Alkali-soluble and insoluble fluoride in erupted and unerupted human enamel from a high fluoride area with a low fluorosis score

• Published in: Archives of oral biology Vol. 39; no. 8; p. 679
• Main Authors: Grobler, S R, van Zyl, J F, Stander, I, Kotze, T J
• Format: Journal Article
• Language: English
• Published: England 01-08-1994
• Subjects: Dental Enamel - chemistry; Dental Enamel - metabolism; Fluoridation; Fluorides - analysis; Fluorides - pharmacokinetics; Fluorosis, Dental - etiology; Fluorosis, Dental - metabolism; Humans; Hydrogen-Ion Concentration; Hydroxides; Molar, Third - metabolism; Potassium Compounds; Solubility; Statistics, Nonparametric; Tooth, Unerupted - chemistry; Tooth, Unerupted - metabolism; Toothpastes
• ISSN: 0003-9969
• DOI: 10.1016/0003-9969(94)90093-0

The amounts of fluoroapatite and 'CaF2-like' fluoride (F) were determined in enamel of unerupted and erupted teeth that had been exposed in vivo to 1.8-2.6 parts/10(6) F in the drinking water and to brushing with F dentifrice at least once a day, and occasionally to a F mouth-rinse (0.022% F). Enamel was sampled by acid-etching and the F levels were measured with an adapted F ion-selective electrode. More F was built into the deeper enamel in the high-F area than in a similar low-F area. Unerupted enamel did not etch significantly (p > 0.05) deeper than erupted enamel. No significant differences (p > 0.05) were found in the F concentrations amongst the following: alkali-washed erupted, unwashed erupted, alkali-washed unerupted and unwashed unerupted at the outer most enamel (approx. 6 microns). However the erupted enamel (alkali-washed or not) showed higher F levels than unerupted enamel (alkali-washed or not) between approx. 6 microns and greater than 100 microns. The increase of F for this high-F area was about 100% in the deeper enamel while for a low-F area it was approx. 78% in the most outer enamel with no increase after a depth of about 20 microns. In contrast to a similar low-F area (water F < 0.10 parts/10(6)), no significant 'CaF2-like' F could be detected in erupted or unerupted enamel for the high-F area.