Effect of fluoride/essential oils-containing mouthrinse on the microhardness of demineralized bovine enamel.

Purpose: To assess the ability of a fluoride mouthrinse containing a fixed combination of essential oils (thymol, menthol, eucalyptol, and methyl salicylate) to inhibit demineralization as compared with that of a clinically established NaF rinse.

Methods: Inhibition in sound bovine enamel to demineralization was assessed utilizing a cyclic T/R/D (treatment/remineralization/demineralization) in vitro model where Knoop microhardness was monitored over 6, 12, and 18 T/R/D cycles.

Results: Both fluoride-containing mouthrinses resulted in statistically significant increase in microhardness when compared to the non-fluoride control mouthrinse, possibly demonstrating and validating the in vitro model's ability to parallel the clinically established benefit of a 0.022% NaF rinse to inhibit demineralization. In addition, the test formulation was shown to be "at least as good as" the NaF positive control in increasing enamel microhardness following each of the 6, 12, and 18 T/R/D cycles.