Polycaprolactone-20% Tricalcium Phosphate Scaffolds in Combination With Platelet-Rich Plasma for the Treatment of Critical-Sized Defects of the Mandible: A Pilot Study

Purpose: Our group has recently fabricated 3-dimensional scaffolds of unique architecture to mediate favorable cell binding, proliferation, and differentiation. In this study, the osteoconductive and bioactive polycaprolactone-20% tricalcium phosphate (PCL-TCP) scaffolds were assessed for the treatment of critical-sized defects of the mandible, with respect to new bone formation. Platelet-rich plasma (PRP) was combined with some scaffolds to test if bone regeneration could be enhanced. Materials and Methods: Autologous PRP was prepared from whole blood collected from 8 mongrel dogs. In each dog, 3 defects (18 × 10 × 7 mm) were created at either the left or right mandible and treated with 1 of 2 treatment modalities: 1) grafting with scaffolds alone; or 2) grafting with scaffolds loaded with PRP. The scaffolds were stabilized using 2 dental implants each to prevent rotation. Micro-CT and histologic analysis were carried out on samples after 6 and 9 months. Results: Micro-CT measurements showed that PRP-treated defects had 98.3% and 58.3% more bone volume fraction than defects grafted with scaffolds alone at 6 and 9 months, respectively (P < .05). No significant difference was noted between caudal and frontal situated PRP-treated defects, but a significant difference was observed between male and female dogs. Histologic analyses verified the deposition of osteoid and new bone trabeculae throughout the section at 6 months. The defect margins were filled with mature bone trabeculae at 9 months but the middle section of the scaffolds manifested disturbed mineralization. The scaffolds experienced 33% degradation from 6 to 9 months. PRP treatment had negligible effect on the degradation of the scaffolds. Conclusions: The pilot study showed that the treatment of critical-sized defects of the mandible with PCL-TCP scaffolds may be augmented by the addition of PRP.