Rehabilitating Sites Grafted WithCadaver Bone Grafts
With the implant removed, it is important that the sclerotic bone be completely removed. It is easy to see the difference between sclerotic bone and normal bone. Sclerotic bone is dense, stark white with very little vascularity, and cuts like chalk. In this image on the distal (right) of the socket, bleeding is present, indicating that sclerotic bone has been removed. However, on the mesial (left) of the socket apex, sclerotic bone remains evidenced by the dense white areas of sclerosis and no bleeding. This bone on the mesial needs to be removed. As you can see, there is no clinical evidence of vascular supply in the sclerotic bone.
Lecturers who use cadaver bone always talk about the need to create bleeding for the success of the graft and they are correct when using cadaver bone grafts. When using cadaver bone grafts, the process of bone formation is called antigenic ossification. For antigenic ossification to occur, bleeding is needed for the migration of the inflammatory cells via the blood stream. Mineralization begins on the surface of the allograft particles that are infiltrated with dense lymphocytes. When the cadaver particles are covered with mineralization, the inflammatory infiltrate disappears because the host is now isolated from the foreign material. Once mineralization is complete and sclerotic bone is formed, the vascular supply disappears, and the bone never remodels because this would expose the antigenic inflammatory bone graft particles. Once sclerotic bone is formed, this bone never changes until the sclerotic bone breaks up and the implant is lost.
However, when using SteinerBio Socket Graft or Sinus Graft, the goal is not to create blood flow but to access cancellous bone that contains regenerative cells. The regenerative cells enter our graft material before blood vessels and migrate throughout the graft material and then the vascular supply follows behind. During the removal of the sclerotic tissue, the presence of bleeding indicates that the sclerotic bone has been fully removed and you have reached healthy cancellous bone where regenerative cells can migrate into the graft material.
From this photograph, you can see that the white sclerotic bone has been removed evidenced by bleeding throughout the socket except the lingual cortical bone.
When a socket is grafted with a cadaver bone graft, the area of sclerosis is not limited to the extraction socket where the cadaver bone graft is placed. The area of sclerosis encompasses the majority of the cancellous bone of the alveolar ridge. In this case, the sclerotic bone required removal of virtually all of the cancellous bone between the buccal and lingual cortical ridges and between the teeth. With the need to create such an extensive defect to remove the sclerotic bone, this defect will be slow to heal. In this case, the site was grafted with Socket Graft Plus and covered with a d-PTFE membrane. The implant was replaced after 3 months and has functioned without complication for many years.
Isolated sockets grafted with cadaver bone grafts can be reasonably rehabilitated. However, in cases where sockets and the sinus has been grafted with cadaver bone grafts, there is little to no normal bone. These patients face virtually no options for reliable implant replacement. SteinerBio has been studying bone graft biology for 15 years. We have also watched implant loss in the clinic and we estimate that approximately 50% of all lost implants are the result of bone graft failure of implants placed in cadaver bone grafts.