Effect of phosphoric acid etching of enamel margins on the microleakage of a simplified all-in-one and a self-etch adhesive system.

Sixty buccal Class V cavities with beveled enamel margins were made at the cemento-enamel junction of extracted human premolars and randomly divided into five groups of 12 specimens. Clearfil SE bond was applied to Group 1; Group 2 had 35% phosphoric acid etching of the enamel margins plus Clearfil SE Bond; Group 3 was administered iBond; Group 4 had 35% phosphoric acid etching of the enamel margins plus iBond and Scotchbond Multi-Purpose was used on Group 5. All the groups were restored with a resin composite. After 24 hours of storage in 100% humidity, the samples were thermocycled, immersed in a dye solution and sectioned buccolingually and microleakage of the enamel margins was evaluated on a scale of 0 to 2. Differences among Groups 3 and 4 and Groups 3 and 5 were significant (p < 0.05); however, no statistically significant differences were found between the other groups (p > 0.05). The current study shows that simplified all-in-one adhesive systems need pre-etching of the enamel margins with phosphoric acid for an effective seal.