Fluoride uptake around cavity walls; Two-dimensional mapping by electron probe microanalysis

This study reports fluoride uptake around the cavity wall of teeth by two-d imensional mapping. Fluoride concentration was measured using the wavelengt h dispersive x-ray analysis (WDX) method. The buccal cavity wall of a human tooth was coated five times with 2% sodium fluoride solution at three-day intervals for 12 days, and then immersed in a normal saline solution at 37 degrees C. After one month, the tooth was bisected longitudinally through t he center of the cavity surface perpendicular to the axial wall. On the pol ished surface of the cut tooth, the fluoride concentration was measured. Fl uoride distribution maps around the cavity wall were drawn using a bundle o f the observed analytical lines, Fluoride uptake from fluoride-releasing ma terials (conventional glass-ionomer cement, light-cured glass-ionomer cemen t, light-cured composite resin, light-cured bonding agent) around the cavit y wall was investigated using the same method. The maps showed higher fluor ide uptake in dentin than in enamel and a strong location dependence of flu oride uptake in a tooth, especially in the dentin, Fluoride uptake from the resin was greater than that from the cement, It was summarized from these results that a two-dimensional map of fluoride uptake can provide valuable information on the cariostatic properties of fluoride-releasing materials.