Enhancement of Corrosion and Biocompatibility of Implants by Thermal Spray Coatings

In the recent era, distinct metallic materials such as titanium, stainless steel, titanium alloys, and Co-Cr alloy are widely used for implant manufacturing. But for successful implantation, these biomaterials require good biocompatibility, corrosion resistance, low elastic modulus, which is required closer to actual human bone, high strength, and non-cytotoxic. These biomaterials have primarily been used in specific applications such as orthopaedic fixation devices, dental implants, and cardiovascular stents. The corrosion of metal implants, on the other hand, determines the service period of implantation due to the release of incompatible metal ions into the human body, which may cause allergic reactions. As a result, the focus of this chapter is initially on metal biomaterials and their properties. The causes of implant failure are then highlighted, with a focus on corrosion mechanism details. Finally, various surface modification techniques, such as thermal-based surface modification techniques, are discussed in detail, as are their applications in improving corrosion resistance, biocompatibility, and osseointegration of various biomaterials.