Evaluation of antimicrobial photodynamic therapy with Butyl toluidine blue O for inactivation of Aggregatibacter actinomycetemcomitans biofilm
Abstract As an adjunctive intervention to mechanical periodontal treatment, antimicrobial photodynamic therapy aims to induce the production of reactive oxygen species, thereby reducing microbial infection. Butyl toluidine blue O, a novel photosensitizer from the phenothiazine family, was developed through physicochemical modifications of the structure of toluidine blue, demonstrating decreased aggregation and increased singlet oxygen production and lipophilicity. The objective of this study was to evaluate the effects of butyl toluidine blue O on Aggregatibacter actinomycetemcomitans biofilm. A biofilm was grown on bovine dental samples, followed by the application of antimicrobial photodynamic therapy. The experimental design included the following groups: Control, Light, incubation with PS without irradiation (0), and three aPDT groups (1, 3, or 5 min of irradiation time duration). A laser with a wavelength of 660 nm and 100 mW of radiant power was employed. After the procedures, the samples were cultivated under microaerophilic conditions, counted, and converted into colony-forming units for analysis and comparison. The samples exhibiting statistically significant differences were analyzed through scanning electron microscopy. Antimicrobial photodymanic therapy with 5 min irradiation period achieved a 99.99% reduction in biofilm microbial load. In conclusion, the approach mediated by butyl toluidine blue O demonstrated efficacy against A. actinomycetemcomitans biofilm.
Citação
@online{ana_carolina_a._c.2026,
author = {Ana Carolina A. C. , Tortamano and Claudio T. , Kassa and
Fabiana D. , Magalhães and Giovanna Fontgalland , Ferreira and
Holanda Lima, Shirlene, De and Christiane , Pavani and Valherya S. ,
Rodriguez and Ilka T. , Kato and Mark , Wainwright and Renato Araujo
, Prates},
title = {Evaluation of antimicrobial photodynamic therapy with Butyl
toluidine blue O for inactivation of Aggregatibacter
actinomycetemcomitans biofilm},
volume = {25},
number = {3},
date = {2026-03-01},
doi = {10.1007/s43630-026-00851-x},
langid = {pt-BR},
abstract = {Abstract As an adjunctive intervention to mechanical
periodontal treatment, antimicrobial photodynamic therapy aims to
induce the production of reactive oxygen species, thereby reducing
microbial infection. Butyl toluidine blue O, a novel photosensitizer
from the phenothiazine family, was developed through physicochemical
modifications of the structure of toluidine blue, demonstrating
decreased aggregation and increased singlet oxygen production and
lipophilicity. The objective of this study was to evaluate the
effects of butyl toluidine blue O on Aggregatibacter
actinomycetemcomitans biofilm. A biofilm was grown on bovine dental
samples, followed by the application of antimicrobial photodynamic
therapy. The experimental design included the following groups:
Control, Light, incubation with PS without irradiation (0), and
three aPDT groups (1, 3, or 5~min of irradiation time duration). A
laser with a wavelength of 660~nm and 100 mW of radiant power was
employed. After the procedures, the samples were cultivated under
microaerophilic conditions, counted, and converted into
colony-forming units for analysis and comparison. The samples
exhibiting statistically significant differences were analyzed
through scanning electron microscopy. Antimicrobial photodymanic
therapy with 5~min irradiation period achieved a 99.99\% reduction
in biofilm microbial load. In conclusion, the approach mediated by
butyl toluidine blue O demonstrated efficacy against A.
actinomycetemcomitans biofilm.}
}