A comparison of the levels of microleakage of five adhesive systems

Objective: The aim of this study was a comparative assessment of in vitro microleakage of five different new generation self-etching adhesive systems. Materials and Methods: One hundred recently extracted fresh caries-free human permanent molars were used. Teeth were randomly assigned to one of five groups (n = 20). Clearfil S 3 Bond (Group I), Xeno V (Group II), G Bond (guanine-cytosine) (Group III), Optibond All in One (Group IV) and iBond (Group V) were applied, then polymerized with light emitting diode and restored with a nanofill composite. Teeth were coated twice with acid resistant varnish and immersed in 0.5% methylene blue. Specimens were cut bucco-palatinally/lingually, with microleakage scores evaluated on a scale from 0 to 4 under a stereomicroscope and then analyzed under a scanning electron microscope. Results: The differences among the gingival and occlusal microleakage scores of the groups were statistically significant (P < 0.05) (P = 0.043, P = 0.005). Occlusal microleakage scores of Clearfil S 3 Bond and Optibond All in One were considerably lower than those of the other three groups. While the highest microleakage was observed with iBond, there was no statistical difference between the Xeno V and G Bond groups (P > 0.05). The highest gingival microleakage scores were in the iBond group; though, statistically there was no significant difference among the other groups (P > 0.05). Conclusion: The occlusal and gingival microleakage scores of self-etching adhesive systems in this study were satisfactory except for one group (Group V-iBond).