Shear bond strength of composite resin to unbleached and bleached human dentine.

The purpose of this study was to compare the shear bond strength of composite resin to unbleached and bleached human dentine when used in conjunction with new dentine bonding systems. One hundred extracted, caries free, permanent human molars were used in this study. An in vitro walking bleach model was developed to stimulate clinical conditions during bleaching. It was found that the mean shear bond strength of composite resin to bleached dentine attained was lower than that to unbleached dentine. The value of 6.7 MPa bond strength to bleached human dentine demonstrated by All-Bond dentine conditioner and adhesive (Technique 1B) was much higher than in previous reports.