Tensile Bond Strength of Different Repaired Resin Composite Materials

Objectives: To evaluate and compare tensile bond strength of Filtek Silorane-Filtek Silorane adhesion,Filtek Silorane-conventional methacrylate-based resin composite adhesion, as well as conventional methacrylate-base resin composite-conventional methacrylate-based resin composite adhesion. Methods: Three commercial resin composites, Filtek Silorane (3M ESPE), Filtek Z 350 (3M ESPE) and Premise (Kerr), were separately prepared in cylindrical shape with 8 mm in diameter and 5 mm in height and then polymerized by light curing unit. All of the cylindrical shaped materials were immersed in distilled water at 37 degree Celsius for 3 months. After the immersion time, the surfaces of cylindrical shape of resin composites were ground with 600-grit SiC paper. Each of cylindrical shaped specimens was divided into three groups according to the primer/bonding agents and fresh resin composites filled over them. The primer/bonding agents corresponded to the filling materials: Silorane system adhesive bond-Filtek Silorane, Adper Single Bond-Filtek Z350 and OptiBond FL-Premise. After polymerization by using light curing unit, the specimens were being thermocycled in water between 5 degree Celsius and 55 degree Celsius for 20,000 cycles. Mini-dumbbell test specimens were performed according to ISO/TS 11405 (n=15/group). Their tensile bond strengths were measured by Universal testing machine at crosshead speed of 1.0 mm/ min and data were statically analyzed by ANOVA. Failure modes were observed at higher magnification. Results: No statistically significant difference (p>0.05) in the means of tensile bond strength was found among the experimental groups. The tensile bond strength ranged from 18.69±2.1 to 20.35 ±1.9 MPa. Mode of failure showed a higher number of adhesive failure (86%). Conclusions: This experiment demonstrated no significant difference of tensile bond strength among different repaired resin composite materials: Silorane and Silorane, Silorane and conventional methacrylate–based resin composite as well as conventional methacrylate–based resin composite and conventional methacrylate-based resin composite.