Novel alkali free bioactive fluorapatite glass ceramics

Alkali free bioactive glasses with the presence of Ca/SrF2 were synthesized and then characterised by Differential Scanning Calorimetry, X-ray Diffraction, Fourier Transform Infrared Spectroscopy and Magic Angle Spinning-Nuclear Magnetic Resonance Spectroscopy. The crystallisation of the glasses was explored by heat treatment. An increased crystallisation tendency of the as quenched glasses was evident with an increase in the Ca/SrF2 content, where Ca10(PO4)6F2 (fluorapatite), Ca4Si2O7F2 (cuspidine) and CaF2 crystallise in sequence for the Ca-containing system, and Sr10(PO4)6F2, SrSiO3 and SrF2 for the Sr-containing system. Upon heat treatment, Ca10(PO4)6F2 or Sr10(PO4)6F2, which is mainly nucleated from bulk is the primary crystalline phase. Although partially crystallised these sodium free fluorapatite glass ceramics are proposed to have enhanced bioactivity comparable to bioactive glasses.