G-Force Dilemma: A Call for Standardization of PRF Preparation Protocols

Abstract

Platelet-rich fibrin (PRF), a second-generation platelet concentrate, has been widely investigated for its potential in soft and hard tissue regeneration. The preparation of PRF matrices depends heavily on centrifugation parameters, particularly the relative centrifugal force (RCF). However, inconsistencies in reporting RCF values, variations in rotor dimensions, and differences in the calculation site (RCF-clot, RCF-min, or RCF-max) have resulted in significant confusion within the literature. This review aims to clarify the inconsistencies in reporting centrifugation forces for PRF preparation, highlight the biological consequences of varying RCF, and emphasize the need for standardization of protocols to improve reproducibility and clinical outcomes. A comprehensive review of studies from 2001 to 2024 was conducted, analysing centrifugation protocols used for leukocyte- and platelet-rich fibrin (L-PRF) preparation. Data regarding RPM, RCF values, centrifugation times, and clot characteristics were extracted and compared. Emphasis was placed on the site of RCF calculation, device characteristics, and their influence on clot formation, cellular content, and growth factor release. Protocols for PRF preparation varied widely, with reported centrifugation speeds ranging from 2500–3000 rpm and RCF values from 200–1000 g. Discrepancies were largely attributed to inconsistent reporting of RCF location and variations in centrifuge design. Lower RCF protocols favoured greater incorporation of leukocytes and platelets, resulting in clots with enhanced release of growth factors and more uniform cell distribution. Conversely, higher RCF produced denser fibrin matrices with reduced biological activity. Despite these variations, a consensus statement in 2019 advocated for reporting standardized RCF values at the bottom of centrifuge tubes (RCF-max) to improve reproducibility. Significant scientific inaccuracies persist regarding the reporting of centrifugation parameters in PRF-related research. Given the influence of RCF on clot characteristics and biological properties, standardized reporting, particularly the use of RCF-max, is essential to ensure reproducibility and optimize clinical outcomes. Adoption of the 2019 consensus recommendations will improve comparability across studies and enhance the predictability of PRF applications in patient care.