Effect of 850 nm LED irradiation on the alignment of crowded mandibular anterior teeth: a randomized controlled clinical trial

This study aims to determine if intraoral 850 nm LED irradiation could reduce the duration of lower anterior crowding alignment.

In a parallel-designed, randomized controlled clinical trial 60 patients with 2 to 6 mm of lower incisor crowding who need non-extraction treatment, were randomly assigned to the intervention and control groups by block randomization (36 females, 24 males, mean age: 19.93 ± 3.05). MBT brackets (0.022 × 0.28-inch) were bonded for both groups and the NiTi wires in sequences were put in place until correction of crowding. The intra-oral LED device with a wavelength of 850 nm and power density of 70 mW/cm² was used for 5 min per day in the intervention group. The control group did not receive any light. The primary outcome was the duration of crowding correction. The patient's pain according the modified McGill pain questionnaire was the secondary outcome. The Cox regression model was used to compare groups. Mann–Whitney test was used for pain analysis.

The crowding at baseline was the same between the two groups (P > 0.05). Duration of treatment in the intervention group was 104.7 days (95% CI: 95.6 -113.8) and significantly shorter than 161.9 days (95% CI: 151.5 -171.2) in the control group. The control group experienced a significantly higher pain score of 6.8 (95% CI: 6.1–7.5) immediately after archwire placement than the intervention group 5.4 (95% CI: 4.6–6.3).

Intra-oral LED 850 nm significantly decreased the relieving time of lower incisor crowding by up to 36% and reduced pain experience.