Efficiency of Plasma Rich Fibrin in Accelerating Canine Retraction with Correlation of Timing of Extraction: A Split-mouth Randomised Controlled Trial

Introduction: The chief concern for any patient seeking orthodontic treatment is the duration of the treatment. Various methods have been proposed to accelerate orthodontic tooth movement. In recent years, injectable Platelet-Rich Fibrin (i-PRF) has been shown to enhance cellular activity by increasing bone turnover and promoting healing. Aim: To study the effectiveness of submucosal injection of i-PRF in accelerating canine retraction and to compare the effectiveness of i-PRF in immediate post-extraction and four weeks post-extraction. Materials and Methods: The study was designed as a pilot split-mouth randomised controlled trial and was conducted in the Department of Orthodontics and Dentofacial Orthopaedics in CSI College of Dental Sciences and Research, Madurai, Tamil Nadu, India during the period October 2021 to February 2022. A sample size of 12 patients aged 13-21 years who required all first premolar extraction as a part of treatment was enrolled. All four quadrants of each patient were included, and each quadrant was categorised into one of four groups. All four quadrants of each patient were included and allocated to four groups using simple randomisation (lot method). Groups 1 and 2 were from the maxillary arch, while Groups 3 and 4 were from the mandibular arch. Groups 1 and 2 differed by intervention, whereas Groups 3 and 4 received the same intervention but differed in extraction timing to compare immediate and delayed extraction. Individual canine retraction was attempted using a NiTi closed coil spring. The rate of tooth movement was assessed 21 days (T-1) after the intervention; the intervention was then repeated and reassessed at day 42 (T-2). One-way Analysis of Variance (ANOVA) was done for comparison of intragroup variables, followed by a post-hoc Tukey test. Results: A statistically significant difference in canine retraction (T0-T2) was observed among the study groups (p<0.001). The intervention groups (groups 1, 3, and 4) demonstrated significantly greater canine retraction than the control group (group 2). Post-hoc analysis confirmed significantly greater canine retraction in each intervention group compared with the control group. Furthermore, comparison between the healed extraction socket with i-PRF (group 3) and the immediate extraction socket with i-PRF (group 4) at the incisal level during T0–T2 revealed a statistically significant difference (p=0.011), with greater canine retraction observed in the immediate extraction group. No statistically significant difference was observed between groups 1 and 4 in canine retraction; however, these groups differed in extraction/intervention timing and arch location, indicating that immediate extraction itself did not influence the amount of canine retraction, whereas i-PRF administration significantly enhanced tooth movement. Conclusion: It can be concluded that injectable PRF has been shown to increase the rate of orthodontic tooth movement and that i-PRF administered immediately after extraction was associated with greater canine retraction than i-PRF administered in the healed extraction site.