The bonding of composite resin to moist enamel

Objective To determine the effect on the bond strength of modern dentine bo nding agents to etched enamel of surface contamination with water. Design Fifteen bond strength measurements were made for bonds prepared to b oth moist and dry etched enamel for each of three test and one control mate rials. Results For two materials (Scotchbond 1 and Prime and Bond 2.1) the bond st rength was not affected by the presence of water on the etched enamel surfa ce. A mean bond strength in excess of 25 MPa was achieved for both material s under all conditions. One material (Optibond Solo) showed a 30% increase in bond strength when bonds were formed under wet condition (21.10 MPa comp ared with 15.35 MPa). The bond strength of the control material, a conventi onal unfilled bonding resin, decreased markedly with aqueous contamination (9.14 MPa compared with 26.75 MPa). Conclusion Etched enamel should be rehydrated routinely prior to bonding co mposite resin to its surface using a water displacing dentine bonding syste m.