Effect of 1-bottle light-cured adhesive acidity on microleakage of a self-cured composite

This in vitro study examined the effect of 1-bottle light-cured adhesives with different acidities on the microleakage of a self-cured composite in Class II restorations. Forty-five Class II cavities were prepared on the proximal surfaces of extracted human intact third molars that were randomly assigned to 3 groups (15 cavities in each group). The following adhesives were applied according to the manufacturer's instructions: Single Bond (Group 1), Excite (Group 2) and One-Step (Group 3). The teeth were restored with a combination of a self-cured resin composite (Concise) and a light-cured resin composite (Filtek P60). After thermocycling (500 cycles at 5 degrees C/55 degrees C) and immersion in 2% basic Fushin, the teeth were sectioned and evaluated for microleakage using a stereomicroscope (16x). Microleakage was scored on a scale of 0 to 3. Kruskal-Wallis analysis showed that there was a significant-difference in microleakage values of 3 adhesives with a self-cured composite, and low pH may have contributed to high microleakage values. Also, 2 by 2 comparisons with the Mann-Whitney U-test revealed a significant difference at the p<0.05 level between Groups 1 and 2 and between Groups 2 and 3. However, there was no statistically significant difference between Groups 1 and 3.