Rate of Canine Retraction and Expression of Receptor Activator of Nuclear factor Kappa-B Ligand (RANKL) and Osteoprotegerin (OPG) in Gingival Crevicular Fluid (GCF) Following the Placement of Autologous Leukocyte-Platelet Rich Fibrin (L-PRF) Among Subjects with Class I Bimaxillary Protrusion Malocclusions: A Split-Mouth Randomized Controlled Trial

Abstract

Abstract Objectives: To assess the outcome of L-PRF on the rate of maxillary canine retraction and its correlation with the levels of RANKL and OPG in the GCF. Subjects and Methods: Eighteen females who required all 1st premolars extraction for the correction of their Class-I bimaxillary protrusion malocclusions were included. The L-PRF plugs were placed in the experimental side 1st premolar extraction sockets. Canine retraction was performed by sliding mechanics. Canine retraction was assessed from the maxillary study models prepared just before the extraction (T0), then at 1-week (T1), 2-weeks (T2), 4-weeks (T3), and 8-weeks (T4) after the 1st premolars extraction and placement of L-PRF plugs. The concentrations of RANKL and OPG in the GCF were evaluated at T0, T1, T2, T3 and T4. Results: In experimental sides, the amount of canine retraction was statistically more during the T0-T1 (P=0.035), T1-T2 (P=0.001), and T2-T3 (P=0.038) periods. The mean concentration of RANKL at T1 (P=0.001), T2 (P=0.002) and T3 (P=0.010) was significantly more in the experimental sides. The mean concentration of OPG was significantly less in the experimental sides at T2 (P=0.016), T3 (P=0.020) and T4 (P=0.023). The RANKL:OPG was significantly more in the experimental sides at T1 (P=0.002), T2 (P=0.001), T3 (P=0.001) and T4 (P=0.005). No significant correlation found between canine retraction and RANKL and OPG concentrations in GCF. Conclusions: The L-PRF accelerated the rate of maxillary canine retraction by 0.28mm over 8-weeks period. The L-PRF favored the local osteoclastogenesis by enhancing the RANKL and suppressing the OPG concentrations. Trial registration: The Clinical Trials Registry of India (Reg. No. CTRI/2020/10/028390, Date-13.10.2020).