effect of er:yag laser application and sandblasting on shear bond strength of veneering ceramic to zirconia core

Objectives: porcelain chipping and delamination are among the shortcomings of all-ceramic restorations. this study aimed to assess the effect of laser irradiation and sandblasting on shear bond strength (sbs) of zirconia to veneering porcelain.materials and methods: in this in vitro, experimental study, 60 zirconia blocks were randomly divided into three groups (n=20) for surface treatment with er:yag laser, sandblasting, and no surface treatment (control). each group was randomly divided into two subgroups (n=10) for porcelain application by the layering or the pressing technique. the surface roughness, sbs, and failure mode were determined and analyzed using two-way anova, tukey’s hsd test, chi-square test, and pearson’s correlation test (alpha=0.05).results: the mean sbs was 8.16±3.66 mpa, 9.32±2.7 mpa, and 11.85±3.06 mpa in the control, laser, and sandblasting groups, respectively. the sbs was significantly different among the three groups (p=0.002). the failure mode of the three groups was not significantly different (p>0.05). the sandblasted group showed significantly higher surface roughness than the control and laser groups (p<0.001).conclusion: sandblasting yielded higher sbs particularly when the porcelain was applied by the layering technique. although laser irradiation increased the sbs, the difference with the control group was not statistically significant.