Manufacture of macroporous β-tricalcium phosphate bioceramics

β-Tricalcium phosphate (β-TCP) macroporous ceramics were produced by a new manufacturing procedure. An organic skeleton constituted of polymethylmethacrylate balls (PMMA) is carried by a chemical forming treatment. This treatment consists to establish a connection between PMMA balls by a chemical superficial dissolution of the individual beads. This reaction is accompanied of significant shrinkage of the organic skeleton which is correlated with the interconnection size between beads.An empirical relation and a geometrical model, based on a theoretical arrangement of spheres of uniform sizes, were developed to determine the necessary shrinkage of the organic skeleton to obtain a desired interconnection size.PMMA skeleton is impregnated by using an aqueous suspension of β-TCP, after drying, the ceramic/polymeric composite undergoes the traditional steps of debinding and sintering to obtain finished material.This process allows a total control of the porous architecture of the part (sizes of pores and interconnections) and also to perform materials with very varied forms and dimensions with specific properties as a gradient of pore sizes or a gradient of the interconnection sizes.