Comparison of 3D-printed porous tantalum and titanium scaffolds on osteointegration and osteogenesis.

Metals such as Ta (tantalum) and Ti (titanium) have been popularly used as a bone substitute or implants in orthopedic surgery and dentistry, since they have excellent corrosion. For manufacturing porous implants with precise structure, SLM (Selective laser melting), which is one of the 3D (three-dimensional) printing techniques, is always be chosen. To compare biological performances between porous Ta and Ti implants, we designed them with the same porosity, pore shape, pore size, and pore distribution via CAD (computer aided design), and then produced them by SLM. It was shown that the equivalent stress of porous Ta and Ti were 393.62 ± 1.39 MPa and 139.75 ± 14.50 MPa, and their Young's modulus were 3.10 ± 0.03GPa and 5.42 ± 0.07GPa, respectively. Meanwhile, we investigated their biological performance with hBMMSCs (human Bone marrow mesenchymal stem cells) in vitro. The results revealed that both two scaffolds were in favor of hBMMSCs proliferation and osteogenic differentiation. In addition, porous scaffolds were implanted in the femur bone defects rabbits in vivo showed the both porous scaffolds were beneficial to the bone ingrowth and bone-implant fixation. In summary, porous Ta has an equivalent biological performance as traditional porous Ti implants in small bone defect repair. Taken together, porous Ta is a promising material for bone regeneration.