Resin composites: Strength of the bond to dentin versus surface energy parameters

Objectives The strength of the bond to dentin treated with two adhesive systems was investigated. The bond was tested with six resin composites. It was hypothesized that the surface energy parameters of composite and adhesive-treated dentin would influence the bond strength. Methods The investigated adhesive systems were Prompt L-Pop and OptiBond FL, which were used as recommended. The bond strengths were tested in shear. The dispersive, the acid, and the base component of the surface energy were determined from measurements of the contact angle of four test liquids placed on the composites and on the adhesive-treated dentin. Relationships were investigated by regression analysis. Results The strength of the bond to dentin varied with the resin composite and with the adhesive system. The bond strength with both adhesive systems increased with the base component of the surface energy of the resin composites. Dentin treated with OptiBond FL had higher surface energy and gave higher bond strengths than was the case with Prompt L-Pop. Significance It is advisable to use a resin composite that is compatible with the adhesive system.