Efficacy of composite surface sealers in sealing cavosurface marginal gaps

Objectives: The ability of commercially available composite surface sealers to penetrate and seal a controlled gap formed in all-enamel margin, Class V in vitro resin composite restorations in human bicuspids was examined. Methods: A fluorescent red dye (Rhodamine B) was incorporated to a variety of commercially available composite surface sealers. The teeth were restored using acid etching, a dentin bonding agent, and a photo-activated microfilled composite, finished, polished, and sealed. The teeth were thermocycled and then immersed in an aqueous solution of a green fluorescent dye (Dextran-Fluorescein) to evaluate the sealing ability and penetration of surface sealers into the controlled gaps formed at unbonded margins. Teeth were embedded, sectioned, and images recorded using confocal microscopy. Results: All sealers leaked, and use of a dentin-bonding agent to seal the gap performed better than the commercial sealing products. Conclusions: Commercial surface sealers evaluated were not able to totally seal controlled-size cavosurface gaps, and sealer penetration into the controlled gap varied greatly. Composite restorative procedures should be performed to obtain ideal marginal sealing, minimizing the need for composite surface sealers, which were found to not totally seal an exposed cavosurface margin. Use of a dentin-bonding agent may provide better sealing than commercial products developed specifically for this purpose.