Microleakage of hydrophilic adhesive systems in Class V composite restorations

Purpose: To investigate the microleakage of four hydrophilic adhesive syste ms: one "multiple-bottles" (Scotchbond Multi-Purpose Plus); two "one-bottle " (Single Bond, Stae); and one self-etching (Etch & Prime 3.0). Materials a nd Methods: 120 bovine incisor teeth were divided into four groups (n = 30) and Class V cavities were prepared at the cemento-enamel junction. The cav ities were restored with the adhesive systems and with Z100 composite. The teeth were thermocycled 1,000 times between 5 +/- 2 degreesC and 55 +/- 2 d egreesC with a dwell time of 1 min, and then placed in a 2% methylene blue dye (pH 7.0) for 4 hrs, washed and sectioned vertically through the center of the restorations. The qualitative evaluation was made by three examiners who distributed pre-established scores (0-4) for each tooth using a stereo microscope at x30 magnification. Results: In enamel margins little microlea kage was observed and the Kruskal-Wallis analysis did not show differences. In dentin margins the KruskaI-Wallis and multiple comparison analyses were applied: microleakage was significantly greater with Stae (median 3) and S cotchbond MP Plus (median 4). Single Bond (median 1) and Etch & Prime 3.0 ( median 2) showed the best results in dentin margins, and the statistical an alysis did not demonstrate differences in microleakage among these groups.