Effects of Laser Therapy in CO 2 Laser Wounds in Rats

Abstract

Objective: 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. Background Data: 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. Methods: 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 λ685-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 (αSMA). Results: 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. Conclusion: 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.