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The temporomandibular muscle dysfunction is characterized by myofascial pain and is more prevalent in women of reproductive age. Sex steroid hormones are hypothetically involved in the dysfunction, but few are the studies of steroid receptors in masticatory and mastication-related muscles. Our aim was to determine estrogen and testosterone receptor expression in rat masticatory and mastication-related muscles within the context of age and gender. Twelve rats were equally divided into four groups: (a) 10-month-old females; (b) 10-month-old males; (c) 24-month-old females; and (d) 24-month-old males. Euthanasia of the females was performed in the proestrous phase (vaginal smears) and the masticatory and accessory muscles were removed for immunohistochemical analysis. Statistical analysis was performed with ANOVA and the Tukey test. Estrogen receptor expression was similarly low in all muscles and groups. Testosterone receptor expression in the Masseter muscle of the 24-month-old male rats was higher than that in the other groups and significantly superior to its expression in the Posterior Digastric muscle. In short, testosterone receptor expression was highest in old male rats. If we generalize to humans, this fact could indicate age- and sex-related hormonal influence on temporomandibular muscle dysfunction. Further studies, however, are necessary to strengthen this hypothesis.

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OBJECTIVE: The aim of this review was to update the literature with regard to the digital methods available by CEREC Chairside system to register and design the occlusion, to report their efficacy and technical innovations in the field of Restorative Dentistry. A search strategy was performed using the key-words: "virtual articulator," or "CAD-CAM and occlusal recording," or "CAD-CAM and occlusion register," or "CAD-CAM and occlusal contacts," or "CAD-CAM and prosthesis." MATERIAL AND METHODS: Inclusion criteria comprised studies evaluating the use of digital methods available by CEREC System for occlusal registration and design during prosthodontics treatment. PubMed and Cochrane library and reference lists were searched up to January 2016. RESULTS: The search resulted in 280 articles after removing duplicates. Subsequently, 233 records were excluded and 49 studies were selected for reading in full. Eleven articles were considered eligible for the systematic review (4 in vitro and 7 clinical studies). CONCLUSION: Scientific evidence suggests that digital methods were accurate to register and design the occlusion of dental prostheses. Nevertheless, further clinical studies are required to establish a conclusion with regard to its accuracy in prosthodontics treatment. CLINICAL SIGNIFICANCE: Digital technologies allow the design of occlusal surfaces of CAD-CAM fabricated prostheses using innovative approaches. This systematic review aimed to update the literature to help dentists determine the most appropriate digital method to register and design the occlusal surface of CAD-CAM crowns. (J Esthet Restor Dent 28:208-220, 2016).

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Since the dental implant/abutment interface cannot totally seal the passage of microorganisms, the interior of implant becomes a reservoir of pathogenic microorganisms that produce and maintain chronic inflammation in the tissues around implants. Silver nanoparticles (nano-Ag) are potent and broad-spectrum antimicrobial agents. The aim of this study was to evaluate the capacity of the nano-Ag to prevent the contamination of the implant internal surface by Candida albicans, caused by the implant/abutment microgap infiltration. Thirty-six implants were used in this experiment. Three study groups were performed: experimental group (implants receiving an application of nano-Ag in their inner cavity before installation of the abutment); positive-control group (implants receiving sterile phosphate buffer saline application instead of nano-Ag) and negative-control group (implants receiving the application of nano-Ag in the inner cavity and immersed in a sterile medium). In the positive-control and experimental groups, the implants were immersed in a Candida albicans suspension. The abutments of all three groups were screwed with a 10 N torque. After 72 h of immersion inC. albicans suspension or sterile medium, the abutments were removed and the inner surface of the implants was sampled with absorbent paper cone for fungal detection. No C. albicans contamination was observed in the negative-control group. The positive-control group showed statistically higher values of colony forming units (CFUs) of C. albicans compared with the experimental group. In conclusion, silver nanoparticles reduced C. albicans colonization inside the implants, even with low torque screw abutment.

