Effect of an MDP-containing Primer on the Bond Strength Between Ten Different Resin Cements and Air-abraded Monolithic Zirconia

Abstract

Objective: The aim of the present study was to evaluate the shear bond strength (SBS) of different self-adhesive luting systems to airborne-particleabraded monolithic zirconia ceramic, with or without the application of a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based ceramic primer. Materials and Methods: A total of 200 monolithic zirconia specimens were prepared and air-abraded using 50-mu m aluminum oxide particles under a pressure of 2.5 bar. Ten different self-adhesive resin cements were then bonded to the zirconia specimens with or without the use of an MDP-containing primer. After 24 h of water storage, all of the resin-bonded samples were thermocycled 5,000 times (5-55 degrees C). The SBS of the specimens was measured using a universal testing machine, and failure types were examined under a stereomicroscope. The data were statistically analyzed using two-way ANOVA and Tukey's honestly significant difference tests. Results: Statistical analyses revealed significant differences between the different resin cement groups (p<0.001). All of the primer-applied groups showed statistically higher SBS values than the non-primed groups (p<0.05). The SBS values of primer-applied groups ranged between 8.56 +/- 0.91 and 16.08 +/- 0.67 MPa. Adhesive failures were more predominant in the nonprimed groups than in the primed groups for each resin cement tested. MDP-based resin cements used did not result in the highest bond strengths. Conclusion: In the case of every self-adhesive resin cement tested, application of an additional MDP-containing priming agent yielded enhanced bond strength to air-abraded monolithic zirconia specimens. However, no association between the MDP content of the resin cements and the SBS values was observed.