenic vascularization of the dental papilla. Therefore, these data demonstrated that molar mesenchyme is progressively vascularized by mechanisms of both vasculogenesis and angiogenesis and apoptosis partially contributes to the vascularization of the dental papilla. PMID:24477797

  2. Effect of synthesis temperature and molar ratio of organic lithium salts on the properties and electrochemical performance of LiFePO 4 \\/C composites

    Microsoft Academic Search

    Zhongqi Shi; Ming Huang; Kerun Yang; Xuebu Hu; Bin Tan; Xinglan Huang; Zhenghua Deng

    LiFePO4\\/C cathode materials were synthesized through in situ solid-state reaction route using Fe2O3, NH4H2PO4, Li2C2O4, and lithium polyacrylate as raw materials. The precursor of LiFePO4\\/C was investigated by thermogravimetric\\/differential thermal analysis. The effects of synthesis temperature and molar ratio\\u000a of organic lithium salts on the performance of samples were characterized by X-ray diffraction, scanning electron microscopy,\\u000a electrochemical impedance spectra, cyclic

  3. Effect of Molar Ratio of (CaxBay)F2 Films on Electrical Characteristics of Metal\\/Fluoride\\/InP Structures

    Microsoft Academic Search

    Atsushi Hidaka; Hideaki Ikoma

    1995-01-01

    (Ca xBa y)F2 (x:y=7:3, 1:1 and 3:7)\\/n-type InP (100) metal-insulator-semiconductor (MIS) structures were investigated by means of capacitance-voltage ( C-V) measurements and X-ray photoelectron spectroscopy (XPS) to study the effect of the molar ratio (x:y) of the fluoride films on the quality of the interface between the fluoride and InP. The fluoride films were deposited on the InP substrates by

  4. Fracture resistance and failure patterns of endodontically treated mandibular molars restored using resin composite with or without translucent glass fiber posts.

    PubMed

    Salameh, Ziad; Sorrentino, Roberto; Papacchini, Federica; Ounsi, Hani F; Tashkandi, Esam; Goracci, Cecilia; Ferrari, Marco

    2006-08-01

    The elastic modulus of the restorative material is important in restoring endodontically treated teeth. This study aimed to compare the fracture resistance and failure patterns of 90 mandibular molars restored using resin composites with or without fiber posts, with respect to the number of residual cavity walls. Five restoration types were performed corresponding to different wall defects (groups 1-5). Groups were divided in two subgroups corresponding to the use or absence of fiber posts. Teeth were loaded and resistance of specimens was measured as the axial compressive load to cause fracture and macroscopic fracture patterns were observed. One way ANOVA revealed a significant difference in fracture resistance (p < 0.001). Tukey post hoc test also revealed significant differences between groups as samples restored with fiber posts exhibited mostly restorable fractures. It was concluded that the resistance of endodontically treated mandibular molars restored with composite resins is mainly affected by the number of residual walls. Using fiber-reinforced posts optimized fracture patterns. PMID:16861075

  5. Radiographic Assessment and Chair Time of Rotary Instruments in the Pulpectomy of Primary Second Molar Teeth: A Randomized Controlled Clinical Trial

    PubMed Central

    Makarem, Abbas; Ravandeh, Navid; Ebrahimi, Masoumeh

    2014-01-01

    Background and aims. The superiority of rotary systems has been reported in several clinical studies on permanent teeth. This study consisted of radiographic assessment and chair time of rotary instruments in the pulpectomy of primary second molar teeth. Materials and methods. In this randomized controlled clinical study, 46 children, 3-6 years of age, were selected. The patients were divided randomly into two groups. In the first group (group A) pulpectomy was carried out with hand instruments and in the second group (group B) the Rotary FlexMaster System was used. T-test and chi-squared test were used to analyze data. Results. The mean instrumentation time in group A was significantly more than that in group B (P<0.001). Also there was a significant difference between both groups in relation to the distance between the apex of mesial root (P<0.001) and distal root (P=0.007) and the canal filling level. Conclusion. Superior radiographic findings and less chair time of pulpectomy with rotary instruments in second primary molar teeth were achieved. PMID:25093051

  6. Comparison of Hero 642 and K3 rotary nickel-titanium files in curved canals of molars and a systematic review of the literature.

    PubMed

    Cai, Hua-Xiong; Cheng, Hui-Ling; Song, Jie-Wen; Chen, Su-Ya

    2014-10-01

    The aim of the present study was to compare the root canal preparation ability of rotary nickel-titanium (NiTi) Hero 642 and K3 files in curved mandibular or maxillary molars. A total of 40 extracted mandibular molars with two separate mesial canals, an apical width of approximately size ?15 and a root canal curvature of 15-30° were randomly divided into two groups and instrumented using Hero 642 (n=20) or K3 files (n=20). Canal straightening, working length, transportation, cross-sectional area, minimum dentin thickness and the canal angle curvature degree were examined, and a systematic review of the literature was conducted. No statistically significant differences were observed between the two groups with regard to the mean degree of straightening, mean change in working length, mean transportation, amount of dentin removed or remaining minimum dentin thickness (P>0.05). The canal angle curvature decreased in the two groups postoperatively. The systematic review identified six studies, and overall the two files performed similarly in the majority of categories examined. Therefore, the rotary NiTi Hero 642 and K3 files demonstrated comparable shaping abilities and maintenance of working length. PMID:25187795

  7. Valeriana officinalis L. for conscious sedation of patients submitted to impacted lower third molar surgery: A randomized, double-blind, placebo-controlled split-mouth study

    PubMed Central

    Pinheiro, Marcos Luciano Pimenta; Alcântara, Carlos Eduardo Pinto; de Moraes, Márcio; de Andrade, Eduardo Dias

    2014-01-01

    Introduction: Anxiety is one of the components of patient stress in the dental office and is recognized as one of the main factors that negatively affect treatment. The control of anxiety can be performed through conscious sedation, for which benzodiazepine is the drug of choice in dental practice, however present side-effects. Objective: The objective of the following study is to evaluate the efficacy of Valeriana officinalis L. (Valerian) for control of anxiety during the third molar surgery. Materials and Methods: A single oral dose of either Valerian (100 mg) or placebo was randomly administered 1 h before each surgical procedure to 20 volunteers between 17 and 31 years of age. Anxiety level was assessed by physiological parameters (blood pressure and heart rate [HR]) and the observation of signs. Descriptive analysis, Chi-square test, Friedman test, Wilcoxon test and effect size test were performed (P < 0.05). Results: According to the researcher's (80%) and surgeon's (75%) evaluations, the patients treated with Valerian were calmer and more relaxed during surgery. Valerian had a greater effect on the maintenance of systolic blood pressure and HR after surgery. Conclusion: Valerian was more effective at controlling anxiety than a placebo when used for the conscious sedation of adult patients submitted to impacted lower third molar surgery. PMID:24741279

  8. Estimation of band broadening in size-exclusion chromatography. I. A method based on analyzing narrow standards with a molar mass-sensitive detector.

    PubMed

    Yossen, Mariana M; Vega, Jorge R; Meira, Gregorio R

    2006-09-22

    A method is proposed for estimating the (asymmetrical and non-uniform) band broadening function (BBF) in size-exclusion chromatography (SEC). The following data are required: the molar mass calibration and the concentration- and molar mass chromatograms of a set of narrow standards. In the narrow range of each standard, the BBF is uniform but skewed. Each uniform BBF is estimated through a nonlinear optimization procedure that compares one (of the two) measured chromatograms with its theoretical prediction based on the other chromatogram. The method is validated with numerical examples that simulate the analyses of narrow standards exhibiting log-normal and Poisson weight chain length distributions. The BBF can be assumed of arbitrary shape, or represented by an exponentially-modified Gaussian (EMG). From the uniform BBF estimate, the true polydispersity of the standard can be determined. The global non-uniform BBF is obtained by interpolation between a set of uniform BBFs covering a wide range of elution volumes. PMID:16828786

  9. Evaluation of fibrin sealant as a wound closure agent in mandibular third molar surgery-a prospective, randomized controlled clinical trial.

    PubMed

    Gogulanathan, M; Elavenil, P; Gnanam, A; Krishnakumar Raja, V B

    2015-07-01

    The aim of this randomized controlled trial was to assess the effectiveness of fibrin sealants in achieving haemostasis and wound closure following mandibular third molar extraction, in comparison with conventional suturing. Thirty patients with bilateral mandibular third molar impactions were recruited for the study. Using a split-mouth study design, wound closure following extraction was done using fibrin sealant on the study side and suturing on the control side. Sample allocation was done by simple randomization. The primary outcome measures were (1) the time taken to achieve wound closure and haemostasis and (2) postoperative mouth opening, pain, and swelling. Data analysis involved descriptive statistics and paired t-tests (P<0.05). IBM SPSS software (v.20.0) was used for the data analysis. The study group demonstrated a statistically significant reduction in duration to achieve haemostasis (1.2 vs. 251.9s; P<0.001) and wound closure (152.8 vs. 328.8s; P<0.001) in comparison with the control group. The study group also exhibited significantly reduced pain scores (2.0 vs. 3.5; P<0.001) and increased post-surgical mouth opening (P<0.001). No adverse effects of fibrin sealant were observed. In conclusion, fibrin sealant is a superior intraoral wound closure and haemostatic agent and a worthy alternative to suturing. PMID:25721919

  10. Comparison of Hero 642 and K3 rotary nickel-titanium files in curved canals of molars and a systematic review of the literature

    PubMed Central

    CAI, HUA-XIONG; CHENG, HUI-LING; SONG, JIE-WEN; CHEN, SU-YA

    2014-01-01

    The aim of the present study was to compare the root canal preparation ability of rotary nickel-titanium (NiTi) Hero 642 and K3 files in curved mandibular or maxillary molars. A total of 40 extracted mandibular molars with two separate mesial canals, an apical width of approximately size ?15 and a root canal curvature of 15–30° were randomly divided into two groups and instrumented using Hero 642 (n=20) or K3 files (n=20). Canal straightening, working length, transportation, cross-sectional area, minimum dentin thickness and the canal angle curvature degree were examined, and a systematic review of the literature was conducted. No statistically significant differences were observed between the two groups with regard to the mean degree of straightening, mean change in working length, mean transportation, amount of dentin removed or remaining minimum dentin thickness (P>0.05). The canal angle curvature decreased in the two groups postoperatively. The systematic review identified six studies, and overall the two files performed similarly in the majority of categories examined. Therefore, the rotary NiTi Hero 642 and K3 files demonstrated comparable shaping abilities and maintenance of working length. PMID:25187795

  11. GENERAL: Low-temperature heat capacities and standard molar enthalpy of formation of 4-(2-aminoethyl)-phenol (C8H11NO)

    NASA Astrophysics Data System (ADS)

    Di, You-Ying; Kong, Yu-Xia; Yang, Wei-Wei; Tan, Zhi-Cheng

    2008-09-01

    This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of the temperature was fitted by the least square method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at the interval of 5 K. The energy equivalent, ?calor, of the oxygen-bomb combustion calorimeter has been determined from 0.68 g of NIST 39i benzoic acid to be ?calor = (14674.69±17.49)J.K-1. The constant-volume energy of combustion of the compound at T = 298.15 K was measured by a precision oxygen-bomb combustion calorimeter to be ?cU = -(32374.25±12.93)J.g-1. The standard molar enthalpy of combustion for the compound was calculated to be ?cHmominus = -(4445.47 ± 1.77) k. J · mol-1 according to the definition of enthalpy of combustion and other thermodynamic principles. Finally, the standard molar enthalpy of formation of the compound was derived to be ?fHmominus(C8H11NO, s) = -(274.68 ± 2.06) kJ · mol-1, in accordance with Hess law.