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Abstract: Since the dental implant/abutment interface cannot totally seal the passage of microorganisms, the interior of implant becomes a reservoir of pathogenic microorganisms that produce and maintain chronic inflammation in the tissues around implants. Silver nanoparticles (nano-Ag) are potent and broad-spectrum antimicrobial agents. The aim of this study was to evaluate the capacity of the nano-Ag to prevent the contamination of the implant internal surface byCandida albicans, caused by the implant/abutment microgap infiltration. Thirty-six implants were used in this experiment. Three study groups were performed: experimental group (implants receiving an application of nano-Ag in their inner cavity before installation of the abutment); positive-control group (implants receiving sterile phosphate buffer saline application instead of nano-Ag) and negative-control group (implants receiving the application of nano-Ag in the inner cavity and immersed in a sterile medium). In the positive-control and experimental groups, the implants were immersed in a Candida albicans suspension. The abutments of all three groups were screwed with a 10 N torque. After 72 h of immersion inC. albicans suspension or sterile medium, the abutments were removed and the inner surface of the implants was sampled with absorbent paper cone for fungal detection. No C. albicans contamination was observed in the negative-control group. The positive-control group showed statistically higher values of colony forming units (CFUs) of C. albicans compared with the experimental group. In conclusion, silver nanoparticles reduced C. albicans colonization inside the implants, even with low torque screw abutment.

Resumo: A interface implante/pilar não pode ser totalmente selada para passagem de microrganismos, com isso o interior do implante torna-se um reservatório de microrganismos patogênicos que promovem e mantêm a inflamação crônica nos tecidos em volta dos implantes. Nanopartículas de prata são agentes antimicrobianos potentes e de amplo espectro. O objetivo deste estudo foi avaliar a capacidade das nanopartículas de prata em evitar a contaminação porCandida albicans do interior de implantes, originada da infiltração do fungo através da interface implante/pilar. 36 implantes foram utilizados neste experimento. Três grupos de estudo foram estabelecidos: grupo experimental (os implantes receberam aplicação de nanopartículas de prata na sua cavidade interna, antes da instalação do pilar); grupo controle positivo (os implantes receberam PBS estéril em vez das nanopartículas de prata) e grupo controle negativo (implantes receberam aplicação de nanopartículas de prata na cavidade interna, mas os implantes foram imersos em meio estéril). Nos grupos controle positivo e experimental, os implantes foram imersos em suspensão deCandida albicans. Os pilares protéticos de todos os grupos foram parafusados com torque de 10 N. Após 72 h imersos na suspensão deC. albicans ou em meio estéril, os pilares foram removidos e amostras da superfície interna dos implantes foram coletadas com cone de papel absorvente para a detecção de Candida. No grupo controle negativo não foi observada contaminação por C. albicans. O grupo-controle positivo mostrou valores de unidades formadoras de colônia deCandida estatisticamente maiores quando comparado com o grupo experimental. Conclui-se que nanopartículas de prata reduzem a colonização de C. albicans dentro dos implantes, mesmo quando o pilar é parafusado com torque baixo.

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A interação entre macrófagos e a superfície do implante considera a adsorção de proteínas como primeiro acontecimento no qual determina os processos celulares consequentes e pode ser fulcral para o desenvolvimento de novas estratégias de biocompatibilidade e engenharia de tecidos. Os macrófagos além de participarem do infiltrado inflamatório em reposta durante a implantação no estado inicial da fase inflamatória, onde predominam atividades fagocitárias, também atuam na fase tardia predominante de atividades anti- inflamatórias e reparação tecidual. Eles podem ser identificados na polarização de dois fenótipos diferentes, denominados æÆclássicoÆÆ ativado (M1) ou æÆalternativoÆÆ ativado (M2). São dois subgrupos funcionais os quais apresentam quadros comportamentais inflamatórios e anti-inflamatórios. M2 pode ser ordenado em três subtipos distintos, denominados M2a, M2b e M2c, baseados, sobretudo, nos agentes de indução e expressão do marcador molecular. M2d é resultante de mediadores dependentes da adenosina do macrófago M1, que exibe um padrão de expressão do marcador distinto do IL-4 / IL-13 dependente dos macrófagos M2...

Interaction between macrophages and the implant surface considers protein adsorption as the first event in which the resulting cellular processes are determined and can be crucial for development of new strategies for biocompatibility and tissue engineering. Besides taking participating of the inflammatory infiltrate in response during deployment in the initial stage of the inflammatory phase, in which predominate phagocytic activities, macrophages also act on the predominant late stage of anti-inflammatory activity and tissue repair. They can be identified in two different polarization phenotypes, called ôclassicõ activated (M1) or ôalternativeõ activated (M2), sub-groups with inflammatory and anti-inflammatory functional behavior. M2 can be ordered in three different subtypes, named M2a, M2b, and M2c grounded mainly on inducing agents and expression of molecular marker. M2d results from macrophage mediators of adenosine M1, which exhibits a distinct pattern of expression of marker IL-4 / IL-13 dependent on the M2 macrophages...

