Evaluation of the effects of different surface treatments on the bonding strength of recent CAD/CAM hybrid ceramics

The aim of this in vitro study was to evaluate the effect of different surface treatments (control, HF acid, sandblasting with Al2O3 particles, tribochemical silica coating and fiber laser) on surface structure and shear bond strength of different ceramics. In our study, 130 specimens were used totally including 120 specimens for shear bond strength and 10 specimens for SEM for each ceramic systems. For shear bond strength, ceramic specimens embedded to clear acrylic resin were firstly divided into 2 groups according to be used ceramics type and divided into 5 subgroups according to surface treatments. After applying the surface treatments, SEM images were taken from each group. Clearfil Ceramic Primer Plus silan was applied to all specimens for 60 seconds before cementation. Panavia V5 adhesive resin cement was manipulated by a mold on the specimens which embedded in acrylic. After this procedure, all specimens were subjected to thermal cycling (5000 cycles, 5-552 C). Bond strength was measured by means of a shear test using universal testing machine with 0,5 mm/min. speed until failure. A stereomicroscope was used to analyse the surfaces for type of failure. To determine the statistical significance of the differences between the mean shear bond strength values, Oneway Anova Test, Tamhane Multiple Comparison Test, Kruskal Wallis H Test, Mann Whitney U Test and Bonferoni Correct Mann Whitney U Test were used. Between all groups, the highest bond strengths were obtained the groups which treated with HF acid and sandblasting with Al2O3. It was observed that the bonding strength values of Vita Enamic ceramic material higher than Lava Ultimate ceramic material. After shear bond strength test, under the stereomicroscope the most prevalent type of failure was seen as adhesive failure and the least prevalent type of failure was seen as cohesive failure.