Bond strength to deep coronal dentin: effect of bonding strategies.

The aim of this study was to evaluate bond strength at the composite-adhesive-deep dentin interface following pre-treatment with sodium hypochlorite using 4 different types of enamel-dentin adhesive and a composite for the core. From 60 healthy human molars, cylindrical samples (3 mm high) were obtained using a special slow-speed saw. Cavities with 2-5-mm diameters were made in all the samples. Samples were assigned to 8 groups, 4 groups were designated as experimental groups and were irrigated with NaOCl and the other 4 groups designated as control groups were irrigated with distilled water. Adhesive systems were applied to the samples and then restored using a core build-up composite. Samples were subjected to shear stress test using an electronic dynamometer. The data were analyzed using one-way ANOVA and the Tukey test (P<0.05). The results, in terms of bond strength, demonstrate that the two-step self-etch adhesive systems generate a stronger bond than the other systems considered in the study (P<0.05). The results also show that pre-treatment with hypochlorite does not seem to influence the bond strength of self-etch adhesive systems. This in vitro study demonstrates that there exist differences in bond strength between self-etch and etch & rinse adhesive systems on deep dentin pretreated with sodium hypochlorite to simulate endodontic treatment.