Effects of leucocyte and platelet-rich fibrin on post-extraction socket healing

Abstract

Objectives: This study aimed to evaluate the effects of leucocyte and platelet-rich fibrin (L-PRF) on a cluster of growth factors during the period of post-extraction socket healing. Methods: Eleven systemically healthy subjects requiring extraction of two non-adjacent single-rooted teeth were recruited. Individual L-PRF clots were prepared via a well-established Choukroun's protocol. They were then randomly placed in one of the extraction sockets (L-PRF group) and the other socket was left to heal naturally (Control group). Wound fluids were collected by paper strips (PerioPaper®) from post-extraction sockets at 6 hours, 1 day, 3 days, and 7 days. L-PRF clots after a gentle squeeze were cultured in vitro in DMEM, and the supernatants were collected along the same timeline shown above. The levels of growth factors, including TGF-β1, PDGF-AA, PDGF-AB/BB, EGF, FGF-2 and VEGF, were measured by multiplex assays. Results: Clinically, L-PRF group showed better wound healing with the faster closure of extraction sockets as compared with the Control group, especially at 7 days. In terms of biological effects, there were decreased levels of multiple growth factors from 6 hours to 7 days in both L-PRF and Control groups, while VEGF levels increased consistently over time. Notably, the levels of TGF-β1, PDGF-AB/BB and EGF were significantly higher in the L-PRF group than those of Control group (P<0.05); while no significant difference was found in the levels of PDGF-AA, FGF-2 and VEGF between the two groups. The levels of TGF-β1, PDGF-AA, PDGF-AB/BB, EGF and FGF-2 in the culture supernatants decreased gradually, in line with the findings of wound fluids. Conclusions: The present study shows that L-PRF may enhance the in situ expression of multiple growth factors, especially TGF-β1, PDGF-AB/BB and EGF, thereby contributing to favorably promoting early wound healing of post-extraction socket.