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Silver has been used in medicine for centuries because of its antimicrobial properties. More recently, silver nanoparticles have been synthesized and incorporated into several biomaterials, since their small size provides great antimicrobial effect, at low filler level. Hence, these nanoparticles have been applied in dentistry, in order to prevent or reduce biofilm formation over dental materials surfaces. This review aims to discuss the current progress in this field, highlighting aspects regarding silver nanoparticles incorporation, such as antimicrobial potential, mechanical properties, cytotoxicity, and long-term effectiveness. We also emphasize the need for more studies to determine the optimal concentration of silver nanoparticle and its release over time.

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OBJECTIVES: To compare the prevalence of signs and symptoms of temporomandibular dysfunction (TMD) in female adolescent athletes and non-athletes and to examine the association between signs and symptoms of TMD in female adolescents in different Tanner stages. METHODS: The subjects were 89 female basketball and handball players ages 10-18 years and 72 female non-athlete adolescents ages 10-19 years selected from the Department of Pediatrics (School of Medicine, Federal University of São Paulo) as a control group. A survey was used to assess the signs and symptoms of TMD. According to the answers on the survey the adolescents were classified in two categories: no signs or symptoms present (score A-absent), at least one sign or symptom present (score P-present). The ones who got score "P" were submitted to a standardized functional examination of the masticatory system by four previously calibrated examiners. Pubertal status was assessed based on physical examination by physicians from our Division. The adolescents were classified according to Tanner stages into three subgroups: subgroup 1 (before the growth spurt), subgroup 2 (growth spurt period), subgroup 3 (end of growth spurt). Significant differences between athletes and non-athletes were assessed for categorical variables (Chi-square and Fisher's exact test) and for continuous variables (Mann-Whitney test). The level of significance used was 5%. There was significant agreement between raters, kappa-values (0.621-1.000) and ICC values (0.757-0.899). RESULTS: There was no significant difference between the athletes and non-athletes in exhibiting at least one sign or symptom of TMD (p=0.301). When comparing the adolescents who presented at least one symptom of TMD to the different subgroups of Tanner stages no statistically significant differences were found (p=0.124). CONCLUSION: The lack of significant differences among female adolescent athletes and non-athletes and among the subgroups of Tanner stages may suggests that although contact sports increase the risk of temporomandibular joint lesions and estrogen levels are risk factor for onset of TMD, they do not impact significantly on the onset of this disorder, when considered alone.

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The present study evaluated the interchangeability of prosthetic components for external hexagon implants by measuring the precision of the implant/abutment (I/A) interface with scanning electron microscopy. Ten implants for each of three brands (SIN, Conexão, Neodent) were tested with their respective abutments (milled CoCr collar rotational and non-rotational) and another of an alternative manufacturer (Microplant) in randomly arranged I/A combinations. The degree of interchangeability between the various brands of components was defined using the original abutment interface gap with its respective implant as the benchmark dimension. Accordingly, when the result for a given component placed on an implant was equal to or smaller then that gap measured when the original component of the same brand as the implant was positioned, interchangeability was considered valid. Data were compared with the Kruskal-Wallis test at 5% significance level. Some degree of misfit was observed in all specimens. Generally, the non-rotational component was more accurate than its rotational counterpart. The latter samples ranged from 0.6-16.9 µm, with a 4.6 µm median; and the former from 0.3-12.9 µm, with a 3.4 µm median. Specimens with the abutment and fixture from Conexão had larger microgap than the original set for SIN and Neodent (p<0.05). Even though the latter systems had similar results with their respective components, their interchanged abutments did not reproduce the original accuracy. The results suggest that the alternative brand abutment would have compatibility with all systems while the other brands were not completely interchangeable.

