In vitro bioactivity of glass and glass-ceramics of the 3CaO•P2O5–CaO•SiO2–CaO•MgO•2SiO2 system

A glass of nominal composition (wt%) 40.0 CaO–34.5 SiO2–16.5 P2O5–8.5 MgO–0.5 CaF2 has been obtained (G13). The glass showed in vitro bioactivity evidenced by the formation on its surface of a calcium phosphate-rich layer when soaked in a solution with ionic composition analogous to human plasma. By thermal treatments of G13, a glass-ceramic (GC13) containing apatite, diopside, althausite and akermanite as crystalline phases was developed. GC13 as-made did not show in vitro bioactivity. However, after chemical treatment of GC13 with 1 HCl (GC13-HCl), the in vitro studies showed the formation of an apatite-like layer covering certain areas of the material surface. The influence of both chemical and morphological factors on the in vitro bioactivity has been studied.