The Effect of Photobiomodulation Therapy in Different Doses on Bone Repair of Critical Size Defects in Rats: A Histomorphometric Study

Andrea Carvalho de Marco, Letícia Cavassini Torquato, Paulo Roberto Gonçalves, Tatiana Camacho Ribeiro, Camilla Moretto Nunes, Daniella Vicensotto Bernardo, Mônica Fernandes Gomes, Maria Aparecida Neves Jardini, Mauro Pedrine Santamaria

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5 Scopus citations


Introduction: Photobiomodulation therapy (PBM) appears to induce osteogenesis and stimulate fracture repair; because of its capacity, it is considered a promising treatment, but the characteristics of response to different radiation doses must be investigated through in vivo studies to establish their safety and effectiveness. Thus, this paper aims to analyze the effects of the PBM at different doses on the repair of critical bone defects through histological and histomorphometric analyses. Methods: Sixty 90-day-old adult rats (Rattus norvegicus, albinus, Wistar) weighing approximately 300 g were used. Critical bone defects of 5 mm in diameter were performed in their calvaria. The animals were randomly separated into 5 groups: C-Blood clot, L15-PBM 15J/cm2, L30-PBM 30 J/cm2, L45-PBM 45 J/cm2, L60-PBM 60 J/cm2. Each group was subdivided according to observation periods of 30 and 60 days with 6 rats in each subgroup. Low-level gallium aluminum arsenide (GaAlAs) lasers were used at a 660 nm wavelength, 30 mW and 0.04 cm2 in area. The PBM was applied over 5 points; 4 points of application were distributed on the edges while one point of application was located in the center of the bone defect. PBM occurred right after the procedure. In 30 and 60 days, the animals were euthanized by anesthesia overdose and the analyses were performed. The data were analyzed statistically by the ANOVA, together with the Tukey test, whose significance level was 5%. Results: As regards the treatment factor, the highest percentage of bone neoformation was achieved by group L45-60. The group with the highest closure, despite not having a statistically significant difference with the other doses, was 45 J with only 0.49 mm between edges. Conclusion: Thus, the present study allowed concluding that the highest percentage of bone neoformation area was achieved at 45 J/cm2 in 60 days; that is, it was significantly effective in comparison with other doses.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalJournal of Lasers in Medical Sciences
Issue number1
StatePublished - 2021

Bibliographical note

Funding Information:
This work was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP (2015/10376-3 – Scientific initiation scholarship).

Publisher Copyright:
© 2021. Journal of Lasers in Medical Sciences.All Rights Reserved


  • Bone Regeneration
  • Lasers
  • Low-Level Light Therapy
  • Rats

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine
  • Dentistry (miscellaneous)
  • Dermatology
  • Nephrology
  • Urology


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