Effect of conditioner and restorative resin on enamel bond strengths

Purpose: To evaluate the effect of three enamel conditioners and four resto rative materials on enamel shear bond strengths. Materials and Methods: 120 bovine incisors were polished to 600-grit and randomly assigned to three e namel adhesive systems (n=40): Syntac Single Component with phosphoric acid etching (PA-SSC), Syntac Single Component without phosphoric acid etching (SSC), and Experimental Prompt L-Pop (LP1), a self-etching adhesive. The sp ecimens were restored with one of four resin restorative materials (n=10): (1) Compoglass F, a high-viscosity compomer; (2) Compoglass Flow, a low-vis cosity compomer; (3) Tetric Ceram, a high-viscosity resin-based composite ( RBC); and (4) Tetric Flow, a low-viscosity RBC. After thermocycling, shear tests were carried out with an Instron Universal Testing Machine. Mean enam el bond strengths were analyzed with ANOVA and Duncan post hoc test at PI 0 .05. Results: PA-SSC resulted in higher mean bond strengths than LP1, but t he difference was not statistically significant. Both PA-SSC and LPI result ed in statistically higher mean bond strengths than SSC at P less than or e qual to 0.0001. The lowest mean bond strengths of all the groups were obtai ned when SSC was used with an RBC (Tetric Ceram or Tetric Flow). SSC and PA -SSC resulted in statistically higher mean bond strengths when used with a compomer than when used with an RBC, regardless of the viscosity. Although recommended to be used only with compomers, LP1 resulted in statistically s imilar enamel bond strengths when used with the composite of corresponding viscosity (Tetric Ceram vs. Compoglass F; Tetric Flow vs. Compoglass Flow). LP1, however, resulted in higher enamel bond strengths when combined with Tetric Ceram than when combined with Tetric Flow. When the results were poo led for "viscosity", high-viscosity restorative materials resulted in highe r bond strengths than low-viscosity materials at P less than or equal to 0. 041. When the data were pooled for "restorative material", compomers result ed in higher bond strengths than composites at P less than or equal to 0.00 01.