Efeito de diferentes parâmetros do LED vermelho na viabilidade e modulação da produção de óxido nítrico em células do tecido pulpar de dentes decíduos

Abstract

The aim of this study was to evaluate the effect of different red LED parameters on cell viability and nitric oxide modulationby pulp cells from primary teeth. Cells obtained from two exfoliated healthy teeth were cultured (100,000 cells/ compartment) using culture medium supplemented with 10% fetal bovine serum. After 24 hours, the cells were exposed to LPS (10 μg/mL) and submitted to a single irradiation (630 nm, 40 mW/cm2 and 80 mW/cm2) at the radiant exposure (RE) 0 (control), 4, 15 and 30 J/cm2. After 24 hours, the viability and quantification of nitric oxide (NO) were evaluated by the MTT Assay and Griess reagent tests, respectively. Data were analyzed by the Kruskal-Wallis and Mann-Whitney tests (significance level of 5%). In the presence of LPS, the RE of 15 and 30 J/cm2, at the irradiance of 40 mW/cm2 and the RE of 4 and 15 J/cm2, at the irradiance of 80 mW/cm2, increased the cell viability when compared to the control group (p<0.05). In addition, in the presence of LPS, the RE of 4 J/cm2 at the irradiance of 40 mW/cm2 and the RE of 15 and 30 J/cm2 at the irradiance of 80 mW/cm2 reduced the production of NO by the pulp cells when compared to the non-irradiated group (p<0.05). It was possible to conclude that the radiant exposure of 15 J/cm2 and irradiance of 80 mW/cm2 was the most effective irradiation parameter to stimulate and modulate oxidative stress in pulp cells from deciduous teeth.