Effect of cleaning agent, primer application and their combination on the bond strength of a resin cement to two yttrium-tetragonal zirconia polycrystal zirconia ceramics

OBJECTIVE: The objective of this study is to evaluate the effect of a cleaning agent and priming on the bond strength (BS) of a resin cement (RC) to zirconia ceramics after 24 h and 1 year of water-storage. MATERIALS AND METHODS: Fifty-six Katana and 56 ZirCAD zirconia ceramic plates were prepared and each zirconia brand was divided into four groups (n = 14): (1) untreated; (2) treated with Ivoclean cleaning agent; (3) treated with Monobond Plus coupling agent; (4) treated with Ivoclean + Monobond Plus. Cleaning and coupling agents were applied to zirconia following the manufacturers' instructions. The RC was manipulated, inserted into tubes (0.75 mm diameter/1 mm height) that were positioned on the zirconia surfaces and light activated. Specimens were tested after 24 h and 1 year of water storage. A shear load was applied to the base of the RC cylinders (until failure. Data were analyzed by three-way ANOVA and Tukey tests (α = 5%). RESULTS: No significant difference in BS was noted between zirconia ceramics, except when the combination of cleaning and coupling agents was used. This combination increased the BS for Katana zirconia. One year of water storage leads to a decrease in BS for all experimental groups. CONCLUSION: The combination of cleaning agent and priming can yield higher BS for Katana at 24 h. BS to zirconia ceramics reduced approximately 50% after 1 year.