Use of grape seed extract for improving the shear bond strength of total-etching adhesive to bleached enamel.

This study was to ascertain if grape seed extract (GSE) can restore the shear bond strength (SBS) of total-etching adhesive to enamel immediately after bleaching. Immediately after bleaching with Beyond gel, different concentrations of GSE were applied to the surface of bovine enamel for 1 min before bonding of resin composite with Adper single bond 2 or All-Bond 3 adhesive. SBS values and debonding modes were recorded. Structure of the bonding interface and elements on enamel surface were analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy (XPS). SBS was found to be compromised significantly in 0 and 2.5% GSE groups. GSE (≥5%) could restore the SBS to the level of control. Failure in the adhesive joint was always the major debonding mode. No significant difference was found by XPS. Thus, GSE can restore the SBS compromised after bleaching in 1 min if the concentration is ≥5%.