  12. Influence of the Metal Nitrates to Citric Acid Molar Ratio on the Processing of Nickel Zinc Ferrite Nanocrystalline Powders Synthesized by a Sol-Gel Auto Combustion Method

    NASA Astrophysics Data System (ADS)

    Barati, M. R.; Ebrahimi, S. A. Seyyed; Badiei, A.

    2009-06-01

    Nanocrystalline powder of the single phase nickel-zinc ferrite have been prepared by a sol-gel auto-combustion process. The nitrate-citrate gels were prepared from metal nitrates and citric acid solutions with various molar ratios of the metal nitrates to citric acid. The results showed that the nitrate citrate gels exhibit a self-propagating behavior after ignition in air. The thermal decomposition of nitrate-citrate gels and the phase evolution of the as-burnt powder were investigated by differential thermal analysis and thermogravimetry (DTA/TG) and X-ray diffraction (XRD) techniques respectively. Transmission electron microscope (TEM) was used to characterize the microstructure of the material. Magnetic properties were also measured by a vibrating sample magnetometer (VSM) with a maximum applied field of 10 kOe. The results also revealed that the molar ratio of the metal nitrates to citric acid has important effects on the formation temperature and the crystallite size which affect the magnetic properties of the nickel-zinc ferrite.

  13. Effect of surfactant/silica molar ratios on the formation of mesoporous molecular sieves: Inorganic mimicry of surfactant liquid-crystal phases and mechanistic implications

    SciTech Connect

    Vartuli, J.C.; Schmitt, K.D.; McCullen, S.B.; Hellring, S.D.; Beck, J.S.; Schlenker, J.L.; Olson, D.H.; Sheppard, E.W. [Central Research Lab., Princeton, NJ (United States); Kresge, C.T.; Roth, W.J. [Paulsboro Research Lab., NJ (United States)] [and others

    1994-12-01

    The influence of surfactant/silica molar ratio (Sur/Si) in the synthesis of mesoporous molecular sieve materials (M41S) was studied in a simple ternary synthesis system containing tetraethylorthosilicate (TEOS), water, and the cetyltrimethylammonium (CTMA) cation at 100{degrees}C. The resulting silicate materials were characterized by X-ray diffraction, {sup 29}Si NMR, and FTIR. As the Sur/Si molar ratio increased from 0.5 to 2, the siliceous products obtained could be classified into four separate groups: MCM-41 (hexagonal), MCM-48 (cubic), thermally unstable M41S, and a molecular species, the cubic octamer [(CTMA)SiO{sub 2.5}]{sub 8}. One of the thermally unstable structures has been identified as a lamellar phase. These results are consistent with known micellar phase transformations that occur at various surfactant concentrations and reinforce the concept that liquid-crystal structures serve as templating agents for the formation of M41S type materials. 48 refs., 13 figs., 5 tabs.

  14. Prevalence of First Permanent Molar Caries in and Its Relationship to the Dental Knowledge of 9–12-Year Olds from Jeddah, Kingdom of Saudi Arabia

    PubMed Central

    Al-Samadani, Khalid H. M.; Ahmad, Mohammad Sami

    2012-01-01

    The carious status of the first permanent molar (FPM) was studied in 432 school children (aged 9–12 years) from a randomly selected primary schools from Sharfia area of Jeddah, Kingdom of Saudi Arabia. The sample consisted of 108 children from each age group of 9, 10, 11, and 12 years old. In total, 24.5% had all of their FPMs sound and 6% had all FPMs carious. The prevalence of four sound FPMs varied according to age with the highest (33%) amongst the nine-year olds and the lowest (16.5%) in the oldest children (12 years). Almost one-third (32.5%) of the children, who knew the age of eruption of the FPMs, had all of their molars sound. The children who had received advice regarding oral hygiene from a dentist or parent had more sound FPMs compared to the children who did not receive any advice. The number of carious FPMs increased with age. The prevalence of caries of the FPM was high and increased with increasing age. The level of knowledge had a positive correlation with the caries levels amongst this cohort of scholars. PMID:22461990

  15. Molar absorbance coefficient of pyrene aggregates in water generated by a poly(ethylene oxide) capped at a single end with pyrene.

    PubMed

    Siu, Howard; Duhamel, Jean

    2012-02-01

    The molar absorbance coefficient of ground-state pyrene aggregates (?(E0)(?)) in water generated by a short poly(ethylene oxide) chain labeled at a single end with a 1-pyrenemethoxide unit, namely, the polymeric construct Py?-PEO(2.5K), was determined by a combination of UV-vis absorption and time-resolved fluorescence experiments. Since direct excitation of ground-state pyrene aggregates results in instantaneous excimer emission, whereas excimer formation by diffusive encounters between an excited- and a ground-state pyrene is delayed, acquisition of a pyrene monomer and excimer fluorescence decays with 1 nm increments of the excitation wavelength can probe the subtle effect that the excitation wavelength has on the extent of instantaneous excimer formation. These differences were taken advantage of to determine the fraction f(agg)(f)(?) of the total absorbance of the Py?-PEO(2.5K) solution that is due to ground-state pyrene aggregates. This was achieved by fitting the pyrene monomer and excimer fluorescence decays globally with the model free analysis. For each wavelength, an f(agg)(f)(?) value was obtained which was then related to ?(E0)(?) and f(agg), the molar fraction of aggregated pyrenes that is wavelength independent. These experiments were conducted for three Py?-PEO(2.5K) concentrations yielding three similar ?(E0)(?) spectra as expected since ?(E0)(?) is an intrinsic property of the pyrene aggregates that should not depend on pyrene concentration. The ?(E0)(?) spectra of the pyrene aggregates of Py?-PEO(2.5K) in water were substantially broader and red-shifted compared to that of the pyrene monomer. Its measure provides a simple means to calculate the molar fraction of aggregated pyrene units in a Py?-PEO(2.5K) aqueous solution from the absorption of the solution. This procedure should become widely applicable to determine f(agg) of water-soluble polymers which have been hydrophobically modified with a pyrene derivative and used as models for associative polymers. PMID:22268689

  16. Effects of molarity and solvents on the optical properties of the solutions of tris[4-(5-dicyanomethylidenemethyl-2-thienyl)phenyl]amine (TDCV-TPA) and structural properties of its film

    NASA Astrophysics Data System (ADS)

    Gündüz, Bayram

    2013-12-01

    The surface morphology of the tris[4-(5-dicyanomethylidenemethyl-2-thienyl)phenyl]amine (TDCV-TPA) film was investigated by high performance atomic force microscopy and the surface roughness parameters such as roughness average (sa), root mean square roughness (sq), surface skewness (ssk) and surface kurtosis (sku) of the TDCV-TPA film were obtained. The TDCV-TPA film indicated the low valleys with bumpy surface. The optical properties of the solutions of the small-molecule semiconducting dye TDCV-TPA for different high molarities, lower molarities and different solvents were investigated in detail. The molar extinction coefficient, optical band gap, angle values of refraction of the TDCV-TPA decreased with increasing molarity, while the absorbance at maximum absorption wavelengths, angle of incidence, electric susceptibility, real part values of the optical conductivity of the TDCV-TPA increased with increasing molarity. The maximum molar extinction coefficient (?max) at ?max values (510 and 509 nm) of the solutions of the TDCV-TPA for 0.024 and 0.010 mM were found to be 1.175 × 105 and 1.931 × 105 L mol-1 cm-1, respectively. The maximum mass extinction coefficient (?max) of the solutions of the TDCV-TPA for 0.024 and 0.010 mM were found to be 163.226 and 268.247 L g-1 cm-1, respectively. The optical band gap (Eg) values of the TDCV-TPA for 1, 2 and 3 mM were found to be 1.916, 1.898 and 1.892 eV, respectively. The absorption band edge for DCM varied from 1.882 to 1.997 eV, while the absorption band edge for chloroform varied from 1.923 to 2.027 eV. To obtain lower optical band gap of the TDCV-TPA can be prefered DCM solvent.

  17. An autoradiographical study of [3H]thymidine incorporation into subcutaneously transplanted mouse molar teeth. Cell proliferation and migration in transplanted teeth.

    PubMed Central

    Atkinson, M E

    1976-01-01

    Mice bearing either allografts or isografts of 10 day old molar teeth were injected with [3H]thymidine to identify proliferating and migrating cells within the graft and surrounding tissues. In isografts proliferating cells were found successively in the area underlying the cervix, in the cervical pulp and the coronal pulp. However, cells did not migrate from the cervical host tissue into the pulp, and it was concluded that donor cells are responsible for reparative processes in tooth isografts. Very few labelled cells were identified at any time in tooth allografts, which were not repaired. It is suggested that allografts are not repaired because allogeneic inhibition prevents the residual donor tissue from proliferating and differentiating. Inhibition of proliferation of residual cells may also account for the absence of a cell-mediated immune response to tooth allografts. PMID:1018004

  18. Infrared spectra and molar absorption coefficients of the 20 alpha amino acids in aqueous solutions in the spectral range from 1800 to 500 cm -1

    NASA Astrophysics Data System (ADS)

    Wolpert, Martina; Hellwig, Petra

    2006-07-01

    In this work, we present the absorption spectra and molar coefficients of all 20 amino acids in aqueous solutions down to 500 cm -1. The spectral region between 1200 and 500 cm -1 was yet disregarded for protein infrared spectroscopy, mainly due to the strong H 2O absorption. Absorption spectra were obtained mainly for physiological relevant pH region. Intense bands for aromatic amino acids, histidine and such with OH group could clearly be identified throughout the given spectral region. For sulfur-containing amino acids cysteine and methionine some strong bands besides the weak carbon-sulfur stretching vibration was shown. Effects of aqueous solution environment, pH, protonation states were discussed, together with previously reported data from theoretical approaches. With this complete set of spectral information application to proteins in the whole mid infrared region could be described precise and the potential of the lower spectral region to study typical cofactor ligands like histidine, shown.

  19. A combined endodontic retrofill and periodontal guided tissue regeneration technique for the repair of molar endodontic furcation perforations: report of a case.

