The remineralization effect of topical fluoride agents on artificial enamel caries

Lee, Min Sun; Park, Deok Young; Ma, Deuk Sang

Abstract

OBJECTIVES
The aim of this study was to compare the remineralization effect of the topical fluoride agents on artificial enamel caries, under the chemical pH cycling model, using surface microhardness.
METHODS
Bovine enamel specimens, embedded in acrylic resin with the labial surfaces exposed, were developed artificial enamel caries. Thereafter, this study used 56 samples on VHN 25-45. The experimental groups were divided into 4 groups: control, 2% NaF solution, 1.23% APF gel, 5% NaF varnish. Samples, except in the control group, were applied to each topical fluoride agent for 4 minutes. All groups were exposed to a pH cycling model, which consisted of demineralization (4 hours) and remineralization (20 hours) for 17 days. The Vickers surface microhardness number (VHN) was measured, using the microhardness tester. The results were analyzed, using a repeated measures analysis of variance of a general linear model, and compared the baseline, each day, using a contrast analysis (simple) about within a subject factor at a significance level of 0.05.
RESULTS
Result of a repeated measures analysis regarding the surface microhardness of topical fluoride agents, there were significant differences at P-values of within and between the subject factor (P<0.001, 0.034). VHN of the experiment groups were higher than that of the baseline, until 10 days after a fluoride application, except in the control group (P<0.001). However, there were no significant differences between VHN at the baseline and 14 days after a fluoride application (P>0.05).
CONCLUSIONS
In this study, although there were significant differences at P-values of within and between the subject factor, there were no significant differences between the experiment groups on chemical pH cycling model in vitro, and it was limited to utilize this result in a clinical situation of the fluoride application.