Do the New Protocols of Platelet-Rich Fibrin Centrifugation Allow Better Control of Postoperative Complications and Healing After Surgery of Impacted Lower Third Molar? A Systematic Review and Meta-Analysis

Platelet concentrate generation protocols have undergone several modifications in recent years; in light of these new developments, this study review aims to evaluate the effects of platelet-rich fibrin (PRF) and the new centrifugation protocols, advanced platelet-rich fibrin (A-PRF), and leukocyte platelet-rich fibrin (L-PRF), after extraction of impacted mandibular third molar. Specifically, we assessed pain control, edema, trismus, and soft tissue healing, and also measured the degree of periodontal regeneration adjacent to the second molar. PubMed, MEDLINE, EMBASE, Web of Science, Virtual health library (BVS), and Cochrane Library were searched up to Julye 2021; randomized controlled studies were included. This report followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and PICO (population, intervention, comparison, outcome) questions. This review has been registered at the International Prospective Register of Ongoing Systematic Reviews (PROSPERO) under the number CRD42019136701. The risk of bias screening and data extraction was performed according to the guidelines recommended by Cochrane. The quantitative analysis was performed using RevMan version 5.4. Of 17 studies included in the systematic review, 11 were eligible for the meta-analysis. The use of L-PRF was not associated with better soft tissue healing at day 7. (standard mean difference = −0.70; 95% confidence interval, −3.50 to 2.10; Z = 0.49; P = .62; heterogeneity = 0.00001; I2 = 97%). With L-PRF, qualitative analysis revealed better pocket depth and insertion level, and also better pain control at 1 and 3 days. With A-PRF, a lower consumption of analgesics was observed than with L-PRF. With both A-PRF and L-PRF, better control of edema (but not trismus) was observed. The use of L-PRF and A-PRF allows better control of pain and edema compared with the use of standard PRF protocols, but neither has an effect on trismus. The PRF and L-PRF protocols improve soft tissue healing, although not to a statistically significant degree; however, they could improve probing depth at the third month after third molar surgery.