Bond strength of simplified-step adhesives to enamel prepared with two different diamond burs.

Background: Self-etching primers are reported to produce considerable etching on flat enamel surfaces. However, little is known about the influence of different enamel surface textures. In this study the influence of grinding enamel on bond strength of two all-in-one and one two-step adhesives was investigated. Methods: Resin composite was bonded to the ground enamel of extracted human third molars that was reduced 0.5mm from the buccal or lingual surfaces using either regular- or superfine-grit diamond burs with each of the three adhesives. After 24 hours in 37°C water, the specimens were sectioned into slabs of 0.7mm thickness, trimmed to an hourglass configuration, and subjected to micro- tensile bond strength (MTBS) testing. Results: For all adhesive systems, MTBS to enamel ground with a regular-grit diamond bur was not significantly different from that with a superfine-grit diamond bur. The etching patterns of these adhesives were partly varied according to the aggressiveness of the adhesives. Conclusion: The use of two different burs does not affect the tensile bond strength of the adhesives to enamel.