The feasibility of the preparation of porous hydroxyapatite (HA) implant by three-dimensional printing (3DP) was evaluated in the study. The nanoscale HA powders were blended with a water soluble binder to form the implant. The HA implants were divided into two groups according to the bonding area. The bonding area of group one was reserved to 100% in each layer, while the group two was reserved to 80%. The porous HA implant prototypes were fabricated by 3DP and sintered at 1250 oC. The porous HA implants were chemically stable and well crystallized after the sintering process with no distortion, showing an interconnected porous structure. The 80% HA implants had relatively larger pore size (100-200 μm) than 100% HA implant (50-150 μm). The sintered 100% and 80% HA implants had porosity of 58.58%-68.18% and compressive strength of 84.3-50.9MPa. The properties of the porous HA implants matched well with bone tissue and exhibited excellent biomechanical compatibility.

Keywords: Solid freeform fabrication, Porous materials, Composites, Microstructure