Lateral Alveolar Ridge Augmentation With Allogenic Block Grafts: Observations From a Multicenter Prospective Clinical Trial

Abstract

Statement of the Problem: The use of autogenous bone block grafts in guided bone regeneration procedures for alveolar ridge augmentation is limited by donor-site morbidity and the need for advanced bone-harvesting skills. The need for advanced bone-harvesting techniques was highlighted as a key factor. It became apparent that the success of these early techniques was dependent upon operator skill and training with flap designs, membranes and stabilization screws, as well as the ability to harvest sufficient intraoral autogenous bone. The necessary skill level and postoperative patient morbidity have limited the potential for most clinicians to incorporate horizontal and vertical ridge augmentation techniques into their clinical practices. To enable more dental clinicians to use lateral ridge augmentation as a treatment option in patients with inadequate bone volume prior to implant placement, this paper describes the use of an allogenic bone block graft as an alternative to conventional GBR and autogenous block-grafting techniques. In this study, allogenic block grafts were used for ridge augmentation prior to implant placement. Materials and Methods: Twenty seven patients with severe ridge width deficiency underwent augmentation using an allogenic corticocancellous iliac bone block graft. The mean bone block size was 11 13 5 mm. Two miniscrews were used for each block graft. In 15 patients the block graft was placed in the anterior maxilla. After rigid fixation of the graft with miniscrews, the graft site was covered with a type I collagen membrane and tension-free closure was performed. Patients received postoperative antibiotics. Implants were placed 6 months later and bone-core biopsies were taken for histological examination. Six months after implant placement, computed tomography scans and panoramic radiographs were taken. Further bone-core biopsies were taken from one patient. Method of Data Analysis: Cumulative data and histological examination of bone-core biopsies. Results: No clinical problems were encountered. The block graft became well integrated into the surrounding bone, and the augmented bone remained stable throughout the implant placement procedures. Six months after implantation, there was no bone resorption, and bonecore biopsies showed newly formed woven bone and new lamellar bone within the graft. Conclusion: Evidence demonstrates that allogenic bone block grafts in conjunction with resorbable membranes might be a viable alternative to autogenous grafts in patients with alveolar ridge deficiencies. Further study and data accumulation is required.