Effect of chlorhexidine on bond strength of a self-etching adhesive

Objectives: It has been reported that host-derived matrix metalloproteinases(MMPs) degrade the collagen matrix of hrbrid layer in resin-dentin bonding interface,and chlorhexidine can inhibit MMPs.This in vitro study aimed to evaluate the effect of chlorhexidine on the microtensile bond strength of a self-etching dentin adhesive. Methods: 20wt% chlorhexidine was added to the primer of a self-etching dentin adhesives(Clearfil SE Bond) to obtain four primers containing 0.05, 0.1, 0.5 and 1.0wt% . Flat dentinal surfaces prepared in extracted human third molars were sectioned into two halves, and treated respectively with Clearfil SE Bond containing and not containing chlorhexidine in the primers. Composite resin blocks were built up over the treated surfaces. Microtensile bond strengths were analyzed immediately after specimens preparation. Results: No statistically significant differences of bond strength values were found between chlorhexidine and non-chlorhexidine groups. Conclusions: Incorporation of 0.05, 0.1, 0.5 and 1.0wt% chlorhexidine in the primer did not interfere with the microtensile bond strength of Clearfil SE Bond bonding system.