Enhancing the bioactivity of a calcium phosphate glass-ceramic with controlled heat treatment

In this paper synthesis and characterization of a bioactive calcium phosphate glass-ceramic is presented, synthesized using a facile method. The glass-ceramic samples are synthesized with heat treating the parent glass at appropriate temperatures, where different calcium phosphate crystalline phases are grown in the parent glass samples during the heat treatment. The amounts of elements and oxides in the parent glass are 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 are determined. Several calcium phosphate crystalline phases are identified in the glass-ceramic samples. With the increase of heat treatment temperature from 540 ℃ to 560 ℃, β-Ca3(PO4)2 and β-Ca2P2O7 crystalline phases become the dominant crystalline phases among the other crystalline phases in the glass-ceramic samples. Bioactivity of the glass-ceramic samples are investigated by immersing the samples in Ringer's solution for 7, 21 and 28 days. By analyzing X-ray diffraction patterns, Fourier transform infrared spectra, and scanning electron microscopy images of the samples immersed in Ringer's solution, the formation of hydroxyapatite on the samples confirmed. The results show that the samples with β-Ca3(PO4)2 and β-Ca2P2O7 crystalline phases are more bioactive than the others.