Relationship between plasma, dentin and bone fluoride concentrations in rats following long-term fluoride administration.

A detailed knowledge of fluoride (F) pharmacokinetics is necessary if its pharmacologic and toxicologic effects are to be adequately understood. In the present study plasma F concentrations have been analysed using repeated blood samples taken from the ethmoidal sinus of rats given 25, 50, 100 and 150 p.p.m. F in drinking water ad libitum for 79 days. A close relationship between the F-concentration in the drinking water and plasma F concentrations was found. When the administration of F was stopped, a rapid decline in plasma F concentration was noted during 48 hrs in all groups. The plasma F concentrations in the 25 p.p.m. group returned to preexperimental levels but remained elevated in the other groups. The F concentrations of dentin and bone were determined and calculated on a dry fat free basis. The results show that there was a close relationship between plasma, bone and dentin concentrations.