Preparation of hydroxyapatite/fluoroapatite-zirconia composites using Indian corals for biomedical applications

Hydroxyapatite (HA) has been widely used in the field of orthopaedics and dentistry. Due to HA's lack of mechanical properties, composites containing hydroxyapatite and zirconia have been suggested for the purpose of increasing strength and fracture toughness. This paper reports the preparation of fluorine-doped hydroxyapatite from Indian coast corals and zirconia composites using coralline hydroxyapatite and coralline fluoroapatite. The fluoroapatite and composites were prepared by two methods: (i) low temperature (LT) or hydrothermal method and (ii) high temperature (HT) or solid state reaction method. These materials were characterized by X-ray diffraction (XRD) analysis, Fourier-transform. infrared spectroscopy (FT-IR) and thermal analysis. Decrease in the a-axis of HA lattice was observed in the fluoroapatite, suggesting partial fluorination of hydroxyapatite resulting in hydroxy/fluoroapatite solid solution. The analysis of the composites shows the formation of beta -tricalcium phosphate due to the decomposition of hydroxyapatite. (C) 2001 Elsevier Science B.V. All rights reserved.