The purpose of this study was to compare the microtensile bond strength (µTBS) of three adhesives to bovine enamel prepared with 600-grit silicon carbide paper, diamond rotary instrument, or carbide bur. Bovine teeth (n = 36) were randomly divided into three treatment groups and bonded using a total-etch adhesive (Single Bond, 3M ESPE), a self-etching primer system (Clearfil SE Bond, Kuraray), or a self-etching adhesive (One-Up Bond F, Tokuyama). A 4-mm composite crown was built on the bonded surfaces and specimens were stored in water for one day at 37°C. Specimens were sectioned into 0.7-mm-thick slabs, trimmed to a cross-sectional area of 1 mm2, and loaded to failure at a crosshead speed of 1 mm/min using a tabletop tester (EZ-Test, Shimadzu). Microtensile bond strength data were analyzed using ANOVA and Fisher's PLSD test (α = 0.05). The bond strength of each self-etching system was lower when the enamel was prepared using a diamond or carbide bur, rather than with 600-grit silicon carbide paper. Differences in µTBS between carbide- and diamond-prepared surfaces were not significant. The surface preparation method did not affect the total-etch system. Different preparation instruments are unlikely to affect resin-enamel bond strengths. Parole chiave: adhesion, enamel bonding, burs, self-etching primer