Deposition of Fluorine in the Bones and Teeth of the Growing Rat

Rats 30 days of age received 10 p.p.m. F as sodium fluoride for a period of 420 days. At various intervals during this period representative rats were sacrificed and the molar teeth, femurs and mandibles were analyzed for fluorine. It appears that the growing rat shows a diminishing ability to store fluorine in the bones and teeth with advancing age and after the period of rapid growth accumulates little or no additional fluorine. Rats put on a fluoride regimen at various ages of from 30 to 330 days without prior exposure to fluorine, and receiving equal quantities of fluorine, also showed a pronounced decreasing capacity to incorporate fluorine in the bones and teeth with advancing age. The results agree with previous evidence that the animal body accumulates fluorine at a comparatively rapid rate during growth, but reaches a relatively constant level of skeletal fluorine at maturity. This is maintained throughout the remaining years of life so long as the fluorine intake remains stabilized.