Resumo O objetivo deste estudo foi avaliar a adaptação marginal vertical e horizontal de infraestruturas de prótese fixas de três elementos confeccionadas por diferentes técnicas e diferentes sistemas CAD/CAM. Um total de 40 infraestruturas foram confeccionadas e divididas em quatro grupos: fundição por cera perdida (G1); fundição por cera perdida com ponto de solda (G2); escaneamento óptico extraoral para escaneamento do modelo (3S/DWOS); escaneamento óptico intraoral (Cerec Bluecam/Sirona) (G4). Uma matriz metálica foi utilizada para simular uma prótese fixa de três elementos (com pôntico central). As infraestruturas do G1 e G2 foram fundidas em liga metálica de níquel-cromo (NiCr), enquanto que as infraestruturas de G3 e G4 foram fresadas em zircônia. Todos os grupos foram analisados quanto à adaptação marginal vertical e horizontal (sobrecontorno e subcontorno) em microscópio óptico tridimensional (Quick Scope, Mitutoyo). Os resultados apresentaram maiores valores de desadaptação marginal vertical no G1 comparados aos outros grupos (p<0,001). Em relação a desadaptação marginal horizontal, maiores valores de sobrecontorno foram observado no G3 em comparação com os demais grupos (p<0,001). Não foi observado valores de subcontorno para o G3, enquanto que os demais grupos não apresentaram diferença significante para o subcontorno (p> 0,05). Dentro das limitações do presente estudo, pode-se concluir que a técnica convencional após ponto de solda é uma alternativa viável para confecção de infraestruturas de próteses fixas de três elementos comparado ao uso de sistemas CAD/CAM, uma vez que as técnicas apresentaram valores de adaptação marginal vertical similares. Os sistemas CAD/CAM extraoral apresentou o maior desajuste horizontal (sobrecontorno) em comparação com outros grupos.

Abstract The aim of this is was evaluate the vertical and horizontal marginal adaptation of 3-unit fixed partial denture frameworks fabricated using different techniques and CAD/CAM systems. A total of 40 framework specimens were fabricated and divided into four groups as follows: lost-wax casting (G1); lost-wax casting with welding (G2); extraoral optical scanning of models (3S/DWOS) (G3); intraoral optical scanning (Cerec Bluecam/Sirona) (G4). A reference model was used to simulate a fixed partial denture with three elements (with a central pontic). The frameworks of G1 and G2 were cast in nickel-chromium (NiCr) alloy, whereas those of G3 and G4 were milled in zirconia. In all groups, vertical and horizontal marginal adaptation (over-contour and under-contour) was evaluated using a three-dimensional optical microscope (Quick Scope, Mitutoyo). The results showed higher vertical marginal misfit in G1 than in the other groups (p<0.001). Regarding horizontal marginal misfit, higher over-contour values occurred in G3 than in the other groups (p<0.001). G3 did not show under-contour at all, whereas the other groups did not differ from each other in this regard (p>0.05). Within the limitations of this study, it can be concluded that lost-wax casting with welding is a viable alternative to the use of CAD/CAM systems to fabricate frameworks of three-unit FPDs, since the techniques yielded similar vertical misfit values. Extra-oral CAD/CAM systems showed the highest horizontal misfit (over-contour) compared to other groups.

