Efficacy of Different Regiments of 980 nm Low-Level Laser Therapy to Reduce Pain Caused by Orthodontic Separators: A Randomized, Double-Blind, Split-Mouth Placebo-Controlled Study

Thirty-one (n=31) participants from the Department of Orthodontics and Pediatric Dentistry, University of Szeged will be randomly assigned using a split-mouth design, to avoid inter-individual variability between participants from confounding our results. Patients' upper and lower dental arches will be divided into right and left halves (i.e. quadrants). In each participant, three quadrants will be used to administer the different LLLT treatment regimens, while the fourth quadrant will be designated for placebo. The random assignment of quadrants to receive LLLT or placebo will be determined using cards denoting the possible four quadrants and the four treatment variations, respectively. Participants will be asked to blindly choose from among the prepared cards to determine assignment; to ensure adherence to double-blinding, patients and the operator will be blinded to the assignment of quadrants and treatments. In the treatment quadrants a low-level medical gallium-aluminum-arsenide (GaAlAs) diode laser device (wavelength 980 nm, power: 0.1-0.2W, producing 6-12 J energy), with either a continuous or pulsed wave mode will be used on the first permanent molars in the appropriate treatment (R1-R3) quadrants. The efficacy of the treatment will be evaluated in two energy-levels (i.e. intensity; 6 and 12 J, respectively) and regimes (continuous vs. pulsed). The assigned LLLT treatments in the appropriate three quadrants will be applied as follows: regiment 1 (R1: 6 J, continuous), regiment 2 (R2: 12 J, continuous), regiment 3 (R3: 6 J, pulsed), while placebo treatment (P) will be applied in the remaining, fourth quadrant. Using the split mouth design, patients will receive only a single dose immediately after the placement of orthodontic separators. Specified points in each quadrant will be treated from mesial, central and distal directions on the mucosa both buccally and lingually/palatinally with 10-10 sec for each, altogether for 60 sec, producing either 36 or 72 J