Purpose: Mechanical interlocking is the key to improve bond strength of computer-aided design and computer-aided manufacturing (CAD-CAM) resin-based materials. The purpose of this study was to evaluate the effect of air abrasion with a newly developed variable pressure chair-side particle abrader on bond strengths of a resin luting agent to a CAD-CAM resin material.

Methods: A CAD-CAM resin block (Katana Avencia) was abraded with either a conventional Miniblaster (MIN) or Adprep (ADP) at an air pressure of either 0.2 or 0.4 MPa. The CAD-CAM resin block was bonded with a dual cure resin luting agent (Panavia V5) and light cured. After 24 h storage in water, specimens were divided into two groups; one group remained in water (thermal cycling [TC] 0), while the second group was subjected to thermal stress (5-55°C) for 10,000 cycles (TC10,000). Following this, microtensile bond strength (µTBS) testing was performed. The surface morphology of the CAD-CAM resin block specimens after air abrasion was observed by a confocal laser scanning microscopy (CLSM). The µTBS data were statistically analyzed using a t-test (Welch’s method) with Bonferroni's correction (α = 0.05).

Results: The µTBS to the CAD-CAM resin blocks significantly increased using 0.4 MPa pressure compared with 0.2 MPa pressure. The µTBSs significantly decreased after TC stress, except for MIN at 0.2 MPa. From the CLSM observations, air abrasion with MIN at 0.4 MPa showed deeper surface concavities on the surface compared with ADP.

Conclusion: The current results suggest the performance of ADP could be acceptable as a chair-side particle abrader.