EFFECT OF POROSITY ON THE STRUCTURE AND PROPERTIES OF CALCIUM POLYPHOSPHATE BIOCERAMICS

Calcium polyphosphate (CPP) bioceramics with different porosities were prepared by controlling the concentration of the pore-forming agent. The effect of porosity (0%, 15%, 30%, 45% and 60%) on the microstructure, pores interconnection, dissolution behaviour and compressive strength of CPP bioceramics was investigated. SEM and capillarity test results indicated that CPP with higher porosity (45% and 60%) had a three-dimensional interconnected pore structure with a pore size of about 200-400 micron, while the pores of lower porosity scaffolds (0%, 15% and 30%) were isolated. The dissolution behaviour in vitro indicated that the dissolution rate accelerated as the porosity increased and the CPP with 60% porosity showed the highest dissolution rate. The compressive strength of porous CPP scaffolds was the same as human cancellous bone, and decreased with increasing porosity. While, dense CPP scaffolds had increased strengths.