O presente estudo avaliou a intercambiabilidade dos componentes protéticos de implantes de hexágono externo medindo-se a precisão da interface implante/pilar com microscopia eletrônica de varredura. Foram utilizados dez implantes para cada uma de três marcas (SIN, Conexão, Neodent) com seus respectivos pilares (base metálica de CoCr , rotacional e não rotacional) e um de marca alternativa (Microplant) em um arranjo com todas as combinações de implante/pilar possíveis. O valor de referência para a intercambiabilidade das várias marcas de componentes foi definido pela diferença do pilar original para com seu respectivo implante. Dessa maneira, a intercambiabilidade foi considerada válida quando o resultado para um dado pilar colocado sobre um implante fosse igual ou menor que a diferença medida quando o pilar da mesma marca do implante fora posicionado. Os dados foram comparados pelo teste de Kruskal-Wallis com nível de significância de 5%. Um grau de desajuste foi observado em todos os espécimes. De uma maneira geral, o pilar anti-rotacional foi mais preciso do que o rotacional. Estes variaram de 0,6-16,9 µm, com mediana 4,6 µm; enquanto o anti-rotacional foi de 0,3-12,9 µm, com mediana de 3,4 µm. Os espécimes com o pilar e o implante Conexão tiveram uma diferença maior que o conjunto original para SIN e Neodent (p<0,05). Apesar destes últimos apresentarem resultados semelhantes com seus respectivos pilares, quando trocados não mantiveram a mesma precisão original. Os resultados sugerem que a marca alternativa seria a única que apresentaria compatibilidade com todos os sistemas, enquanto as outras marcas não seriam completamente intercambiáveis.

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The present study evaluated the interchangeability of prosthetic components for external hexagon implants by measuring the precision of the implant/abutment (I/A) interface with scanning electron microscopy. Ten implants for each of three brands (SIN, Conexão, Neodent) were tested with their respective abutments (milled CoCr collar rotational and non-rotational) and another of an alternative manufacturer (Microplant) in randomly arranged I/A combinations. The degree of interchangeability between the various brands of components was defined using the original abutment interface gap with its respective implant as the benchmark dimension. Accordingly, when the result for a given component placed on an implant was equal to or smaller then that gap measured when the original component of the same brand as the implant was positioned, interchangeability was considered valid. Data were compared with the Kruskal-Wallis test at 5% significance level. Some degree of misfit was observed in all specimens. Generally, the non-rotational component was more accurate than its rotational counterpart. The latter samples ranged from 0.6-16.9 µm, with a 4.6 µm median; and the former from 0.3-12.9 µm, with a 3.4 µm median. Specimens with the abutment and fixture from Conexão had larger microgap than the original set for SIN and Neodent (p<0.05). Even though the latter systems had similar results with their respective components, their interchanged abutments did not reproduce the original accuracy. The results suggest that the alternative brand abutment would have compatibility with all systems while the other brands were not completely interchangeable.

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A região do colar cervical do implante é constantemente exposta aos esforços mastigatórios/parafuncionais, representando uma zona em potencial à ocorrência de deformações, principalmente nos implantes de conexão interna e de reduzido diâmetro. Estas sobrecargas representam um dos fatores responsáveis pela perda óssea ao redor dos implantes. O presente estudo avaliou o comportamento do colar de implantes friccionais (Kopp) de dois diâmetros (4,3 mm e 5,5 mm) sob cargas compressivas estáticas (cêntrica e excêntrica) de duas intensidades (50 N e 100 N) por meio da Interferometria Eletrônica de Padrões de Speckle (Espi – Electronic Speckle Pattern Interferometry). A técnica Espi consiste na comparação de imagens, de antes e após o carregamento, obtidas a partir da reflexão de uma fonte de luz laser incidida sobre um objeto real de superfície rugosa, resultando em um padrão de franjas. O estudo in vitro visou testar a aplicabilidade da técnica Espi para avaliar implantes e a hipótese de que quanto maior o diâmetro do implante, maior é sua resistência ao deslocamento. Foi possível obter resultados qualitativos reprodutíveis acerca da deformação ao nível do colar do implante frente aos carregamentos, validando a técnica. Franjas horizontais foram observadas nas cargas cêntricas, demonstrando o deslocamento vertical do colar do implante e franjas diagonais nas cargas excêntricas, demonstrando o deslocamento de forma oblíqua. Estes deslocamentos podem sugerir a deformação sofrida pela amostra. A técnica Espi mostrou-se viável para avaliar as deformações da região observada e a hipótese foi confirmada, visto que no implante de menor diâmetro houve maior deformação.

