Composite Resin to Yttria Stabilized Tetragonal Zirconia Polycrystal Bonding: Comparison of Repair Methods

Abstract

SUMMARY Purpose The purpose of the current study was to evaluate different approaches for bonding composite to the surface of yttria stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics. Methods One hundred Y-TZP blocks were embedded in acrylic resin, had the free surface polished, and were randomly divided into 10 groups (n=10). The tested repair approaches included four surface treatments: tribochemical silica coating (TBS), methacryloxydecyldihidrogenphosphate (MDP)–containing primer/silane, sandblasting, and metal/zirconia primer. Alcohol cleaning was used as a “no treatment” control. Surface treatment was followed by the application (or lack thereof) of an MDP-containing resin cement liner. Subsequently, a composite resin was applied to the ceramic surface using a cylindrical mold (4-mm diameter). After aging for 60 days in water storage, including 6000 thermal cycles, the specimens were submitted to a shear test. Analysis of variance and the Tukey test were used for statistical analyses (α=0.05). Results Surface treatment was a statistically significant factor (F=85.42; p<0.0001). The application of the MDP-containing liner had no effect on bond strength (p=0.1017). TBS was the only treatment that had a significantly positive effect on bond strength after aging. Conclusion Considering the evaluated approaches, TBS seems to be the best surface treatment for Y-TZP composite repairs. The use of an MDP-containing liner between the composite and Y-TZP surfaces is not effective.