The influence of low-level laser therapy on biomodulation of collagen and elastic fibers

Pesqui Odontol Bras. 2003 Oct-Dec;17(4):307-13. doi: 10.1590/s1517-74912003000400003. Epub 2004 Apr 19.


The study of low-level laser therapy upon extracellular matrix elements is important to understand the wound healing process under this agent. However, little is known about the interference of laser light in relation to collagen and elastic fibers. Cutaneous wounds were performed on the back of 72 Wistar rats and a Ga-Al-As low-level laser was punctually applied with different energy densities. The animals were killed after 24, 48, 72 hours and 5, 7 and 14 days. Tissues were stained with hematoxilin-eosin, sirius red fast green and orcein and then analyzed. It was observed that the treated group exhibited larger reduction of edema and inflammatory infiltrate. The treated animals presented a larger expression of collagen and elastic fibers, although without statistical significance (p > 0.05). Treatment with a dosage of 4 J/cm(2) exhibited more expressive results than that with 8 J/cm(2). In this study, the authors concluded that low-level laser therapy contributed to a larger expression of collagen and elastic fibers during the early phases of the wound healing process.

MeSH terms

  • Analysis of Variance
  • Animals
  • Collagen / biosynthesis*
  • Disease Models, Animal
  • Dose-Response Relationship, Radiation
  • Elastic Tissue / metabolism*
  • Extracellular Matrix / metabolism*
  • Female
  • Low-Level Light Therapy*
  • Male
  • Random Allocation
  • Rats
  • Rats, Wistar
  • Statistics, Nonparametric
  • Wound Healing / physiology
  • Wound Healing / radiation effects*


  • Collagen