Effectiveness of the Addition of Water-soluble Photoinitiator into the Self-etching Primers on the Adhesion of a Resin Composite to Polished Dentin and Enamel.

The effectiveness of the addition of a photoinitiator into self-etching primer was investigated by measuring the tensile bond strength between a resin composite and dentin or enamel. The addition of camphorquinone to 5 M (5 wt% MDP -35 wt% HEMA aqueous solution) or 30 M (30 wt% MDP -35 wt% HEMA aqueous solution) did not increase the bond strengths of resin composite to dentin or enamel. On the other hand, the bond strength to dentin was increased by the addition of a water-soluble photoinitiator, 2-hydroxy-3-(3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy)-N,N, N-trimethyl-1- propanaminium chloride (QTX) to 5 M or 30 M. The bond strengths to enamel were not influenced by the addition of QTX to 5 M or 30 M.