The ceramic crowns cemented onto the customized zirconia abutments offered greater fracture resistance than ceramic crowns with customized zirconia abutments screw retained onto implants. The cyclic fatigue did not seem to influence the fracture resistance of these crowns, whether cemented or screw retained onto implants. Fracture of the veneering ceramic was the predominant failure in this study.
Introduction Sterilization methods adopted in Human Teeth Bank can promote structural changes in enamel and dentin. Thus, the ideal method should combine the antimicrobial efficacy and preservation of the substrate biomechanical properties. Aim Evaluated the morphology and physical properties of enamel and dentin of extracted human teeth, after being submitted to different sterilization methods. Method Sixteen extracted third molars were sectioned in the following tooth regions: mesio-distal, vestibular-lingual and at the cement enamel junction. Forty specimens were selected according to values of microhardness and roughness initials, and distributed in four experimental groups (n = 10/group): Group 1 = Autoclave 121 °C (30 minutes); Group 2 = 2.5% Sodium hypochlorite (07 days); Group 3 = 5.25% Sodium hypochlorite (07 days); Group 4= 30% Acetic Acid (7 days). After sterilization, the microhardness, roughness and morphology of enamel and dentin were evaluated. Data were analyzed by paired t-test, Wilcoxon, Kruskal-Wallis and Analysis of Variance. A significance level of 5% was adopted. Result All sterilization methods altered the microhardness and roughness of the dentine (p <0.05). Regarding to enamel, the microhardness was affected only by Autoclave and 2.5% Sodium hypochlorite treatment (p <0.05). A large aperture of the enamel pores and dentinal tubules was verified in the micrographs. Conclusion The sterilization methods adopted altered the morphology and/or physical properties of enamel and dentine.
Banco de dentes humanos (BDH) é uma entidade sem fins lucrativos que tem a finalidade de recepcionar, armazenar, catalogar e manter em boa conservação dentes humanos para pesquisa e treinamento laboratorial pré-clínico de estudantes. No entanto, muitos cirurgiões-dentistas desconhecem a importância do BDH. O objetivo deste estudo foi avaliar o conhecimento dos cirurgiões-dentistas das Unidades Básicas de Saúde (UBS) do município de Teresina/PI sobre condutas diversas relacionadas aos BDHs. O presente estudo é do tipo observacional com amostragem probabilística estratificada com alocação proporcional, que utilizou entrevistas. Mais da metade dos cirurgiões-dentistas afirmaram ter conhecimento da existência de BDHs no Brasil, porém 81% desconheciam a existência do BDH da Universidade Federal do Piauí (UFPI). Todos os entrevistados foram a favor da doação e consideram o dente como um órgão, entretanto 95,2% nunca fez doação de dentes para um BDH. O lixo foi o destino mais comum após exodontias. Diante disto, foi possível concluir que não há doação de dentes humanos pelos cirurgiões-dentistas entrevistados, possivelmente, devido ao desconhecimento da existência do BDH da UFPI e suas peculiaridades.
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