COMPARISON OF THE EFFECTS OF LASER THERAPY ON WOUND HEALING USING DIFFERENT LASER WAVELENGTHS

Abstract

Comparison of the effects on wound healing in rats using HeCd, Argon, HeNe and GaAlAs lasers was investigated. Our results showed that the acceleration in healing days was 15, 23, 29, 23 and 20% and the acceleration in size reduction was 32, 42, 50, 42, and 40% with 442 nm, 488-514 nm, 632nm, 780 nm, and 830 nm, respectively at the optimum incident dose of ≈ 20 J/cm², for a wound area of 0.39 cm² in 27-wk old rodents and three times per week treatment schedule. There were significant differences between the control group and the treated rats in each laser group used (p < 05). The results suggested that the HeNe laser at 632 nm was the most effective (6% ∼ 14% higher in healing days and 8% ∼ 18% higher in size reduction) in promoting wound healing amongst all the wavelengths used. The laser tissue penetration (transmission and absorption) were dependent on the laser wavelengths. The effects of wound healing acceleration were not apparently dependent on the laser tissue penetration depth. The wound healing acceleration was in proportion to the absorption spectrum of fibroblasts. There was no detectable temperature rise up to 150 J/cm² dose for an incident power density of up to 31.85 mW/cm².