LOW-TEMPERATURE COFIRED FLUOROHYDROXYAPATITE CERAMICS FOR RECONSTRUCTION OF BONE DEFECTS

摘要

FIELD: medicine.;SUBSTANCE: invention refers to medicine, particularly to calcium-phosphate fluorohydroxyapatite ceramics for bone graft manufacturing and/or defect replacement in various bone pathologies. Making strong FHA is connected with high temperature of ceramic burning. For sintering temperature reduction, a nanodispersed fluorhydroxyapatite powder and an additive of sodium and lithium fluoride system in amount up to 5 wt % are used. When burned, the additive forms a low-temperature melt that promotes liquid-phase sintering at temperatures less than 700°C. Besides, the high concentration of fluorine ions leads to FHA stabilisation of ceramics at temperatures 600-700°C and prevents formation of the other isomorphic hydroxyapatite modifications. The fine-crystalline structure with crystal size less than 250 nm and porosity less than 5 % and bending strength to 90 MPa allows using the manufactured fluorohydroxyapatite ceramics as strong nonresorbable bone grafts.;EFFECT: provided high strength and slow destruction in aqueous mediums observed as ceramic strength loss as a result of chemical corrosion under mechanical pressure.;1 tbl, 1 ex