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


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/cm2). 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.

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  1. 1.

    Brezniak N, Wasserstein A (2002) Orthodontically induced inflammatory root resorption. Part I: The basic science aspects. Angle Orthod 72(2):175–179

    PubMed  Google Scholar 

  2. 2.

    Fuss Z, Tsesis I, Lin S (2003) Root resorption–diagnosis, classification and treatment choices based on stimulation factors. Dent Traumatol 19(4):175–182

    PubMed  Article  Google Scholar 

  3. 3.

    Brezniak N, Wasserstein A (2002) Orthodontically induced inflammatory root resorption. Part II: The clinical aspects. Angle Orthod 72(2):180–184

    PubMed  Google Scholar 

  4. 4.

    Brudvik P, Rygh P (1993) The initial phase of orthodontic root resorption incident to local compression of the periodontal ligament. Eur J Orthod 15(4):249–263

    PubMed  Article  CAS  Google Scholar 

  5. 5.

    Tripuwabhrut P, Brudvik P, Fristad I, Rethnam S (2010) Experimental orthodontic tooth movement and extensive root resorption: periodontal and pulpal changes. Eur J Oral Sci 118(6):596–603

    PubMed  Article  Google Scholar 

  6. 6.

    Baba S, Kuroda N, Arai C, Nakamura Y, Sato T (2011) Immunocompetent cells and cytokine expression in the rat periodontal ligament at the initial stage of orthodontic tooth movement. Arch Oral Biol 56(5):466–473

    PubMed  Article  CAS  Google Scholar 

  7. 7.

    Asano M, Yamaguchi M, Nakajima R, Fujita S, Utsunomiya T, Yamamoto H, Kasai K (2011) IL-8 and MCP-1 induced by excessive orthodontic force mediates odontoclastogenesis in periodontal tissues. Oral Dis 17(5):489–498

    PubMed  Article  CAS  Google Scholar 

  8. 8.

    Bletsa A, Berggreen E, Brudvik P (2006) Interleukin-1alpha and tumor necrosis factor-alpha expression during the early phases of orthodontic tooth movement in rats. Eur J Oral Sci 114(5):423–429

    PubMed  Article  CAS  Google Scholar 

  9. 9.

    Mavragani M, Amundsen OC, Selliseth NJ, Brudvik P, Selvig KA (2004) Early root alterations after orthodontic force application studied by light and scanning electron microscopy. Eur J Orthod 26(2):119–128

    PubMed  Article  Google Scholar 

  10. 10.

    Mohandesan H, Ravanmehr H, Valaei N (2007) A radiographic analysis of external apical root resorption of maxillary incisors during active orthodontic treatment. Eur J Orthod 29(2):134–139

    PubMed  Article  Google Scholar 

  11. 11.

    Brudvik P, Rygh P (1995) The repair of orthodontic root resorption: an ultrastructural study. Eur J Orthod 17(3):189–198

    PubMed  Article  CAS  Google Scholar 

  12. 12.

    Brudvik P, Rygh P (1995) Transition and determinants of orthodontic root resorption-repair sequence. Eur J Orthod 17(3):177–188

    PubMed  Article  CAS  Google Scholar 

  13. 13.

    Mirabella AD, Artun J (1995) Prevalence and severity of apical root resorption of maxillary anterior teeth in adult orthodontic patients. Eur J Orthod 17(2):93–99

    PubMed  Article  CAS  Google Scholar 

  14. 14.

    Walker S (2010) Root resorption during orthodontic treatment. Evid Based Dent 11(3):88

    PubMed  Article  CAS  Google Scholar 

  15. 15.

    Gameiro GH, Nouer DF, Pereira-Neto JS, de Araujo Magnani MB, de Andrade ED, Novaes PD, de Arruda Veiga MC (2008) Histological analysis of orthodontic root resorption in rats treated with the cyclooxygenase-2 (COX-2) inhibitor celecoxib. Orthod Craniofacial Res 11(3):156–161

    Article  CAS  Google Scholar 

  16. 16.

    Gonzales C, Hotokezaka H, Matsuo K, Shibazaki T, Yozgatian JH, Darendeliler MA, Yoshida N (2009) Effects of steroidal and nonsteroidal drugs on tooth movement and root resorption in the rat molar. Angle Orthod 79(4):715–726

    PubMed  Article  Google Scholar 

  17. 17.

    Jerome J, Brunson T, Takeoka G, Foster C, Moon HB, Grageda E, Zeichner-David M (2005) Celebrex offers a small protection from root resorption associated with orthodontic movement. J Calif Dent Assoc 33(12):951–959

    PubMed  Google Scholar 

  18. 18.

