Bone Regeneration of Canine Peri-implant Defects Using Cell Sheets of Adipose-Derived Mesenchymal Stem Cells and Platelet-Rich Fibrin Membranes

Purpose: Insufficient bone volume compromises the success rate and osseointegration of immediate implantation. The objective of the present study was to engineer bone tissue by using adipose-derived stem cell (ASC) sheets and autologous platelet-rich fibrin (PRF) to enhance new bone formation and osseointegration around dental implants. Material and Methods: The proliferation and osteogenic potential of ASCs treated with autologous PRF were evaluated with CCK-8 assays, alkaline phosphatase staining, and real-time quantitative polymerase chain reaction. A 3-wall bone defect around each immediate implant was generated in the mandible and randomly treated with ASC sheets plus PRF (group A), ASC sheets only (group B), PRF only (group C), or no treatment (group D). Micro-computed tomography, biomechanical tests, fluorescent bone labeling, and histologic assessments were performed to evaluate bone regeneration capacity. Results: The proliferation and osteogenic potential of canine ASCs were markedly enhanced by PRF. Group A exhibited considerably more new bone formation and re-osseointegration (41.17 ± 1.44 and 55.06 ± 0.06%, respectively) than did the other 3 groups. Fluorescent labeling showed that the most rapid bone remodeling activity occurred in group A (P <.05). Conclusion: These results suggest that sheets of ASC combined with autologous PRF could be a promising tissue-engineering strategy for bone formation in immediate implantation.