Autogenous free tooth transplantation with a two-stage operation technique.

If tooth transplantation is to succeed, it is crucial to preserve the vitality of the cells on the root surface of the tooth transplant. Insufficient postoperative nutrition to the cells on the root surface of the tooth transplant was thought to contribute to their devitalization of these cells. Impaired nutrition may be a result of poor contact between the recipient bed and the root surface of the transplanted tooth, and development of an interposed blood clot. To improve postoperative nutrition to the root surface cells, teeth were transplanted to the recipient beds in which the tissues were regenerated during a 14 day period, i.e., using the two-stage transplantation technique. In a clinical study of this technique, a total of 95 autogenous teeth with fully developed roots were transplanted in 84 patients, and examined both clinically and radiographically for up to 13 years after the transplantation. In a dog model, a comparative experimental study was made between teeth transplanted to beds left to heal for 5 days and teeth transplanted to beds prepared immediately before the transplantation. The clinical study showed a low prevalence of tooth graft loss and root resorption even when infection of the root canal occurred. Periodontal attachment loss of less than 3 mm was found in 97% of 6 defined surfaces around the transplanted teeth. Transplanted teeth which were later extracted were often hypermobile, and signalled pain when provoked with heavy loading. Excessive extraction trauma, fixation failure, and excessive plaque accumulation after transplantation were all shown to be detrimental to tooth transplant. Transplanted teeth were used as abutments for fixed partial dentures and provided the necessary dental support for crowns and bridges even in patients with atrophic alveolar bone. The experimental histological study showed no differences between test and control teeth in terms of the prevalence of root resorption, which was suspected to be caused by traumatic injuries to the roots during extraction and non-rigid fixation of the transplanted teeth.