Current trends in additive manufacturing of selective laser melting for biomedical implant applications

Additive manufacturing (AM) has obtained great attentions in the productions of customizable implants with complex shapes and good mechanical properties. AM fabricated implants of Ti alloy (Ti), stainless steel (SS), cobalt chromium (CoCr), iron (Fe) have been revolutionized in the productions of medical instruments, such as in artificial organs, including heart stents, drug delivery, scaffolds and orthopedic implants. However, high Young's modulus, superior mechanical characteristic, lack of surface integration, high corrosions, failed bone remodeling, and antibacterial performance are still incomparable to be used in anatomical structure. This review studied the issue of metallic implants designed by powder bed fusion of selective laser melting (SLM) techniques on the surface morphology, stress shielding effects, osseointegration, and antibacterial capabilities owing to implant failure. The rate of degradation and corrosion resistance of the metallic SLM implant, which would have an impact on cell proliferation and bone remodeling between the surrounding tissue, were discussed. The current review article also highlighted the various SLM parameters, like mechanical, chemical, and biological modifications, that might enhance the implant. Finally, applications, challenges, opportunities, and future developments of metallic implants using SLM techniques were addressed.