The bonding of composite resin to moist enamel

Objective To determine the effect on the bond strength of modern dentine bonding agents to etched enamel of surface contamination with water. Design Fifteen bond strength measurements were made for bonds prepared to both moist and dry etched enamel for each of three test and one control materials. Results For two materials (Scotchbond 1 and Prime and Bond 2.1) the bond strength was not affected by the presence of water on the etched enamel surface. A mean bond strength in excess of 25 MPa was achieved for both materials under all conditions. One material (Optibond Solo) showed a 30% increase in bond strength when bonds were formed under wet condition (21.10 MPa compared with 15.35 MPa). The bond strength of the control material, a conventional 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 composite resin to its surface using a water displacing dentine bonding system.