Comparative analysis of reflection photoelasticity in mandible’s segment with or without base

Introduction and Objective: To analyze if axial loads of 50 N and 100 N, applied on an implant of 3.75 X 10 mm (Conexão-Jaú, SP, Brazil) fixed on the central portion of a prototype of the mandible with and without support base, generate isochromatic fringes of different intensity and ways. Material and methods: The sample was a segment of the mandible with 115 mm in length, 30 mm height,and 12 mm in thickness, from a block of #7 rose wax. This matrix was adapted to a modified articulator in such way that its base could or not keep contact with the lower arm of the articulator, simply by modifying the support axis. An implant was put perpendicular to the segment of the mandible’s body and then the photoelastic model obtained. The healing abutment was screwed to the implant to receive loads from 50 N to 100 N, with the model with or withoutcontact of its base with the inferior arm of the articulator. Results: Alterations in the reflections of the colors was observed when the implants had been submitted to loads of 50 N and 100 N with or without supported base. Conclusion: Based on the results, it can be concluded that during the photoelasticity analyses alterations in the color standards occurred depending on the support of the sample and the applied load.Introduction and Objective: To analyze if axial loads of 50 N and 100 N, applied on an implant of 3.75 X 10 mm (Conexão-Jaú, SP, Brazil) fixed on the central portion of a prototype of the mandible with and without support base, generate isochromatic fringes of different intensity and ways. Material and methods: The sample was a segment of the mandible with 115 mm in length, 30 mm height,and 12 mm in thickness, from a block of #7 rose wax. This matrix was adapted to a modified articulator in such way that its base could or not keep contact with the lower arm of the articulator, simply by modifying the support axis. An implant was put perpendicular to the segment of the mandible’s body and then the photoelastic model obtained. The healing abutment was screwed to the implant to receive loads from 50 N to 100 N, with the model with or withoutcontact of its base with the inferior arm of the articulator. Results: Alterations in the reflections of the colors was observed when the implants had been submitted to loads of 50 N and 100 N with or without supported base. Conclusion: Based on the results, it can be concluded that during the photoelasticity analyses alterations in the color standards occurred depending on the support of the sample and the applied load

Epigenetic and genetic approach to the transmissibility of dental characteristics in twins: Report of two cases

Transmissibility of dental and jaw characteristics is strongly influenced by environmental factors during the years of extra uterine life when odontogenesis occurs. Through biochemical factors, such as enzymes, proteins, hormones and other mediators, genes are activated or silenced to suit the cell or organism to its environment. These changes are not transmitted to our descendants, because of that, these factors are called epigenetic. Among the most cited epigenetic factors are food, pollution, drugs and exercise. The objective of this study was to assess the transmissibility of dental characteristics in two pairs of twins. In one case, 13-year-old boys had the same basic dental and jaw characteristics with prolonged retention of the second upper deciduous molars and the presence of permanent successors. In the other case, 14-year-old boys had prolonged retention of lower deciduous second molars and absence of permanent successors, but only one of them had the germs of third lower molars. The phenotypic difference in the dentition of twins from clinical case 2 could be due to epigenetic factors, showing the absence of genetic determinism in the transmissibility of dental characteristics

Epigenetic and genetic approach to the transmissibility of dental characteristics in twins: report of two cases

Transmissibility of dental and jaw characteristics is strongly influenced by environmental factors during the years of extra uterine life when odontogenesis occurs. Through biochemical factors, such as enzymes, proteins, hormones and other mediators, genes are activated or silenced to suit the cell or organism to its environment. These changes are not transmitted to our descendants, because of that, these factors are called epigenetic. Among the most cited epigenetic factors are food, pollution, drugs and exercise. The objective of this study was to assess the transmissibility of dental characteristics in two pairs of twins. In one case, 13-year-old boys had the same basic dental and jaw characteristics with prolonged retention of the second upper deciduous molars and the presence of permanent successors. In the other case, 14-year-old boys had prolonged retention of lower deciduous second molars and absence of permanent successors, but only one of them had the germs of third lower molars. The phenotypic difference in the dentition of twins from clinical case 2 could be due to epigenetic factors, showing the absence of genetic determinism in the transmissibility of dental characteristics

