Histological findings in post-extraction sockets after alveolar ridge preservation with leukocyte- and platelet-rich fibrin: a randomized clinical trial.

INTRODUCTION Leukocyte- and platelet-rich fibrin (L-PRF) has gained considerable attention due to its regenerative potential and biocompatibility in alveolar ridge preservation (ARP).

Objective

To evaluate the histological findings in post-extraction sockets after ARP with L-PRF (experimental group) and compare them with those obtained using allograft plus a collagen membrane (control group). Histological findings may contribute to the evaluation of bone quality and the rate of bone remodelling. METHODOLOGY Twenty-six sites in 26 patients requiring extraction of a single-rooted maxillary or mandibular tooth were included in this study. Treatment options were randomly assigned. Post-extraction sockets were filled with either an L-PRF matrix or an allograft covered with a collagen membrane. Dental implant placement was performed subsequently. After 12 weeks, bone biopsies were obtained from the sites at the time of implant placement. Histological evaluation of the bone specimens assessed the area of new bone formation and the presence of osteoblasts, osteoclasts, osteolytic lacunae, osteocytes, and blood vessels.

Results

Histological evaluation showed that: a) the proportion of cases with >50% new bone formation was higher in the experimental group compared to the control group (53.8% [7/13] versus 30.8% [4/13]) (p=0.033) b) the presence of osteoblasts was higher (p=0.066) in the experimental group (100% versus 76.9%); c) the presence of osteoclasts was higher (p=0.004) in the experimental group (92.3% versus 38.5%); d) the presence of osteolytic lacunae was higher (p=0.063) in the experimental group (92.3% versus 61.5%); e) the presence of osteocytes was higher (p=0.03) in the experimental group (100% versus 69.2%); and f) the presence of blood vessels was higher (p=0.016) in the experimental group (84.6% versus 38.5%). The presence of osteoblasts and osteolytic lacunae were higher but were not statistically significant.

Conclusions

Within the limitations of this study, ARP with L-PRF may result in accelerated healing, improved bone quality, and a higher rate of bone remodelling. These results reflect the exploratory nature of this study and support the need of additional research, preferably with a larger sample size.