The Effect of Different Multimode Adhesives On Microleakage of Class V Composite Restorations in Three Etching Modes

Objective: The aim of this in vitro study was to evaluate the effects of different multimode adhesives in three etching modes on occlusal and gingival microleakage of Class V composite restorations. Materials & Methods: One hundred and twenty human molars were randomly assigned to four groups (G2-Bond Universal GBU, Clearfil Tri-S Bond Universal CTU, OptiBond Universal OBU, and Tokuyama Universal Bond TUB), and then three etching subgroups (total etch, self etch, and selective etch) (n = 10). Standard Class V cavities were prepared and restored with a microhybrid resin composite. All teeth were exposed to a 30-second thermal cycle for 10000 times at 5–55°C and then kept in 0.5% basic fuchsine solution for 24 hours. After the teeth were buccolingually cut, dye penetration was evaluated under a light microscope. Scanning electron microscopy analysis were also performed. Kruskal–Wallis and Mann–Whitney U tests were used for statistical evaluation (p  0.05). Results: GBU, CTU, OBU, and TUB showed the least microleakage score with self etch, selective etch, total etch and self etch modes, respectively. In self etch mode, GBU had the least and CTU had the most microleakage on occlusal margin (p < 0.05), while there was no difference among adhesives on gingival margin. In total etch mode, GBU had the most microleakage on gingival margin (p < 0.05), while there was no difference on occlusal margin among adhesives. Conclusion: Occlusal or gingival microleakages of Class V composite restorations vary depending on the adhesives and etching modes.