ResumoIntroduçãoOs materiais restauradores provisórios são amplamente utilizados, porém pouco se sabe a respeito de sua estabilidade de cor.ObjetivoAvaliar a estabilidade de cor de materiais restauradores provisórios: resina acrílica e resinas bisacrílicas, após a imersão em soluções pigmentantes, durante diferentes períodos de armazenamento.Material e métodoQuatro materiais foram testados (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) sendo confeccionadas 30 amostras (15 mm de diâmetro e 2 mm de espessura) por material. Estes foram divididos de acordo com o meio de imersão (saliva artificial, saliva + refrigerante tipo cola e saliva + café) e período de armazenamento (2, 5, 7 e 15 dias). As mensurações de cor foram realizadas antes e após as imersões, com auxílio de um espectrofotômetro, através do sistema CIE L*a*b*. Os dados foram analisados com análise de variância (ANOVA) e Tukey, com nível de significância à 5%.ResultadoA resina acrílica apresentou maior estabilidade de cor quando comparada às resinas bisacrílicas (p<0,001). Comparando as resinas bisacrílicas, não foi observado diferença significativa entre as resinas Structur e Luxatemp (p=0,767). Em relação as soluções testadas, o café apresentou os maiores valores de alteração de cor (p<0,001), sendo que quanto maior o período de armazenamento, maior foi a alteração de cor de todos os materiais provisórios analisados (p<0,001).ConclusãoA resina acrílica apresentou maior estabilidade de cor, quando comparada às bisacrílicas. O café causou a maior alteração de cor, e o tempo de imersão foi determinante na estabilidade de cor dos materiais provisórios analisados.

AbstractIntroductionTemporary restorative materials are widely used, however, little is know about their color stability.Objectiveto evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage.Material and methodFour materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) and 30 test specimens (15 mm in diameter and 2 mm thick) per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee) and storage time intervals (2, 5, 7 and 15 days). Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%.ResultAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767). As regards solutions tested, coffee showed the highest color change values (p<0.001), and the longer the storage time interval, the greater was the color change in all the temporary restorative materials analyzed (p<0.001).ConclusionAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

A proposta deste estudo foi avaliar a influência da altura da coroa de implantes de hexágono externo sobre o deslocamento e distribuição de tensões para o sistema implante/osso utilizando o método de elementos finitos. Os softwares InVesalius e Rhinoceros 4.0 foram usados para gerar o modelo de osso por meio de uma tomografia computadorizada. Cada modelo foi composto de um bloco ósseo com um implante (3.75 x 10.0 mm) com conexão de hexágono externo e coroas de 10 mm, 12.5mm e 15 mm em altura. Uma carga axial de 200 N e oblíqua (45°) de 100 N foram aplicadas. Os modelos foram resolvidos pelo software NeiNastram 9.0 e Femap 10.0 para obtenção dos resultados que foram visualizados por meio de mapas de deslocamento, de von Mises (coroa/implante) e tensão máxima principal (osso). A altura da coroa sob carga axial não influenciou o deslocamento e concentração de tensões, enquanto que a carga oblíqua aumentou a ação destes fatores. A maior concentração de tensões foi observada no pescoço do parafuso do implante no lado oposto à aplicação de carga. Esta tensão foi transferida para a interface coroa/plataforma/interface óssea. Os resultados deste estudo sugerem que o aumento da coroa amplia a concentração de tensões no tecido ósseo/implante, aumentando o deslocamento no tecido ósseo, principalmente sob carga oblíqua.

The purpose of this study was to assess the influence of the crown height of external hexagon implants on the displacement and distribution of stress to the implant/bone system, using the three-dimensional finite element method. The InVesalius and Rhinoceros 4.0 softwares were used to generate the bone model by computed tomography. Each model was composed of a bone block with one implant (3.75x10.0 mm) with external hexagon connections and crowns with 10 mm, 12.5 mm and 15 mm in height. A 200 N axial and a 100 N oblique (45°) load were applied. The models were solved by the NeiNastran 9.0 and Femap 10.0 softwares to obtain the results that were visualized by maps of displacement, von Mises stress (crown/implant) and maximum principal stress (bone). The crown height under axial load did not influence the stress displacement and concentration, while the oblique loading increased these factors. The highest stress was observed in the neck of the implant screw on the side opposite to the loading. This stress was also transferred to the crown/platform/bone interface. The results of this study suggest that the increase in crown height enhanced stress concentration at the implant/bone tissue and increased displacement in the bone tissue, mainly under oblique loading.

