Effects of light emitting diode (LED) therapy at 940 nm on inflammatory root resorption in rats

Abstract

The effects of LED therapy at 940 nm on periodontal healing, inflammatory cell infiltration, and root resorption were analyzed in an experimental model of orthodontic tooth movement in rats. Twenty-five male Wistar rats were allocated into four experimental groups: Control animals (Co, n = 5), Controls + LED therapy (CoLED, n = 6), animals submitted to orthodontic force (RR, n = 7) and submitted to orthodontic force + LED therapy (RRLED, n = 7). All procedures were approved by the Committee for Ethics in Animal Experimentation of the Universidade Estadual de Londrina (protocol CEEA 5/2010 37359). A force of 50 g was applied to the right upper molars of RR and RRLED groups. On days 2, 3, and 4 after orthodontic treatment, the CoLED and RRLED groups received LED irradiation (940 nm, 4 J/cm(2)). The animals were killed on day 7 for histological analysis. An increased number of root resorption lacunae was found only in the RR group (p < 0.05). The RR group also presented more osteoclasts (p < 0.005) and inflammatory cell infiltration (p < 0.005) than the control group. The RRLED group presented fewer osteoclasts (p < 0.005) and inflammatory cells (p < 0.005) in the periodontal ligament than the RR group. The CoLED and RRLED groups presented more periodontal fibroblasts (p < 0.005) than non-irradiated groups. RRLED presented more blood vessels (p < 0.01) in the periodontal ligament than the RR group. In conclusion, the results suggest that LED therapy improved periodontal tissue repair and decreased inflammation and root resorption after the application of orthodontic force.

Low-Level Laser Action on Orthodontically Induced Root Resorption: Histological and Histomorphometric Evaluation

“…The movement was achieved with a nickel titanium spring and 50 g of force on the upper first molars. 15 The results presented an increase of periodontal tissue repair, reduced inflammation and reduced root resorption by phototherapy, thus contradicting the results of the present study. Despite the fact that the methodology was distinct, the difference found between these two studies could be due to different doses and wavelengths employed.…”

“…[18][19][20] This review found only one study that assessed the phototherapy on the inflammatory root resorption, but with LED. 15 Considering that LED and laser phototherapy exhibit similar effects 21 and the coherence of light generate a benefit particularly in the deeper tissue layers, 22 these studies were compared. Fonseca et al 15 investigated the effect of phototherapy on inflammatory root resorption, in Wistar rats.…”

“…15 Considering that LED and laser phototherapy exhibit similar effects 21 and the coherence of light generate a benefit particularly in the deeper tissue layers, 22 these studies were compared. Fonseca et al 15 investigated the effect of phototherapy on inflammatory root resorption, in Wistar rats. Their study applied a power density of 4 J/ cm² on the day two, three and four, with the euthanasia on the seventh day of tooth movement.…”

Effects of medications and laser on induced tooth movement and associated root resorption: four key points

“…1,3,4,5,[7][8][9][10][11][12][14][15][16][17][18]20,[23][24][25][26] We describe four fundamental points for experimental models to ensure that the evaluation of the effects of medication and phototherapy on induced tooth movement and associated root resorption is free of external influence.…”

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).…”