Shear bond strength, microleakage and SEM study of the XR Bond adhesive system

A new resin dentin adhesive consisting of a primer (phosphonate dimethacrylate) and bonding agent (phosphonated BIS-GMA) was evaluated with bond strength tests, marginal microleakage studies, and SEM examination. The mean bond strength to dentin was 15.6 +/- 3.7 MPa. Microleakage studies found no marginal leakage at the enamel cavosurface margin and very minimal microleakage at the dentin/cementum margins. SEM examination showed that the primer was very effective in modifying the smear layer.