The in vitro Uptake of Fluoride by Secretory and Maturation Stage Bovine Enamel

Abstract

The objectives of this study were to determine the specific surface area of secretory-stage and of maturation-stage enamel, to compare the fluoride uptake by isolated enamel at these two stages on a surface-area basis, and to examine the effect of the organic matrix on the fluoride uptake by whole enamel. Fetal bovine secretory and maturation stage enamel samples were collected, and a portion of the enamel at each developmental stage was treated with hydrazine for removal of the organic matrix. The specific surface areas of the enamel mineral, as determined by the multi-point BET method, were 59.3 m2/g in the secretory stage and 37.9 m2/g in the maturation stage. Whole and deproteinated enamel samples were equilibrated in buffered solutions containing 10(-5) to 10(-3) mol/L fluoride, and the uptake was measured with a fluoride specific electrode. The results indicate that the in vitro fluoride uptake was controlled solely by the surface area of the apatitic mineral and that the organic matrix did not contribute to the fluoride uptake.

Characterization of the porosity of human dental enamel and shear bond strength in vitro after variable etch times: initial findings using the BET Method

“…Still, the number of studies on dental enamel that used the gas absorption method is limited. 10,25,26 We sought to expand on the knowledge of enamel topography by using this same method in our studies to compare how enamel properties are altered by acid-etching procedures.…”

Surface Analysis of Etched Molar Enamel by Gas Adsorption

“…Still, a literature search identified only two studies in dental enamel that utilized the gas absorption method (Misra et al, 1978;Fridell et al, 1988). Only one was performed on human dental (Misra et al, 1978).…”

The Effect of Fluoride On Apatite Structure and Growth

“…After this forming stage, the fluoride content in the surface region of enamel continuously increases up to a few 1000 ppm during the maturation stage and further still in the oral environment after tooth eruption. Previous studies unveiled several mechanistic aspects regarding fluoride incorporation into the forming enamel: (a) The fluoride levels in the developing enamel are directly related to plasma fluoride levels (Speirs, 1986), (b) the enamel organ cells may not actively regulate the fluoride transport (Bawden et al, 1987), and (c) fluoride incorporation into the crystals may depend on the available surface area of enamel mineral (Fridell et al 1988). Under in vivo situations during the secretory stage of amelogenesis, it is likely that abundant matrix proteins coat enamel crystal surfaces, thereby retarding fluoride incorporation into the forming enamel mineral.…”