Bond strength of a sealant to permanent enamel: evaluation of 3 application protocols

The purpose of this study was to compare sealant-enamel bond strengths of 3 application protocols.

Sixty extracted third molars were randomly distributed into 3 groups according to the sealant's application protocol. The enamel was conditioned with: phosphoric acid in group 1; phosphoric acid and a single-bottle dentin bonding agent in group 2; and a self-etching adhesive in group 3. The specimens were thermocycled and tested in a shear mode at a cross-head speed of 1 mm/minute until fracture. Groups were compared using Kruskall-Wallis one-way analysis of variance and Mann-Whitney U tests.

No statistically significant difference was observed between groups 2 and 3 (P=.96), but both groups showed significantly higher bond strength than group 1. Group 3 appeared to be the most reproducible application protocol as shown by its coefficient of variation (27).

Self-etch adhesives are potentially attractive because of the easier clinical protocol required, provided that they have similar bond strengths compared to other products. The bond strength tests used in this study suggest that self-etch adhesives are equivalent to those using a separate bonding agent. Long-term clinical trials should be performed to assess performance of self-etch adhesives before definitive conclusions can be drawn.