Glass reinforced hydroxyapatite for hard tissue surgery - Part 1: mechanical properties

Commercial hydroxyapatite (HA) was reinforced by adding 2.5 and 5wt% of a N a2O-CaO-P2O5 glass and then sintered. The resulting composites have chemica l compositions that are similar to the inorganic constituent of the mineral part of bone, and are closely related to the trace elements that are prese nt, in this case Na. X-ray diffraction showed no decomposition of HA to sec ondary phases; however, the glass reinforced-HA composites contained a HA p hase and variable amounts of tricalcium phosphate phase, depending on the s intering temperature and the amount of glass added. The HA-composite materi al exhibited higher flexural strength overall compared to sintered HA. The presence of secondary phases beta- and alpha -tricalcium phosphate in the m icrostructure of the composites has a major influence on the mechanical pro perties. Additionally, the presence of porosity also has a bearing on the m echanical properties of the material. (C) 2001 Elsevier Science Ltd. All ri ghts reserved.