Evaluation of Shear Bond Strength between Amalgam and Composite: An in vitro Study

Background & Aims: Repair of defective restoration is more conservative than replacing it. Veneering the amalgam restorations with opaque resin materials can satisfy the esthetic demands. Evaluation of interfacial bond quality between amalgam and composite surface is one of the important factors in assessing the quality of repaired amalgam which can be achieved by micro leakage test and bond strength test. The aim of this study was to assess the effect of introduced amalgam and also the bonding agent on shear bond strength of amalgam and composite interface. Methods: First, ۷۲ acrylic models (۲۰*۳۳ mm) were provided and categorized into two groups of A and B. we used Tytin (kerr,USA) amalgam in group A and Cinalux (Shahid faghihi, Tehran) amalgam in group B. Amalgam surface was scratched by using a diamond bur. All the groups were etched and rinsed. In A۱ group, nothing was done after etching and rinsing. In A۲ group, single bond and in A۳ group Excite was used. B۱, B۲ and B۳ groups were respectively prepared like A۱, A۲ and A۳ groups. DenFil composite was used in all groups. Shear bond strength was assessed by using Universal testing machine. All the specimens were seen under stereo microscope (Olympus, Germany) with ۷۵% magnification. Tukey HSD test was used for statistical analysis. Results: In the groups which were filled with Tytin, A۳ group had significantly higher bond strength than A۱ group (P=۰.۰۰۱). In groups which were filled with Sinalux, B۳ group had significantly higher bond strength than B۱ and B۲ groups (P=۰.۰۰۱ and ۰.۰۳ respectively). Bond strength was significantly higher in A۱ compare to B۱, A۲ compare to B۲, and A۳ compared to B۳ (P=۰.۰۰۱). Conclusion: According to the obtained results, the type of introduced amalgam and also the bonding agent can affect shear bond strength of amalgam and composite interface. Tytin amalgam compared to Cinalux amalgam can create more shear bond strength. Also, excite bonding causes higher bond strength compared to single bond.

کلیدواژه ها:

Shear bond strength ، Amalgam ، Composite