[Comparative studies of sinus floor elevation with autologous or allogeneic bone tissue].

In 63 patients, 82 elevations of the maxillary sinus were performed. As augmentation, materials autografts from the iliac crest (combined with alveolar ridge augmentations in 16 sinus lifts) were transplanted in 39 cases and osteoinductive, allogeneic bone powder (AAA bone (autolyzed, antigen-extracted, allogeneic bone): n = 8, DFDBA (demineralized freeze-dried bone allograft) and/or Grafton (demineralized bone matrix gel): n = 35) were used in 43 cases. Some 4-6 months after implantation, osteoinductive, allogeneic (demineralized) bone implants showed radio-opaque areas as an equivalent of bone formation. Histological examinations revealed that osteoinductive implants were completely transformed into patients' own bone tissue. The average augmentation height after autograft transplantations was 14 (+/- 3) mm in comparison with 9 (+/- 3) mm after allograft implantations. Histologically as well as radiologically no differences of the bone quality could be determined between the two augmentation materials. Endoscopic controls showed, in both groups, nonirritated mucous membranes. On an average 2 endosseous implants (Bone Lock or ITI-screw implants) were inserted into the augmentated maxillary sinus floors in both groups. No osseointegration was achieved in 4 out of 67 dental implants when bone autografts were used and in 2 out of 74 dental implants of the allogeneic bone group. Patients with bone autografts suffered from postoperative complaints on an average of 19 (+/- 9) days (without consideration of 2 patients with postoperative complaints persisting for more than 90 days). The average postoperative complaints of recipients of allogeneic bone implants continued for 3 (+/- 5) days. The 13 patients who underwent an ambulant sinus lift procedure with allogeneic bone powder were already symptom-free several hours after the operation. Under critical consideration of all investigated parameters, osteoinductive bone implants are preferable to iliac bone autografts for maxillary sinus augmentations in those cases in which no additional alveolar ridge augmentation is required.