ABSTRACT
Introduction: Fiber-reinforced composite posts (FRC posts) have been used for tooth reinforcement after endodontic treatment. The mechanical characteristics of FRC posts can influence the clinical prognostic. Objective:The aim of this study was to evaluate the flexural strength and fracture resistance of commercially available FRC posts. Material and methods: Fourteen human single-rooted premolars with completely formed apices were selected and received endodontic treatment. The specimens were divided into two groups related to the post system: i) Group A - cylindrical-conical fiber-reinforced post (White post DC, FGM), and ii) group B - conical fiber-reinforced post (EXACTO, Angelus). The fracture resistance was evaluated and two point bending tests were carried out. The glass fiber characteristics and the tag penetration of the luting material into the radicular dentin structure were evaluated through scanning electronic microscopy in an illustrative way. One-way ANOVA and Tukey's HSD test (α = 0.05) were applied. Results: The values obtained for fracture resistance and two point bending test were, respectively, 399.29 N and 109.5 N for group A, and 386.25 N and 119.5 N for group B. No significant differences in strength values among the groups were found. Conclusion: There were no significant statistical differences between the two post groups regarding to fracture strength and two point bending strength. It can be concluded that the posts selected for this study performed satisfactorily in terms of mechanical properties so that they can be used for tooth reinforcement after endodontic treatment.
ABSTRACT
A demanda por estética e por restaurações que cada vez mais mimetizem as estruturas dentais levaram ao desenvolvimento de novos sistemas cerâmicos. Além de excelência estética, tais sistemas exibem excelentes propriedades mecânicas, o que amplia a gama de procedimentos aos quais podem ser aplicados. Atualmente, diversos materiais estão disponíveis, o que exige conhecimento por parte do profissional para uma adequada seleção. Dentro desse contexto, objetivou-se neste artigo realizar uma breve revisão sobre os atuais sistemas cerâmicos disponíveis no mercado e apresentar um relato de caso clínico com o sistema IPS e.max Press (Ivoclar Vivadent AG)
The demand for the aesthetic and restorative procedures that mimetize the dental structures, had lead to the development of new ceramic systems. Besides aesthetic excellency, such systems show excellent mechanical properties, that extend the gamma of procedures which can be applied. Nowadays, as diverse materials are avaiable, the adequate selection demands knowledge of the professionals. The objective of this article is to review the ceramic systems available on the market and show a clinical case with one of them, the system IPS e.max Press (Ivoclar Vivadent AG)
Subject(s)
Humans , Female , Ceramics/chemistry , Zinc Oxide-Eugenol Cement/chemistry , Esthetics, Dental , Dental Materials/chemistry , Computer-Aided Design/instrumentation , Composite Resins/chemistry , Dental Restoration, Permanent/methodsABSTRACT
Purpose: To evaluate the effect of light-curing techniques on in vitro microleakage of class I and class V composite restorations. Methods: Sixty human premolars were used to prepare 30 class I and 30 class V cavities, which were cleaned and treated with one step self-etching adhesive (Xeno III - Dentsply). A resin composite (TPH 3 - Dentsply) was inserted in two layers and light-cured using two protocols (n=15 each): conventional curing (500 mW/cm ² , 30 s each increment) and pulse delay technique (first increment similar to the conventional technique and the last increment initially cured with 200 mW/cm ² for 3s and after 5 min light-cured again with 500 W/cm² for 30 s). The specimens were polished, submitted to 800 thermal cycles, sealed, and immersed in a 2% basic fuchsin solution. The teeth were cleaned, sliced, and scored according to the dye penetration. Data were analyzed by Mann-Whitney U test. Results: In class I cavities the pulse delay light-curing technique showed statistically significant better sealing than the conventional technique. In class V restorations no difference was detected between the two techniques in enamel and dentin.Conclusion: Light-curing technique affected the microleakage in class I composite restorations but not in class V.
Objetivo: Avaliar o efeito da técnica de fotoativação na microinfiltração in vitro em cavidades de classes I e V restauradas com resina composta. Metodologia: Em 60 pré-molares humanos, foram confeccionadas cavidades de classe I em 30 dentes e de classe V nos demais 30 dentes. As cavidades foram limpas e tratadas com o sistema adesivo autocondicionante de um passo (Xeno III - Dentsply). A resina composta (TPH 3 - Dentsply) foi inserida em dois incrementos e fotoativada de dois modos (n=15 cada): A) Convencional, sendo cada incremento fotoativado com intensidade de 500mW/cm ² por 30 s; B) Pulso tardio, sendo o primeiro incremento fotoativado da mesma forma que o grupo convencional e o último incremento inicialmente fotoativado com 200mW/cm ² , durante 3 s, 5 min de espera e fotoativação final com 500 mW/cm ² por 30 s. Os espécimes foram polidos, submetidos a 800 ciclos térmicos, impermeabilizados e imersos em fucsina básica a 2%. Os dentes foram limpos, seccionados e avaliados quanto à penetração do corante usando-se escores de 0 a 5. Os dados foram analisados por teste U de Mann-Whitney. Resultados: Nas cavidades de classe I houve diferença estatisticamente significativa entre os grupos. Nas cavidades de classe V não houve diferença entre os dois métodos de fotoativação, tanto em margem de esmalte quanto em dentina. Conclusão: Em cavidades de classe I a fotoativação por pulso tardio proporcionou maior vedamento marginal que a fotoativação convencional. Em cavidades de classe V não houve diferença de penetração do corante.