Effects of the combination of Er: YAG laser and sandblasting on the shear bond strength between zirconia and resin cement

ABSTRACT

Aim: This study was conducted to determine the bond strength between zirconia ceramic and resin luting cement according to the type of surface treatment applied. Methods: Sixty zirconia cylinders measuring 4 x 4 mm were manufactured and distributed into five experimental groups and a control group (n = 10) G1 - sandblasting with 110 µm aluminum oxide; G2 - sandblasting with 30 µm Rocatec Soft®; G3 - ErYAG laser irradiation at 400 mJ; G4 - ErYAG laser combined with sandblasting with aluminum oxide; G5 - ErYAG laser combined with sandblasting with Rocatec Soft®; G6 - no treatment (Control). The zirconia cylinders were bonded in the center of composite resin cylinders (6 mm diameter) using RelyX Ultimate® cement. Shear strength was measured after thermocycling (6000 cycles and 5-55° C). Data were analyzed using one-way ANOVA and Tukey's post-hoc with a 5% significance level. Results: Group 4 had a significantly higher shear strength than all the other groups, except Group 1. Group 3 had a significantly lower shear strength compared with Groups 1 and 4. Conclusion: Sandblasting with 110µm aluminum oxide particles after laser irradiation may be an effective zirconia surface treatment. The use of Er YAG laser alone is not effective at increasing the bond between resin cement and zirconia