Effect of Surface Preparation on Microtensile Bond Strength of Three Adhesive Systems to Bovine Enamel

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