Structural characterization of synthetic and biological carbonated hydroxyapatite

Abstract

It is well known that inorganic part of bones and teeth are impure form of hydroxyapatite, (HAp) Ca10(PO4)6(OH) 2. During the past few decades, great efforts have been invested to develop synthetic equivalent of natural apatite. The major difference of natural bioapatites from hydroxyapatites is in the presence of certain content of 2- CO3 ions in the structure. The presence of the 2- CO3 ions in the HAp structure influences the reactivity and stability. Therefore, the exact content of 2- CO3 ions as well as their arrangement in the structure is very important. The aim of our work is comparative analysis of the biological carbonated hydroxyapatite extracted from human alveolar bone and synthesized carbonated hydroxyapatite (BCHAp). Structural and microstructural parameters were determined through Rietveld refinement of recorded XRPD data, and with transmission electron microscopy (TEM). Microstructure analysis showed anisotropic X-ray line broadening due to the small crystallite size (about 10 nm) as well as anisotropic growth of crystallites. The Raman spectroscopy confirmed the apatite structure and crystallinity.