Effects of the HeNe laser and of the application mode on healing burns in rats

Abstract

The aim of this study was to verify the effect of therapeutic laser in treating burns in Wistar rats. Sixty-two male rats had a 4 cm² area trichotomized at the dorsal region, were submitted to burn with hot vegetable oil at 300ºC, and were then divided into three groups. Treatment begun on the first day following burn. Experimental group 1 was treated with helium-neon (HeNe) array laser at 4 J/cm² and experimental group 2 with punctual laser at the same intensity, on four different points previously marked. Control group didn’t receive any treatment. Histological samples were collected on the 3rd, 7th, 14th, and 21st days after burn, blades being then analysed. Results show that the group treated with array laser was fully healed after 14 days of treatment, presenting normal structure skin, while the other groups only showed improvement after 21 days. Neutrophile cells were noticed on the 14th day in the group treated with punctual laser, suggesting that a new inflammatory process had taken place, probably due to the use of an intensity too high for this mode of laser therapy. Results allow concluding that the HeNe laser at 4 J/cm² intensity speeds up the healing process of skin burns and that, if applied in the array mode, it is still more effective.