Effect of Surface Nano-Porosities Fabricated by Powder Mixed Electric Discharge Machining on Bone-Implant Interface: An Experimental and Finite Element Study

Nano-porous layer on implant surface has been considered as the most advantageous and advisable factor for the bone ingrowth and to improve the overall stability of the implant. In the present research work, a biomimetic novel nanoporous layer was fabricated directly on the β-Ti implant using powder mixed electrical discharge machining (PMEDM). PMEDM produce microscale pits of size 70 μm and a biomimetic interconnected porous layer of size 200–500 nm was produced in these pits. The application of PMEDM not only imparted the nanoporous topography but also altered the surface chemistry favorable for bioactivity. The viability and mineralization of human osteoblast-like (MG-63) cells in a nano-porous surface produced by PMEDM was analyzed by the In-Vitro bioactivity analysis. The results confirmed that the nano-porous surface obtained by PMEDM facilitated the higher adhesion and growth of osteoblast-like cell (MG-63) when compared to non-porous specimen's surface. At last finite element analysis (FEA) was performed to the estimate the tensile and shears strength of bone-implant interface of bone-Implant models containing PMEDM-attainable intersecting nano-porous layer. The results obtained by FEA of bone-Implant models suggested that the nano-porous surface produced by PMEDM produce exhibit higher bone/implant interface strengths as compared with models containing EDMed pores geometry and plane surface geometries (non-porous). In conclusion, the PMEDM treatment has potential to produce micro-pits of the intersecting porous layer which have a considerable effect on cell attachment, proliferation, bone ingrowth and enhances the bone-implant interface strength.