Recuperação da dimensão vertical em pacientes com parafunção severa

The association between emotional stress and intense bruxism has as consequence the Temporomandibular Disorder (TMD), which is an increasingly apparent problem at the dental clinic, requiring judicious means of diagnosis and especially treatment.. Several factors, of equivalent importance, may be related to the DTM, one of them is the loss of vertical dimension of occlusion (VDO), and parafunctional habits and also the loss of stable contacts between the posterior teeth or lack thereof, which generates an increase functional anterior teeth for excessive wear or buccal and consequent.. This paper proposes using a clinical case, to present and discuss the steps for clinical diagnosis, planning and execution of oral rehabilitation with Fixed Partial Denture for restoring vertical dimension of occlusion in a patient with severe parafunction.. Oral rehabilitation of these patients should be carefully planned, respecting the functional and aesthetic aspects.. The parafunction control by monitoring the Temporomandibular Disorder is essential to the longitudinal prediction of rehabilitation performed in these types of rehabilitative treatment.A associação entre o estresse emocional e o bruxismo intenso, tem como conseqüência a Disfunção Temporomandibular (DTM), que representa um problema cada vez mais frequente na clínica odontológica, exigindo meios criteriosos de diagnóstico e, principalmente, de tratamento.. Diversos fatores, de equivalente importância, podem estar relacionados com a DTM, um deles é a alteração da Dimensão Vertical de Oclusão (DVO), sendo os hábitos parafuncionais e também a perda de contatos estáveis entre os dentes posteriores ou ausência dos mesmos, o que gera um aumento funcional excessivo aos dentes anteriores e conseqüente desgaste ou vestibularização.. Este trabalho se propõe através de um caso clínico, a apresentar e discutir as etapas clínicas para diagnóstico, planejamento e execução da reabilitação oral com Prótese Parcial Fixa para o restabelecimento da dimensão vertical de oclusão em paciente com parafunção severa.. A reabilitação Oral destes pacientes deve ser rigorosamente planejada, respeitando os aspectos funcionais e estéticos.. O controle da parafunção mediante o acompanhamento da Disfunção Temporomandibular é essencial ao prognóstico longitudinal da reabilitação executada nestes tipos de tratamento reabilitadores

Influence of Different Base Thicknesses on Maxillary Complete Denture Processing: Linear and Angular Graphic Analysis on the Movement of Artificial Teeth

Objective: The purpose of this study was to compare the dental movement that occurs during the processing of maxillary complete dentures with 3 different base thicknesses, using 2 investment methods, and microwave polymerization.Methods: A sample of 42 denture models was randomly divided into 6 groups (n = 7), with base thicknesses of 1.25, 2.50, and 3.75 mm and gypsum or silicone flask investment. Points were demarcated on the distal surface of the second molars and on the back of the gypsum cast at the alveolar ridge level to allow linear and angular measurement using AutoCAD software. The data were subjected to analysis of variance with double factor, Tukey test and Fisher (post hoc).Results: Angular analysis of the varying methods and their interactions generated a statistical difference (P = 0.023) when the magnitudes of molar inclination were compared. Tooth movement was greater for thin-based prostheses, 1.25 mm (-0.234), versus thick 3.75 mm (0.2395), with antagonistic behavior. Prosthesis investment with silicone (0.053) showed greater vertical change compared with the gypsum investment (0.032). There was a difference between the point of analysis, demonstrating that the changes were not symmetric.Conclusions: All groups evaluated showed change in the position of artificial teeth after processing. The complete denture with a thin base (1.25 mm) and silicone investment showed the worst results, whereas intermediate thickness (2.50 mm) was demonstrated to be ideal for the denture base

Implant-retained finger prosthesis with modified retention system

Background: Amputations affect both the physical and the psychological aspects of an individual, causing significant impact on self-esteem. The main causes of finger amputations are work-related accidents with dangerous machinery, road traffic accidents, and animal bites, as well as systemic diseases such as diabetes. This report aims to describe a simple technique for fabrication of implant-retained finger prosthesis with a modified base of the retention system.Case Description and Methods: The O-Ring retention system was used with a modified hexagon-shaped base and a metallic capsule adapted to the acrylic resin to attach the prosthesis to the implant.Findings and Outcomes: The prosthesis was made with silicone, and after osseointegration, it was installed without complications, leading to a patient satisfied with the end result and encouraged to return to social life

Cerâmicas odontológicas: propriedades, indicações e considerações clinicas

The demand for esthetic restorations has resulted in an increased use of dental ceramics and is the main alternative restorative material to tooth structure due to its favorable properties. Therefore, the aim of this work is to study the evolution of ceramic systems, involving different types and properties, indications, and clinical issues as aesthetic, cementing and longevity. In a detailed and advanced search in the database PubMed, 98 articles were found using the following key words: dental porcelain dental all-ceramic and ceramic according to the criteria for inclusion and exclusion left only 35 articles for review. Several ceramic systems are available in the market, making the prosthetic professionals need a constant recycling about their properties and directions, since good results are due to the selection of the best material for a particular case in all the skill of the practitioner.A demanda por restaurações estéticas tem resultado em um aumento do uso de cerâmicas dentais, constituindo a principal alternativa de material restaurador para a estrutura dental devido as suas propriedades favoráveis. Com isso, o objetivo desse trabalho será estudar, através de uma revisão de literatura, a evolução dos sistemas cerâmicos, envolvendo os diferentes tipos e propriedades, indicações e considerações clínicas. Em uma busca detalhada e avançada no banco de dados PubMed, foram encontrados 98 artigos utilizando os seguintes descritores: dental porcelain, dental ceramic e all-ceramic, de acordo com os critérios de inclusão e exclusão restaram apenas 35 artigos para a revisão. Diversos sistemas cerâmicos estão disponíveis no mercado, fazendo com que os profissionais da área protética necessitem de uma constante reciclagem acerca das suas propriedades e indicações, visto que bons resultados são devidos à seleção do melhor material para determinado caso em conjunto à habilidade do profissional

