Effect of surface-active agents on fluoride enamel interactions. II.

Abstract

The effect of surface-active agents (SAA) on fluoride deposition in enamel from topical application was studied in vitro. Preliminary imbibition experiments with blocks of human enamel showed that some SAA increased the fluoride penetration in depth during a 5-min fluoride application. Inclusion of several SAA in the fluoride solutions caused increased deposition of apatitically bound fluoride during a postapplication incubation period. Detailed observations on cetylpyridinium chloride or Lodyne S-110 fluorosurfactant showed that addition of these SAA to solutions of KF at pH 8.5, 7.0, and 5.0 tended to decrease the immediate penetration of fluoride at the acidic pH without compromising fluorapatite formation during the postapplication incubation. The fluorapatite formation was greatly enhanced when Lodyne S-110 was added to a treatment solution of KF with orthophosphate at pH 5. Addition of cetylpyridinium chloride to the currently frequently used acid phosphate fluoride solution increased the ability of this formulation to cause fluorapatite formation in enamel. Both SAA reduced the immediate fluoride penetration from acidic solutions of ammonium fluoride with orthophosphate without compromising postapplication fluorapatite formation and increased fluorapatite formation from application of neutral solutions.