Control of the microstructure of porous tricalcium phosphate: Effects of addition of Mg, Zn and Fe

Tricalcium phosphate (TCP) ceramics are known as biodegradable materials for use as bone substitutes in orthopedic applications. We recently reported the fabrication of porous α-TCP ceramics with continuous pores ranging from 10 to 50 μm, through a conventional sintering process using a slurry consisting of β-TCP and potato starch. α-TCP shows higher solubility than β-TCP. Therefore, one can expect that biphasic porous ceramics consisting of α- and β-phases of TCP will allow controlled degradation in the body. In the present study, we attempted to synthesize a porous TCP body consisting of a mixture of α- and β-TCP with an additive of Mg, Zn or Fe. It was revealed that the porosity and phase of porous tricalcium phosphate can be controlled by the addition of these additives. The addition of Mg was most effective in decreasing the porosity and α-TCP content. When the Mg content was 0.1 mass%, a porous body consisting of α- and β-TCP with continuous pores ranging from 10 to 50 μm can be prepared by the conventional sintering method.