Method: The following AS were tested: Adper Single Bond Plus (SB, 3M ESPE- HC), All Bond 3 (AB, Bisco- Adhesive Resin is HF), G-Aenial Bond (GA, GC Corp.- HF) and BeautiBond (BB, Shofu- HF). Forty human third molars were used (n=10). The ASs were applied according to the manufacturer’s instructions and a Filtek Z350 XT resin block (6mm high) was incrementally built up. After 24 hs, the teeth were prepared for the microtensile BS test and for SEM observations. Failure modes were classified among cohesive within the dentin (CD), cohesive within the resin (CR) and adhesive along the composite-adhesive layer interface (AI). BS data were analyzed by one-way Anova and Tukey’s test (α=5%), and failure pattern were analyzed by percentage.
Result: The BS means (SD) to dentin were (MPa): SB: 47.4(5.1)b; AB: 57.7(4.3)a; GA: 21.5(7.6)c; BB: 22.7(3.0)c. The failure pattern of AS were: SB: 4%(CD), 9%(CR), 87%(AI); AB: 26%(CD), 9%(CR), 65%(AI); GA: 3%(CD), 3%(CR), 94%(AI); BB: 0%(CD and CR), 100%(AI). The GA and BB self-etching adhesives presented thin hybrid layer and short resin tags when compared to SB and AB.
Conclusion: The AB presented the highest BS values among AS tested. The BS of GA and BB was significantly less than those of the SB and AB. All groups showed AI as the predominant type of failure pattern. The morphology of RDI influenced the BS.