EDTA CONCENTRATION IN THE EFFECTIVENESS OF ANTIMICROBIAL PHOTODYNAMIC THERAPY WITH CURCUMIN ON STREPTOCOCCUS MUTANS BIOFILM

Objective: Evaluate the optimal concentration of ethylenediaminetetracetic acid (EDTA) in curcumin-mediated antibacterial photodynamic therapy (aPDT) with blue LED light on S. mutans biofilms. Materials and Methods: Biofilms of S. mutans grown on resin discs were used, exposed to two concentrations of EDTA (1% and 17%). The experimental groups included: negative control, positive control (chlorhexidine), 1% EDTA, 17% EDTA, 100 μM curcumin, 100 μM curcumin + 1% EDTA, and 100 μM curcumin + 17% EDTA, with and without exposure to blue LED light, except for the positive control. Bacterial viability was assessed by counting colonyforming units (CFU/ml) after treatment application. Data were analyzed using one-way ANOVA adjusted by a generalized linear model (GLM) (p < 0,05). Results: The groups treated with 100µM curcumin and 100 μM curcumin + 1% EDTA, activated with blue LED light, showed the greatest reduction in bacterial viability. The combination with 17% EDTA did not significantly enhance the effect of aPDT. Conclusions: The addition of EDTA did not significantly enhance the activity of curcumin-mediated aPDT against S. mutans biofilms. The 1% EDTA concentration showed results comparable to the use of curcumin alone, suggesting that higher concentrations do not provide additional benefit.