Influence of different surface treatments on the shear bond strength of a methacrylate resin composite repaired with silorane-based resin

ABSTRACT

Introduction: When repairs are needed in restorations made with methacrylate-based resin composites, the clinician still has doubts whether it is possible to use a silorane-based material and which is the best procedure. Objective: To evaluate the shear bond strength between a methacrylate-based resin composite and a silorane-based material using different surface treatments. Material and methods: Eighty flat bases made with methacrylate resin composite (Filtek Z350 XT) were prepared (n = 8). The bases were stored into water at 37°C for one week. Ten groups were evaluated G1 (control - no repair); G2 (surface grinding, washing, drying, adhesive and repair with Filtek Z350 XT); G3 (surface grinding, washing, drying, adhesive and repair with silorane - Filtek P90); G4 (surface grinding, washing, drying, adhesive, silane and repair with Filtek Z350 XT); G5 (surface grinding, washing, drying, application of silane, adhesive and repair with silorane - Filtek P90). All groups were kept at 37°C for 24 h in either water (G1 to G5) or ethanol (G6 to G10). The results were analyzed with one-way ANOVA and Tukey test (α = 0.05). Results: There were significant differences between groups (p < 0.001). Only repairs made with silane and Z350 XT (G4 = 46.2 ± 12.9; G9 = 48.1 ± 16.3) resulted in values similar to controls (G1 = 59.2 ± 15.8; G6 = 62.3 ± 15.9) (p = 0.33). The smallest value occured when the repair was performed with silane and silorane-based based and stored into ethanol (G10 = 29.9 ± 12.4). The storage media had little influence on the results. Conclusion: The silorane-based resin composite was not effective for repair of the methacrylate-based material.