Lasers in Medical Science

, Volume 28, Issue 2, pp 651–656 | Cite as

Effects of low-level laser therapy (LLLT) on bone repair in rats: optical densitometry analysis

  • Danillo Barbosa
  • Renato Aparecido de SouzaEmail author
  • Murilo Xavier
  • Fabiano Fernandes da Silva
  • Emilia Ângela Loschiavo Arisawa
  • Antonio Guillermo Jose Balbin Villaverde
Original Article


The aim of this study was to evaluate the process of bone repair in rats submitted to low-level laser therapy using optical densitometry. A total of 45 rats which underwent femoral osteotomy were randomly distributed into three groups: control (group I) and laser-treated groups using wavelengths in the red (λ, 660–690 nm) and in the infrared (λ, 790–830 nm) spectra (group II and group III, respectively). The animals (five per group) were killed after 7, 14, and 21 days and the femurs were removed for optical densitometry analysis. Optical density showed a significant increase in the degree of mineralization (gray level) in both groups treated with the laser after 7 days. After 14 days, only the group treated with laser therapy in the infrared spectrum showed higher bone density. No differences were observed between groups after 21 days. Such results suggest the positive effect of low-level laser therapy in bone repair is time- and wavelength-dependent. In addition, our results have confirmed that optical densitometry technique can measure bone mineralization status.


Laser biomodulation Digital radiography Bone defects Rats 



R.A. Souza thanks Fundação de Amparo a Pesquisa do Estado de Minas Gerais for the research grant support (APQ-02900-10).


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Copyright information

© Springer-Verlag London Ltd 2012

Authors and Affiliations

  • Danillo Barbosa
    • 1
  • Renato Aparecido de Souza
    • 2
    Email author
  • Murilo Xavier
    • 3
  • Fabiano Fernandes da Silva
    • 2
  • Emilia Ângela Loschiavo Arisawa
    • 4
  • Antonio Guillermo Jose Balbin Villaverde
    • 1
  1. 1.Instituto de Engenharia BiomédicaUniversidade Camilo Castelo Branco, UNICASTELOSão José dos CamposBrazil
  2. 2.Grupo de Estudos e Pesquisa em Ciências da SaúdeGEP-CS, Instituto Federal de Educação, Ciência e Tecnologia do Sul de Minas Gerais, IFSULDEMINASMuzambinhoBrazil
  3. 3.Departmento de FisioterapiaUniversidade Federal dos Vales do Jequitinhonha e Mucuri, UFVJMDiamantinaBrazil
  4. 4.Laboratório de Instrumentação Biomédica, Instituto de Pesquisa e Desenvolvimento, IP&DUniversidade do Vale do Paraíba, UNIVAPSão José dos CamposBrazil

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