Evaluation of suitable porosity for sintered porous β-tricalcium phosphate as a bone substitute

Structural and mechanical characterization is performed for sintered porous beta tricalcium phosphate (beta-TCP) to determine the appropriate porosity for use as a bone substitute. Four different types of porous beta-TCP specimen with different porosities are fabricated through a sintering process. For structural characterization, scanning electron microscopy and a Microfocus X-ray computed tomography system are used to investigate the pore openings on the specimen's surface, pore size, pore distribution, and pore interconnections. Compression tests of the specimens are performed, and mechanical properties such as the elastic modulus and compressive strength are obtained. Also, the geometric shape and volume of the beta-TCP around the contact region of two pores, which need to be initially resolved after implantation in order to increase the size of the pore openings, are evaluated through simple calculations. The results show that porous beta-TCP with 42.1% porosity may be a suitable bone substitute candidate in terms of sustaining external loads, and inducing and cultivating bone cells. (C) 2012 Elsevier Inc. All rights reserved.