    PubMed

    Duggins, L D; Clay, J R; Himel, V T; Dean, J W

    1994-02-01

    This is a report of a case in which the techniques of endodontic retrofill and guided tissue regeneration were used together to treat a perforation of the mesiofacial root of a maxillary left first molar (a strip perforation). After full-thickness flap reflection, the root received a retrograde filling and a large fenestration defect was surgically created to allow access to the furcal (distal) surface of the mesiofacial root. The roots were treated with tetracycline, the defect was filled with freeze-dried, demineralized, irradiated human cadaver bone, and the access fenestration was covered with a piece of barrier membrane. Healing was uneventful and the defect showed 100% bone fill at the time of reentry to retrieve the membrane 7 months after the initial surgery. Fifteen months after surgery the area appears clinically and radiographically healthy and the tooth has been employed as an abutment for a fixed partial denture. PMID:8183975

  20. Non-invasive endodontic management of fused mandibular second molar and a paramolar, using cone beam computed tomography as an adjunctive diagnostic aid: A case report

    PubMed Central

    Ghogre, Priyanka; Gurav, Sandeep

    2014-01-01

    Tooth fusion is a developmental anomaly characterized by the union between the dentin and/or enamel of at least two separately developing teeth. Fusion is a rare occurrence, with overall prevalence to be approximately 0.5% in deciduous teeth and 0.1% in permanent dentition. The significance of this particular case was that the unilateral fusion occurred in a permanent mandibular second molar with a paramolar and successful endodontic management was done. The rarity with which this entity appears, along with its complex characteristics, often makes it difficult to treat. In this case, a new advanced three-dimensional imaging Cone Beam Computed Tomography (CBCT) was used as an adjunctive diagnostic aid to differentiate between fusion occurred before or after root formation and help to reach the correct diagnosis. PMID:25298654

  1. Standard molar enthalpies of formation of eight lanthanide(III) 2,2,6,6-tetramethyl-3, 5-heptanedione chelates in the crystalline and gaseous states: mean Ln–O bond dissociation enthalpies

    Microsoft Academic Search

    Edward Giera

    2000-01-01

    The standard (po= 0.1 MPa) molar enthalpies of formation of lanthanum(III), praseodymium(III), neodymium(III), samarium(III), gadolinium(III), dysprosium(III), holmium(III) and erbium(III) crystalline chelate complexes with 2,2,6,6-tetramethyl-3,5-heptanedione (dipivaloylmethane, HDPM) at the temperature 298.15 K were determined by precision solution and reaction calorimetry. From the available literature data of standard molar enthalpies of sublimation, the enthalpies of formation of the complexes in the gaseous

  2. [Atmospheric CO2 data filtering method and characteristics of the molar fractions at the Longfengshan WMO/GAW regional station in China].

    PubMed

    Luan, Tian; Zhou, Ling-Xi; Fang, Shuang-Xi; Yao, Bo; Wang, Hong-Yang; Liu, Zhao

    2014-08-01

    Based on the in-situ observation results of atmospheric CO2 molar fractions at two levels (10 m and 80 m above the ground) at Longfengshan (LFS) regional background station in Heilongjiang Province during January 2009 to December 2011, this study mainly focused on the results from 10 m above the ground level (a. g. l.). The results indicated that the observed data from 10 m were strongly affected by the local sources/sinks. The differences between the 10 m and 80 m results were relatively small during the daytime (08:00-17:00) with values smaller than (0.5 +/- 0.5) x 10(-6). In spring, summer and winter, higher CO2 molar fractions were observed when surface winds came from the E-ESE-SE-SSE sectors, while, in winter, surface winds from the N-NNW-NW-WNW sectors obviously enhanced the observed values. Generally, lower CO2 values were accompanied with higher wind speed in the four seasons. This phenomenon was most obvious in winter. Based on the analysis of the observed diurnal cycles and the local meteorological conditions, the observed data from 10 m were filtered into background/non-background events. About 30.7% valid hourly data were filtered as regional background representative. The background CO2 variation displayed a peak in winter and a valley in summer with a seasonal peak to peak amplitude of (36.3 +/- 1.4) x 10(-6), which was higher than the values at similar latitude from Marine Boundary Layer (MBL) References and WMO/GAW stations. The yearly CO2 increasing rate at LFS was roughly estimated to be 2.4 x 10(-6) a(-1). PMID:25338353

  3. Plaque Bacterial Microbiome Diversity in Children Younger than 30 Months with or without Caries Prior to Eruption of Second Primary Molars

    PubMed Central

    Xu, He; Hao, Wenjing; Zhou, Qiong; Wang, Wenhong; Xia, Zhongkui; Liu, Chuan; Chen, Xiaochi; Qin, Man; Chen, Feng

    2014-01-01

    Objective Our primary objective is to phylogenetically characterize the supragingival plaque bacterial microbiome of children prior to eruption of second primary molars by pyrosequencing method for studying etiology of early childhood caries. Methods Supragingival plaque samples were collected from 10 caries children and 9 caries-free children. Plaque DNA was extracted, used to generate DNA amplicons of the V1–V3 hypervariable region of the bacterial 16S rRNA gene, and subjected to 454-pyrosequencing. Results On average, over 22,000 sequences per sample were generated. High bacterial diversity was noted in the plaque of children with caries [170 operational taxonomical units (OTU) at 3% divergence] and caries-free children (201 OTU at 3% divergence) with no significant difference. A total of 8 phyla, 15 classes, 21 orders, 30 families, 41 genera and 99 species were represented. In addition, five predominant phyla (Firmicute, Fusobacteria, Proteobacteria, Bacteroidetes and Actinobacteria) and seven genera (Leptotrichia, Streptococcus, Actinomyces, Prevotella, Porphyromonas, Neisseria, and Veillonella) constituted a majority of contents of the total microbiota, independent of the presence or absence of caries. Principal Component Analysis (PCA) presented that caries-related genera included Streptococcus and Veillonella; while Leptotrichia, Selenomonas, Fusobacterium, Capnocytophaga and Porphyromonas were more related to the caries-free samples. Neisseria and Prevotella presented approximately in between. In both groups, the degree of shared organism lineages (as defined by species-level OTUs) among individual supragingival plaque microbiomes was minimal. Conclusion Our study represented for the first time using pyrosequencing to elucidate and monitor supragingival plaque bacterial diversity at such young age with second primary molar unerrupted. Distinctions were revealed between caries and caries-free microbiomes in terms of microbial community structure. We observed differences in abundance for several microbial groups between the caries and caries-free host populations, which were consistent with the ecological plaque hypothesis. Our approach and findings could be extended to correlating microbiomic changes after occlusion establishment and caries treatment. PMID:24586647

  4. Clinical Comparison of Autogenous Bone Graft with and without Plasma Rich in Growth Factors in the Treatment of Grade II Furcation Involvement of Mandibular Molars

    PubMed Central

    Lafzi, Ardeshir; Shirmohammadi, Adileh; Faramarzi, Masoumeh; Jabali, Sahar; Shayan, Arman

    2013-01-01

    Background and aims Plasma rich in growth factors (PRGF) is a concentrated suspension of growth factors, which is used to promote periodontal tissue regeneration. The aim of this randomized, controlled, clinical trial was to evaluate of the treatment of grade II mandibular molar furcation involvement using autogenous bone graft with and without PRGF. Materials and methods In this double-blind clinical trial, thirty mandibular molars with grade II furcation involvement in 30 patients were selected. The test group received bone graft combined with PRGF, while the control group was treated with bone graft only. Clinical parameters included clinical probing depth (CPD), vertical clinical attachment level (V-CAL), horizontal clinical attachment level (H-CAL), location of gingival margin (LGM), surgically exposed horizontal probing depth of bony defect (E-HPD), vertical depth of bone crest (V-DBC), vertical depth of the base of bony defect (V-DBD), and length of the intrabony defect (LID). After six months, a re-entry surgery was performed. Data were analyzed by SPSS 14, using Kolmogorov, Mann-Whitney U, and paired t-test. Results After 6 months, both treatment methods led to significant improvement in V-CAL and H-CAL and significant decreases in CPD, E-HPD, V-DBD and LID; there was no significant difference in LGM and V-DBC in any of the treated groups compared to the baseline values. Also, none of the parameters showed significant differences between the study groups. Conclusion Although autogenous bone grafts, with or without PRGF, were successful in treating grade II furcation involvement, no differences between the study groups were observed. PMID:23486928

  5. Influence of contact points on the performance of caries detection methods in approximal surfaces of primary molars: an in vivo study.

    PubMed

    Ribeiro, Apoena A; Purger, Flávia; Rodrigues, Jonas A; Oliveira, Patrícia R A; Lussi, Adrian; Monteiro, Antonio Henrique; Alves, Haimon D L; Assis, Joaquim T; Vasconcellos, Adalberto B

    2015-01-01

    This in vivo study aimed to evaluate the influence of contact points on the approximal caries detection in primary molars, by comparing the performance of the DIAGNOdent pen and visual-tactile examination after tooth separation to bitewing radiography (BW). A total of 112 children were examined and 33 children were selected. In three periods (a, b, and c), 209 approximal surfaces were examined: (a) examiner 1 performed visual-tactile examination using the Nyvad criteria (EX1); examiner 2 used DIAGNOdent pen (LF1) and took BW; (b) 1 week later, after tooth separation, examiner 1 performed the second visual-tactile examination (EX2) and examiner 2 used DIAGNOdent again (LF2); (c) after tooth exfoliation, surfaces were directly examined using DIAGNOdent (LF3). Teeth were examined by computed microtomography as a reference standard. Analyses were based on diagnostic thresholds: D1: D 0 = health, D 1 –D 4 = disease; D2: D 0 , D 1 = health, D 2 –D 4 = disease; D3: D 0 –D 2 = health, D 3 , D 4 = disease. At D1, the highest sensitivity/specificity were observed for EX1 (1.00)/LF3 (0.68), respectively. At D2, the highest sensitivity/ specificity were observed for LF3 (0.69)/BW (1.00), respectively. At D3, the highest sensitivity/specificity were observed for LF3 (0.78)/EX1, EX2 and BW (1.00). EX1 showed higher accuracy values than LF1, and EX2 showed similar values to LF2. We concluded that the visual-tactile examination showed better results in detecting sound surfaces and approximal caries lesions without tooth separation. However, the effectiveness of approximal caries lesion detection of both methods was increased by the absence of contact points. Therefore, regardless of the method of detection, orthodontic separating elastics should be used as a complementary tool for the diagnosis of approximal noncavitated lesions in primary molars. PMID:25572115

  6. Effectiveness of Ozone with or without the Additional Use of Remineralizing Solution on Non-Cavitated Fissure Carious Lesions in Permanent Molars

