Fabrication and Chemical Durability of Porous Bodies Consisting of Biphasic Tricalcium Phosphates

We recently developed α-tricalcium phosphate (TCP) ceramic with continuous pores in the range 10-50 μm by a conventional sintering processing. It is important to control the degradation rate of porous biodegradable ceramics for an application as scaffold for bone regeneration. β-TCP is well known as biodegradable ceramic showing lower solubility than α-TCP. To develop porous calcium phosphate ceramics with controlled degradation rate, this study focused on fabrication of biphasic TCP porous body consisting of a mixture of α-and β-TCP. Their chemical durability was evaluated by exposure to aqueous solutions with pH=6. Biphasic TCP porous body with the continuous macro-pores was successfully fabricated through the same process of the α-TCP porous body by addition of Mg. The biphasic TCP ceramic formed octacalcium phosphate (OCP) after soaking in the buffered solution at pH=6 for I day, while delayed formation of OCP was identified from α-TCP porous body after soaking for 7 days. The addition of Mg to TCP composition easily brings about a production of biphasic TCP bodies consisting of α- and β-phase with continuous macro-pores, and allows control of degradation rate of the porous calcium phosphate ceramics.