Abstract
The purpose of this study was to examine the effects of fluoride varnish on the dentin. Experiments were made in vitro of applications of fluoride varnish with the intact dentin as material. Fluoride varnishes contained 5% and 2% NaF were used, and non-fluoride varnish as control. The fluoride content in succesive layers of dentin was determined by chemical analysis, using an ORION ion meter (model 801) and fluoride ion electrodes. The calcium content was determined by Yanagisawa's method, using plasmocorinth B.
The distributions of fluorine, calcium and phosphorus in the dentin treated with fluoride varnish have been studied by means of electron probe microanalysis.
An acid solubility test was made to determine the released calcium content from dentin treated with varnishes into a 0.4M acetate-sodiumacetate buffer (pH 4.0) during three hours in every thirty minutes.
In the experiments of applications of fluoride varnish on the dentin, the fluoride content of the dentin was increased, especially the outer surface layer of dentin contained greater amounts of fluoride. The distribution of fluoride was about 70-100 μm from the outer surface layer of dentin. An acid solubility test proved that the acid resistance was increased as 2-6 times much in the fluoride varnish treated dentin as the control varnish.
