Fresh-frozen bone blocks for horizontal ridge augmentation in the upper maxilla: 6-month outcomes of a randomized controlled trial.

PURPOSE: This randomized controlled trial compared fresh-frozen versus autologous bone blocks for maxillary horizontal ridge augmentation in patients with Cawood and Howell class IV atrophies. MATERIALS AND METHODS: Twenty-four patients were allocated to the autologous and fresh-frozen groups in a 1:1 ratio. Patients underwent computed tomography scans 1 week and 6 months after surgery for graft volume and density analysis. Doxycycline was administered at day 120 and day 150 to label new bone formation. Biopsy for histologic and histomorphometric analyses was performed at reentry for implant insertion, 6 months after grafting. RESULTS: Fresh-frozen grafts had lower density than autologous bone. Autologous and fresh-frozen grafts lost, respectively, 25% and 52% of their initial volume (p = .0041). Histology revealed the presence of newly formed bone within both graft types, but clear signs of inflammation were present in fresh-frozen blocks. CONCLUSIONS: According to these 6-month results, autologous bone blocks are preferable to fresh-frozen bone grafts.