Abstract

--- - Objective. This study aimed to test the efficacy of photodynamic inactivation (PDI) mediated Photodynamic therapy by curcumin with EDTA against Streptococcus mutans in planktonic suspension using blue Curcumin LED light. - Methods. Antibacterial activity of curcumin and EDTA was evaluated by determination of Photosensitizing agents their minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Streptococcus mutans The fractional inhibitory concentration index (FICI) was used to estimate the synergistic Dental curing lights effect of various combination ratios of curcumin and EDTA against S. mutans. Cultures of S. mutans (18 h, 37 degrees C, 5% CO2) were prepared to test the effect of curcumin-mediated PDI (50 mu M and 500 mu M) with or without 0.4% EDTA and 40 s of light-activation with blue light. EDTA and each concentration of curcumin were also tested individually. Chlorhexidine (0.2%), was used as positive control. Planktonic suspensions were also analyzed by viable colony counts (VCC), confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and polymerase chain reaction (PCR). - Results. The MIC values of curcumin and EDTA were 5 mM and 0.125% respectively. FICI showed a synergistic interaction between curcumin and EDTA. All the combinations with curcumin and blue LED light resulted in a complete inactivation of the S. mutans and CLSM confirms these results, TEM showed morphological changes produced by the PDI. No damage on DNA structure was detected by PCR. - Significance. Curcumin-mediated PDI with EDTA using a blue light, shows a strong inhibitory effect against S. mutans in planktonic culture. Because of the unspecific target mechanism, it could be a promising technique for disinfection of dental tissues. (C) 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.