Marginal microleakage of a sealant applied to permanent enamel: evaluation of 3 application protocols.

The purpose of this in vitro study was to investigate and compare the microleakage-occurring after the placement of a light-curing sealant-to unground permanent enamel which had been previously conditioned using 3 different application protocols. Sixty-three molars were randomly distributed in 3 different groups according to the application protocol of the sealant: (1) conditioning of the enamel with 38% phosphoric acid (group 1); (2) conditioning with phosphoric acid and single-bottle dentin bonding agent (group 2); or (3) conditioning with a self-etching adhesive (group 3). Samples were: (1) thermocycled; (2) stained; (3) sectioned; and (4) examined for marginal microleakage. No dye penetration was noted for 25%, 59%, and 40% of cases for groups 1, 2, and 3, respectively. Placement of a bonding agent layer prior to the sealant allows significantly less microleakage than the traditional conditioning of enamel with phosphoric acid alone. The self-etching adhesive used here seems to be an attractive alternative to the acid-etch and adhesive technique for sealant application in young children, since it would simplify the procedure. Clinical trials should be performed to assess the performance of these products before definitive conclusions can be formulated.