During the last 90 years, man-made materials and devices have been developed to replace parts of living systems in the human body. These special materials function in intimate contact with living tissue with minimal adverse reaction or rejection by the body. Devices made from these materials which perform specific functions in the body are referred to as biomedical devices or implants.
Biomaterials play a major role in replacing or improving the function of every major body system (skeletal, circulatory etc.). Some common implants include orthopedic devices such as total knee and hip joint replacements, spinal implants, bone fixtures; cardiac implants such as artificial heart valves and pacemakers; soft tissue implants such as breast implants and injectable collagen for soft tissue augmentation; dental implants to replace teeth/root systems and bone augmentation materials to increase deficient bony tissue in the oral cavity. The biocompatibility of synthetic material with the surrounding tissues mainly depends on the surface properties of the biomaterials. Therefore, material selection, biocompatibility and design are the three vital issues emphasized to achieve osseointegration of dental implants.