Efficacy of various commercial dentin bonding systems

Abstract

Objectives. The purpose of this study was to test the bonding efficacy of fifteen commercial dentin bonding systems and also to determine the effect of various commercial dentin cleaners on bonding and dentin hardness. Methods. Each commercial bonding system was examined by two methods: 1) measuring the maximum contraction gap of a light-cured composite in a cylindrical dentin cavity; and 2) determine the tensile bond strength to a flat dentin surface. In addition, various commercial dentin cleansers were investigated to determine if dentin hardness was reduced after cleaning. As a control, the dentin surface was cleaned with neutralized EDTA prior to the combined application of an experimental dentin primer, a commercial bonding agent, and a commercial light-cured composite. Results. The study demonstrated that complete marginal adaptation was obtained by the experimental dentin bonding system used as the control. However, it was not possible to completely prevent gap formation with the commercial dentin bonding systems tested. A high correlation ( R=0.88) was observed between maximum contraction gap width and reduction of hardness only in the group in which the dentin was rinsed after cleaning. Significance. It is very important to combine optimal dentin cleansers, primers, and bonding agents to compensate for the polymerization contraction stress of the composite. Therefore, it was speculated that the commercial dentin bonding systems tested in this study consisted of unsuitable materials.