Objectives: The aim of this study intended to evaluate the effect of various surface treatments on the adhesion of CAD/CAM fabricated Y-TZP ceramic onlays.
Materials and methods: Forty-eight, cracks-free extracted human molars have been acquired in the study. The specimens have been divided randomly according to surface treatment of Zirconia into four main groups of twelve specimens each as follows (n=12): group1: tribochemical silica coating; group 2: sandblasting; group 3: sandblasting with primer; and group 4: sandblasting and laser with primer. The first half of the specimens were put through the tests right away, whereas the other half were put through the tests after being subjected to thermo-mechanical cyclic stress. Buehler Isomet 4000 Cutting Machine (IsoMetTM 4000, Buehler Ltd, Lake bluff, LL, USA) was used for the preparation of standardized onlays cavities. Then micro-tensile bond strength test μTBS was performed. Data were statistically analyzed using the Shapiro-Wilk, post hoc-Tukey, student t-test, and one-way ANOVA tests.
Results: The outcome of the study revealed statically significant differences in μTBS between all groups. The most favorable bonding was in the group of sandblasting with primer (12.50 ± 2.40) and the least was with the tribochemical silicoating (3.70 ± 0.96) (P=0.002).
Conclusions: Within the parameters of this study, the different surface treatments had a significant difference in μTBS. Sandblasting with primer consider the most favorable outcome of the current study. However, thermomechanical cyclic loading deteriorates the bond strength when using sandblasting alone.