Method: Class V cavities ( 3X4X2 mm) were prepared on the buccal surfaces of 30 human molars, Teeth were classified into three groups . Group 1: Adper Single Bond2 was used . Group 2: l-bond was applied to the cavities . Group 3: is a control group of composite resin restoration without bonding was used. All cavities were restored with FiltekZ250 composite resin. Then stored in distilled water at 37° c for 24 hours then thermal cycled for 500 cycles. The root apices all the surfaces were cpated with wax, except for 1mm from the margins, The teeth were immersed in a 3% methylene blue dye solution for 24 hours, and blot-dried and sectioned longitudinally . The sections (n=20 for each group) were assessed for microleakage of dye penetration using a stereomicroscope
Results: A Mann-Whitney test was demonstrate a highly significantly more dye penetration in Group I than in the other groups at both the occlusal and gingival scores (p<0.05). When comparing the occlusal and gingival scores for each group, the Wilcoxon Rank test showed significant difference in dye penetration for all groups where the dentin margins subjecting a highly significant dye penetration scores than enamel margins. Etch &rinse adper single bond2 adhesive record a lower significant scores of dye penetration than self etch adhesive I-bond at both enamel and dentin margins.
Conclusion: All adhesive systems exhibited dye penetration (leakage) at both occlusal (enamel) and gingival (dentin) margins. Etch and rinse system still considers a gold standard one. At enamel and dentin margins, Adper single bond2 revealed significantly less leakage compared to the other adhesive group I-Bond.