Análise comparativa da emissão de luz por led e lasers emitindo no vermelho do espectro eletromagnético na redução de bactérias periodontopatogênicas: estudo "In Vitro"

Abstract

The aim of the present study is to evaluate in vitro lethal sensibilization of periodontopathogenic bacteria: Fusobacterium nucleatum (Fn), Actinobacillus actinomycetemcomitans (Aa) and Prevotella intermedia (Pi) by using toluidine blue (0.01% w/v) as photo sensitizer and comparing the irradiation of identical solutions of bacteria with photo sensitizer by three light sources: two lasers systems of different companies (660 nm) and one LED equipment (light emitting diode, 630 nm). For each species, they were established a control group anddifferent test groups, among them: Group 6 (Fn, Aa and Pi) bacteria solution irradiated by laser 1; Group 7 (Fn, Aa and Pi) bacteria solution irradiated by laser 2 and Group 8 (Fn, Aa and Pi) bacteria solution irradiated by LED. Irradiation protocol followed the literature recommendations: 5 minutes of preirradiation time and 3 minutes of irradiation. Results reveal that the bacteria reduction for the irradiated groups (6, 7 and 8) in comparison with control group is statistically significant (p<0.05). Actinobacillus actinomycetemcomitanspresented important level of reduction (99.8% for Group 6Aa, 81.9% for Group 7Aa and 99.8% for Group 8Aa) as well as Fusobacterium nucleatum (93.7% for Group 6Fn, 84% for Group 7Fn and 99.8% for Group 8Fn). Prevotella intermedia presented low level of reduction (26.3% for Group 6Pi, 38.6% for Group 7Pi and 49.5% for Group 8Pi). Toluidine blue at concentration of 0.01% w/v is an effective photosensitizer for Actinobacillus actinomycetemcomitans and Fusobacterium nucleatum when irradiated with the light wavelength in the range of 630 to 660 nm using laser or LED light sources.