Microshear bond strength of a self-etching primer adhesive to enamel according to the type of bur

Abstract

Objectives: The purpose of this study was to compare the microshear bond st rength (uSBS) to enamel pre-pared with different burs and to determine what type of bur wer e chosen when a self-etching primer adhe-sive was used. Materials and Methods: Enamel of forty-two human molars were used. They were divided i nto one of sixgroups (n = 7), Group 1, coarse (125 - 150 μm) diamond bur; Group 2, standard (106 - 125 μm) diamondbur; Group 3, fine (53 - 63 μm) diamond bur; Group 4, extrafine (20 - 30 μm) diamond bur; Group 5, plain-cut carbide bur (no. 245); Group 6, cross-cut carbide bur (no. 557). Clearfil SE Bond and Clearfil AP-X(Kuraray Medical Inc.) was bonded to enamel surface. The bonded specimens were subjected to uSBS testing.Results: The uSBS of Group 4 was the highest among groups and it was sig nificantly higher than that ofGroups 1, 2, 3, and 6 (p< 0.05), but it was not significantly different from that of Group 5.Conclusions: Different burs used on enamel surface affected the microshear bond strengths of a self-etchingprimer adhesive to the enamel surface. In the case of Clearfil SE Bond, extrafine diamond and plain-cutcarbide bur are recommended for bonding to enamel.