The study of Biomaterials is biomaterials science. It covers elements of biology, tissue engineering, chemistry etc. They are used widely in dental surgeries and drug delivery. Biomaterials can be used in Bone plates, Stents, Heart Valves, Drug Delivery Mechanisms etc. Biomaterials are classified into 3 categories based on their reaction to the tissue. They are Biotolerant Materials, Bioinert Materials and Bioactive Materials. Biomaterials must be compatible with the body.