Objective: Ideal implant placement in atrophied posterior mandibular regions is challenging due to surgical difficulties and anatomical limitations. This study aimed to evaluate the use of allogeneic bone rings for vertical augmentation of atrophied posterior mandibular regions with simultaneous implants compared to autogenous bone rings, while avoiding donor site morbidity.
Method and materials: A total of 24 vertically atrophied posterior mandibular segments (in 14 patients) were equally randomized into a study group in which mineralized freeze-dried allogeneic bone rings were used, and a control group in which autogenous bone rings with prepared implant osteotomies were harvested from the chin and used. All augmentation sites were prepared before inserting the bone rings. Implants were simultaneously inserted, fixing the bone rings into the native bone. All patients were clinically assessed after 1 week, 2 weeks, and 1 month. Crestal bone level was radiographically assessed after 1 week, 6 months, and 3 months of prosthetic loading.
Results: None of the 24 bone rings showed signs of implant or graft failure. There was no significant difference in the crestal bone level between the groups.
Conclusion: Allogeneic bone rings can be a viable alternative to autogenous bone rings in augmenting the posterior aspect of the mandible, mitigating the concerns associated with donor site complications.
Keywords: allograft, alveolar ridge augmentation, bone ring, dental implants, mandible
