Additive manufacturing of bioceramic scaffolds by combination of FDM and slip casting

Bioceramic scaffolds consisting of bioactive glasses or calcium phosphates have a high biocompatibility and are able to stimulate the ingrowth and regeneration of bone. For the production of these complex, highly porous structures, the additive manufacturing technologies are of particular importance. Normally, the image of the CAD model is printed directly. In this study, the indirect approach was chosen. The Fused Deposition Modeling (FDM) process was used to print thermoplastic molds, which were the negative of the ceramic to be produced. Subsequently, these molds were filled with ceramic slurries as in the slip casting process and the thermoplastic form was burnt out. The viscosity of the slurries as well as the thermal behaviour of the green bodies was characterized. The resulting bioceramic scaffolds have a filigree structure with moderate porosity. The compressive strength of these components is above the strength of cancellous bone.