    PubMed Central

    Atabek, Didem; Oztas, Nurhan

    2011-01-01

    Objectives: The aim of this study was to evaluate the efficiency of ozone alone and with a re-mineralizing solution following application on initial pit and fissure caries lesions in permanent molars. Methods: Forty children (9–12 years) having non-cavitated fissure caries lesions on bilateral 40 first permanent mandibular molar teeth were participated in the study. Patients were randomly allocated to 2 experimental groups consisting of 20 subjects. In the first group, ozone was applied once for 40 seconds to the assigned test teeth of each pair. In the second group, ozone was applied once for 40 seconds to the assigned test teeth of each pair with the use of re-mineralizing solution. Progression or improvement of the caries was assessed at baseline, immediately after treatment and at 1-,2-,3-, and 6 month follow-up by comparing the DIAGNOdent values, Clinical Severity Indexes, Oral Hygiene Scores. The results were analyzed statistically by using the Wilcoxon-Test for dependent samples in each group. When comparing different test groups (control and experimental groups) the Friedman S test followed by the Mann-Whitney U test was used. Results: A statistically significant difference was found between all of the control and experimental test lesions in each group (P<.001). However, there was no statistically significant difference between the ozone treated groups and those using the additional re-mineralizing solution (P>.001). Conclusions: Ozone treatment either alone or combined with a re-mineralizing solution was found to be effective for remineralization of initial fissure caries lesions. PMID:22654551

  7. Antimicrobial activity of Calendula officinalis, Camellia sinensis and chlorhexidine against the adherence of microorganisms to sutures after extraction of unerupted third molars

    PubMed Central

    FARIA, Raquel Lourdes; CARDOSO, Lincoln Marcelo Lourenço; AKISUE, Gokithi; PEREIRA, Cristiane Aparecida; JUNQUEIRA, Juliana Campos; JORGE, Antonio Olavo Cardoso; SANTOS JÚNIOR, Paulo Villela

    2011-01-01

    Objective The objective of this study was to compare the antimicrobial effect of mouthwashes containing Calendula officinalis L., Camellia sinensis (L.) Kuntze and 0.12% chlorhexidine digluconate on the adherence of microorganisms to suture materials after extraction of unerupted third molars. Material and Methods Eighteen patients with unerupted maxillary third molars indicated for extraction were selected (n=6 per mouthwash). First, the patients were subjected to extraction of the left tooth and instructed not to use any type of antiseptic solution at the site of surgery (control group). After 15 days, the right tooth was extracted and the patients were instructed to use the Calendula officinalis, Camellia sinensis or chlorhexidine mouthwash during 1 week (experimental group). For each surgery, the sutures were removed on postoperative day 7 and placed in sterile phosphate-buffered saline. Next, serial dilutions were prepared and seeded onto different culture media for the growth of the following microorganisms: blood agar for total microorganism growth; Mitis Salivarius bacitracin sucrose agar for mutans group streptococci; mannitol agar for Staphylococcus spp.; MacConkey agar for enterobacteria and Pseudomonas spp., and Sabouraud dextrose agar containing chloramphenicol for Candida spp. The plates were incubated during 24-48 h at 37ºC for microorganism count (CFU/mL). Results The three mouthwashes tested reduced the number of microorganisms adhered to the sutures compared to the control group. However, significant differences between the control and experimental groups were only observed for the mouthwash containing 0.12% chlorhexidine digluconate. Conclusions Calendula officinalis L. and Camellia sinensis (L.) Kuntze presented antimicrobial activity against the adherence of microorganisms to sutures but were not as efficient as chlorhexidine digluconate. PMID:21986652

  8. Plasma variations in stress markers: Clinical trial of two anesthetics used in regional block in the extraction of impacted inferior third molars

    PubMed Central

    Arteagoitia, Iciar; Zumarraga, Mercedes; Dávila, Ricardo; Barbier, Luis; Santamaría, Gorka

    2014-01-01

    Objectives: Was to evaluate the effect of different regional anesthetics (articaine with epinephrine versus prilocaine with felypressin) on stress in the extraction of impacted lower third molars in healthy subjects. Sutdy Desing: A prospective single-blind, split-mouth cross-over randomized study was designed, with a control group. The experimental group consisted of 24 otherwise healthy male volunteers, with two impacted lower third molars which were surgically extracted after inferior alveolar nerve block (regional anesthesia), with a fortnight’s interval: the right using 4% articaine with 1:100.000 epinephrine, and the left 3% prilocaine with 1:1.850.000 felypressin. Patients were randomized for the first surgical procedure. To analyze the variation in four stress markers, homovanillic acid, 3-methoxy-4-hydroxyphenylglycol, prolactin and cortisol, 10-mL blood samples were obtained at t = 0, 5, 60, and 120 minutes. The control group consisted of 12 healthy volunteers, who did not undergo either extractions or anesthetic procedures but from whom blood samples were collected and analyzed in the same way. Results: Plasma cortisol increased in the experimental group (multiple range test, P<0.05), the levels being significantly higher in the group receiving 3% prilocaine with 1:1.850,000 felypressin (signed rank test, p<0.0007). There was a significant reduction in homovanillic acid over time in both groups (multiple range test, P<0.05). No significant differences were observed in homovanillic acid, 3-methoxy-4-hydroxyphenylglycol or prolactin concentrations between the experimental and control groups. Conclusions: The effect of regional anesthesia on stress is lower when 4% articaine with 1:100,000 epinephrine is used in this surgical procedure. Key words:Stress markets, epinephrine versus felypressin. PMID:24316704

  9. A Low Molar Ratio of Retinol Binding Protein to Transthyretin Indicates Vitamin A Deficiency during Inflammation: Studies in Rats and A Posteriori Analysis of Vitamin A-Supplemented Children with Measles1-4

    Microsoft Academic Search

    Francisco J. Rosales; A. Catharine Ross

    To assess whether the molar ratio of retinol-binding protein (RBP) to transthyretin (TTR) is of utility in detecting vitamin A (VA) deficiency during inflammation, we analyzed data from a rat model of endotoxin- induced inflammation and from a previously reported randomized, placebo-controlled trial of VA supplementation in children with acute measles. In rats, both marginal VA deficiency and inflammation were

  10. Proteins Specified by Herpes Simplex Virus XI. Identification and Relative Molar Rates of Synthesis of Structural and Nonstructural Herpes Virus Polypeptides in the Infected Cell

    PubMed Central

    Honess, Robert W.; Roizman, Bernard

    1973-01-01

    Analyses of polypeptides made in HEp-2 cells infected with herpes simplex virus type 1 by high-resolution polyacrylamide gel electrophoresis revealed the synthesis of at least 49 infected cell polypeptides (ICP) ranging in molecular weight from 15,000 to 280,000. Evidence for virus specificity based on increased rates of synthesis postinfection, immunological specificity, and viral control of mobility and rate of synthesis was available for 47 of the ICP. These 47 polypeptides can account for 75% of the virus genetic information assuming a DNA molecular weight of 108 and asymmetric transcription. On the basis of their mobility relative to virion proteins, the ICP were classified as structural (S, 23 polypeptides), nonstructural (NS, 16 polypeptides), and unassigned (U, 10 polypeptides). Analysis of the synthesis of the ICP revealed the following. (i) Rapid posttranslational cleavages of HSV proteins were not detected; in parallel experiments rapid posttranslational cleavages were readily demonstrated in poliovirus-infected cells and these were blocked by protease inhibitors. (ii) Slow posttranslational changes in the mobility of at least two polypeptides were observed. (iii) Analysis of the rates of synthesis of ICP examined at four intervals postinfection revealed regulation of the pattern and amount of ICP synthesized. ICP formed six classes (A to F) differing in their kinetics of synthesis. S and NS ICP were distributed nonrandomly among these classes. Thus, of the sum of S protein amino acid sequences apportioned among these kinetic classes, 47%, constituting class A and comprising “late” structural proteins, were characterized by progressively increasing rates of synthesis until at least 12 h postinfection; whereas “early” structural proteins constituting class C, amounting to 31% of the total amino acid sequences, were synthesized with initially increasing rates until 4 h postinfection and with declining rates thereafter. NS polypeptides and remaining S polypeptides were distributed among the other kinetic classes—B, D, E, and F. Control of protein abundance was evident in that the polypeptides were not made in equimolar amounts. However, S and NS polypeptides could not be differentiated on the basis of their molar rates of synthesis. The bulk of the detected polypeptides did not differ by more than eightfold in their molar rates of synthesis. Images PMID:4357511

  11. High-molar-mass hyaluronan behavior during testing its radical scavenging capacity in organic and aqueous media: effects of the presence of manganese(II) ions.

    PubMed

    Rapta, Peter; Valachová, Katarína; Gemeiner, Peter; Soltés, Ladislav

    2009-02-01

    This study compares the radical scavenging capacity of high-molar-mass hyaluronan (HA) using standardized methods applying 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and 2,2'-azinobis[3-ethylbenzthiazoline sulfonate] (ABTS) radical cations as oxidants. Additionally, spin-trapping technique combined with electron paramagnetic resonance (EPR) was used to evaluate the ability of HA to scavenge reactive radicals. The thermal decomposition of K2S2O8 in pure H2O or in a H2O/dimethyl sulfoxide (DMSO) mixture at 333 K was used as a source of reactive paramagnetic species. We found that HA does not exhibit radical-scavenging activity when DPPH radicals or ABTS(.+) radical cations are used as oxidant, but that HA is an effective radical scavenger at low concentrations, if the oxidation reactions are initiated by the decomposition of K2S2O8. At higher HA concentrations, a more complex behavior and prooxidant HA action was observed. The influence of Mn(II) ions on the reaction mechanisms of radical generation and termination in the K2S2O8/H2O/DMSO system in the presence of HA was studied in detail. PMID:19235158

  12. Structures and standard molar enthalpies of formation of a series of Ln(III)-Cu(II) heteronuclear compounds with pyrazine-2,3-dicarboxylic acid

    NASA Astrophysics Data System (ADS)

    Yang, Qi; Xie, Gang; Wei, Qing; Chen, Sanping; Gao, Shengli

    2014-07-01

    Fifteen lanthanide-copper heteronuclear compounds, formulated as [CuLn2(pzdc)4(H2O)6]·xH2O (1-6(x=2), 8(x=3), 9-10(x=4); [CuLn2(pzdc)4(H2O)4]·xH2O (7, 12-13, 15(x=4), 14(x=5), 11(x=8) (Ln(III)=La(1); Ce(2); Pr(3); Nd(4); Sm(5); Eu(6); Gd(7); Tb(8); Dy(9); Ho(10); Er(11); Tm(12); Yb(13); Lu(14); Y(15); H2pzdc (C6H4N2O4)=pyrazine-2,3-dicarboxylic acid) have been hydrothermally synthesized. All compounds were characterized by element analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analyses confirm that all compounds are isostructural and feature a 3D brick-like framework structure with {4.62}2{42.62.82}{63}2{65.8}2 topology. Using 1 mol cm-3 HCl(aq) as calorimetric solvent, with an isoperibol solution-reaction calorimeter, the standard molar enthalpies of formation of all compounds were determined by a designed thermochemical cycle. In addition, solid state luminescence properties of compounds 5, 6, 8 and 9 were studied in the solid state.

