The major long-term objective of this work is to provide data and knowledge that can be used to maximize the beneficial effects of fluoride and minimize the frequency and degree of unwanted side effects. Previous studies supported by this grant have shown that the levels of fluoride in the oral fluids and the developing enamel are directly related to plasma fluoride levels. Thus, the development and severity of dental fluorosis and perhaps the cariostatic effect of the ion are dependent on the quantitative aspects of fluoride metabolism which determine systemic fluoride levels. Several studies of factors that may influence plasma and other tissue fluoride levels are proposed for the next grant period. The only environmental variable taken into account for the determination of the appropriate water fluoride level for a community is the average regional temperature. One of the proposed studies will further examine the effects of the level of water intake on the balance and tissue levels of fluoride and the prevalence and severity of dental fluorosis. The results of this study will also be relevant to the fluoridation of water supplies for the prevention of dental caries. Another study will examine the balance, tissue levels and pharmacokinetics of fluoride and the prevalence and severity of dental fluorosis in diabetes mellitus and diabetes insipidus. These diseases are associated with high levels of urine output and water intake (therefore fluoride intake) and affect over 12 million U.S. citizens. There is good evidence that the urinary excretion and balance of fluoride are affected by the composition of the diet. These effects will be further examined in chronic feeding studies with rats involving four different grains. Another study with human volunteers will examine the effects of diets that tend to alkalinize or acidify the urine on the pharmacokinetics of fluoride. The results of studies done in the 1940s indicated that the fluoride levels of sweat and urine were similar and that fluoride excretion in sweat was quantitatively important under hot and moist conditions. Using modern analytical techniques, it has been determined that sweat fluoride levels are at least an order of magnitude lower than those of urine so it appears unlikely that there are any conditions under which sweat is an important route for fluoride excretion. Two of the proposed studies will examine this matter.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE006113-12
Application #
2129309
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Project Start
1981-07-01
Project End
1996-03-31
Budget Start
1994-04-01
Budget End
1996-03-31
Support Year
12
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Medical College of Georgia (MCG)
Department
Dentistry
Type
Schools of Dentistry
DUNS #
City
Augusta
State
GA
Country
United States
Zip Code
30912
Whitford, G M; Sampaio, F C; Arneberg, P et al. (1999) Fingernail fluoride: a method for monitoring fluoride exposure. Caries Res 33:462-7
Borke, J L; Whitford, G M (1999) Chronic fluoride ingestion decreases 45Ca uptake by rat kidney membranes. J Nutr 129:1209-13
Whitford, G M; Thomas, J E; Adair, S M (1999) Fluoride in whole saliva, parotid ductal saliva and plasma in children. Arch Oral Biol 44:785-8
Steckel, S E; Rueggeberg, F A; Whitford, G M (1999) Effect of resin cure mode and fluoride content on bracket debonding. Angle Orthod 69:282-7
Adair, S M; Hanes, C M; Russell, C M et al. (1999) Dental caries and fluorosis among children in a rural Georgia area. Pediatr Dent 21:81-5
Chen, X; Whitford, G M (1999) Effects of caffeine on fluoride, calcium and phosphorus metabolism and calcified tissues in the rat. Arch Oral Biol 44:33-9
He, H; Ganapathy, V; Isales, C M et al. (1998) pH-dependent fluoride transport in intestinal brush border membrane vesicles. Biochim Biophys Acta 1372:244-54
Whitford, G M (1997) Determinants and mechanisms of enamel fluorosis. Ciba Found Symp 205:226-41; discussion 241-5
Whitford, G M (1996) The metabolism and toxicity of fluoride. Monogr Oral Sci 16 Rev 2:1-153
Whitford, G M; Adair, S M; Hanes, C M et al. (1995) Enamel uptake and patient exposure to fluoride: comparison of APF gel and foam. Pediatr Dent 17:199-203

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