The impact of artificially caries-affected dentin on bond strength of multi-mode adhesives

AIM: The aim of this study is to evaluate the impact of dentin condition on bond strength of multi-mode adhesive systems (MMAS) to sound and artificially induced caries-affected dentin (CAD). METHODS: Flat dentin surfaces of 112 bovine incisors were assigned to 16 subgroups (n = 7) according to the substrate condition (sound and CAD– pH-cycling for 14 days); adhesive systems (Scotchbond Universal, All-Bond Universal, Prime and Bond Elect, Adper Single Bond Plus and Clearfil SE Bond) and etching strategy (etch-and-rinse and self-etch). All systems were applied according to the manufacturer's instructions, and resin composite restorations were built. After 24 h of water storage, specimens were sectioned (0.8 mm(2)) and submitted to the microtensile test. STATISTICAL ANALYSIS: Data (MPa) were analyzed using three-way analysis of variance and Tukey's test (α = 0.05). RESULTS: MMAS presented similar bond strength values, regardless etching strategy in each substrate condition. Bond strength values were lower when MMAS were applied to CAD in the etch-and-rinse strategy. CONCLUSION: The etching strategy did not influence the bond strength of MMAS to sound or CAD, considering each substrate separately. However, CAD impact negatively on bond strength of MMAS in etch-and rinse mode.