Comparative study of symphysis-donor defects: Unfilled or filled with bone-substitute

Aim: Intra-oral autogenous bone grafts are a convenient source of bone in reconstruction of the residual ridge prior to dental implant placement. The aim of this study is to evaluate bone volume and density of symphysis donor defects filled with bovine bone material compared with unfilled symphysis donor defects. Patients and methods: The study included 26 patients who underwent either alveolar ridge reconstruction or maxillary sinus elevation. Two groups were studied: symphyseal donor defects filled with bovine bone material, and unfilled symphyseal donor defects. Pre- and post-operative volumetric and bone density variables were determined using CT scans and the software program SimPlant®. Results: At 6 months post-operative, the filled donor defects exhibited a significant increase in bone volume and density (97.7% and 89.8%, respectively) compared with unfilled donor defects (73.4% and 37.1%, respectively). At 18 months post-operative, volume and density of unfilled donor defects were re-evaluated, yet no significant increase was found in bone volume. Conclusions: Unfilled donor sites generate defects that cannot achieve a "restitutio ad integrum", while filled donor sites associate with complete bone regeneration as determined by bone volume and density analysis. High bone density of filled donor defects may indicate high bone quality and could enable re-entering of the site.