Dhara Yanka Tiburtino Galdino1, Gabriela da Rocha Leódido2, Christiane Pavani3, Letícia Machado Gonçalves4, Sandra Kalil Bussadori3, Marco Aurélio Benini Paschoal5. 1. Ceuma University, São Luís, Brazil. 2. Postgraduate Program in Dentistry, Ceuma University, São Luís, Brazil. 3. Postgraduate Program in Biophotonics Applied to Health Sciences, Universidade Nove de Julho, São Paulo, Brazil. 4. Department of Dentistry I, Federal University of Maranhão, São Luís, Brazil. 5. Department of Child and Adolescent Oral Health, Federal University of Minas Gerais, Belo Horizonte, Brazil. Electronic address: marcobpaschoal@hotmail.com.
Abstract
OBJECTIVE: The photokilling rate in antimicrobial photodynamic therapy (a-PDT) is highly related to interaction of reactive oxygen species (ROS) produced, ability of photosensitizers (PS) in incorporating into microorgansims and light devices/microorganism type. Since xanthene dyes (Rose Bengal and Erythrosine) are present in the dental practice as PS, have high quantum yield of singlet oxygen and are efficiently incorporated into bacterial cells, the additive bactericidal ability of a combination of xanthene dyes was tested on planktonic cultures and biofilms of Streptococcus mutans when irradiated by a hand-held LED photopolymerizer unit. METHODS: Planktonic cultures of S. mutans (UA 159 ATCC 700610) were grown in BHI broth with 1 % sucrose. This culture was exposed to a concentrations of Rose Bengal (RB) and Erythrosine (ER) at 1.5, 3.5 μM, in combination (RB + ER + L+) / alone (RB + L+/ ER + L+) and irradiated with a blue LED high light intensity (L). Accordingly, concentrations of dyes and time irradiation were increased in 10 times and applied on 120 h - biofilms of S. mutans and compared with a 0.12 % Chlorhexidine solution (0.12 % - CHX). For statistical analysis, parametrical procedures were applied (n = 6; ANOVA test and Tukey post hoc test; α = 0.05) and data transformed into log 10. RESULTS: Substantial antimicrobial reduction was verified in planktonic cultures (∼ 7 log reduction) and biofilm (∼ 1 log reduction) for combined a-PDT group (RB + ER + L+) presenting a significant statistical difference to control group (p < 0.05) with similar effect to CHX group (p > 0.05). CONCLUSION: Different forms of S. mutans can be effectively controlled by photodynamic therapy and optimized when in combination of xanthene dyes.
OBJECTIVE: The photokilling rate in antimicrobial photodynamic therapy (a-PDT) is highly related to interaction of reactive oxygen species (ROS) produced, ability of photosensitizers (PS) in incorporating into microorgansims and light devices/microorganism type. Since xanthene dyes (Rose Bengal and Erythrosine) are present in the dental practice as PS, have high quantum yield of singlet oxygen and are efficiently incorporated into bacterial cells, the additive bactericidal ability of a combination of xanthene dyes was tested on planktonic cultures and biofilms of Streptococcus mutans when irradiated by a hand-held LED photopolymerizer unit. METHODS: Planktonic cultures of S. mutans (UA 159 ATCC 700610) were grown in BHI broth with 1 % sucrose. This culture was exposed to a concentrations of Rose Bengal (RB) and Erythrosine (ER) at 1.5, 3.5 μM, in combination (RB + ER + L+) / alone (RB + L+/ ER + L+) and irradiated with a blue LED high light intensity (L). Accordingly, concentrations of dyes and time irradiation were increased in 10 times and applied on 120 h - biofilms of S. mutans and compared with a 0.12 % Chlorhexidine solution (0.12 % - CHX). For statistical analysis, parametrical procedures were applied (n = 6; ANOVA test and Tukey post hoc test; α = 0.05) and data transformed into log 10. RESULTS: Substantial antimicrobial reduction was verified in planktonic cultures (∼ 7 log reduction) and biofilm (∼ 1 log reduction) for combined a-PDT group (RB + ER + L+) presenting a significant statistical difference to control group (p < 0.05) with similar effect to CHX group (p > 0.05). CONCLUSION: Different forms of S. mutans can be effectively controlled by photodynamic therapy and optimized when in combination of xanthene dyes.
Authors: Michał Osuchowski; David Aebisher; Dorota Bartusik-Aebisher; Magdalena Krupka-Olek; Klaudia Dynarowicz; Maria Przygoda; Aleksandra Kawczyk-Krupka Journal: Diagnostics (Basel) Date: 2022-04-28