Behavior of implants in bone grafts or free flaps after tumor resection

The authors compared bone resorption of autogenous bone grafts and revascularized free flaps used for the reconstruction of mandibular continuity defects following resection for tumors, before and after the placement of endosseous implants. Ten patients (group 1) were treated with autogenous bone grafts taken from the fibula or the anterior iliac crest; 8 patients (group 2) were treated with iliac or fibula revascularized flaps. Four to 8 months later, 72 endosseous implants were placed in the reconstructed areas. After a further healing period of 4-6 months, patients were rehabilitated with implant-borne prostheses. The following parameters were evaluated and compared between the two groups: 1) bone resorption of grafts and free flaps before and after implant placement; 2) periimplant bone resorption mesial and distal to each implant, immediately after prosthetic rehabilitation and then during yearly follow-ups. Bone resorption before implant placement showed mean values of 3.53 mm in group I, and 0.96 mm in group 2. Peri-implant bone resorption was: 0.49 mm (39 implants) in group 1, and 0.45 mm (30 implants) in group 2, at time of prosthetic rehabilitation; 0.78 mm (39 implants) in group 1, and 0.89 mm (30 implants) in group 2, 12 months after prosthetic load; 1.16 mm (24 implants) in group 1, and 1.02 mm (13 implants) in group 2, 24 months after the prosthetic load. A significant difference in bone resorption before implant placement was found between the two groups, whereas it was not found after implant placement and prosthetic load. The failure rate according to Albrektsson criteria was 4.9% (2/41 implants) in group 1, and was 3.2% (1/31) in group 2.