Correlation between bioactivity and thermodynamic stability of glasses of the molar formula 20.15[(2.038 + x)SiO₂-(1.457 - x)Na₂O]-2.6P₂O₅-25.73CaO-1.22MgO

Abstract

The purpose of this study is to establish the influence of composition on the glass transition temperature, density, enthalpy of dissolution in an acid bath and bioactivity in glasses of the molar formula 20.15[(2.038 + x)SiO2-(1.457 − x)Na2O]-2.6P2O5-25.73CaO-1.22MgO. It is also a question of correlating bioactivity and stability in this oxide glass system. Nine samples were prepared by high temperature melting followed by quenching. These samples were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), dissolution calorimetry and pycnometry. Their bioactivity was estimated using the Anderson model. The results indicate that the effect of magnesium composition can lead to a decrease in the glass transition temperature (Tg). These results also show that a decrease in glass stability leads to a decrease in bioactivity.

Keywords

• bioactive glasses
• phosphosilicate
• calorimetry
• free enthalpy of formation
• bioactivity