Comparative Evaluation of Microtensile Bond Strength of Three Adhesive Systems.

The aim of this study was to assess the microtensile bond strength of three universal adhesives to dentin and enamel. Sixty extracted human third molar teeth were chosen and divided into six groups regarding the adhesive (G-Premio Bond, Clearfil S3 Bond or Single Bond) and tooth surface. All the applied bonding agents were universal adhesives. The teeth were polished and the adhesives were applied; then the teeth were restored with composite resin. The samples were mounted in acrylic resin and sectioned. The specimens were subjected to a universal testing machine and the microtensile bond strength was measured. The failure mode of each specimen was determined under a stereomicroscope. Data were analyzed using two-way ANOVA (α=0.05). The microtensile bond strength of G-Premio Bond to enamel and dentin was 11.79±8.27 and 17.55±9.47 MPa, respectively which was not significantly different from the values in Single Bond group (15.59±10.66 and 17.19±10.09 MPa to enamel and dentin, respectively; P>0.05). However, the values for Clearfil S3 Bond were 7.11±4.23 and 7.88±8.83 MPa to enamel and dentin, respectively, which were significantly lower than the values for G-Premio Bond (P<0.05). Scanning electron microscopic (SEM) images showed that the adhesive failure was dominant in both enamel and dentin groups and in all adhesive systems. G-Premio Bond and Single Bond provided higher microtensile bond strength compared with Clearfil S3 Bond. Universal adhesives with their acceptable performance can be applied in self-etch mode on both enamel and dentin.