The aim of this study was evaluated, in vitro, the tensile bond strength to dentin of the Single Bond (3M) adhesive system applied over dentin surfaces treated with hith-speed handpiece, Er.YAG laser or air abrasion. Thity four enclosed molars extracted due to therapeutic indication had been used. The teeth was sectioned on the mesial-distal sense. The dental portions was included in a selfcured acrilic resin and so fourty five samples was randomly divided in three groups. The first group was treated with a diamond bur plus high-speed handpiece (Kavo) for five seconds under water cooling. On the laser group was used the Er:YAG KavoKey laser (Kavo) with enerv of 450 mJ/pulse and 2 Hz under water cooling. In the air abrasion group was used a Mach 5 (Kreativ) device with 27 mm alumina oxide particles powder. After the treatments was applicd the Single Bond (3M) and Z 100 resin composite. The tensile test was realized in a universal testing machine EMIC DL-2000 at cross-head speed of mm / minute. The average results was: high-speed handpiece (17,52 MPa), Er:YAG laser ( 16,65 MPa) and air abrasion ( 15,83). The results was submitted to statistical treatment by ANOVA and Tukey's test (p ) that showed the diffemcc between the tested groups was not significant.