Osseointegration of metal.

The healing response of bone to the injury of implant insertion is similar to its response to fracture. If there is absolute stability between the bone and the implant, the injury to the bone will result in bone formation, the bone growing and conforming to the surface configuration of the implant. There is first appositional bone growth and subsequently bone ingrowth into the interstices of the surface. The newly formed bone is not an uninterrupted layer of bone. It is mixed with well-differentiated fibrous tissue; only 13% to 20% of the bone is in contact with the implant. If the implant is relatively stable after insertion the healing response results in the implant becoming enveloped by dense organized fibrous tissue with occasional areas of fibrocartilage, without any areas of resorption in the surrounding bone. If the implant is unstable after insertion the healing response causes the implant to become surrounded by loosely organized fibrous tissue with active bone resorption occurring in the surrounding bone.