Natural Hydroxyapatite-Ti-Dioxide Bone Substitutes

This paper aims to develop a bioceramic that actives the osteogenesis on the surface of Ti implants. This material is a mixture of natural hydroxyapatite, Ca5(PO4)3(OH) (HAB), with different weight fractions of TiO2, X. The HAB is obtained from pyrolyzed (900 °C) and ground (45-100 μm) fresh bovine bone, which is mixed with TiO2, shaped by pressing (200 MPa), and sintered at 1000-1300 °C per 2 hours. The electron microscopy observations and X-ray diffraction analysis show that increasing sintering temperature and X, promote the formation of a nearly continuous TiO2 matrix, with embedded grains of tri and tetra-calcium phosphates, products of HAB decomposition. Also, the process leads the formation of calcium titanate, CaTiO3, which is the phase responsible for the possible sought biological effect.