Platelet-rich fibrin after mandibular third molar extraction: an umbrella review of systematic reviews and meta-analyses.

PURPOSE: To synthesize evidence on platelet-rich fibrin (PRF) and its derivatives for postoperative outcomes after mandibular third molar extraction, and to re-evaluate the methodological quality of available systematic reviews against the prior umbrella review (Yang 2024). METHODS: PubMed, Cochrane CDSR, and Epistemonikos were searched without language restriction up to May 2026. Systematic reviews evaluating PRF for mandibular third molar extraction outcomes were included. Two reviewers independently screened, extracted data, applied AMSTAR-2 under the strict algorithm, and computed the corrected covered area (CCA). Yang 2024 was excluded as comparator. RESULTS: Nineteen systematic reviews were included, four post-dating Yang's cutoff. PRF consistently reduced alveolar osteitis (RR/OR 0.22-0.43) and postoperative pain (SMD - 0.38 to - 1.84). In the highest-quality network meta-analysis (Costa 2023), L-PRF effects on pain remained below the ~ 10-mm minimum clinically important difference (MCID), whereas A-PRF and CGF exceeded it. Effects on swelling were large but highly heterogeneous; effects on trismus and healing were derivative-dependent. Strict AMSTAR-2 classified 1/19 reviews as high, 1/19 as moderate, 8/19 as low, and 9/19 as critically low confidence. The CCA was 12.77% (high overlap). None of the nine reviews previously rated high by Yang reached high confidence in our evaluation. CONCLUSION: PRF provides clinically meaningful benefits after mandibular third molar extraction, particularly for alveolar osteitis prevention and early pain control with A-PRF and CGF. However, the methodological quality of the underlying systematic-review evidence is substantially lower than previously characterized, and recommendations should be calibrated accordingly. PROTOCOL REGISTRATION: Open Science Framework (OSF), https://doi.org/10.17605/OSF.IO/ED4MJ , registered 21 May 2026.