Fresh frozen versus autogenous iliac bone for the rehabilitation of the extremely atrophic maxilla with onlay grafts and endosseous implants: Preliminary results of a prospective comparative study

Purpose: The purpose of this study was to compare (1) the clinical outcome of the reconstruction of extremely atrophic edentulous maxillae with fresh frozen allogeneic bone (FFB) (group A) and autogenous bone (AB) (group B) iliac blocks; and (2) the peri-implant bone resorption and the survival rate of implants in the two groups. Materials and Methods: In a 1-year period, eight patients were treated with FFB and seven with AB iliac grafts. Five to seven months afterward, 108 implants were inserted (59 in group A and 49 in group B). Four to five months afterward, patients were rehabilitated with implant-supported prostheses. The mean follow-up was 24 months. Results: Prior to implant placement, graft exposure occurred in two patients in group A and in one patient in group B. The mean graft resorption prior to implant placement was 0.78mm and 0.54mm in group A and B, respectively. After implant placement, bone graft exposures with partial loss of the graft occurred in six out of eight patients in group A and in none of the group B patients. The survival rate of implants was 90.1% and 100% in group A and B, respectively. The mean values of peri-implant bone resorption at the end of the follow-up period were 1.64mm and 0.92mm in group A and B, respectively. Conclusion: Results of this study seem to demonstrate that FFB does not represent a reliable alternative to AB blocks because of the higher rate of bone exposure and partial loss of the grafts, the lower implant survival, and the higher peri-implant bone resorption in FFB patients.