Microtensile Bond Strength of CAD/CAM Resin Blocks to Dual-Cure Adhesive Cement: The Effect of Different Sandblasting Procedures

Abstract

Purpose To investigate the effect of sandblasting powder particles on microtensile bond strength (mu TBS) of dual-cure adhesive cement to CAD/CAM blocks. Materials and Methods CAD/CAM blocks (Cerasmart, VITA, and LAVA) were cut in slabs and divided into groups: group 1, no sandblasting; group 2, sandblasted with 27-mu m Al2O3; group 3, sandblasted with 30-mu m CoJet; group 4, sandblasted with 50-mu m Al2O3. After sandblasting, all specimens were silanized and luted using dual-cure adhesive cement (G-CEM LinkForce). After 24 hours, bonded specimens were cut into 1 +/- 0.2 mm(2) sticks, and mu TBS values were obtained (N = 30). Additionally, 132 CAD/CAM block sections were prepared for surface roughness testing and scanning electron microscopy (SEM) evaluations. Results were analyzed using Kruskal-Wallis One-way ANOVA and Dunn's Post Hoc Test (p 0.05). For LAVA, mu TBS values of specimens that were sandblasted with 50-mu m Al2O3 powder were significantly higher than 30-mu m-SiO2 and 27-mu m Al2O3 (p < 0.05). Conclusions The sand particles investigated (27-mu m Al2O3, 30-mu m SiO2, or 50-mu m Al2O3) did not significantly affect mu TBS results of CAD/CAM blocks for Cerasmart and VITA, although the results changed significantly for LAVA. The ideal bond protocol for CAD/CAM blocks is specific to the material used.