No effect of waxed dental floss on enamel fluoride uptake or on enamel dissolution changes

Enamel specimens were flossed in vitro with "waxed" dental floss and then treated with water, Act, Meridol, or Elmex Gel to evaluate the effect of "waxed" floss on the enamel fluoride uptake and on the enamel dissolution rate. The flossed and treated enamel was etched 4 times successively in 2N HCl for 5, 10, 15 and another 15 s. The concentrations of fluoride, calcium and phosphorus were assayed in the etching solutions. The enamel fluoride concentration was significantly increased in only the first layer of the Elmex Gel group compared to the other 3 groups. Respective etching depths were similar for the water, Act and Elmex Gel groups. However, the first layer in the Meridol group was less etched than that in the 3 other groups. This study showed that "waxed" dental floss did not compromise the fluoride uptake by surface enamel after treatment with a concentrated acidic topical fluoridating agent. Moreover, previously reported results showing that Meridol solution containing SnF2 and amine fluoride 297 significantly decreased the in vitro dissolution rate of enamel were confirmed by the present study. Even though the enamel was first treated with "waxed" dental floss, the SnF2/amine fluoride 297 still produced a decreased enamel dissolution rate.