Effects of Laser Therapy in CO2Laser Wounds in Rats

Abstract

The aim of this study was to assess the effects of laser therapy and its possible dose dependency on the healing of CO2 laser surgical wounds. Several reports from our group and others have indicated that light therapies may improve healing, depending on wavelength, dose, intensity of the light, and both local and systemic conditions. Circular surgical wounds were created on the dorsum of Wistar rats, which were separated into three groups (A, B, and C). Group A acted as control and had no additional treatment. Groups B and C were irradiated with GaAlAs lambda685-nm laser light, either with 20 J/cm2 (Group B) or 40 J/cm2 (Group C). The animals were humanely killed at the end of the experimental period; specimens were taken and routinely processed to wax and stained with Hematoxylin and Eosin, Sirius Red, and alpha-Smooth Muscle Actin (alphaSMA). Laser-irradiated groups showed a healing process characterized by a more prominent fibroblastic proliferation, with young fibroblasts actively producing collagen; no myofibroblasts were found. No statistically significant differences were observed when the different doses were compared. It may be concluded that, using this methodology, laser therapy has a positive effect in wound healing produced by CO2 laser, and the dose has no influence on the treatment.