Evaluation and comparison of two current self etching adhesives on sealing enamel margins Objectives: To evaluate effect of phosphoric acid etching on microleakage of two current self-etching adhesives on enamel margins in comparsion with that of a conventional total- etch system. Methods: Sixty buccal class V cavities were prepard with dentin and beveled enamel margins in extracted human premolar teeth and randomly divided into five groups of 12 specimens etch. Group 1 was bonded with Clearfil SE bond, group 2 with 35% phosphoric acid etching of enamel margins plus Clearfil SE bond, group3 with i bond, group4 with 35% phosphoric acid etching of enamel margins plus i bond and group5 with Scotchbond multi-purpose. After 2th of 100% humidity storage, the teeth were thermocycled, immersed in adhesive dye; sectioned buccoligually and enamel margins microleakage were evaluated on a scale of 0 to 2. Results: Statistical analysis revealed no significant differences between groups1 and 2 or groups 1 and 5, but there were statistically significant differences between group 3 and 4 or group 3 and 5. Conclusion: The findings suggest that, Clearfil SE bond can seal enamel margins effectively with no need of alternative etchant but enamel margins should be etched with phosphoric acid when i bond is used.