The collar region of osseointegrated implants is frequently exposed to masticatory/parafunctional loads, representing a potential area subjected to deformation, especially in narrow-diameter and internal connection dental implants. This study evaluated the effect of the collar of frictional implants (Kopp) at two different diameters (4.3 mm and 5.5 mm) under static compressive loads (centric and eccentric) of two magnitudes (50 and 100 N) through the Electronic Speckle Patterns Interferometry (Espi). The Espi is a technique still little used in dentistry that consists in comparing images before and after loading, obtained from the reflection of a laser light source focused on a real object surface resulting in a fringe pattern. The in vitro study aimed to test the applicability of the ESPI technique and the hypothesis that as larger is the implant diameter, as greater is the resistance to strain at level of implant collar. It was possible to obtain reproducible qualitative results about the deformation of the implant collar when subjected to loading, validating this technique. Fringes were observed horizontally in the centric loads and diagonally in eccentric loads. These results may suggest the deformation suffered by the sample. The Espi technique was feasible to assess the deformation of the region observed and the hypothesis was confirmed, since the smaller implant diameter presented greater strain.

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Os dentes caninos, o quarto pré-molar superior, seguidos por pré-molares, molares e incisivos, são os mais acometidos por fratura. Quando há exposição pulpar, são tratados endodonticamente e restaurados. Para os dentes com grande destruição coronária, indica-se reconstrução protética coronal com metal fundido, que recebe o nome de restauração metálica fundida (RMF) e recobre toda a superfície da coroa clínica. Tais restaurações utilizam retentores intrarradiculares com núcleo e ferulação (cintamento). O retentor intrarradicular serve para aumentar a retentividade do conjunto. A base do núcleo é a estrutura do espelho, que apoia-se no remanescente coronal, sendo protegida pela férula (ou cintamento), que promove um abraçamento cervicocoronal e aumenta a resistência a possíveis novas fraturas. A ação protetora do espelho e da férula associados neutralizará o efeito de cunha causado pelos pinos intrarradiculares.(AU)

The most often fractured teeth are the upper canines, fourth pre-molars (carnassial teeth), pre-molars and incisors. In cases of pulp exposure, the animals undergo endodontic treatment and subsequent restoration of the broken tooth. When there is extensive coronal destruction, metallic coronal prostheses with molten metal, which are often called full cast metal restorations, are indicated. These cover the whole surface of the clinical crown and often make use of a cast post and core with a ferrule (crown bracing). This kind of technique improves the stability of the restoration. The mirror structure forms the base of the core, which leans on the remainder of the crown and is protected by the ferrule, which, in turn, promotes a cervico-coronal bracing that increases the resistance to new fractures. The protective effect of the association of mirror and ferrule will neutralize the bevel effect caused by the metallic post.(AU)

Los caninos, cuarto premolar superior y los premolares, molares e incisivos, son los dientes con mayor incidencia de fracturas en el perro. En los casos en que hay exposición de la pulpa, se realiza un tratamiento de endodoncia. En dientes con una gran destrucción coronaria, se indica una restauración protésica coronal con metal fundido, que normalmente es llamada restauración metálica fundida (RMF), que recubre la totalidad de la superficie de la corona. Estas restauraciones requieren de retenedores intrarradiculares con núcleo y ferulización (abrazamiento cervical). El retenedor intrarradicular sirve para aumentar la estabilidad del conjunto. La base del núcleo es la estructura “en espejo” que se apoya en el resto de la corona, que está protegida por la férula (o abrazo). Esto induce un “abrazo cérvico coronal” aumentando la resistencia a nuevas fracturas. La acción protectora asociada del espejo y de la férula, neutraliza el efecto de cuña causado por los pernos intrarradiculares.(AU)

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Os dentes caninos, o quarto pré-molar superior, seguidos por pré-molares, molares e incisivos, são os mais acometidos por fratura. Quando há exposição pulpar, são tratados endodonticamente e restaurados. Para os dentes com grande destruição coronária, indica-se reconstrução protética coronal com metal fundido, que recebe o nome de restauração metálica fundida (RMF) e recobre toda a superfície da coroa clínica. Tais restaurações utilizam retentores intrarradiculares com núcleo e ferulação (cintamento). O retentor intrarradicular serve para aumentar a retentividade do conjunto. A base do núcleo é a estrutura do espelho, que apoia-se no remanescente coronal, sendo protegida pela férula (ou cintamento), que promove um abraçamento cervicocoronal e aumenta a resistência a possíveis novas fraturas. A ação protetora do espelho e da férula associados neutralizará o efeito de cunha causado pelos pinos intrarradiculares.

