Osteoinductive and Osteopromotive Variability among Different Demineralized Bone Allografts

ObjectiveThe purpose of this investigation was to compare the osteoinductive and osteopromotive potential of two widely used demineralized freeze-dried bone allografts (DFDBA) (Osteotech (R) DFDBA and LifeNet (R) DFDBA). Material and MethodsTwenty-seven male Wistar rats (mean body weight 200g) were treated with either DFDBA from Osteotech and LifeNet or control for femoral and intramuscular defects and assigned to histological analysis at 2, 4, and 8 weeks postimplantation. Hematoxylin and eosin (H&E), Safranin-O, tartrate-resistant acid phosphatase (TRAP), and osteopontin (OPN) staining were performed. Quantitative analysis of mineralized new bone to total volume (BV/TV) was assessed by micro-computed tomography. ResultsBoth allografts demonstrated osteoinductive potential at 2 weeks as assessed by intramuscular bone formation. LifeNet DFDBA displayed continual new bone formation at 4 and 8 weeks, whereas Osteotech particles were fully resorbed by 4 weeks postimplantation. Femur defects demonstrated significantly greater BV/TV at 4 and 8 weeks with higher expression of OPN staining around LifeNet DFDBA particles. TRAP-positive cells were visible in and around both allograft materials. ConclusionThe results from the present study indicate that variability among allografts exists. In the present, LifeNet DFDBA supported more new bone formation. Further larger animal models or clinical trials are required to validate these findings.