Abstract: Objective: To evaluate the effect of simplified ethanol wet bonding technique on caries affected dentin(CAD) bonding properties through micro-tensile strength(μTBS) test. Methods: 36 extracted human molars with coronal dentin caries were selected. The softened carious dentin was removed with a slow speed carbon steel bur. The remaining cavity wall was removed and a relatively flat surface in the same level of CAD lesion was obtained using a high speed diamond bur with water coolant. The teeth were randomly distributed across three groups of bonding agent (Experimental hydrophobic adhesive, Adper Single bond plus, Prime & Bond NT)and two subgroups of substrate condition (water- or ethanol-wet). A 4-5mm high resin crown was built up on the adhesive interface using resin composite, stratified cured. Samples were prepared into beams about 1mm×1mm×8mm for μTBS tests with universal testing machine. 8 specimens were selected from each group. Results: In the experimental hydrophobic adhesive group, simplified ethanol wet bonding can significantly improve the adhesion bond strength of the CAD. A significant difference was observed. In the SB and PB groups, compared with traditional wet bonding, simplified ethanol wet bonding had higher bond strength, but no significant difference was observed. Conclusion: Simplified ethanol wet bonding technique can improve the bond strength of CAD, especially when combined with hydrophobic adhesive

Key words: Simplified ethanol-wet bonding, Caries affected dentin , Micro-tensile strength test