Influence of Light Irradiation Condition on Microshear Bond Strength of Dual-cured Resin Luting Agents

Abstract

The purpose of this study was to evaluate the microshear bond strength and bond durability between ceramic and two dualcured resin luting agents irradiated by different light intensities. Ceramic specimens were bonded with two resin bonding systems: Ceramic Primer and Linkmax HV (CP/LMHV) and Monobond S and Variolink IIHV (MBS/VLIIHV), and were either irradiated by 800, 310, 160, 80, and 40 mW/cm² light or not irradiated. Bond strength was measured after 24-hour water storage at 37°C and after subsequent 10,000 times of thermal cycling. Failure modes were determined by stereomicroscopy. After 24-hour water storage, there were no significant differences among the various irradiation conditions for both MBS/VLIIHV and CP/LMHV. However, regardless of light intensity, MBS/VLIIHV showed higher bond strength than CP/VLIIHV at each thermal cycling, except for no irradiation condition at 10,000 thermal cycles. In conclusion, thermal cycling significantly reduced the bond strength for all groups.