The most often fractured teeth are the upper canines, fourth pre-molars (carnassial teeth), pre-molars and incisors. In cases of pulp exposure, the animals undergo endodontic treatment and subsequent restoration of the broken tooth. When there is extensive coronal destruction, metallic coronal prostheses with molten metal, which are often called full cast metal restorations, are indicated. These cover the whole surface of the clinical crown and often make use of a cast post and core with a ferrule (crown bracing). This kind of technique improves the stability of the restoration. The mirror structure forms the base of the core, which leans on the remainder of the crown and is protected by the ferrule, which, in turn, promotes a cervico-coronal bracing that increases the resistance to new fractures. The protective effect of the association of mirror and ferrule will neutralize the bevel effect caused by the metallic post.

Los caninos, cuarto premolar superior y los premolares, molares e incisivos, son los dientes con mayor incidencia de fracturas en el perro. En los casos en que hay exposición de la pulpa, se realiza un tratamiento de endodoncia. En dientes con una gran destrucción coronaria, se indica una restauración protésica coronal con metal fundido, que normalmente es llamada restauración metálica fundida (RMF), que recubre la totalidad de la superficie de la corona. Estas restauraciones requieren de retenedores intrarradiculares con núcleo y ferulización (abrazamiento cervical). El retenedor intrarradicular sirve para aumentar la estabilidad del conjunto. La base del núcleo es la estructura “en espejo” que se apoya en el resto de la corona, que está protegida por la férula (o abrazo). Esto induce un “abrazo cérvico coronal” aumentando la resistencia a nuevas fracturas. La acción protectora asociada del espejo y de la férula, neutraliza el efecto de cuña causado por los pernos intrarradiculares.

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A perda da pré-carga e o consequente afrouxamento dos parafusos de fixação das próteses sobreimplantes é uma preocupação permanente nas reabilitações protéticas, principalmente nas próteses unitárias. O objetivo deste estudo foi avaliar a influência das dimensões da conexão cônica entre o implante e o pilar protético no torque e no destorque em implantes do tipo cone-morse. Foram utilizados 20 corpos de prova divididos em dois grupos experimentais: grupo 1 – dez corpos de prova compostos de implantes do tipo Titamax Cone Morse (Neodent, de 3,75 mm de diâmetro) e dez pilares CM (Neodent); grupo 2 – dez implantes do tipo Titamax WS (Neodent, de 5,0 mm de diâmetro) sobre os quais foram aplicados dez pilares WS (Neodent). Esses pilares que são indicados para próteses unitárias parafusadas foram submetidos a torque inicial de 32 Ncm, conforme indica o fabricante, seguidos de nove tratamentos de destorque e retorques sempre em 32 Ncm. Os valores de destorque para cada pilar, dados em Ncm, foram catalogados e submetidos a testes estatísticos. Os resultados demonstraram que, para os implantes CM, houve redução na média do valor do torque, estatisticamente significante, desde a primeira aferição de destorque (30,0 ± 2,1 Ncm, p = 0,017) até a última aferição (28,87 ± 0,35 Ncm, p = 0,000). Para os implantes WS, houve um aumento estatisticamente significante na média do valor do destorque na primeira aferição (36,25 ± 1,99 Ncm, p = 0,027) e uma redução estatisticamente significante a partir da terceira aferição de destorque (31,12 ± 0,35 Ncm, p = 0,000). Foi possível concluir que o destorque inicial nos implantes WS foi maior que o torque inicial e nos implantes CM foi menor. Após o afrouxamento do pilar e retorqueamento com o mesmo torque inicial, o destorque foi menor para ambos os grupos WS e CM e que, após alguns afrouxamentos e reapertos (quatro a cinco vezes), o torque de afrouxamento manteve-se constante para os dois grupos, por volta de 28 Ncm

