Site preservation refers to a specific application of bone grafting that attempts to prevent the resorption of bone that normally follows the removal of a tooth.  At the time of tooth removal, the resulting socket is filled with bone material and covered with a protective dressing.  Filling the socket with bone in this manner dramatically delays the normal bone resorption process that would occur at an extraction site.  It also hastens the process of bone maturation at the site, thus allowing the placement of a dental implant sooner than would be possible if the socket was left to heal without the benefit of the added bone.  This procedure is very successful in preserving the ridge of bone that is necessary for implant placement.