Comparison of microleakage of new generation self-etching adhesive systems in resin composite restorations

Aim: The aim of this study was to assess in vitro microleakage amounts of five different new generation self-etching adhesive systems comparatively in composite resin restorations.Materials and Method: In this study 100 caries-free human permanent molar teeth extracted because of orthodontic or periodontal reasons were used. After extraction, soft tissues on teeth were cleaned with a scaler and polished with brush and pumice. Until the date of use teeth were stored in distilled water at room temperature. Teeth were randomly assigned to five groups (n=20) and standardized class V cavities with 3 mm mesio-distal diameter, 2 mm occluso-gingival diameter and 1.5 mm depth were prepared 1mm below the enamel-cement junction (servical) line of facial surfaces, and enamel margins of the cavities were bevelled in a 0.5-1 mm area with diamond round burs (Diatech, Swiss Dental Instruments, Heerbrugg, Switzerland). Then Clearfil S3 Bond (Kuraray Medical Inc. Japan) in Group I, Xeno V (Dentsply DeTrey, Konstanz, Germany) in Group II, G Bond (GC America) in Group III, Optibond All In One (Kerr Corporation, Orange, CA) in Group IV and iBond (Heraeus Kulzer, Germany) in Group V were applied to prepared cavities, composite resin were placed, and were polymerized by LED device (Light Emitting Diode-Elipar Freelight, 3M ESPE, Germany) according to manufacturers? recommandations. Before finishing and polishing, teeth were immersed into distilled water at 37 oC (Nüve Incubator EN 120, Ankara, Türkiye) for 24 h. After 24 h polishing and finishing of restorations were done with diamond finishing burs (Diatech Dental AG, Heerbrugg, Switzerland) under water and were completed with aluminium oxide coated disks (Sof-Lex, 3M ESPE, St. Paul, MN, USA). Then were subjected to thermocycling 10.000 times with a dwell time of 30 s at 5 ± 2 ºC and 55 ± 2 ºC. Following this, all teeth, except 1mm surrounding of the restorations, were coated twice with acid resistant varnish and stained in 0.5 % methylene blue at 37 oC (Nüve Incubator EN 120, Ankara, Türkiye) for 24 h. Then teeth were sectioned bucco-palatinally/lingually by the help of Isomet 1000 device (Isomet 1000 Precision Saw, BUEHLER, USA) and microleakage of occlusal and gingival walls were scored on a standart 0-4 ordinal scale under stereomicroscope (Olympus SZ 40, SZ-PT, Japan) at 15X magnification. And also SEM (Scanning Electron Microscopy) ( JSM-5600 JEOL SEM, Jeol Co., Tokyo, Japan) photographs of resin-tooth hard tissue interfaces were taken at different magnifications after microleakage assessment. Results of microleakage test were statistically analyzed by Cruskall-Wallis and Mann Whitney U tests.Results: Statistically differences of gingival and occlusal microleakage scores among groups were significant (p<0.05)(p=0.043, p=0.005). Occlusal microleakage scores of Clearfil S3 Bond and Optibond All in One were observed considerably lower than other 3 groups. While microleakage of iBond was determined as the highest, statistically no difference was observed between Xeno V and G Bond groups (p>0.05). As gingival microleakage scores of iBond were the highest; statistically there was no difference among other groups (p>0.05).Conclusion: In our study oral conditions were tried to be simulated by thermocycling. In prepared class V cavities occlusal and gingival microleakage scores of self-etching adhesives were observed successful except one group.