Project: Research project

Project Details


Our long-term objective is to provide data and insights that can maximize
the cariostatic benefits of fluoride with the minimum degree of adverse
side effects. Previous studies have shown that the fluoride levels of the
oral fluids and the developing enamel are functions of plasma fluoride
levels as are the development and severity of enamel fluorosis and the
degree of cariostasis. Hence, several studies on factors that may
influence plasma and other tissue fluoride levels are proposed.
Physiologic variables that may be responsible for the observed circadian
rhythm in plasma fluoride levels will be examined in dogs and rats. These
include cyclic variations in the soft tissue distribution of fluoride, the
magnitude of extra-to-intracellular pH gradients, the trapping of fluoride
in the alkaline environment of secreting parietal cells and duodenum, and
the renal handling of fluoride. There are indications that the fractional
retention (balance) of fluoride may be influenced by the dose size and
frequency. This possibility will be examined in acute studies with dogs
and chronic studies with rats. A study with five species of laboratory
animals to quantitatively compare the major features of fluoride metabolism
and the ionic compositions of saliva will be done. This information will
provide a data base for the selection of appropriate animal models in
future studies. As an extension of continuing studies with rodents, the
cariostatic efficacy of systematically derived fluoride will be compared to
orally administered fluoride. Correlations between caries scores and
Streptococcus mutans counts will be determined. Efforts will be made to
determine when the developing molar enamel of rats is susceptible to
fluorosis. When the molar enamel is in discrete developmental stages,
single fluoride doses will be given. After eruption, the teeth will be
examined microradiographically for evidence of fluorosis. In the clinical
dental setting or among patients taking high doses of fluoride for the
treatment of osteoporosis, epigastric distress may be a limiting side
effect. Therefore, the effects of sodium fluoride and of MEP at different
concentrations in neutral or acidic solutions on rat gastric mucosal blood
flow and structure will be determined. In related studies with dogs,
portal and hepatic vein fluoride and enzymatic concentrations will be
determined after the intragastric administration of fluoride ion or MFP.
These studies should contribute to our understanding of the metabolism,
toxicity and cariostatic mechanism of fluoride.
Effective start/end date7/1/813/31/96


  • Medicine(all)
  • Dentistry(all)