A Clinical Study of Alveolar Bone Tissue Engineering Using Autologous Bone Marrow Stromal Cells: Effect of Optimized Cell-Processing Protocol on Efficacy

(1) Objectives: The effect of cell-processing protocols on the clinical efficacy of bone tissue engineering is not well-known. To maximize efficacy, we optimized the cell-processing protocol for bone-marrow-derived mesenchymal stromal cells for bone tissue engineering. In this study, the efficacy of bone tissue engineering using this modified protocol was compared to that of the original protocol. (2) Materials and Methods: This single-arm clinical study included 15 patients. Cells were obtained from bone marrow aspirates and expanded in culture flasks containing basic fibroblast growth factor. The cells were seeded onto β-tricalcium phosphate granules and induced into osteogenic cells for two weeks. Then, the cell–scaffold composites were transplanted into patients with severe atrophic alveolar bone. Radiographic evaluations and bone biopsies were performed. The results were compared with those of a previous clinical study that used the original protocol. (3) Results: Panoramic X-ray and computed tomography showed bone regeneration at the transplantation site in all cases. The average bone area in the biopsy samples at 4 months was 44.0%, which was comparable to that in a previous clinical study at 6 months (41.9%) but with much less deviation. No side effects related to cell transplantation were observed. In regenerated bone, 100% of the implants were integrated. (4) Conclusions: Compared to the original protocol, the non-inferiority of this protocol was proven. The introduction of an optimized cell-processing protocol resulted in a comparable quality of regenerated bone, with less fluctuation. Optimized cell-processing protocols may contribute to stable bone regeneration.