  13. Itm2a Expression in the Developing Mouse First Lower Molar, and the Subcellular Localization of Itm2a in Mouse Dental Epithelial Cells

    PubMed Central

    Kihara, Makiko; Kiyoshima, Tamotsu; Nagata, Kengo; Wada, Hiroko; Fujiwara, Hiroaki; Hasegawa, Kana; Someya, Hirotaka; Takahashi, Ichiro; Sakai, Hidetaka

    2014-01-01

    Itm2a is a type II transmembrane protein with a BRICHOS domain. We investigated the temporospatial mRNA and protein expression patterns of Itm2a in the developing lower first molar, and examined the subcellular localization of Itm2a in murine dental epithelial (mDE6) cells. From the initiation to the bud stage, the in situ and protein signals of Itm2a were not detected in either the dental epithelial or mesenchymal cells surrounding the tooth bud. However, at the bell stage, these signals of Itm2a were primarily observed in the inner enamel epithelium of the enamel organ. After the initiation of the matrix formation, strong signals were detected in ameloblasts and odontoblasts. Itm2a showed a punctate pattern in the cytoplasm of the mDE6 cells. The perinuclear-localized Itm2a displayed a frequent overlap with the Golgi apparatus marker, GM130. A tiny amount of Itm2a was colocalized with lysosomes and endoplasmic reticulum. Minimal or no overlap between the Itm2a-EGFP signals with the other organelle markers for endoplasmic reticulum, lysosome and mitochondria used in this study noted in the cytoplasm. These findings suggest that Itm2a may play a role in cell differentiation during odontogenesis, rather than during the initiation of tooth germ formation, and may be related to the targeting of proteins associated with enamel and dentin matrices in the secretory pathway. PMID:25079563

  14. Effect of low-dose dexketoprofen trometamol and paracetamol on postoperative complications after impacted third molar surgery on healthy volunteers: A pilot study

    PubMed Central

    Durmus, Ercan; Kiresi, Demet

    2014-01-01

    Objectives: The aim of the present study was to investigate the analgesic and anti-inflammatory effects of dexketoprofen trometamol (DT) and paracetamol on deep acute somatic pain and inflammation in patients undergoing impacted third molar surgery. This study was planned to present benefits that we could obtain with low burden of drug. Study Design: Effects of drugs, which were administered preemptively before the procedure, on pain, mouth-opening limitation, and swelling were assessed by visual analogue scale (VAS), magnetic resonance imaging (MRI), and mouth-opening measurement. Following surgery, time intervals when the patients first need to receive the drug were measured. Results: The VAS scores of the patients were lower in the side treated with DT than that in the paracetamol treated side. There was no significant difference between the groups in terms of mouth-opening limitation. MRI recordings revealed that swelling was lower in the side treated with paracetamol than DT treated side. Conclusions: Administration of the drugs before surgery contributed to the postoperative patient comfort. The analgesic activity of 12.5 mg dose of DT was similar to, even better than, the analgesic activity of 500 mg dose of paracetamol; however, DT had insufficient anti-inflammatory efficacy. Key words:Dexketoprofen trometamol, paracetamol, magnetic resonance imaging. PMID:25129247

  15. A Single Dose of Amoxicillin and Dexamethasone for Prevention of Postoperative Complications in Third Molar Surgery: A Randomized, Double-Blind, Placebo Controlled Clinical Trial

    PubMed Central

    Bortoluzzi, Marcelo Carlos; Capella, Diogo Lenzi; Barbieri, Tharzon; Pagliarini, Micheli; Cavalieri, Talita; Manfro, Rafael

    2013-01-01

    Background The aim of this study was to assess the efficacy of a single prophylactic dose of amoxicillin and/or dexamethasone in preventing postoperative complications (PC) after a surgical removal of a single mandibular third molar (M3). Methods This study is a randomized, placebo controlled clinical trial. Four groups were included: Group 1 (G1) included a prophylactic dose of 2 g of amoxicillin and 8 mg of dexamethasone; Group 2 (G2) included a prophylactic dose of 2 g of amoxicillin and 8 mg of placebo; Group 3 (G3) included a prophylactic dose of 8 mg of dexamethasone and 2 g of placebo and; Group 4 (G4) placebo. Results Fifty patients were included. It was observed one case of alveolar infection (2%) and two of alveolar osteitis (4%) resulting in three PC (6%). No statistical differences were observed between therapeutic groups for development of PC, trismus, pain and edema. The use of antibiotics showed an absolute risk reduction (ARR) for PC development of 3.52% and the number needed to treat (NNT) was 29. Conclusion Prophylactic antibiotics and corticoid in a single dose regimen did not bring any benefit on M3 surgeries. PMID:23390473

  16. Pre-emptive effect of dexamethasone and methylprednisolone on pain, swelling, and trismus after third molar surgery: a split-mouth randomized triple-blind clinical trial.

    PubMed

    Alcântara, C E P; Falci, S G M; Oliveira-Ferreira, F; Santos, C R R; Pinheiro, M L P

    2014-01-01

    The aim of this study was to compare the effect of dexamethasone 8 mg and methylprednisolone 40 mg for the control of pain, swelling, and trismus following the extraction of impacted third molars. Sixteen healthy patients with a mean age of 20.3 (standard deviation 1.25) years received a single oral dose of either drug 1 h prior to each surgical procedure (left and right teeth). At 24, 48, and 72 h and 7 days following surgery, swelling was determined using linear measurements on the face and trismus was determined by maximal mouth opening. Postoperative pain was self-recorded by the patients using a visual analogue scale at 8-h intervals for a period of 72 h. Data analysis involved descriptive statistics and the Wilcoxon, and paired t tests (P < 0.05). Dexamethasone controlled swelling better than methylprednisolone at all postoperative evaluations (P < 0.02) and led to greater mouth opening 48 h after surgery (P = 0.029). No statistically significant difference was found between drugs with regard to pain. In conclusion, pre-emptive dexamethasone 8 mg demonstrated better control of swelling and limited mouth opening in comparison to methylprednisolone 40 mg, with no differences between drugs regarding pain control. PMID:23810681

  17. Free-radical degradation of high-molar-mass hyaluronan induced by ascorbate plus cupric ions: evaluation of antioxidative effect of cysteine-derived compounds.

    PubMed

    Hrabárová, Eva; Valachová, Katarína; Juránek, Ivo; Soltés, Ladislav

    2012-02-01

    Based on our previous findings, the present study has focused on free-radical-mediated degradation of the synovial biopolymer hyaluronan. The degradation was induced in vitro by the Weissberger's system comprising ascorbate plus cupric ions in the presence of oxygen, representing a model of the early phase of acute synovial joint inflammation. The study presents a novel strategy for hyaluronan protection against oxidative degradation with the use of cysteine-derived compounds. In particular, the work objectives were to evaluate potential protective effects of reduced form of L-glutathione, L-cysteine, N-acetyl-L-cysteine, and cysteamine, against free-oxygen-radical-mediated degradation of high-molar-mass hyaluronan in vitro. The hyaluronan degradation was influenced by variable activity of the tested thiol compounds, also in dependence of their concentration applied. It was found that L-glutathione exhibited the most significant protective and chain-breaking antioxidative effect against the hyaluronan degradation. Thiol antioxidative activity, in general, can be influenced by many factors such as various molecule geometry, type of functional groups, radical attack accessibility, redox potential, thiol concentration and pK(a), pH, ionic strength of solution, as well as different ability to interact with transition metals. Antioxidative activity was found to decrease in the following order: L-glutathione, cysteamine, N-acetyl-L-cysteine, and L-cysteine. These findings might be beneficial in future development of potential drugs in the treatment of synovial hyaluronan depletion-derived diseases. PMID:22344907

  18. Early treatment of anterior open bite: Comparison of the vertical and horizontal morphological changes induced by magnetic bite-blocks and adjusted rapid molar intruders

    PubMed Central

    Takahashi, Ichiro; Sawan, Mhd Naser

    2015-01-01

    Objective This prospective clinical study aims to determine the differences between two treatment modalities for anterior open bite in growing patients. The treatment modalities involved the use of magnetic bite-blocks (MBBs) or rapid molar intruders (RMIs) applied with posterior bite-blocks. Methods Fifteen consecutive patients with a mean age of 11.2 (standard deviation [SD] = 1.6) years and a mean open bite of -3.9 mm were treated with MBBs. Another 15 consecutive patients with a mean age of 10.9 (SD = 1.8) years and a mean open bite of -3.8 mm were treated with RMIs applied on bite-blocks. Cephalometric radiographs were obtained before (T1) and immediately after appliance removal (T2). The treatments lasted four months, during which the appliances were cemented to the teeth. The morphological changes were measured in each group and compared using logistic regression analysis. Results The MBB group exhibited significantly greater decreases in SNA angle, ANB angle, overjet, and maxillary incisor angle (p < 0.05). The MBBs induced greater effects on the maxilla and maxillary dentition. The MBBs restrained maxillary forward growth and retracted the maxillary incisors more effectively than did the RMIs. Consequently, changes in the intermaxillary relationships and overjets were more distinct in the MBB group. Conclusions The anteroposterior differences between the appliances suggest that MBBs should be preferred for the treatment of patients with Class II open bites and maxillary incisor protrusions. PMID:25667916

  19. THERMAL AND SPECTROSCOPIC ANALYSES OF NEXT GENERATION CAUSTIC SIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 3, 8, AND 16 MOLAR NITRIC ACID

    SciTech Connect

    Fondeur, F.; Fink, S.

    2011-09-30

    A new solvent system referred to as Next Generation Solvent or NGS, has been developed at Oak Ridge National Laboratory for the removal of cesium from alkaline solutions in the Caustic Side Solvent Extraction process. NGS is proposed for deployment at MCU and at the Salt Waste Processing Facility. This work investigated the chemical compatibility between NGS and 16 M, 8 M, and 3 M nitric acid from contact that may occur in handling of analytical samples from MCU or, for 3 M acid, which may occur during contactor cleaning operations at MCU. This work shows that reactions occurred between NGS components and the high molarity nitric acid. In the case of 16 M and 8 M nitric acid, initially organo-nitrate groups are generated and attach to the modifier and that with time oxidation reactions convert the modifier into a tarry substance with gases (NO{sub x} and possibly CO) evolving. Calorimetric analysis of the organonitrate revealed the reaction products are not explosive nor will they deflagrate. NGS exposure to 3 M nitric acid resulted in much slower reaction kinetics and that the generated products were not energetic. We recommended conducting Accelerated Rate calorimetry on the materials generated in the 16 M and 8 M nitric acid test. Also, we recommend continue monitoring of the samples contacting NGS with 3 M nitric acid.

  20. Thermal And Spectroscopic Analyses Of Next Generation Caustic Side Solvent Extraction Solvent Contacted With 3, 8, And 16 Molar Nitric Acid

    SciTech Connect

    Fondeur, F. F.; Fink, S. D.