The loss of preload and consequent screw loosening of implant-supported prostheses is a fundamental concern in prosthetic rehabilitation, especially in single-tooth situations. The aim of this study was to evaluate the influence of implant-abutment connection dimensions on torque and detorque values of Cone Morse implants. Twenty specimens were divided into two groups: G1: 10 consisting of CM abutments connected to Titamax Morse Taper type implants (Neodent, 3.75 mm-diameter) and G2: 10 consisting of WS abutments connected to WS Titamax Morse Taper type implants (Neodent, 5.0 mm-diameter). First, the abutments were subjected to a 32 Ncm torque followed by nine measurement sets of torque/detorque values. Those values were categorized and subjected to statistical analysis. The results demonstrated that for the CM implants, there was a reduction in the average torque values, being statistically significant since the first (30,00 ± 2,13 Ncm, p = 0,017) until the last detorque measurement (28,87 ± 0,35 Ncm, p = 0,000). For WS implants, there was a statistically significant increase in the average value for the first detorque measurement (36,25 ± 1,99 Ncm, p = 0,027) and a statistically significant reduction from the third detorque measurement (31,12 ± 0,35 Ncm, p = 0,000). It was concluded that: initial detorque values for WS implants were greater than initial torque; in the CM implant, the initial detorque value was smaller than the initial torque. After abutment tightening/loosening with the same initial torque value, detorque values were lower in both groups and afterwards detorque was constant in both groups

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O objetivo deste trabalho foi avaliar as discrepâncias de assentamento de copings metálicos fundidos e sinterizados. Para tanto, foram comparados dois grupos de oito copings metálicos; um deles obtido pela técnica de fundição (NiCr) e outro pela técnica da sinterização (Ti-6Al-7Nb). Em ambos foi avaliada a adaptação dos mesmos sobre um troquel metálico com as características e medidas proporcionais a um preparo para coroa total em molar. A leitura da adaptação foi feita em oito pontos equidistantes do perímetro de cada coping por meio de um cabeçote micrométrico digital acoplado a um microscópio óptico de medição (Mitutoyo Mfg. Co., Tó-quio, Japão). Os dados obtidos foram submetidos ao teste t de Student, no qual verificou-se que a comparação entre as médias não apresentou diferenças estatisticamente significantes (t = 0,44; gL = 14; p = 0,668) ao nível de 5%. Os valores médios foram próximos e de mesma variabilidade (coeficiente de variação = 34,41 e 34,50%). Pôde-se concluir que os procedimentos de fundição ou sinterização não influenciaram na justeza de adaptação marginal dos copings metálicos e os copings de titânio, obtidos pela sinterização, podem ser uma alternativa satisfatória para a restauração de elementos protéticos.

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Na reabilitação oral protética, as técnicas e materiais são adaptações que vieram da engenharia, física e química e se adequaram muito bem na Odontologia, tornando os trabalhos protéticos cada vez mais estéticos, funcionais e resistentes. Essa interação entre as áreas é essencial para o aperfeiçoamento técnico e científico, em busca de alternativas mais precisas e eficientes. As áreas mais promissoras, atualmente, abordadas neste trabalho, são as porcelanas, a prototipagem, o laser e a bioengenharia. As pesquisas e interações com outras áreas estão muito avançadas e sugerem que os estudos continuarão até o desenvolvimento da terceira dentição permanente, contando com o desenvolvimento da bioengenharia. O objetivo deste trabalho é fazer uma revisão a respeito das novas tecnologias aplicadas em prótese dentária a fim de que o cirurgião-dentista tenha acesso às novidades e, baseado em pesquisas, possa oferecer ou indicar o melhor, mais moderno e o tratamento mais adequado ao seu paciente.

In oral prosthetic rehabilitation, the majority of techniques and materials are adaptations from engineering, physics and chemistry. They have adjusted very well in Dentistry, making the prosthetic work more aesthetic, functional and strong. This interaction between the areas is essential for the technical and scientific improvement and for the search for more accurate and effective alternatives. Currently, the most promising areas, which will be reviewed in this work, are the porcelains, prototyping, laser and bioengineering. Research and interactions with other areas are very advanced and suggest that the studies will continue until the development of the third permanent dentition, counting on the development of bioengineering. The aim of this work is to undertake a literature review on the new technologies applied in prosthodontics so that the dentist is given access to new features and, based in research, can offer or the best, more modern and more appropriate treatment to the patient.

