Enhancing the bioactivity of a calcium phosphate glassceramic with controlled heat treatment

In this paper, bioactive calcium phosphate glass-ceramic has been synthesized by using a facile method and characterized. The glass-ceramic samples were synthesized through heat treating the parent glass at appropriate temperatures, where different calcium phosphate crystalline phases were grown in the parent glass samples during the heat treatment. The amount of elements and oxides in the parent glass were determined by X-ray fluorescence analysis. Using differential scanning calorimetry method, glass transition temperature of the parent glass, and the temperature range for heat treatments were determined. Several calcium phosphate crystalline phases were identified in the glass-ceramic samples. With the increase of heat treatment temperature from 540 to 560°C, β-Ca3(PO4)2 and β-Ca2P2O7 crystalline phases became the dominant crystalline phases among the other crystalline phases in the glass-ceramic samples. Bioactivity of the glass-ceramic samples was investigated by immersing the samples in Ringer s solution for 7, 21 and 28 days. By analyzing X-ray diffraction patterns, Fourier Transform Infrared (FTIR) spectra, and Scanning Electron Microscopy (SEM) images of the samples immersed in Ringer s solution, the formation of hydroxyapatite on the samples was confirmed. The results show that the samples with β-Ca3(PO4)2 and β-Ca2P2O7 crystalline phases are more bioactive than others.