    Choi J, Baek SH, Lee JI, Chang YI (2010) Effects of clodronate on early alveolar bone remodeling and root resorption related to orthodontic forces: a histomorphometric analysis. Am J Orthod Dentofacial Orthop 138(5):548.e1-8,e541–e548, discussion 548-549

    Google Scholar 

  19. 19.

    Igarashi K, Adachi H, Mitani H, Shinoda H (1996) Inhibitory effect of the topical administration of a bisphosphonate (risedronate) on root resorption incident to orthodontic tooth movement in rats. J Dent Res 75(9):1644–1649

    PubMed  Article  CAS  Google Scholar 

  20. 20.

    Kitaura H, Fujimura Y, Yoshimatsu M, Eguchi T, Kohara H, Jang I, Morita Y, Yoshida N (2009) An M-CSF receptor c-Fms antibody inhibits mechanical stress-induced root resorption during orthodontic tooth movement in mice. Angle Orthod 79(5):835–841

    PubMed  Article  Google Scholar 

  21. 21.

    Liu L, Igarashi K, Haruyama N, Saeki S, Shinoda H, Mitani H (2004) Effects of local administration of clodronate on orthodontic tooth movement and root resorption in rats. Eur J Orthod 26(5):469–473

    PubMed  Article  Google Scholar 

  22. 22.

    Fujimura Y, Kitaura H, Yoshimatsu M, Eguchi T, Kohara H, Morita Y, Yoshida N (2009) Influence of bisphosphonates on orthodontic tooth movement in mice. Eur J Orthod 31(6):572–577

    PubMed  Article  Google Scholar 

  23. 23.

    Xavier M, David DR, de Souza RA, Arrieiro AN, Miranda H, Santana ET, Silva JA Jr, Salgado MA, Aimbire F, Albertini R (2010) Anti-inflammatory effects of low-level light emitting diode therapy on Achilles tendinitis in rats. Lasers Surg Med 42(6):553–558

    PubMed  Article  Google Scholar 

  24. 24.

    Lim W, Lee S, Kim I, Chung M, Kim M, Lim H, Park J, Kim O, Choi H (2007) The anti-inflammatory mechanism of 635-nm light-emitting-diode irradiation compared with existing COX inhibitors. Lasers Surg Med 39(7):614–621

    PubMed  Article  Google Scholar 

  25. 25.

    Serafim KG, Ramos SD, de Lima FM, Carandina M, Ferrari O, Dias IF, Toginho Filho DD, Siqueira CP (2011) Effects of 940-nm light-emitting diode (LED) on sciatic nerve regeneration in rats. Lasers Med Sci 27(1):113-9

    Google Scholar 

  26. 26.

    Eells JT, Wong-Riley MT, VerHoeve J, Henry M, Buchman EV, Kane MP, Gould LJ, Das R, Jett M, Hodgson BD, Margolis D, Whelan HT (2004) Mitochondrial signal transduction in accelerated wound and retinal healing by near-infrared light therapy. Mitochondrion 4(5–6):559–567

    PubMed  Article  CAS  Google Scholar 

  27. 27.

    Tortamano A, Lenzi DC, Haddad AC, Bottino MC, Dominguez GC, Vigorito JW (2009) Low-level laser therapy for pain caused by placement of the first orthodontic archwire: a randomized clinical trial. Am J Orthod Dentofacial Orthop 136(5):662–667

    PubMed  Article  Google Scholar 

  28. 28.

    Carvalho AL, Napimoga MH, Coelho-Campos J, Silva-Filho VJ, Thedei G (2011) Photodynamic therapy reduces bone resorption and decreases inflammatory response in an experimental rat periodontal disease model. Photomed Laser Surg 29(11):735-40l.

    Google Scholar 

  29. 29.

    Kawasaki K, Shimizu N (2000) Effects of low-energy laser irradiation on bone remodeling during experimental tooth movement in rats. Lasers Surg Med 26(3):282–291

    PubMed  Article  CAS  Google Scholar 

  30. 30.

    Vilela RG, Gjerde K, Frigo L, Leal Junior EC, Lopes-Martins RA, Kleine BM, Prokopowitsch I (2011) Histomorphometric analysis of inflammatory response and necrosis in re-implanted central incisor of rats treated with low-level laser therapy. Lasers Med Sci. doi:10.1007/s10103-011-0937-7

  31. 31.

    Mayahara K, Yamaguchi A, Sakaguchi M, Igarashi Y, Shimizu N (2010) Effect of Ga-Al-As laser irradiation on COX-2 and cPLA2-alpha expression in compressed human periodontal ligament cells. Lasers Surg Med 42(6):489–493

    PubMed  Article  Google Scholar 

  32. 32.

    Pesevska S, Nakova M, Gjorgoski I, Angelov N, Ivanovski K, Nares S, Andreana S (2011) Effect of laser on TNF-alpha expression in inflamed human gingival tissue. Lasers Med Sci. doi:10.1007/s10103-011-0898-x

  33. 33.

