A split-mouth randomized controlled trial on leukocyte- and platelet-rich fibrin's role in bone density, trabecular complexity, and canine retraction.

Background: Orthodontic treatment often leads to alveolar bone loss, necessitating interventions to optimize bone preservation during canine retraction. This study evaluated the efficacy of leukocyte- and platelet-rich fibrin (L-PRF) in enhancing bone density (BD), trabecular architecture, and canine movement following first premolar extraction.

Methods: A single-center, split-mouth RCT (ClinicalTrials.gov: CTRI/2024/01/061503) enrolled 35 patients (20 males, 15 females; mean age: 18.8 ± 2.04 years males, 19.13 ± 1.96 years females) with Class I bimaxillary protrusion or Class II Division 1 malocclusion, requiring bilateral first premolar extractions (70 sites). Contralateral sockets were randomized (computer-generated sequence, 1:1 ratio) to L-PRF or natural healing (control) to reduce inter-patient variability. Bone density, trabecular patterns, and fractal dimension were evaluated via cone-beam computed tomography scans (ImageJ analysis), and canine movement measured monthly over 4 months using study models. Blinded evaluators analyzed outcomes using t-tests, mixed-model analysis, and Pearson correlations (P < 0.05). Recruitment occurred January 2024-January 2025.

Results: All 70 sites were analyzed (no loss to follow-up). L-PRF significantly increased bone density (562.28 ± 13.63 HU vs. 533.00 ± 5.84 HU, P = 0.001, Cohen's d = 2.79), fractal dimension (1.8 ± 0.12 vs. 1.52 ± 0.15, P = 0.001, Cohen's d = 2.01), and canine movement (3.53 ± 0.23 mm vs. 2.71 ± 0.22 mm, P = 0.001, Cohen's d = 3.48), but with greater tipping. Trabecular complexity improved significantly (P < 0.05). No adverse events occurred.

Conclusion: L-PRF significantly enhanced bone density, trabecular architecture, and canine retraction over a follow-up period of four months, offering a promising adjunct to orthodontic treatment.