Abstract: PURPOSE: To evaluate the micro-tensile bond strength of 3 different surface managements to non-carious sclerotic dentin. MOTHODS: Fifteen periodontal patients’ occlusal wearing molars which were above 3rd degree were selected. The teeth were equally cut into two pieces along the buccolingual direction, and each piece was randomly divided into 3 groups. Group 1 was processed with polishing, group 2 was processed with EX-26 diamond bur and group 3 was processed with 5# round bur. All teeth were subjected to Optibond treatment, and then filled with composite resin (Premisa) and saved in normal artificial saliva (37℃) for 24 hours. At last, fatigue test pieces were made, the micro-tensile bond strength was evaluated and every specimen was examined under stero-microscope. The micro-tensile bond strength was analyzed with one-way analysis of variance using SPSS17.0 software package. RESULTS: The micro-tensile bond strength of the 3 groups were (10.48±1.29) MPa, (21.52±0.97) MPa and(16.30±1.02) MPa, respectively. The bond strength of EX-26 diamond bur group was significantly greater than that of the other 2 groups(P<0.05). The bond strength of 5# round bur group was significantly greater than that of polishing group (P<0.05). The breakage mostly happened in adhesive dentine surface. CONCLUSIONS: Non-carious sclerotic dentin which is processed with diamond bur has better micro-tensile bonding strength.

Key words: Sclerotic dentin, All-etching adhesive, Micro-tensile bond strength