Biomaterial is acquainted as A nondrug substance proper for listing in systems which increment or replace the function of bodily tissues or organs. <br />Biomaterials are broadly classified into three major categories according to biocompatibility are as follows: bioinert, bioactive, and bioresorbable.<br />Bioinert: These are the materials which when placed has minimal interaction with the tissue surrounding it, thus leading to osteogenesis. Some of the examples are stainless steel, titanium, zirconium, alumina, and ultra‑high‑molecular‑weight polyethylene <br />Bioactive: These are the materials once placed inside the oral cavity react with the hard tissues as well as the soft tissues. Examples are synthetic hydroxyapatite, and glass ceramic. <br />Bioresorbable: These materials on placement begin to resorb which get slowly replaced with bone. Examples are tricalcium phosphate, polylactic–polyglycolic acid copolymers, calcium oxide, calcium carbonate, and gypsum. <br />Biomaterials can also be classified based on chemical composition into metals, ceramics, and polymers as follows: <br /> i.Metals: titanium, titanium alloys, stainless steel, cobalt chromium alloys, and gold alloys. <br /> ii.Ceramics: alumina, hydroxyapatite, beta‑tricalcium phosphate, carbon, carbon/silicon, bioglass, zirconia, and zirconia‑toughened alumina <br /> iii.Polymers: polymethyl methacrylate, polytetrafluoroethylene, polyethylene, polysulfone, polyurethane, and polyether ether ketone. <br /> The first and foremost requirement for the choice of the biomaterial is its acceptability by the living body. The implanted material should not cause any adverse effects like allergy, inflammation and toxicity either immediately after surgery or under post-operative conditions. Secondly, biomaterials should possess sufficient mechanical strength to sustain the forces to which they are subjected, so that they do not undergo fracture and more importantly, a bioimplant should have very high corrosion and wear resistance in highly corrosive body environment and varying loading conditions, apart from fatigue strength and fracture toughness. The success of a biomaterial or an implant is highly dependent on three major factors (i)the properties (mechanical and chemical ) of the biomaterial in question (ii) biocompatibility of the implant and (iii) the health condition of the recipient and the competency of the surgeon. <br /> Application of biomaterials in human body as implants is very common nowadays. In Figure, the locations of implants in different areas of human body are shown. As illustrated, biomaterials can be used in many locations in human body such as shoulders, hips, joints, bones, dental implants, etc. Once these biomaterials are planted in the human body, they will be subjected to human body fluid environment. The living body fluid is corrosive for metallic biomaterials. As a result, biomaterials degradation occurs ultimately unless they are covered with appropriate coatings that could prevent corrosion .