Planejamento reverso em implantodontia: relato de caso clínico

The oral rehabilitation has achieved great prominence in the dental implant, especially in the cases of reposition of units dental elements, so it is possible to replace each missing element to implant into your space where the tooth was loss. The reverse planning is fundamental to an appropriate rehabilitation, because promote the elimination of problems that might compromise the aesthetics and function of future dental implants. The objective of this study was to report the treatment plan for a patient in need of oral rehabilitation with implant dental prosthesis, using indications and techniques based on the literature, emphasizing the importance of reverse planning. We conducted an osseointegrated implant surgery using the principles of a connect procedure, thus allowing their successfully installing increasing the predictability of treatment. It is concluded that the success of rehabilitation treatment is directly related to the initial planning, a correct clinical approach and an integrated multidisciplinary team.As reabilitações orais tem atingido grande destaque na implantodontia, principalmente quando se trata de elementos unitários a serem repostos, pois desse modo é possível substituir cada elemento perdido com implante no respectivo espaço onde houve a perda dental. O planejamento reverso do tratamento reabilitador é de suma importância, promovendo a eliminação de problemas que possam comprometer a estética e função das futuras restaurações implantossuportadas. Assim, o objetivo do presente trabalho foi relatar o plano de tratamento de uma paciente que necessita de reabilitação oral com próteses implantossuportadas, seguindo técnicas e indicações baseadas na literatura, enfatizando a importância do planejamento reverso. Realizou-se uma cirurgia com implantes osseointegráveis seguindo os princípios de uma correta instalação, ampliando-se a previsibilidade de tratamento. Concluiu-se que o sucesso do tratamento reabilitador está diretamente relacionado com o planejamento inicial, uma correta abordagem clínica e uma equipe multi-integrada

Análise por computação gráfica das alterações produzidas em próteses totais superiores imersas diretamente em água e pela termociclagem

Objectives: This study aimed to assess dimensional changes in acrylic resin base and artificial teeth position after water storage and thermocycling using computer graphics measurements. Methods: Twenty-four waxed replicas were obtained from a previous upper complete denture. For linear measurements, points in cusps tips of left central incisor and second premolars and molars were marked in one of the prostheses with graphite and transferred to the others using an acrylic resin guide. The prostheses were scanned after waxing, polymerization and treatments and the images were exported to “AutoCad 2002 Today®” software for measurements. Results: There was no statistically significant difference in changes of each segment for each group and between the phases evaluated after polymerization and thermocycling. In groups I and III, the values after polymerization are higher than those after treatment, which suggests shrinkage while the prostheses in group II have expanded. Conclusion: The three groups exhibited artificial teeth movement after tests in comparison to the polymerized prosthesis. The prostheses submitted to water storage in kiln at 36ºC during seven days showed different behavior than the other groups.Utilizando a metodologia da mensuração por computação gráfica, a proposta do presente trabalho é verificar se ocorrem alterações dimensionais das bases de resina acrílica, modificando a posição dos dentes artificiais, quando as mesmas são submetidas à imersão direta em água por tempos predeterminados e à simulação de uso por termociclagem. A partir de uma prótese total maxilar construída previamente, foram obtidas 24 réplicas em cera. Para as mensurações lineares, foram demarcados pontos nas pontas de cúspides dos segundo molares e pré-molares e incisivo central esquerdo em uma das próteses, evidenciados com grafite e transferidos para as outras através de um guia de resina acrílica. As próteses foram digitalizadas em cera, após a polimerização e após os tratamentos, e estas imagens exportadas para o programa “AutoCad 2002 Today®” onde foram feitas as mensurações. Concluiu-se que não houve diferença estatística significante nas alterações de cada segmento, dentro de cada grupo, entre as fases “polimerizada” e “final”, após os testes. Nos três grupos, ocorreram alterações nas posições dos dentes artificiais após os testes realizados, quando comparados com as próteses polimerizadas. As próteses que permaneceram em água destilada em estufa a 36°C durante sete dias tiveram um comportamento diferente dos demais grupos