Fabrication of Porous β-TCP Bioceramics Using Digital Light Processing

Abstract

Beta-tricalcium phosphate (β-TCP) is an ideal bone repair material with good biocompatibility and osteogenicity. A DLP-system used in this study creates bioceramic green part by stacking up layers of photocurable tricalcium phosphate-filled slurry with various TCP weight fraction. After a thermal debinding and sintering step, the part turns into a dense ceramic according to the results of thermogravimetric (TG) and differential scanning calorimetry (DSC). Results show that the actual ceramic green part size is larger than the design size because of light scattering. The sintering shrinkage in the horizontal direction is 1%-5%, and the sintering shrinkage in the building direction is 6%-9% after sintering. Thus, a compensation model for sintering shrinkage is proposed to obtain high-precision final TCP parts. The obtained porous TCP parts have both macroporous outer structure and microporous inner structure, the macropore size is 400-600μm and the micropore size is 500-1 500 nm. The mechanical tests show that the compressive strength of the porous β-TCP bioceramic is up to 16.53 MPa. DLP is a promising technology in human bone tissue damage repair which can rapidly printing porous structure in high-precision.