title: Plaque fluoride concentrations are dependent on plaque calcium concentrations.
abstract: Despite the 1000-fold difference between the fluoride concentrations ([F]) in dentifrices and fluoridated drinking water, clinical and epidemiological studies have shown that they have similar cariostatic effects. This double-blind, crossover study was done to determine whether the [F] in dental plaque is related more to the [F] of the dentifrice used or to the plaque concentrations of calcium and magnesium. The subjects (n = 13) were adults and residents of a city served with fluoridated drinking water. After 1 week of using a fluoridated dentifrice (940 ppm) or a placebo dentifrice, whole saliva and plaque were collected 1.0 h and approximately 12 h after the last use of the dentifrices. The average salivary [F] after brushing with the F dentifrice was higher than after using the placebo. The average plaque [F] 1.0 h after brushing with the F dentifrice was higher than after using the placebo (p < 0.01), but the difference at 12 h was not significant. Plaque [Ca] and [F] were directly related under all experimental conditions (p = 0.0001). The relationships between plaque [Mg] and [F] were weaker and inconsistent. Based on these findings and reports in the literature it is concluded that, for persons whose drinking water is fluoridated, plaque [F] throughout much of the day is not significantly increased by the use of a fluoridated dentifrice. Instead they are directly related to plaque [Ca]. These findings offer at least a partial explanation for why fluoridated dentifrices and drinking water have similar cariostatic effects.
authors.affiliation: Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, Ga 30912-1129, USA. gwitfor@mail.mcg.edu
authors.forename: Gary M
authors.initials: GM
authors.lastname: Whitford
authors.forename: John L
authors.initials: JL
authors.lastname: Wasdin
authors.forename: Tara E
authors.initials: TE
authors.lastname: Schafer
authors.forename: Steven M
authors.initials: SM
authors.lastname: Adair
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002118:Calcium / Q000032:analysis*; D002327:Cariostatic Agents / Q000008:administration & dosage* / Q000032:analysis; D018592:Cross-Over Studies; D003747:Dental Enamel Solubility; D003773:Dental Plaque / Q000737:chemistry*; D003802:Dentifrices / Q000737:chemistry*; D004311:Double-Blind Method; D005260:Female; D005457:Fluoridation; D005459:Fluorides / Q000008:administration & dosage* / Q000032:analysis*; D006801:Humans; D016014:Linear Models; D008274:Magnesium / Q000032:analysis; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry
chemical_list: D002327:Cariostatic Agents; D003802:Dentifrices; D008274:Magnesium; D005459:Fluorides; D002118:Calcium