Abstract
Mg-containing fluoridated hydroxyapatites with various fluoride contents were synthesized (80℃ and pH 7.4) to examine the effect of Mg2+-F- interrelation on their physicochemical properties, and compared with a corresponding Mg-free series. The a-Axis dimensions of Mg-containing fluoridated hydroxyapatites decreased with the increase of fluoride content and seemed to decreas emore with the increase of magnesium content. The c-axis dimensions decreased with the increase of magnesium content over the whole range of fluoride content. The Mg content of the apatites increased slightly with the degree of fluoridation despite the constant magnesium concentration in the feed solution. With the increase of fluoride content, the crystallinity varied differently in each series: Mg-free fluoridated hydroxyapatites showed a minium crystallinity at a low fluoride content; in those with a lower Mg content this was obliterated; and in the series with a higher Mg content, crystallinity rose to a maximum at about half of the maximum fluoride content, although crystallinity of F-free Mg-containing hydroxyapatites decreased monotonically with the increasing Mg content. Such a crystallinity behavior in each series was not analogous to the solubility behavior. A macroscopic mass transfer model for crysal growth has been proposed.
