Efeito do laser de baixa potência na cicatrização de feridas cutâneas experimentais

• Autor(a) principal: Vieira, Sandra Aparecida Luiz
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório do Centro Universitário Braz Cubas
• Texto Completo: https://repositorio.cruzeirodosul.edu.br/handle/123456789/651
• topic: Cicatrização; Ferida cutânea; Laserterapia; CNPQ::CIENCIAS DA SAUDE::MEDICINA::RADIOLOGIA MEDICA

This work aimed to compare the results obtained in the experimental research with low power laser, AlGa diode, 660nm wavelength, with different doses. 54 Wistar rats were used, divided into control groups, groups submitted to laser therapy at a dose of 4J / cm² and groups submitted to laser therapy at a dose of 8J / cm². Daily macroscopic evaluation of all animals was performed by pachymetry of skin wounds. For that, the animals were anesthetized via inhalation with halothane. The data obtained were analyzed by the Student's T test with 95% significance (p <0.05). All analyzes were performed using the GraphPad Prism 4.0 program. For histopathological examination, at 3, 7 and 14 days, the animals were euthanized on days 4, 8 and 15 after the experimental surgery. The lesion and surrounding areas were surgically removed, which were placed in 10% buffered formalin and identified. The material removed was processed, included in paraffin, cuts of 4 µm thick and stained with hematoxylin-eosin (HE). The samples were analyzed under light microscopy, observed and evaluated semi-quantitatively, inflammatory processes, degree of epithelialization, collagen fibers and edema. The number of new vessels was counted on a microscope grid in a standardized area of ​​0.25 mm2. The results of the macroscopic evaluation showed that 50% of the animals treated with laser therapy at a dose of 4J / cm² had total healing on the 12th day of treatment, and 83.3% of the animals had the same response on the 14th day. In the group of animals submitted to laser therapy at a dose of 8J / cm², only 16.6% of the animals had total healing on the 12th day of treatment, and 66.6% of the animals on the 14th day of treatment. Therefore, the lowest dose had the greatest ability to accelerate the healing process. The morphometric analysis of the cutaneous wound showed that, on the 7th day after the start of treatment, there was a statistically higher average number of new vessels (p <0.05) in animals treated with laser therapy at a dose of 4J / cm2, when compared to the control group. There were no significant differences between groups, control and 8J / cm2 in the same period. On the 14th day, no significant differences were observed between all groups evaluated. All animals, regardless of the group belonging, presented 100% of skin wounds re-epithelialization on the 14th day. This fact was probably due to the fact that the animal model used in this research had spontaneous healing in a relatively short period of time. The methodology used to evaluate edema, formation of collagen fibers and inflammatory infiltrate, was not able to detect significant differences between groups in the analyzed periods (3, 7 and 14 days). It is concluded that the radiation with low-power laser therapy, with a wavelength of 660nm, at doses of 4J / cm² and 8J / cm² did not present statistical differences between them. However, macroscopically there was a difference, in relation to total healing, between animals treated and those not treated with laser radiation. This work came to demonstrate the importance of using low power laser therapy in conditions that compromise the physical, psychological, social and economic integrity of a large number of human beings.