Crystallographic study of hydroxyapatite bioceramics derived from various sources

Hydroxyapatite (HA) is a calcium phosphate based bioceramic material rich in hard tissues such as bones and teeth. It is used as an artificial bone substitute in orthopaedic and dental applications. It can be derived from synthetic or natural resources. It has all the characteristic features of biomaterials, in particular, crystallographic similarity with natural bone minerals. However, crystallographic properties HA prepared from various resources are considerably different due to the material processing conditions and key ingredients used. In the present study, we report the comparative crystallographic analysis of HA derived from the chemical route, coral and xenogeneic bone. As observed from the powder X-ray diffraction (XRD) analysis, crystallinity of HA was also quite dissimilar with respect to preparation methodology. Each lattice cell parameters of prepared HA were calculated using the standard least-squares method and compared with JCPDS data as a reference model. The results showed that the lattice constants of HA have slight changes from batch to batch due to secondary ionic substitution.