Effect of enamel pretreatments on bond strength of compomer

Objectives: The objective of this study was to evaluate the effect of various enamel surface treatments on the bond strength of a compomer to enamel. Methods: Ground bovine enamel specimens were divided into four groups. A compomer (F2000, 3M) was bonded to the specimens using different enamel surface treatments. Two groups examined the effect of application of the F2000 self-etching primer/adhesive (3M) with respect to static or dynamic priming. A third examined use of the primer/adhesive after phosphoric acid etching, and the fourth (control) group provided bond strength of the compomer to phosphoric acid etched enamel with a resin bonding system (Single Bond, 3M). Shear bond strengths for the specimens were measured after 24 h storage in water at 37 degreesC. Effects of the various surface treatments on enamel were examined by SEM. Results: Significant differences in bond strength of compomer to enamel were found that were related to the various surface pretreatments. Dynamic priming resulted in higher enamel bond strengths than static priming, and the best bond strengths were obtained when the enamel was etched with phosphoric acid. SEM analysis showed that depth of etch and resin penetration was also directly related to the bond strengths measured. Significance: Bond strength of compomer to enamel is significantly affected by the method of pretreatment of the enamel. (C) 2001 Academy of Dental Materials. Published by Elsevier Science Ltd. All rights reserved.