    2011-12-07

    A new solvent system referred to as Next Generation Solvent or NGS, has been developed at Oak Ridge National Laboratory for the removal of cesium from alkaline solutions in the Caustic Side Solvent Extraction process. The NGS is proposed for deployment at MCU{sup a} and at the Salt Waste Processing Facility. This work investigated the chemical compatibility between NGS and 16 M, 8 M, and 3 M nitric acid from contact that may occur in handling of analytical samples from MCU or, for 3 M acid, which may occur during contactor cleaning operations at MCU. This work shows that reactions occurred between NGS components and the high molarity nitric acid. Reaction rates are much faster in 8 M and 16 M nitric acid than in 3 M nitric acid. In the case of 16 M and 8 M nitric acid, the nitric acid reacts with the extractant to produce initially organo-nitrate species. The reaction also releases soluble fluorinated alcohols such as tetrafluoropropanol. With longer contact time, the modifier reacts to produce a tarry substance with evolved gases (NO{sub x} and possibly CO). Calorimetric analysis of the reaction product mixtures revealed that the organo-nitrates reaction products are not explosive and will not deflagrate.

  1. Shaping abilities of two different engine-driven rotary nickel titanium systems or stainless steel balanced-force technique in mandibular molars.

    PubMed

    Matwychuk, Michael J; Bowles, Walter R; McClanahan, Scott B; Hodges, Jim S; Pesun, Igor J

    2007-07-01

    The purpose of this study was to compare apical transportation, working-length changes, and instrumentation time by using nickel-titanium (Ni-Ti) rotary file systems (crown-down method) or stainless steel hand files (balanced-force technique) in mesiobuccal canals of extracted mandibular molars. The curvature of each canal was determined and teeth placed into three equivalent groups. Group 1 was instrumented with Sequence (Brasseler USA, Savannah, GA) rotary files, group 2 with Liberator (Miltex Inc, York, PA) rotary files, and group 3 with Flex-R (Union Broach, New York, NY) files. Pre- and postoperative radiographs were superimposed to measure loss of working length and apical transportation as shown by changes in radius of curvature and the long-axis canal angle. Sequence rotary files, Liberator rotary files, and Flex-R hand files had similar effects on apical canal transportation and changes in working length, with no significant differences detected among the 3 groups. Hand instrumentation times were longer than with either Ni-Ti rotary group, whereas the rotary NiTi groups had a higher incidence of fracture. PMID:17804332

  2. Tooth movements are guided by specific contact areas between the tooth root and the jaw bone: A dynamic 3D microCT study of the rat molar.

    PubMed

    Naveh, Gili R S; Shahar, Ron; Brumfeld, Vlad; Weiner, Steve

    2012-02-01

    Teeth sustain high loads over a lifetime and yet intact tooth failure is rare. The different structures of the tooth, jaw bone and the intervening soft periodontal ligament enable the tooth to endure repeated loading during mastication. Although mechanical and functional properties of the different components are thoroughly investigated, the manner in which the whole tooth functions under load is still enigmatic. A custom-made loading system inside a microCT scanner was used to directly visualize the root movements in relation to the jaw bone as the rat molar tooth was loaded. At low loads no contact was observed between the root surface and the bone, whereas at higher loads three specific contact areas between the root surface and the jaw bone were observed. These contact areas restrict tooth movement in the buccal-lingual direction, but enable the tooth to rock in a "seesaw" like manner in the distal-mesial direction. The contact areas appear to play a role in determining tooth motion and in turn define the manner in which the whole tooth moves when loaded. These observations are important for understanding basic structure-function relations of the tooth-PDL-bone system, and have direct implications for better understanding pathological and therapeutic processes in orthodontics, periodontics and jaw bone regeneration. PMID:22138090

  3. A histological and micro-CT investigation in to the effect of NGF and EGF on the periodontal, alveolar bone, root and pulpal healing of replanted molars in a rat model - a pilot study

    PubMed Central

    2014-01-01

    Background This study aims to investigate, utilising micro-computed tomography (micro-CT) and histology, whether the topical application of nerve growth factor (NGF) and/or epidermal growth factor (EGF) can enhance periodontal, alveolar bone, root and pulpal tissue regeneration while minimising the risk of pulpal necrosis, root resorption and ankylosis of replanted molars in a rat model. Methods Twelve four-week-old male Sprague-Dawley rats were divided into four groups: sham, collagen, EGF and NGF. The maxillary right first molar was elevated and replanted with or without a collagen membrane impregnated with either the growth factors EGF or NGF, or a saline solution. Four weeks after replantation, the animals were sacrificed and the posterior maxilla was assessed using histological and micro-CT analysis. The maxillary left first molar served as the control for the corresponding right first molar. Results Micro-CT analysis revealed a tendency for all replanted molars to have reduced root length, root volume, alveolar bone height and inter-radicular alveolar bone volume. It appears that the use of the collagen membrane had a negative effect while no positive effect was noted with the incorporation of EGF or NGF. Histologically, the incorporation of the collagen membrane was found to negatively affect pulpal, root, periodontal and alveolar bone healing with pulpal inflammation and hard tissue formation, extensive root resorption and alveolar bone fragmentation. The incorporation of EGF and NGF did not improve root, periodontal or alveolar bone healing. However, EGF was found to improve pulp vascularisation while NGF-improved pulpal architecture and cell organisation, although not to the level of the control group. Conclusions Results indicate a possible benefit on pulpal vascularisation and pulpal cell organisation following the incorporation of EGF and NGF, respectively, into the alveolar socket of replanted molars in the rat model. No potential benefit of EGF and NGF was detected in periodontal or root healing, while the use of a collagen membrane carrier was found to have a negative effect on the healing response. PMID:24393534

  4. The Performance of ICDAS-II Using Low-Powered Magnification with Light-Emitting Diode Headlight and Alternating Current Impedance Spectroscopy Device for Detection of Occlusal Caries on Primary Molars.

    PubMed

    Ari, Timucin; Ari, Nilgun

    2013-01-01

    Early detection of occlusal caries in children is challenging for the dentists, because of the morphology of pit and fissures. The aim of this study was to compare in vitro the diagnostic performance of low-powered magnification with light-emitting diode headlight (LPMLED) using ICDAS-II criteria and AC Impedance Spectroscopy (ACIS) device, on occlusal surfaces of primary molars. The occlusal surfaces of 18 extracted primary molars were examined blindly by two examiners. The teeth were sectioned and examined under light microscopy using Downer's histological criteria as gold standard. Good to excellent inter- and intraexaminer reproducibility, higher sensitivity, specificity, and AUC values were achieved by LPMLED at D1 threshold. Also the relationship between histology and LPMLED was statistically significant. In conclusion visual aids have the potential to improve the performance of early caries detection and clinical diagnostics in children. Despite its potential, ACIS device should be considered as an adjunct method in detecting caries on primary teeth. PMID:23956865

  5. The Performance of ICDAS-II Using Low-Powered Magnification with Light-Emitting Diode Headlight and Alternating Current Impedance Spectroscopy Device for Detection of Occlusal Caries on Primary Molars

    PubMed Central

    Ari, Nilgun

    2013-01-01

    Early detection of occlusal caries in children is challenging for the dentists, because of the morphology of pit and fissures. The aim of this study was to compare in vitro the diagnostic performance of low-powered magnification with light-emitting diode headlight (LPMLED) using ICDAS-II criteria and AC Impedance Spectroscopy (ACIS) device, on occlusal surfaces of primary molars. The occlusal surfaces of 18 extracted primary molars were examined blindly by two examiners. The teeth were sectioned and examined under light microscopy using Downer's histological criteria as gold standard. Good to excellent inter- and intraexaminer reproducibility, higher sensitivity, specificity, and AUC values were achieved by LPMLED at D1 threshold. Also the relationship between histology and LPMLED was statistically significant. In conclusion visual aids have the potential to improve the performance of early caries detection and clinical diagnostics in children. Despite its potential, ACIS device should be considered as an adjunct method in detecting caries on primary teeth. PMID:23956865

  6. Non-destructive measurement of demineralization and remineralization in the occlusal pits and fissures of extracted 3rd molars with PS-OCT

    NASA Astrophysics Data System (ADS)

    Lee, Chulsung; Hsu, Dennis J.; Le, Michael H.; Darling, Cynthia L.; Fried, Daniel

    2009-02-01

    Previous studies have demonstrated that Polarization Sensitive Optical Coherence Tomography (PS-OCT) can be used to image the remineralization of early artificial caries lesion on smooth enamel surfaces of human and bovine teeth. However, most new dental decay is found in the pits and fissures of the occlusal surfaces of posterior dentition and it is in these high risk areas where the performance of new caries imaging devices need to be investigated. The purpose of this study was to demonstrate that PS-OCT can be used to measure the subsequent remineralization of artificial lesions produced in the pits and fissures of extracted 3rd molars. A PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of occlusal surfaces exposed to a demineralizing solution at pH-4.5 followed by a fluoride containing remineralizing solution at pH-7.0 containing 2-ppm fluoride. The integrated reflectivity was calculated to a depth of 200-µm in the entire lesion area using an automated image processing algorithm. Although a well-defined surface zone was clearly resolved in only a few of the samples that underwent remineralization, the PS-OCT measurements indicated a significant (p<0.05) reduction in the integrated reflectivity between the severity of the lesions that were exposed to the remineralization solution and those that were not. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth. These results show that PS-OCT can be used to non-destructively monitor the remineralization potential of anti-caries agents in the important pits and fissures of the occlusal surface.

  7. A Double-Blind Placebo-Controlled Comparison of a Novel Formulation of Intravenous Diclofenac and Ketorolac for Postoperative Third Molar Extraction Pain

    PubMed Central

    Christensen, Kyle; Daniels, Stephen; Bandy, Donald; Ernst, Cynthia C.; Hamilton, Douglas A.; Mermelstein, Fred H.; Wang, Jianyuan; Carr, Daniel B.

    2011-01-01

    Dyloject is a novel formulation of diclofenac intended for intravenous (IV) administration. This formulation employs the solubilizing agent hydroxypropyl-?-cyclodextrin to permit bolus IV administration. The efficacy and safety of 5 dose levels of IV diclofenac were compared with IV ketorolac and placebo following third molar extraction. This was a single-dose, randomized, double-blind, placebo- and comparator-controlled, parallel-group study. A total of 353 subjects with moderate to severe pain received placebo; ketorolac 30 mg; or IV diclofenac 3.75, 9.4, 18.75, 37.5, or 75 mg (N ?=? 51 for all groups, except N ?=? 47 for ketorolac). The primary endpoint was total pain relief over 6 hours (TOTPAR6) as measured by the visual analog scale (VAS). Secondary endpoints included multiple measures of pain intensity and relief; patient global evaluation; and times to pain relief and rescue medication. Dropouts and adverse effects (AEs) were also monitored. IV diclofenac was superior to placebo as measured by TOTPAR6 (P < .0001 for all doses except 3.75 mg, for which P ?=? .0341). IV diclofenac 3.75 mg was statistically superior to placebo for TOTPAR2 and TOTPAR4. IV diclofenac at both 37.5 and 75 mg was superior to placebo (P < .05) at the earliest (5 minute) assessments of pain intensity and pain relief, but ketorolac was not. The proportion of patients reporting 30% or greater pain relief at 5 minutes was significantly greater after IV diclofenac 37.5 and 75 mg than after ketorolac 30 mg or placebo. Secondary endpoints confirmed the primary findings. Treatment-related AEs were generally mild to moderate and were typical for nonsteroidal anti-inflammatory drugs (NSAIDs). The more rapid onset of action of IV diclofenac compared with the reference injectable NSAID ketorolac suggests additional clinical benefit. If confirmed in larger series, these findings may improve the safety and efficacy of postoperative NSAID analgesia. PMID:21679043

  8. Cul3-mediated Nrf2 ubiquitination and antioxidant response element (ARE) activation are dependent on the partial molar volume at position 151 of Keap1.