    Casalechi HL, Nicolau RA, Casalechi VL, Silveira L Jr, De Paula AM, Pacheco MT (2009) The effects of low-level light emitting diode on the repair process of Achilles tendon therapy in rats. Lasers Med Sci 24(4):659–665

    PubMed  Article  Google Scholar 

  34. 34.

    Corazza AV, Jorge J, Kurachi C, Bagnato VS (2007) Photobiomodulation on the angiogenesis of skin wounds in rats using different light sources. Photomed Laser Surg 25(2):102–106

    PubMed  Article  Google Scholar 

  35. 35.

    Correa F, Lopes Martins RA, Correa JC, Iversen VV, Joenson J, Bjordal JM (2007) Low-level laser therapy (GaAs lambda = 904 nm) reduces inflammatory cell migration in mice with lipopolysaccharide-induced peritonitis. Photomed Laser Surg 25(4):245–249

    PubMed  Article  Google Scholar 

  36. 36.

    de Morais NC, Barbosa AM, Vale ML, Villaverde AB, de Lima CJ, Cogo JC, Zamuner SR (2010) Anti-inflammatory effect of low-level laser and light-emitting diode in zymosan-induced arthritis. Photomed Laser Surg 28(2):227–232

    PubMed  Article  Google Scholar 

  37. 37.

    Kim YD, Kim SS, Kim SJ, Kwon DW, Jeon ES, Son WS (2010) Low-level laser irradiation facilitates fibronectin and collagen type I turnover during tooth movement in rats. Lasers Med Sci 25(1):25–31

    PubMed  Article  Google Scholar 

  38. 38.

    Lim JH, Lee J, Choi J, Hong J, Jhun H, Han J, Kim S (2009) The effects of light-emitting diode irradiation at 610 nm and 710 nm on murine T-cell subset populations. Photomed Laser Surg 27(5):813–818

    PubMed  Article  CAS  Google Scholar 

  39. 39.

    Vinck EM, Cagnie BJ, Cornelissen MJ, Declercq HA, Cambier DC (2003) Increased fibroblast proliferation induced by light emitting diode and low power laser irradiation. Lasers Med Sci 18(2):95–99

    PubMed  Article  Google Scholar 

  40. 40.

    Xu M, Deng T, Mo F, Deng B, Lam W, Deng P, Zhang X, Liu S (2009) Low-intensity pulsed laser irradiation affects RANKL and OPG mRNA expression in rat calvarial cells. Photomed Laser Surg 27(2):309–315

    PubMed  Article  CAS  Google Scholar 

  41. 41.

    Brudvik P, Rygh P (1994) Multi-nucleated cells remove the main hyalinized tissue and start resorption of adjacent root surfaces. Eur J Orthod 16(4):265–273

    PubMed  Article  CAS  Google Scholar 

  42. 42.

    Winter BU, Stenvik A, Vandevska-Radunovic V (2009) Dynamics of orthodontic root resorption and repair in human premolars: a light microscopy study. Eur J Orthod 31(4):346–351

    PubMed  Article  Google Scholar 

  43. 43.

    Pires D, Xavier M, Araujo T, Silva JA Jr, Aimbire F, Albertini R (2011) Low-level laser therapy (LLLT; 780 nm) acts differently on mRNA expression of anti- and pro-inflammatory mediators in an experimental model of collagenase-induced tendinitis in rat. Lasers Med Sci 26(1):85–94

    PubMed  Article  Google Scholar 

  44. 44.

    Safavi SM, Kazemi B, Esmaeili M, Fallah A, Modarresi A, Mir M (2008) Effects of low-level He-Ne laser irradiation on the gene expression of IL-1beta, TNF-alpha, IFN-gamma, TGF-beta, bFGF, and PDGF in rat's gingiva. Lasers Med Sci 23(3):331–335

    PubMed  Article  Google Scholar 

  45. 45.

    Sousa MV, Scanavini MA, Sannomiya EK, Velasco LG, Angelieri F (2011) Influence of low-level laser on the speed of orthodontic movement. Photomed Laser Surg 29(3):191–196

    PubMed  Article  Google Scholar 

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The authors would like to thank Total Vet, Londrina and Virbac do Brasil, for the donation of the reagents used in the study.

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Correspondence to Solange de Paula Ramos.

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Fonseca, P.D., de Lima, F.M., Higashi, D.T. et al. Effects of light emitting diode (LED) therapy at 940 nm on inflammatory root resorption in rats. Lasers Med Sci 28, 49–55 (2013). https://doi.org/10.1007/s10103-012-1061-z

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  • Orthodontics
  • Osteoclasts
  • Inflammation
  • Light emitting diode