Dissolution rate behavior of fluoridated apatite pellets.

The dissolution rate of synthetic fluoridated apatite pellets with various fluoride content was measured in acetate buffer solution at pH 4.0. The dissolution rate decreased with degree of fluoridation. The rate decreased greatly at low fluoride levels. The experimental data were analyzed by means of a diffusion-controlled model and compared with the solubility data. This model showed that the initial dissolution rate is greatly affected by both the solubility and the overall mass transfer resistance. Overall mass transfer resistance is affected by fluoride content.