Phosphate exchange in hydroxylapatite, enamel, dentin, and bone. II. Effect of fluoride on the exchange.

In previous studies of the reactions of fluoride ion with synthetic hydroxylapatite and powdered enamel and dentin (1,2), it was thought that low concentrations of fluoride ion might be affecting the rate of recrystallization of the apatites. Neuman et al. (3) found that fluoride impregnation had no effect on calcium and phosphate exchange of glycol-ashed bone. The experiments described below were designed to study the effect of various amounts of fluoride on the phosphate exchange of various mineralized tissues and synthetic hydroxylapatite. The fluoride was introduced in the buffer solutions, and some of the tissues studied were previously fluoridated either in vitro or in viva.