Effects of air abrasion with alumina or glass beads on surface characteristics of CAD/CAM composite materials and the bond strength of resin cements

Objective: the study aimed to evaluate effects of air abrasion with alumina or glass beads on bond strengths of resin cements to cad/cam composite materials. material and methods: cad/cam composite block materials [cerasmart (cs) and block hc (bhc)] were pretreated as follows: (a) no treatment (none),(b) application of a ceramic primer (cp),(c) alumina-blasting at 0.2 mpa (ab),(d) ab followed by cp (ab+cp),and (e) glassbeads blasting at 0.4 mpa (gbb) followed by cp (gbb+cp). the composite specimens were bonded to resin composite disks using resin cements [g-cem cerasmart (gccs) and resicem (rc)]. the bond strengths after 24 h (tc 0) and after thermal cycling (tc 10,000 at 4–60°c) were measured by shear tests. three-way anova and the tukey compromise post hoc tests were used to analyze statistically significant differences between groups (α=0.05). results: for both cad/cam composite materials,the none group exhibited a significant decrease in bond strength after tc 10,000 (p<0.05). ab showed significantly higher bond strength after tc 10,000 than the none group,while cp did not (p<0.05). gbb exhibited smaller surface defects than did ab; however,their surface roughnesses were not significantly different (p>0.05). the ab+cp group showed a significantly higher bond strength after tc 10,000 than did the ab group for rc (p<0.05),but not for gccs. the gbb+cp group showed the highest bond strength for both thermal cyclings (p<0.05). conclusions: air abrasion with glass beads was more effective in increasing bond durability between the resin cements and cad/cam composite materials than was using an alumina powder and a cp. © 2015,faculdade de odontologia de bauru. all rights reserved.