Two bilateral 6.0 mm round skin defects were made on 60 DDY strain mice. The mice were divided into four groups and treated with low incident doses of laser energy at different wavelengths for 15 days: (a) Group I- Control; (b) Group II - 830 nm wavelength; (c) Group III - 680 nm wavelength; and (d) Group IV - 632.8 nm wavelength. For the treatment groups, only the right skin defect was irradiated. The rate of healing was assessed by examination through a monitor microscope, measurement of skin defect area and histological examination. No significant difference was observed between the four groups by macroscopic examination. The area of skin defect of the treated groups was significantly smaller than that of the control groups (p < 0.05) from the 1st-13th day after irradiation. For both irradiated and non-irradiated skin defects of treatment groups, Group III was smaller than Group II (p < 0.05) and Group IV was smaller than Group II (p < 0.05) Histological examination of the tissue skin defect showed greater proliferation of connective tissue and blood vessels in the dermis in treated groups than in control.
