The effect of resin-coating technique on the bond strength between composite resin blocks for CAD/CAM and luting agents

Hideo Iwashita, Naho Hamano, Takushi Fukuyama, Yuya Tsujimura, Shin Nakao, Satoshi Ino

Division of Minimal Intervention Prosthetic Dentistry, Department of Highly Advanced Stomatology, Kanagawa Dental University, Yokohama Clinic, Yokohama, Japan

Purpose: This study aimed to evaluate the effects of surface treatments on the shear bond strengths of composite resin blocks for CAD/CAM and luting agents.

Materials and Methods: All specimens were air-abraded with alumina particles before shear bond strength testing and categorized into the following pretreatment groups: C, no treatment; S, conventional silane treatment; GP, universal silane treatment; RS, universal silane treatment after silica coating; CM, resin coating after universal silane treatment; and RM, universal silane treatment after silica coating and resin coating. The surface roughness test was conducted to determine the fitting accuracy.

Results: The CM and RM groups demonstrated significantly higher bonding durability compared to the other groups. The film thickness of the resin coating was 12.66 µm, indicating its effectiveness in improving the bond strength without compromising the fitting accuracy.

Conclusion: Thus the clinical application of the resin-coating technique may prove useful for preventing the debonding of CAD/CAM fabricated crowns.
(Asian Pac J Dent 2020; 20: 17-23.)
Key Words: adhesion, CAD/CAM, composite resin, resin-coating technique, shear bond strength