Purpose: To evaluate the microtensile bond strengths (microTBS) of 1-step vs. 2-step self-etch systems to dentin after 24 hours and after 6 months of water storage.
Methods: Resin composite buildups were bonded to occlusal dentin of third molars using the following adhesives: Xeno IV (XE, Dentsply), G-Bond (GB, GC Inc), Clearfil S3 Bond (CS3, Kuraray); Adper Prompt L-Pop (AD, 3M ESPE); Go (GO, SDI), All Bond SE (ABSE 1-step or ABSE 2-step, Bisco) and Clearfil SE Bond (CSE, Kuraray). The bonded sticks (cross-sectioned area of 0.8-0.9 mm2) originated from the same teeth were randomly divided to be tested after 24 hours or after 6 months of water storage. The data was submitted to two-way repeated measures ANOVA and Tukey's test with and without the inclusion of premature failures (PF) (alpha = 0.05).
Results: The inclusion of PF resulted in different statistically significant means for CS3, CSE and AD (P<0.05). Only the ABSE2 showed stable bonds after 6 months of water storage (P>0.05).