Repair of silorane-based composites: microtensile bond strength of silorane-based composites repaired with methacrylate-based composites.

The purpose of our study was to evaluate the effects of surface treatment on the microtensile bond strength (MTBS) of silorane-based composites (Filtek Silorane, 3M ESPE) repaired with methacrylate-based composites (Ceram X, Dentsply). The MTBS were measured before or after thermo-mechanical fatigue simulation (FS). The surface conditioning regimes were: no treatment, bonding agent, silane, and silane+bonding agent. Before and after FS, no significant differences could be observed among the different pretreatment groups. FS did not change the MTBS although FS increased the repair strength of Silorane in our previous study under the same conditions, and after FS all of the failure modes showed adhesive failure, which means that the repair bond strengths between silorane-based composite and methacrylate-based composite were not durable. In conclusion, within the limitations of this study, with this composite neither bonding agent nor silane contributed to an increase in the tensile strength.