Sintering behaviour of calcium phosphate filaments for use as hard tissue scaffolds

Lattices consisting of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) mixtures were prepared by extrusion freeforming to serve as bone substitute structures in which both shape and structural hierarchy are determined by computer control. Fine ceramic filaments were prepared from a non-aqueous, solvent-based, ceramic-polymer paste and sintered at temperatures from 1100 to 1300 degrees C. The characteristics of the sintered filaments were investigated because this determines the resulting microporosity and phase content while the higher levels of porosity are computer controlled. The effects of HA/beta-TCP ratio and sintering temperature on the microstructure, density, shrinkage and final phase content were studied. These results provide a design reference for hard tissue engineering scaffolds built from these materials. (c) 2007 Elsevier Ltd. All rights reserved.