A composition of material suitable for in vivo implantation to provide an environment in which normal tissue growth is fostered which composition is a porous fibrous structure in which the critical surface tension of the fibers is 35 dynes per centimeter or higher. This composition in the preferred form is a porous structure of carbon or graphite fibers bonded together by sintered polytetrafluoroethylene in a manner to expose a maximum amount of fiber surface.
Another composition of material suitable for implantation for wear surfaces includes carbon fibers and polytetrafluoroethylene resin and is processed to align the carbon fibers with the wear surfaces. The method of preparing both material includes the step of mixing, filtering, compressing, rolling, sintering and drying. The method of stabilizing appliances or implants includes bonding the ingrowth material to the appliance or implant. Also the combination of the ingrowth material with appliances, tendon replacement elements and wear material are included.