Pure titanium/titanium alloys are used in orthopedic and dental implants because of previously identified mechanical properties and biocompatibility. However, recent work shoed that these materials suffer from electrochemical corrosion when implanted in the body or the mouth, releasing metallic-oxide particles from oxidized surface, promoting inflammation around the implant, and implant failure. The novel UNCD coating discussed throughout this book exhibits excellent biocompatible and strong resistance to chemical attach by body fluids. This chapter describes the R&D performed to develop UNCD-coated commercial dental implants, hips and knees. The UNCD coating acts as a protective barrier between the implant and the biological environment, preventing release of metallic-oxide particles into the body. Research focused on investigating the osteointegration rate of titanium, UNCD-coated titanium, and UNCD/W-coated titanium implants, using the rat diaphyseal tibia as a model. Optical and SEM pictures showed superior osseointegration and resistance to chemical attach from body fluids, for UNCD-coated metal dental implantsover uncoated ones,