Mg2+-F-interaction during hydroxyapatite formation.

Two series of Mg-containing fluoridated hydroxyapatites with various fluoride contents were synthesized at 80 degrees C and pH 7.4 and compared with a corresponding Mg-free series. The Mg content of the apatites increased slightly with the degree of fluoridation despite the constant magnesium concentration in the feed solution. A small amount of magnesium significantly affected the crystallinity of synthetically fluoridated apatites. The patterns of crystallinity with the increase of fluoride content were unique in each series with different magnesium contents. These phenomena might have been caused by the Mg2+-F-interaction during the apatite formation.