Avaliação da resistência de união de restaurações de compósito confeccionadas pela técnica direta ou indireta / Bond strength evaluation of direct and indirect composite restorations

ABSTRACT

The purpose of this study was to evaluate the bond strength of direct or indirect composite restorations to dentine. Thirty bovine teeth were flattened in order to obtain a plain dentine area. The teeth were divided in 3 groups of 10, according to the restoration fixing methods: 1) Direct technique using Single Bond Adhesive System; 2) Indirect technique using Rely-X resin cement; 3) Indirect technique using high viscosity Filtek Flow composite. For group 1, Z-250 composite discs were fixated (6mm diameter by 2 mm height) directly on the treated area. For groups 2 and 3, composite discs were made 24 hours before being cemented, with the same dimensions of group 1, and according to the Rely-X (group 2) and Filtek Flow (group 3) manufacturer's recommendations. After 24h of water storage, the speciments were submitted to a shear bond test on Instron at a speed of 0.5 mm/min. The data were submitted to ANOVA and Tukey's test (5 por cento)...