Effect of a dental unit waterline additive on resin bond strengths

The literature indicates that the addition of an antimicrobial mouthrinse to self-contained water systems in dental units will control biofilm and effluent contamination; however, reports have varied concerning the possible effects of such agents on adhesive dentistry bond strengths. This study evaluated shear bond strengths and the potential effects of a mouthrinse containing essential oils on cut tooth surfaces by grinding flat the buccal surface of extracted human teeth. Seven groups consisting of five teeth each were etched with 37% H3PO4 solution and rinsed with water or different dilutions of the mouthrinse. Each tooth was blotted dry before a film of adhesive resin was applied to the surface and photocured. A cylinder of composite was placed on the surface and photocured. Shear bond strength testing was performed using a universal test machine. The cut tooth surfaces were ground (using water or the test mouthrinse mixtures as coolant) and evaluated by scanning electron microscopy.