The effect of platelet-rich fibrin on bone regeneration and angiogenesis in rabbit cranial defects

This study evaluated the effect of platelet-rich fibrin (PRF) on the osteogenesis and angiogenesis of rabbit calvarial defects. The calvarium of nine rabbits was exposed. In each rabbit, two circular bone defects, one on each side of the midline, were prepared using a reamer drill. While the experimental site received PRF, the control sites were left filled with blood. The animals were sacrificed after a period of 1 week (n=3), 2 weeks (n=3), and 4 weeks (n=3). The following histomorphometric data were recorded: 1) the area of the newly formed tissue relative to total bone defect (NT) and the area of newly formed osteoid relative to newly formed tissue (NB), 2) the longest and shortest vertical height of the newly formed tissue relative to the vertical height of normal tissue (LH, SH), 3) newly formed osteoid on the defect margin using region of interest (NBR), and 4) bony pontic formation from the margin was used to evaluate bone growth (OS). The expression of vascular endothelial growth factor (VEGF) was evaluated by immunohistochemical staining. The differences between groups were not significant at any experimental time point. However, a significant linear increase of NB and NBR including OS value according to time was observed in the PRF group. In addition, the intensity and percentage range of VEGF expression showed a significant linear decrease trend with the time in the PRF group. The results of this study suggest that PRF may enhance the quality of bone regeneration.