Effect of self-etching primer application method on enamel bond strength

To determine the effect of self-etching primer application method on enamel bond strength.

Five commercial self-etching primer systems, Imperva Fluoro Bond, Mac Bond II, Clearfil Liner Bond II sigma, Clearfil SE Bond and Unifil Bond were used. Bovine mandibular incisors were mounted in self-curing resin and the facial enamel surfaces were ground wet on 600-grit SiC paper. The self-etching primers were only applied without agitation (inactive) or were agitated by brush (active); and resin-based composites were condensed into the mold (ø4 x 2 mm) on the enamel surface and light cured. Fifteen specimens per test group were stored in 37 degrees C water for 24 hours, or followed by thermal cycling, and shear tested at a crosshead speed of 1.0 mm/minute. One-way ANOVA followed by the Student's t-test or Duncan multiple range test were used.

The bond strengths with active application were higher than with inactive application. Significant differences were found for Fluoro Bond, Mac Bond II, and Unifil Bond. From the results of this study, active application of self-etching primer may help to ensure the creation of roughened enamel surface and enhance the penetration of primer into subsurface demineralized enamel.