A sentinel study on viral hepatitis is currently being carried out in the village of Cavunge in a semiarid rural region of the state of Bahia, northeastern Brazil. This study has identified individuals in whom anti-HBc IgG was the only serological marker for hepatitis B virus (HBV). This serological pattern may constitute evidence of occult HBV infection. This study Investigated the possibility of occult hepatitis B virus infection in individuals in a rural community who tested positive for anti-HBc IgG alone. A cross-sectional population-based study. ELISA III was performed on serum samples to test for serological viral markers, and ultrasensitive PCR (US-PCR) was used to assess viremia. Among the 1,536 serum samples, 3.6% (n=55) were positive for anti-HBc alone. Four years after this first serological survey, 31 of those 55 individuals (56.3%) were retested, and 11 (35.5%) remained anti-HBc positive alone. Two of these 31 (6.5%) were HBV-DNA positive based on US-PCR, with normal aminotransferase levels in both cases. Cases of occult hepatitis B infection were identified in this semiarid rural community of northeastern Brazil, where endemicity of HBV is moderate.

Relata-se um caso de espondilodiscite por Brucella em um paciente do sexo masculino, 56 anos, fazendeiro, com manifestações sistêmicas da doença. O diagnóstico foi realizado por sorologia com título de 1/160, hemocultura positiva, o VHS foi elevado, bem como alterações radiológicas mostraram espondilodiscite ao nível de T8/T9 compatíveis com a patologia. O paciente foi tratado com estreptomicina 1gIM/dia por 15 dias, doxaciclina e rifampicina por seis semanas, com melhora clínica do quadro. O envolvimento vertebral na brucelose é uma complicação de ocorrência variável na literatura, mas considerado pouco freqüente, de difícil diagnóstico principalmente em regiões com alta prevalência de tuberculose, visto que esta pode mimetizar o quadro de brucelose. Chama-se atenção a um caso raro de espondilodiscite por brucelose, dada a necessidade de diagnóstico precoce e tratamento a fim de se evitar possíveis seqüelas.

A case of spondylodiscitis due to Brucella with systematic manifestation of the disease, in a 56-year-old male patient who was a farmer, is reported. The diagnosis was made from serological tests, with a titer of 1/160. The blood culture was positive and the blood sedimentation rate was high. Radiological abnormalities showed spondylodiscitis at the T8/T9 level that were compatible with this disease. The patient was treated with streptomycin at 1g IM/day for 15 days, and doxycycline plus rifampicin for six weeks, with a clinical improvement in the condition. Vertebral involvement in brucellosis is a complication of variable occurrence in the literature. However, it is considered to be infrequent and difficult to diagnose, particularly in regions with high prevalence of tuberculosis, given that this may mimic conditions of brucellosis. Attention is drawn to this rare case of spondylodiscitis due to brucellosis, given the need for early diagnosis and treatment in order to avoid possible sequelae.

In the village of Cavunge, located in a dry tropical, semiarid rural region of the state of Bahia, Brazil, a sentinel study on viral hepatitis is underway. We report on the first part of the study. The objective of this study was to determine the prevalence of serological markers for hepatitis A, B and C in the village. Cross sectional study. Blood samples were tested for serological markers of hepatitis A (HAV), B (HBV) and C (HCV) through ELISA-III assay. In HBsAg and anti-HCV carriers, HCV-RNA and HBV-DNA were checked by PCR. The prevalence of anti-HAV IgG was 83.3% (1,210/1,452), being higher among residents from the village (87.4%) than in residents from the rural area (79.5%); it also higher among individuals older than 10 years of age. The prevalence of HBsAg was 2.6% (38/1,476), 9.3% anti-HBc (137/1,476) and 10.5% (155/1,476) anti-HBs of. In more than half (58.1%; 90/155) of anti-HBs carriers, this was the only serological marker found. In 3.7% of the population, (55/1,476), anti-HBc was the only serological marker found. All HBV carriers were infected by genotype A. Only 0.4% (6/1,536) presented anti-HCV antibodies and only one of them was viremic, being infected with genotype 1. The prevalence of patients with antibodies against hepatitis A virus in the village of Cavunge was high, but the prevalence of B virus was moderate, with only genotype A among HBV carriers. The prevalence of C virus was very low, contrasting with the situation in large Brazilian urban centers.