Optimization of Sintering Conditions for Improvement of Mechanical Property of a-Tricalcium Phosphate Blocks

Bioactive ceramic materials have been under research as bone substitute for several decades.To repair the high-load bearing bones, mainly cortical bones, there is a need for the substitute to possess comparable mechanical strength to cortical bone, of which the compressive strength ranges between 100 and 230 MPa. Two prevailing bone repairing material, β-tricalcium phosphate (β-TCP,β-Ca3(PO4)2) and hydroxyapatite (HAp: Ca10(PO4)6(OH)2) have been widely researched and sintered into dense blocks to meet the mechanical requirements. α-tricalcium phosphate (α-TCP, α-Ca3(PO4)2), a high temperature polymorph of β-TCP, received relatively less attention and α-TCP dense sintered blocks have not been reported yet. In this research, we fabricated α-TCP dense blocks by sintering under various temperatures (1150-1400 °C) and the highest compressive strength was around 230 MPa. Intermediate porous blocks (porosity: 33%) were also fabricated from mixed powder of α-TCP and starch. In vitro properties variation of the intermediate porous blocks were investigated by soaking samples in simulated body fluid (SBF) and the compressive strength was maintained above 100 MPa after soaking for 14 d.