Novel approach for quantification of porosity for biomaterial implants using microcomputed tomography (microCT)

Porous bioceramics have been widely investigated in orthopaedic tissue engineering. Attention has been given to manufacturing of a porous bioceramic that mimics the trabecular bone structure for proper bone regeneration. With the advance of biomedical imaging through microcomputed tomography (microCT), this study attempted to quantify the pore structure of different bioceramics. Two bioceramic blocks (BSC and ChronOS) were synthesized by two methods. The specification claimed the porosity of the bioceramic ranged from 40% to 70%. Six blocks of each bioceramic were evaluated by conventional water immersion method and microCT. The pore size and connectivity were evaluated with standardized protocols. By the water immersion method, the porosity of BSC and ChronOS was 60.4% and 74.7%, respectively. The three-dimensional results of microCT showed that BSC porosity was 26.2% and ChronOS was 60.0%. The pore connectivity was evaluated to be 2.6 for BSC and 39.7 for ChronOS. ChronOS had functional pores with 200 microm to 400 microm in diameter (87.8%+/-0.5%), which is significantly more than 52.8%+/-11.5% of pores in BSC (p<0.05). Providing information on the functional pores objectively, the microCT evaluation serves as a good standard for specification of the bioceramic-related implants.