Title: An In-Situ Enamel Fluoride Uptake Model for Fluoride Varnishes
George Stookey, Therametric Technologies, Inc.
Bruce Schemehorn, Therametric Technologies, Inc.
Amy Nuñez (Presenter)
Therametric Technologies, Inc.
William Carr, Therametric Technologies, Inc.
Jenny McClure, Therametric Technologies, Inc.
Objectives: Clinical methods and data assessing enamel fluoride uptake (EFU) from fluoride varnishes are lacking in dental literature. This research was conducted to develop an in-situ model for assessing the deposition of fluoride in enamel following a fluoride varnish application.
Methods: In this double-blind cross-over study, adult subjects (N=10) wore a palatal appliance which held four removable, artificially lesioned human enamel core specimens. Subjects were randomized to five varnish treatment groups which included a placebo varnish (A) and 4 varnishes that differed significantly in the rate of fluoride release in water over 24 hours; the release rates were 112, 3.1, 2.1, and 103% for varnishes B, C, D, and E, respectively. Varnish D was the only clinically-proven cariostatic varnish and served as the gold standard. For each test period, appliances were initially seated in each subjects’ mouth for 5 minutes to allow pellicle formation. Specimens were then treated with the assigned varnish and returned to each subjects’ mouth. Subjects didn’t removed their appliance for four hours and refrained from eating and performing oral care. After four hours, two specimens were removed from the appliance. Subjects continued to wear their appliance for 20 hours, removing it only when eating. Specimens were assayed at four & 24-hrs post-treatment for fluoride uptake using the acid etch technique. Comparisons among groups were performed by ANOVA (p=0.05); individual means were analyzed using SNK analysis.
Results: The average EFU values at 24 hours (Mean ± SEM): Placebo varnish A, 152 ± 12 < B, 1984 ± 139 < C, 3016 ± 100 = D, 3108 ± 203 = E 3331 ± 206.
Conclusions: The calculated aqueous fluoride release of a varnish is not predictive of actual fluoride uptake into enamel. This model appears adequate to assess EFU from fluoride varnishes in-situ.