Evaluation of the quality of calcium phosphate bioceramics via a study of the effects of thermal processing

Thermal conditioning of calcium phosphate bioceramics is often used to enhance the crystallinity and phase purity of the materials. A consideration of the effects that such processing may have on the chemical composition and structure of a particular system can clearly provide information about the nature of the starting material. It is proposed here that carrying out such measurements at a range different temperatures can be helpful in determining the true composition and quality of a given bioceramic material. Accordingly, this paper reports the results of a study to evaluate the properties of commercially available and laboratory synthesised calcium phosphate bioceramic materials before and after heating in the range 400 to 1200 degreesC. FTIR and XRD analyses of the as-received materials indicate that in several cases these data do not provide a definitive assessment of the phase purity of the materials due to poor signal-to-noise and peak broadening. Whereas, EDX and XPS experiments do provide some additional useful information, it was still not always possible to ascertain the precise nature of several of the systems of interest. It is shown here that analyses of samples, which have undergone controlled thermal conditioning at various temperatures, can add significantly to our understanding of their chemical composition and phase purity.