The Effect of Two Wattages of Low-level Laser Therapy on Orthodontic Tooth Movement

The use of low-level laser therapy (LLLT) to accelerate orthodontic tooth movement (OTM) has generated mixed outcomes due to the variability of parameters used. The aims of this study were to test for differences in OTM, gene expression using RT-qPCR, and histological changes of molars exposed to two different wattages at the same energy density. A 10g force was applied to molars of three rat groups: CT (no laser), EX-500 (500 mW)and EX-1000 (1000 mW). There were statistically significant differences in OTM between EX-500 and CT groups and RANKL and MMP-13 expression levels between CT and laser groups. Histologically, 56% of the EX-1000 revealed early dysplastic changes. Both wattages of laser therapy increased remodeling in the PDL that may or may not translate into increased OTM. Future studies should focus on elucidating possible biphasic responses of LLLT before it can be offered as a consistent modality for accelerating OTM.M.Sc