The Application of 3D Printing Technology in Fabrication of Calcium Phosphate-based Biomaterials for Bone Repairment

Bone defect has become a common disease threatening people's health. 3D-printed Calcium phosphate (CaP) is endowed with porous structure, proper mechanical properties and biological properties thus widely considered as an ideal bone substitutive material used for bone repairment. Herein, we reviewed the application of 3D-printing technology in generating CaP-based implants. Among 3D-printing techniques, binder jetting method has been widely applied to print CaP scaffolds since it is convenient and stable. Cubic structure is the most common shape of 3D-printed implants while patient-specific scaffold achieved by computed tomography scan is more preferred for clinical cases. Unified and interconnected porous structure of CaP scaffold desired for excellent biological performance can be obtained by 3D printing technique. Besides, loading bone morphogenetic protein and drugs on printed scaffold is proved to be an effective way to enhance vascularization and antibacterial ability. Most of the 3D-printed CaP scaffolds possess great mechanical strength within the range of 20–500 MPa to meet the requirement of load condition at defect site. Sintering process after printing is vital for achievement of better mechanical properties, sinter method and sinter temperature have marked effects on compressive strength of CaP implants. Finally, limitations and outlook of 3D-printing are summerized in the end.