Effect of pre-etching on sealing ability of two current self-etching adhesives.

We evaluated the effect of phosphoric acid etching on microleakage of two current self-etching adhesives on enamel margins in comparison to a conventional total- etch system.methods: sixty buccal class v cavities were made at the cemento-enamel junction with beveled enamel margins of extracted human premolar teeth and randomly divided into five groups (12 specimens in each group). group 1 was applying with clear-fil se bond, group 2 with 35% phosphoric acid etching of enamel margins plus clearfil se bond, group3 with i bond, group 4 with 35% phosphoric acid etching of enamel margins plus i bond and group5 with scotchbond multi-purpose. all groups restored with a composite resins. after 24 hours storage with 100% humidity, the samples were thermocycled, immersed in a dye solution and sectioned buccoligually and enamel margins microleakage were evaluated on a scale of 0 to 2.results: the differences between groups 1 & 3 and groups 3 & 4 were significant (p<0.05) but no significant differences between groups 1 & 2 or 1 & 5 were observed.conclusion: the findings suggest that all-in-one adhesive systems need pre-etching enamel margins with phosphoric acid for effectively seal.