Influence of four new dentin bonding agents on the coronal microleakage of composite resin restorations

The marginal seal of a restoration is one of the most important factors for clinical success. Studies have reported several advantages for dentin bonding agents in an effort to obtain strong and durable bonds between resin-based composites (RBC) and the tooth structure. This invitro study compared the microleakage via dye penetration of four new commercially available dentin bonding systems (DBS). These adhesive materials improve the quality of the bond while simplifying clinical procedures. Method & Materials: Standaridized Cl V cavities (3mm×2mm×2mm) were prepared on the buccal and lingual surfaces at the cemento-enamel junction of 20 intact extracted human premolars and restored with a microfilled RBC (Filtek A110) following application of either Single Bond (one-bottle total-etch DBS), Prompt L-Pop (one-step self-etch DBS), Clearfill SE Bond or AdheSE (two one-step self-etching DBSs). The teeth were thermocycled, coated with wax and nail varnish and immersed in 2% basic fuschin for 7 days and sectioned longitudinally. The extent of dye penetration in the occlusal and gingival walls were qaulitatively evaluated under stereomicroscopy (×30). The data were analyzed by the Kruskal-Wallis nonparametric and Mann-Whitney U tests. No significant differences were evident between the sealing ability of self-etch DBSs and total-etch adhesive in neither occlusal nor gingival margins. There were significant difference among occlusal and gingival walls in all of the specimens (P<0.0001) and gingival walls presented more leakage than occlusal walls. Among four groups, the difference between microleakage of occlusal and gingival margins was statistically significant only in AdheSE group (P<0.03) and this DBS had a better sealing ability in occlusal than gingival margins. The self-etch DBSs can provide an effective alternative to conventional total-etch systems.