Effect of Short-Duration, Localized Carbamide Peroxide Application to Remove Enamel Staining on Bond Strength of Resin Cement to Enamel

Objective Peripheral enamel staining is often noticed after removal of long-term veneer or crown provisional restorations. Application of carbamide peroxide (CP) easily removes the stain, but the potential for immediate bonding with a resin-based cement is questionable. This project tested the short-term, shear bond strength of a commercial, photo-curable, resin cement to bovine enamel after application of a 10% concentration of CP placed for different exposure times. Materials and Methods Bovine enamel was flattened and polished. Surfaces had either no CP application (control), or 10% CP applied for 10, 20, or 30 seconds. Teeth were acid-etched, rinsed, dried, and controlled sized stubs of a commercial resin cement were photocured onto the treated surfaces. The shear bond strength of each specimen was determined using a universal testing machine, and results were compared using an analysis of variance at a preset alpha of 0.5 (n = 10/group). Results No significant differences (p = 0.819) in shear bond strength were found among any CP cleaning treatments or the experimental (nontreated) control. Conclusions Short-term application of 10% carbamide peroxide prior to acid etching, to remove enamel stains in teeth prepared to receive ceramic veneers or crowns, does not reduce immediate shear bond strength of resin-based cement to enamel. Clinical Significance Clinicians can confidently apply 10% CP for short-term, localized stain removal on enamel and not be concerned about affecting subsequent bond strength of a resin-based cement to enamel.