A three-arm parallel split-mouth randomized controlled trial comparing injectable platelet-rich fibrin and low-level laser therapy on the rate of orthodontic tooth movement and canine angulation during en-masse retraction

Objectives: To compare the effects of injectable platelet-rich fibrin (I-PRF) and low-level laser therapy (LLLT) on the rate and pattern of orthodontic tooth movement, including canine angulation and rotation during en-masse retraction. Materials and Methods: A single-center, single-blind, split-mouth randomized controlled trial was conducted in 33 female patients with Class I bimaxillary protrusion. Patients were assigned into three clusters: I-PRF vs control, LLLT vs control, and I-PRF vs LLLT. After premolar extraction and initial alignment, en-masse retraction was initiated using 150g force nickel-titanium coil springs. I-PRF (0.5 mL/site) was administered at T0 and T1 (2 weeks). LLLT (650 nm, 8 J/cm2, 100 mW Ga-Al-Ar diode laser) was applied at T0, T2 (4 weeks), and T3 (8 weeks). Control sites received no intervention. Digital study models were obtained at T1 (2 weeks), T2 (4 weeks), T3 (8 weeks), and T4 (12 weeks) to measure space closure and canine rotation. canine angulation was assessed on orthopantomograms at T0 and T4. Data were analyzed using mixed-design analysis of variance. Results: Both I-PRF and LLLT significantly enhanced space closure compared to control (P < .001). LLLT showed the greatest retraction (3.02 ± 0.24 mm), followed by I-PRF (2.82 ± 0.27 mm) and control (1.99 ± 0.42 mm). Group differences were large (η2p = 0.62), and time × group interactions were moderate. Anchorage loss was higher in both intervention groups. Conclusions: Both adjuncts accelerated en-masse retraction effectively, with LLLT demonstrating a modest but sustained clinical advantage over I-PRF.