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Microleakage of Class V resin-based composite restorations using five simplified adhesive systems.

PURPOSE
To evaluate microleakage at enamel and dentin margins of Class V resin-based composite (RBC) restorations using five simplified adhesive systems, one self-etching adhesive, three commercial one-bottle adhesives and one experimental one-bottle adhesive.


MATERIALS AND METHODS
Class V cavities (3 mm x 2 mm x 2 mm) were prepared in sound human molars with occlusal margins in enamel and gingival margins in dentin/cementum. Etch & Prime 3.0 (Degussa), Single Bond (3M), PQ1 (Ultradent), Prime & Bond NT (Dentsply) and Experimental BEH (Dentsply DeTrey) were applied strictly according to manufacturers instructions. All adhesive systems were applied on etched substrates, except for the self-etching adhesive Etch & Prime 3.0. Cavities were restored with Z100 RBC. After finishing and polishing, teeth were thermo-cycled (x 700, 5-55 degrees C, 60 s dwell time). Specimens were coated with nail varnish, immersed in silver nitrate for 2 hours and sectioned longitudinally with a diamond disc. The extent of leakage was measured and ranked using a 0-4 scale.


RESULTS
Statistical analysis using Kruskal-Wallis test revealed significantly higher leakage scores (P < 0.001) for Etch & Prime 3.0 on enamel when compared to all other adhesive systems. Regarding dentin margins none of the systems completely eliminated microleakage. PQ1 had significantly lower scores (P < 0.05) when compared to Etch & Prime 3.0 and Single Bond. No statistically significant difference was observed for the other groups.