    PubMed

    Eggler, Aimee L; Small, Evan; Hannink, Mark; Mesecar, Andrew D

    2009-08-15

    Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor that activates transcription of a battery of cytoprotective genes by binding to the ARE (antioxidant response element). Nrf2 is repressed by the cysteine-rich Keap1 (kelch-like ECH-associated protein 1) protein, which targets Nrf2 for ubiquitination and subsequent degradation by a Cul3 (cullin 3)-mediated ubiquitination complex. We find that modification of Cys(151) of human Keap1, by mutation to a tryptophan, relieves the repression by Keap1 and allows activation of the ARE by Nrf2. The Keap1 C151W substitution has a decreased affinity for Cul3, and can no longer serve to target Nrf2 for ubiquitination, though it retains its affinity for Nrf2. A series of 12 mutant Keap1 proteins, each containing a different residue at position 151, was constructed to explore the chemistry required for this effect. The series reveals that the extent to which Keap1 loses the ability to target Nrf2 for degradation, and hence the ability to repress ARE activation, correlates well with the partial molar volume of the residue. Other physico-chemical properties do not appear to contribute significantly to the effect. Based on this finding, a structural model is proposed whereby large residues at position 151 cause steric clashes that lead to alteration of the Keap1-Cul3 interaction. This model has significant implications for how electrophiles which modify Cys(151), disrupt the repressive function of Keap1. PMID:19489739

  9. Non-destructive measurement of demineralization & remineralization in the occlusal pits and fissures of extracted 3rd molars with PS-OCT

    PubMed Central

    Lee, Chulsung; Hsu, Dennis J.; Le, Michael H.; Darling, Cynthia L.; Fried, Daniel

    2011-01-01

    Previous studies have demonstrated that Polarization Sensitive Optical Coherence Tomography (PS-OCT) can be used to image the remineralization of early artificial caries lesion on smooth enamel surfaces of human and bovine teeth. However, most new dental decay is found in the pits and fissures of the occlusal surfaces of posterior dentition and it is in these high risk areas where the performance of new caries imaging devices need to be investigated. The purpose of this study was to demonstrate that PS-OCT can be used to measure the subsequent remineralization of artificial lesions produced in the pits and fissures of extracted 3rd molars. A PS-OCT system operating at 1310-nm was used to acquire polarization resolved images of occlusal surfaces exposed to a demineralizing solution at pH-4.5 followed by a fluoride containing remineralizing solution at pH-7.0 containing 2-ppm fluoride. The integrated reflectivity was calculated to a depth of 200-?m in the entire lesion area using an automated image processing algorithm. Although a well-defined surface zone was clearly resolved in only a few of the samples that underwent remineralization, the PS-OCT measurements indicated a significant (p<0.05) reduction in the integrated reflectivity between the severity of the lesions that were exposed to the remineralization solution and those that were not. The lesion depth and mineral loss were also measured with polarized light microscopy and transverse microradiography after sectioning the teeth. These results show that PS-OCT can be used to non-destructively monitor the remineralization potential of anti-caries agents in the important pits and fissures of the occlusal surface. PMID:21935289

  10. Possible role of immunocompetent cells and the expression of heat shock protein-25 in the process of pulpal regeneration after tooth injury in rat molars.

    PubMed

    Nakakura-Ohshima, Kuniko; Watanabe, Jun-ichi; Kenmotsu, Shin-ichi; Ohshima, Hayato

    2003-01-01

    Recent studies have established that heat shock proteins (HSPs) potentially play a role in immunosurveillance. The purpose of the present study was to clarify the relationship between the chronological changes of immunocompetent cells and the expression of HSP-25 in the process of pulpal regeneration after tooth injury in rat molars by immunocytochemistry for HSP-25 and class II major histocompatibility complex (MHC) antigen. In untreated control teeth, intense HSP-25 immunoreactivity was found in the cell bodies of odontoblasts. Both cavity preparation and tooth replantation caused the degeneration of the odontoblast layer to result in the loss of HSP-25 immunoreactions in the suffered dental pulp at the early stages after tooth injury. Numerous class II MHC-positive cells appeared along the pulp-dentin border and extended their cell processes into the dentinal tubules at 12-24 h after cavity preparation and 3 days after tooth replantation. Newly differentiated odontoblast-like cells with HSP-25 immunoreactivity were arranged at the pulp-dentin border and the class II MHC-positive cells retreated towards the subodontoblastic layer by post-operative days 3-5 after tooth injury. Thus, the common cellular events occur during pulpal regeneration following two different experimental injuries. These findings indicate that the time course of changes in the expression of HSP-25 immunoreactivity reflects the degeneration/regeneration process of odontoblasts and that the temporal appearance of the class II MHC-positive cells at the pulp-dentin border suggests their participation in odontoblast differentiation as well as in initial defence reactions during the pulpal regeneration process. PMID:14756247

  11. Effect of OH ?\\/Al 3+ and Si\\/Al molar ratios on the coagulation performance and residual Al speciation during surface water treatment with poly-aluminum-silicate-chloride (PASiC)

    Microsoft Academic Search

    Zhonglian Yang; Baoyu Gao; Weiying Xu; Baichuan Cao; Qinyan Yue

    2011-01-01

    Coagulation performance, mechanism of poly-aluminum-silicate-chloride (PASiC) and residual Al speciation in the effluent with respect to a specific surface water treatment in China were comprehensively investigated in this study. The impact of OH?\\/Al3+ and Si\\/Al molar ratios on the coagulation performance, mechanism and residual Al speciation of PASiC in surface water treatment was discussed as a function of coagulant dosage.

  12. Effect of intra-alveolar placement of 0.2% chlorhexidine bioadhesive gel on the incidence of alveolar osteitis following the extraction of mandibular third molars. A double-blind randomized clinical trial

    PubMed Central

    Garcia-Linares, Jordi; Hueto-Madrid, Juan-Antonio; González-Lagunas, Javier; Raspall-Martin, Guillermo; Mareque-Bueno, Javier

    2015-01-01

    Alveolar osteitis (AO) is a common complication after third molar surgery. One of the most studied agents in its prevention is chlorhexidine (CHX), which has proved to be effective. Objectives: The aim of this randomized double-blind clinical trial was to evaluate the efficacy of 0.2% bioadhesive chlorhexidine gel placed intra-alveolar in the prevention of AO after the extraction of mandibular third molars and to analyze the impact of risk factors such as smoking and oral contraceptives in the development of AO. Study Design: The study was a randomized, double-blind, clinical trial performed in the Ambulatory Surgery Unit of Hospital Vall d’Hebron and was approved by the Ethics Committee. A total of 160 patients randomly received 0.2% bioadhesive gel (80 patients) or bioadhesive placebo (80 patients). Results: 0.2% bioadhesive chlorhexidine gel applied in the alveolus after third molar extraction reduced the incidence of dry socket by 22% compared to placebo with differences that were not statistically significant. Smoking and the use of oral contraceptives were not related to higher incidence of dry socket. Female patients and the difficulty of the surgery were associated with a higher incidence of AO with statistically significant differences. 0.2% bioadhesive chlorhexidine gel did not produce any of the side effects related to chlorhexidine rinses. Conclusions: A 22% reduction of the incidence of alveolar osteitis with the application of 0.2% bioadhesive chlorhexidine gel compared to placebo with differences that were not statistically significant was found in this clinical trial. The lack of adverse reactions and complications related to chlorhexidine gel supports its clinical use specially in simple extractions and adds some advantages compared to the rinses in terms of duration of the treatment and reduction of staining and taste disturbance. Key words:Alveolar osteitis, dry socket, chlorhexidine bioadhesive gel, mandibular third molar surgery. PMID:25475772

  13. Excess molar enthalpies of ternary mixtures for propanone or benzene + aniline + 2-methyl-1-propanol and of binary mixtures for propanone or aniline + 2-methyl-1-propanol at 298.15 K

    Microsoft Academic Search

    Isamu Nagata; Kazuhiro Tamura; Koichi Miyai

    1996-01-01

    Experimental excess molar enthalpies for the ternary mixtures 2-methyl-1-propanol + aniline + propanone and 2-methyl-1-propanol + aniline + benzene and their constituent binary mixtures 2-methyl-1-propanol + aniline and 2-methyl-1-propanol + propanone at the temperature 298.15 K, measured by using an isothermal dilution calorimeter, are reported. The results have been analyzed using a polynomial equation and the UNIQUAC-associated solution model with

  14. Multiblock copolymers composed of poly(butylene succinate) and poly(1,2-propylene succinate): Effect of molar ratio of diisocyanate to polyester-diols on crosslink densities, thermal properties, mechanical properties and biodegradability

    Microsoft Academic Search

    Liuchun Zheng; Chuncheng Li; Dong Zhang; Guohu Guan; Yaonan Xiao; Dujin Wang

    2010-01-01

    In order to study the relationship between structure and properties, multiblock copolymers composed of poly(butylene succinate) (PBS) and poly (1,2-propylene succinate) (PPSu) have been synthesized by chain-extension at various molar ratios of hexamethylene diisocyanate (HDI) to polyester-diols, which have been abbreviated as R-values in this paper. Molecular weights of soluble fractions, gel fractions and crosslink densities have been determined. Thermal

  15. A counter-intuitive approach to calculating non-exchangeable 2H isotopic composition of hair: treating the molar exchange fraction fE as a process-related rather than compound-specific variable

    USGS Publications Warehouse

    Landwehr, J.M.; Meier-Augenstein, W.; Kemp, H.F.

