Low‐level laser therapy stimulates bone metabolism and inhibits root resorption during tooth movement in a rodent model

Abstract

This study evaluated the biological effects of low-level laser therapy (LLLT) on bone remodeling, tooth displacement and root resorption, occurred during the orthodontic tooth movement. Upper first molars of a total of sixty-eight male rats were subjected to orthodontic tooth movement and euthanized on days 3, 6, 9, 14 and 21 days and divided as negative control, control and LLLT group. Tooth displacement and histomorphometric analysis were performed in all animals; scanning electron microscopy analysis was done on days 3, 6 and 9, as well as the immunohistochemistry analysis of RANKL/OPG and TRAP markers. Volumetric changes in alveolar bone were analyzed using MicroCT images on days 14 and 21. LLLT influenced bone resorption by increasing the number of TRAP-positive osteoclasts and the RANKL expression at the compression side. This resulted in less alveolar bone and hyalinization areas on days 6, 9 and 14. LLLT also induced less bone volume and density, facilitating significant acceleration of tooth movement and potential reduction in root resorption besides stimulating bone formation at the tension side by enhancing OPG expression, increasing trabecular thickness and bone volume on day 21. Taken together, our results indicate that LLLT can stimulate bone remodeling reducing root resorption in a rat model. LLLT improves tooth movement via bone formation and bone resorption in a rat model.

Effects of Photobiomodulation on SOFAT, A T‐cell‐derived Cytokine, May Explain Accelerated Orthodontic Tooth Movement

“…This study evaluated the effects of PBM on SOFAT, a novel activated T‐cell‐secreted cytokine that induces osteoclastogenesis in an independent pathway of the well‐known OPG/RANK‐L/RANK system, on tooth movement in an animal model. Also, the results showed that photobiomodulation may have an effect on these cytokines, as previously reported .…”

“…The RANK‐L/RANK/OPG system plays a fundamental role in alveolar bone remodeling during induced tooth movement, and the effects of low‐power laser irradiation are also well established. Changes in the concentrations of OPG and RANK‐L in the periodontal ligament have been observed in tissue and fluids around teeth under mechanical load and also under low‐power laser irradiation .…”

“…The PBM group received laser irradiation every 48 h, until the end of the experimental period, according to the methodology proposed by Suzuki et al . .…”

Effects of Photobiomodulation on Root Resorption Induced by Orthodontic Tooth Movement and RANKL/OPG Expression in Rats

“…Force delivered by the spring was measured using a precision tensiometer and the initial force applied was 50 g, which has been considered a heavy and capable of inducing root resorption, according to Suzuki et al . .…”

Light transmittance of the periodontium

“…This process results in beneficial therapeutic outcomes including but not limited to the alleviation of pain or inflammation, immunomodulation, and promotion of wound healing and tissue regeneration.^ [1]. PBM therapy was found to have multiple clinical benefits, which includes reducing pain [2][3][4][5][6][7], improving wound healing [8][9][10][11], accelerating bone healing [12][13][14][15][16][17], promoting osteointegration [18], facilitating orthodontic tooth movement [19][20][21][22][23][24][25][26], stimulating bone formation [27][28][29][30][31], and improving periodontal tissue repair and decreasing inflammation and root resorption [23,26,32]. The light sources were laser or a light-emitting diode (LED).…”