Effects of P₂O₅ and CaF₂ on the hydroxyapatite layer formation in bioactive glasses

초록

It has been believed that the biocompatibility of bioactive glasses is directly related to the hydroxyapatite crystal formation on them, and the hydroxyapatite formation depends on the composition of the glasses. In the glass system of 55.1 % SiO₂, 4.0% B₂O₃, 2.6% P₂O₅, 9.6% Na₂O, 28.7% CaO(mole%), the dependence of P₂O₅ and CaF₂ on hydroxyapatite crystal formation was studied. Hydroxyapatite crystal was obtained when low alkali oxide and high silica containing bioactive glass was reacted in tris-buffer solution for a long time. The substitution of CaF₂ for CaO and P₂O₅ for Na₂O in the above glass system promoted the formation of hydroxyapatite. Therefore, it can be concluded that P₂O₅ and CaF₂ in bioactive glasses play very important role of hydroxyapatite formation.