Dental fluorosis as related to the concentration of fluoride in teeth and bone

Rats (N = 58), given a diet low in fluoride, were stomach-fed solutions of NaF and (NH4)3AIF6 in amounts corresponding to 3.3, 8.3, and 16.5 microgram of fluoride per gram of body weight. After five weeks, the incisors were scored for fluorosis and samples of the incisors and mandibles were analyzed for fluoride. Less fluoride was deposited in teeth and bone from AIF6, than from NaF at all dosage levels. Less fluorosis also developed from AIF6, except at the lowest dosage level, which produced very little fluorosis in either group. Both incisor fluoride and fluorosis scores increased with increases in ingestion of fluoride. In a larger group of rats (N = 101) that had been on different fluoride regimens, the fluoride concentrations of the incisors were grouped according to the fluorosis scroes. There was a consistent trend of increase in fluoride with increase in fluorosis scores, but each score had a wide range and overlap in fluoride concentrations.