Analysis of in vitro reaction layers formed on Bioglass using thin-film X-ray diffraction and ATR-FTIR microspectroscopy.

Fourier transform infrared spectroscopy and thin-film X-ray diffraction (TF-XRD) techniques were used to analyze the inorganic carbonate apatite (CA) layer developed on a bioactive glass (45S5 type Bioglass) in an in vitro environment. The C-O and P-O vibrational modes appeared on the bioactive glass surface following immersion in the simulated body fluid solution. Initially, the C-O and P-O peaks increased with immersion time as crystallization of CA phase progressed. The TF-XRD confirmed that the deposited layer was apatite, crystallographically. Furthermore, evidence of preferred orientation in the 001 direction was seen, indicated by very strong 002 reflection. With time, the crystal growth became more random and the intensity of the 002 reflection decreased.