Effect of Ga-As (904nm) and He-Ne(632.8nm) laser on the improvement of biomechanical characteristics recovery in full thickness wound

Many different results reported about low level laser therapy effects on inflammatory, proliferation, and remodeling phases of repair. Purpose of this study was to evaluate the influences of He-Ne632/8 nm & Ga-As 904nm low level laser irradiation on biomechanical parameters and decrease of surface wound area in full thickness wounds of Rats. 30 male Sprague-dawly rats (200-350 g) were randomly divided into three groups: Ga-As laser, He-Ne laser and control group (10 animals in each group). A 2.5 cm full thickness skin incision was made on animals’ thoracic dorsal region. Up to 21st day of healing, the treatment were done by Ga-As or He-Ne laser with energy density of 2 j/cm2 as every other day. After each treatment session, wound surface area was measured and at 21st day, uniaxial tensile test was made. After recording of load-deformation and stress-strain curves, biomechanical parameters (Stress, Strain, Tensile strength, Elastic modulus, Area under load-deformation curve (were obtained. Both laser groups have faster decrease of wound surface area in comparison with control group (P<0.05). the increase of stress, strain, tensile strength (Fmax), deformation and area under curve(energy absorption) was shown in two laser groups in comparison with control group, but these incremental effects were significant only in Ga-As group (P<0.05). It seems that Ga-As laser is more effective for improvement of wound biomechanical parameters.