Composite Resin Repairs Bond Strength Prepared With Different Restorative Combinations

Objectives: The aim of this study was to evaluate the microtensile bond strength of composite repairs performed with different combinations of restorative materials, and submitted to mechanical load cycling. Methods: Fifty blocks of high-viscosity composite resin (Tetric Ceram HB) were prepared, and randomly allocated into five groups (n=6) according to the following combinations: G1 – Control (without repair); G2 – Single Bond + Filtek Z250; G3 – Single Bond + Filtek Flow + Filtek Z250; G4 – Single Bond + Tetric Ceram HB; G5 – Single Bond + Filtek Flow + Tetric Ceram HB. Following repair procedures, the specimens were submitted to mechanical load cycling (100,000 cycles; 80N). Then, three slices of each block were obtained, in which constrictions were made in the adhesive interface, in order to obtain an area of approximately 1mm2. The microtensile test was performed in an universal testing machine (V=0.5mm/min). Results: The statistical analysis (ANOVA/Tukey, p<0.05) showed the following results (mean and SD/MPa): G1: 42.97/11.96A; G2: 28.66/6.54AB; G3: 28.93/3.86AB; G4: 25.98/12.28B; G5: 24.91/8.79B. Conclusions: It could be concluded that the procedure of repair can be affected by the restorative material used