Absorption, Distribution in Body Fluids, and Bioavailability of Fluoride

Abstract

The mechanisms by which fluoride acts in caries prevention and in the therapy of osteoporosis can be understood only in the light of the pharmacokinetic behavior of fluoride. More detailed studies of the dynamics of fluoride absorption, distribution, retention in hard tissues, and excretion in urine, saliva and sweat are now possible, since modern and more sensitive techniques of F⁻ analysis have become available, e.g. F⁻-specific electrometry and gas chromatography. They provide a continuous follow-up of F⁻ levels in body fluids. The concentrations of free F⁻ ions in plasma and saliva of man, and the rate and duration of F⁻ elevation in these body fluids following fluoride uptake and absorption are of special importance with regard to the availability of fluoride for the calcified tissues. Therefore, we evaluated fluoride levels in human plasma and saliva during 24-h periods under controlled dietary conditions.

The study was supported by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 92, University of Würzburg. The authors wish to thank Mrs. H. BLEIFUSS and Mrs. I. STAHR for their skilful help during the study, as well as the dental students of the Würzburg University for their cooperation as volunteers.