    2011-01-01

    Hair is a keratinous tissue that incorporates hydrogen from material that an animal consumes but it is metabolically inert following synthesis. The stable hydrogen isotope composition of hair has been used in ecological studies to track migrations of mammals as well as for forensic and archaeological purposes to determine the provenance of human remains or the recent geographic life trajectory of living people. Measurement of the total hydrogen isotopic composition of a hair sample yields a composite value comprised of both metabolically informative, non-exchangeable hydrogen and exchangeable hydrogen, with the latter reflecting ambient or sample preparation conditions. Neither of these attributes is directly measurable, and the non-exchangeable hydrogen composition is obtained by estimation using a commonly applied mathematical expression incorporating sample measurements obtained from two distinct equilibration procedures. This commonly used approach treats the fraction of exchangeable hydrogen as a mixing ratio, with a minimal procedural fractionation factor assumed to be close or equal to 1. Instead, we propose to use full molar ratios to derive an expression for the non-exchangeable hydrogen composition explicitly as a function of both the procedural fractionation factor ? and the molar hydrogen exchange fraction fE. We apply these derivations in a longitudinal study of a hair sample and demonstrate that the molar hydrogen exchange fraction fE should, like the procedural fractionation factor ?, be treated as a process-dependent parameter, i.e. a reaction-specific constant. This is a counter-intuitive notion given that maximum theoretical values for the molar hydrogen exchange fraction fE can be calculated that are arguably protein-type specific and, as such, fE could be regarded as a compound-specific constant. We also make some additional suggestions for future approaches to determine the non-exchangeable hydrogen composition of hair and the use of standards.

  16. Electrochemical properties of yolk-shell-structured CuO-Fe(2)O(3) powders with various Cu/Fe molar ratios prepared by one-pot spray pyrolysis.

    PubMed

    Yang, Kwang Min; Hong, Young Jun; Kang, Yun Chan

    2013-12-01

    Several yolk-shell-structured CuO-Fe2 O3 powders with various Cu/Fe molar ratios have been successfully prepared under equivalent reaction conditions using a one-pot spray pyrolysis process. The Cu and Fe components are uniformly distributed throughout the powders, irrespective of composition. The Brunauer-Emmett-Teller surface areas of the yolk-shell CuO-Fe2 O3 systems increased from 5 to 16?m(2) ?g(-1) if the Cu/Fe molar ratios are decreased from 3:1 to 1:3. The initial discharge and charge capacities of the yolk-shell CuO-Fe2 O3 system (Cu/Fe=1:2), showing maximum values at a constant current density of 1000?mA?g(-1) , are 1436 and 1012?mA?h?g(-1) , respectively. After 130?cycles, the discharge capacities of the yolk-shell CuO-Fe2 O3 powders with Cu/Fe molar ratios of 1:3, 1:2, 1:1, 2:1, and 3:1 are 1159, 1151, 755, 655, and 651?mA?h?g(-1) , respectively. The discharge capacities of the yolk-shell and dense powder samples after 50?cycles, when subjected to a series of current density increases from 500 to 5000?mA?g(-1) , are 735 and 495?mA?h?g(-1) , respectively. PMID:24106078

  17. Comparison of Buccal Infiltration of 4% Articaine With 1?:?100,000 and 1?:?200,000 Epinephrine for Extraction of Maxillary Third Molars With Pericoronitis: A Pilot Study

    PubMed Central

    Lima, José Lacet; Dias-Ribeiro, Eduardo; Ferreira-Rocha, Julierme; Soares, Ramon; Costa, Fábio Wildson Gurgel; Fan, Song; Sant'ana, Eduardo

    2013-01-01

    We compared the buccal infiltration of 4% articaine with 1?:?100,000 or 1?:?200,000 epinephrine without a palatal injection for the extraction of impacted maxillary third molars with chronic pericoronitis. This prospective, double-blind, controlled clinical trial involved 30 patients between the ages of 15 and 46 years who desired extraction of a partially impacted upper third molar with pericoronitis. Group 1 (15 patients) received 4% articaine with 1?:?100,000 epinephrine and group 2 (15 patients) received 4% articaine with 1?:?200,000 epinephrine by buccal infiltration. None of the patients in group 1 reported pain, but 3 patients in group 2 reported pain, which indicated a need for a supplementary palatal injection. The palatal injections were all successful in eliminating the pain. Two additional patients in group 2 experienced pain when the suture needle penetrated their palatal mucosa. Based on these results, 4% articaine with 1?:?100,000 epinephrine was found to be more effective for the removal of upper third molars in the presence of pericoronitis than 4% articaine hydrochloride with 1?:?200,000 epinephrine when only a buccal infiltration was used. PMID:23763558

  18. The Hall Technique; a randomized controlled clinical trial of a novel method of managing carious primary molars in general dental practice: acceptability of the technique and outcomes at 23 months

    PubMed Central

    Innes, Nicola P; Evans, Dafydd JP; Stirrups, David R

    2007-01-01

    Background Scotland has high levels of untreated dental caries in primary teeth. The Hall Technique is a simplified method of managing carious primary molars using preformed metal crowns (PMCs) cemented with no local anaesthesia, caries removal or tooth preparation. This study compared the acceptability of the Hall Technique for children, their carers, and dentists, and clinical outcomes for the technique, with conventional restorations. Methods General dental practice based, split mouth, randomized controlled trial (132 children, aged 3–10). General dental practitioners (GDPs, n = 17) in Tayside, Scotland (dmft 2.7) placed conventional (Control) restorations in carious primary molars, and Hall Technique PMCs on the contralateral molar (matched clinically and radiographically). Dentists ranked the degree of discomfort they felt the child experienced for each procedure; then children, their carers and dentists stated which technique they preferred. The teeth were followed up clinically and radiographically. Results 128 conventional restorations were placed on 132 control teeth, and 128 PMCs on 132 intervention teeth. Using a 5 point scale, 118 Hall PMCs (89%) were rated as no apparent discomfort up to mild, not significant; for Control restorations the figure was 103 (78%). Significant, unacceptable discomfort was recorded for two Hall PMCs (1.5%) and six Control restorations (4.5%). 77% of children, 83% of carers and 81% of dentists who expressed a preference, preferred the Hall technique, and this was significant (Chi square, p < 0.0001). There were 124 children (94% of the initial sample) with a minimum follow-up of 23 months. The Hall PMCs outperformed the Control restorations: a) 'Major' failures (signs and symptoms of irreversible pulpal disease): 19 Control restorations (15%); three Hall PMCs (2%) (P < 0.000); b) 'Minor' failures (loss of restoration, caries progression): 57 Control restorations (46%); six Hall PMCs (5%) (P < 0.000) c) Pain: 13 Control restorations (11%); two Hall PMCs (2%) (P = 0.003). Conclusion The Hall Technique was preferred to conventional restorations by the majority of children, carers and GDPs. After two years, Hall PMCs showed more favourable outcomes for pulpal health and restoration longevity than conventional restorations. The Hall Technique appears to offer an effective treatment option for carious primary molar teeth. Trial registration number Current Controlled Trials ISRCTN47267892 – A randomized controlled trial in primary care of a novel method of using preformed metal crowns to manage decay in primary molar teeth: the Hall technique. PMID:18096042

  19. Comparative Evalution of G bone (Hydroxyapatite) and G-Graft (Hydroxyapatite with Collagen) as Bone Graft Material in Mandibular III Molar Extraction Socket

    PubMed Central

    Panday, Vijayendra; Upadhyaya, Vivekananda; Jain, Kapil; Sah, Nupur; Sarathi, Partha; Swami, Pushp Chander

    2015-01-01

    Background: Bone grafting is a dynamic phenomenon. It is a surgical procedure that replaces missing bone with material either from patient’s own body, or, an artificial, synthetic or natural substitute. A successful bone graft when applied, heals, becomes incorporated, re-vascularises and eventually assumes the form desired. Aims and Objective: The main purpose of this present study was to radiologically assess and compare the regenerative potential of hydroxyapatite with Collagen (G-Graft) and hydroxyapatite (G-Bone) and to evaluate the clinical usefulness of these materials to enhance bone healing in third molar extraction sites through bone formation. Materials and Methods: The study was carried out in the Department of Oral & Maxillofacilal Surgery, patients were divided into three groups. The rationale for assigning the patients to the groups was strictly random: Group I – G-Graft (Hydroxyapatite with Collagen) was used as Bone graft material, Group II – Bone graft material used was G-Bone (Hydroxyapatite), Group III—control group (no grafts was used). Orthopentomogram(OPG) images were taken intra-operatively, just after extraction in the Group III (control), after extraction but before graft placement in Group I & II (study groups) and post-operatively at the end of first month and third month. Bone density of the post-extraction sockets was measured at four random areas through ‘densitometric analysis’ software in the OPG program (Kodak 8000C Digital Panoramic System, Eastman Kodak Company) and an average value was recorded at each review. Results: The percentage increase in bone density between 1st month & 3rd month was 7.55± 12.43 in Group I (G Graft), 4.41± 5.4859 in Group II (G Bone), while that Group III (control) was found to be -0.82 ± 3.96. The bone density increase was found to be statistically highly significant (p<0.01)) between all groups. Conclusion: The present study concluded that G-Graft has a definite regenerative potential and is better than G-bone and can be used in bony defects to enhance the bone healing without provoking any significant inflammatory process. The study also indicates that defects treated with G-Graft attain more density initially and that G-Graft enhances bone healing in early stage. PMID:25954705

  20. A randomized clinical trial compared the effect of intra-alveolar 0.2 % Chlorohexidine bio-adhesive gel versus 0.12% Chlorohexidine rinse in reducing alveolar osteitis following molar teeth extractions

    PubMed Central

    Alqahtani, Abdullah; Abu-Hasna, Mohammed; Alhokail, Ahmed; Aladsani, Ammar

    2015-01-01

    Objectives: To evaluate socket healing, incidence of acute alveolar ostieitis (AO) and associated pain following single molar tooth extraction in patients who receive intra-alveolar 0.2% chlorhexidine (CHX) gel, and those who rinsed with 0.12 % CHX rinse. Study Design: A prospective randomized clinical trial was conducted on two parallel groups of patients. Group1 (141 patients): Rinsed with 0.12 % CHX rinse from the second postoperative day, two times daily for a week. Group2 (160 patients): Who had direct intra-alveolar application of 0.2% CHX gel and day 3 post-operatively. The socket was evaluated 3 and 7 day post operatively for the presence of AO by checking probing tenderness in the socket, empty socket, food debris, halitosis and pain assessment by VAS. Results: Forty-eight AO cases were diagnosed out of 301 extractions (15.9%). In Group1, 25 cases were found (17.7%) while 23 cases were found in Group2 (14.4%). The difference was not statistically significant (p=0.428). Presence of empty socket and food debris in Group1 were higher than in Group2 but the difference was not statistically significant (p= 0.390 & p = 0.415). Occurrence of halitosis in Group2 was more than Group1, but the difference was not significant (p= 0.440). Statistical significance was found between AO in extraction done by root separation (29%) and those routinely extracted (12.3 %) (p=0.001). Conclusions: Postoperative evaluation of molar extraction sockets that received direct intra-alveolar application of 0.2% CHX gel showed insignificant less occurrence of AO when compared with 0.12 % CHX rinse. Key words:Chlorhexidine rinse, bio adhesive gel, alveolarosteitis, dry socket, molar teeth extraction, post-extraction socket. PMID:25475768