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The purpose of this study was to compare the results of different hierarchical models in engineering analysis applied to dentistry with 2D and 3D models of a tooth and its supporting structures under 100 N occlusal loading at 45° and examine the reliability of simplified 2D models in dental research. Five models were built from computed-tomography scans: four 2D models with Plane Strain and Plane Stress State with linear triangular and quadratic quadrilateral elements and one 3D model. The finite element results indicated that the stress distribution was similar qualitatively in all models but the stress magnitude was quite different. It was concluded that 2D models are acceptable when investigating the biomechanical behavior of upper central incisor qualitatively. However, quantitative stress analysis is less reliable in 2D-finite element analysis, because 2D models overestimate the results and do not represent the complex anatomical configuration of dental structures. Therefore 3D finite element analyses of dental biomechanics cannot be simplified.

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O objetivo deste estudo foi analisar a distribuição de tensões de von Mises em uma prótese parcial fixa de três elementos em metalocerâmica e em dois sistemas de cerâmica pura através de carregamento estático aplicado em modelos matemáticos bidimensionais obtidos pelo método de elementos finitos. A partir da imagem de uma peça anatômica de estudo, os desenhos foram confeccionados e suas imagens vetorizadas foram “exportadas” para o programa MSC/PATRAN e a análise foi feita utilizando-se um carregamento de 100N distribuídos em 17 pontos das superfícies oclusais dos modelos. Em todos os modelos as maiores concentrações de tensões localizaram-se no interior dos pinos e na região médio-inferior dos conectores. Os dois sistemas cerâmicos se comportaram satisfatoriamente em comparação à metalocerâmica.

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Com o crescimento paulatino da longevidade da população, a incidência da doença de Alzheimer, que afeta, principalmente, a terceira idade, aumentou. A doença de Alzheimer afeta o cérebro, principalmente as áreas da memória e da linguagem, levando a um progressivo prejuízo dessas funções. Estudos relatam que a falta de uma mastigação eficiente pode ser um dos fatores de risco para a doença de Alzheimer. O objetivo deste estudo foi fazer uma revisão da literatura sobre a importância da mastigação e sua relação com a doença de Alzheimer.

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PURPOSE: The aim of the study was to compare the prevalence of signs and symptoms of temporomandibular dysfunction (TMD) in male adolescent athletes-basketball players and non-athletes and to examine the association between signs and symptoms of TMD in male adolescents in different Tanner stages. METHODS: The subjects were 46 male basketball players ages 10-13 years and 41 male adolescent non-athletes ages 10-18 years selected from the Department of Pediatrics (School of Medicine, Federal University of São Paulo) as a control group. A questionnaire was used to assess the signs and symptoms of TMD. According to the answers on the questionnaire the adolescents were classified in two categories: no signs or symptoms present (score A-absent), at least one sign or symptom present (score P-present). The ones who got score "P" were submitted to a standardized functional examination of the masticatory system by the same examiner. Pubertal status was assessed based on physical examination by physicians from our Division. The adolescents were classified according to Tanner stages into three subgroups: subgroup 1 (before the growth spurt), subgroup 2 (growth spurt period), subgroup 3 (end of growth spurt). Significant differences between athletes and non-athletes were assessed using non-parametric Wilcoxon test for continuous variables and the Fisher's exact test for categorical variables. The level of significance used was 5%. RESULTS: There was no significant difference between the athletes and non-athletes in exhibiting at least one sign or symptom of TMD (p=0.1148). When comparing the adolescents who presented at least one symptom of TMD to the different subgroups of Tanner Stages no statistically significant differences were found (p=0.8357). CONCLUSION: The lack of significant differences among male adolescents athletes and non-athletes may be caused by the size of the sample, the age of the athletes or by a probable protective action of testosterone levels in male athletes. The lack of statistical difference comparing the adolescents who presented at least one sign or symptom of TMD to subgroups of Tanner is probably because estrogen is the risk factor hormone and the levels of estrogen in male adolescents are very low.

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The purpose of this work was the force-displacement response analysis of the masticatory process in a dried human skull by Double-Exposure Photorefractive Holographic Interferometry Technique (2E-PRHI). The load concentration and dissipation of the forces from dried human skull were analysed at applied loading stands as a Simulation of Isolated Contraction (SIC) of some mastication muscles. The 2EHI and Fringe Analysis Method were used to obtain the quantitative results of this force-displacement response. These results document quantitatively the real biomechanical response from dried human skull under applied loading and it can be used for complementary study by finite element model and others analysis type.

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