RESUMO
The aim of this study was to compare enamel shear bond strength to resin composite following preparation with a carbide bur, fine diamond bur, or erbium doped, yttrium-aluminium-garnet [Er:YAG] laser. Forty-eight human anterior teeth, randomly assigned to each preparation group, were studied. Each tooth was mounted in self-curing acrylic resin with the desirable flat facial surface exposed and was randomly assigned to 3 groups according to surface preparation: Er:YAG laser irradiation, carbide bur, or fine-grit diamond bur. A polypropylene cylinder was fixed to the prepared surface, which was demarcated for the area to be bonded with the single bonding system. Restorative composite was then incrementallyinserted into the tubing lumens. The teeth were shear tested to failure at a crosshead speed of 1.0mm/minute. One-way ANOVA and the Tukey test were used for analysis. The mean bond strength values were as follows: fine diamond bur, 23.88MPa; carbide bur, 13.28 MPa; and Er:YAG laser, 12.61 MPa. Different enamel preparation methods affect the shear bond strength between enamel and resin composite