Susceptibility of planktonic cultures of Streptococcus mutans to photodynamic therapy with a light-emitting diode

• Autor(a) principal: da Costa, Anna Carolina Borges Pereira [UNESP]
• Data de Publicação: 2010
• Outros Autores: Chibebe Junior, José [UNESP], Pereira, Cristiane Aparecida [UNESP], Machado, Ana Karina da Silva [UNESP], Beltrame Junior, Milton, Junqueira, Juliana Campos [UNESP], Jorge, Antonio Olavo Cardoso [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/S1806-83242010000400007; http://hdl.handle.net/11449/71906
• topic: Erythrosine; Photochemotherapy; Rose bengal; Streptococcus mutans; erythrosine; photosensitizing agent; rose bengal; analysis of variance; bacterial load; biofilm; cell culture; dental caries; drug effect; isolation and purification; methodology; photochemotherapy; radiation exposure; time; Analysis of Variance; Bacterial Load; Biofilms; Cells, Cultured; Dental Caries; Photosensitizing Agents; Rose Bengal; Time Factors

The objective of this study was to evaluate the effect of photodynamic therapy with erythrosine and rose bengal using a light-emitting diode (LED) on planktonic cultures of S. mutans. Ten S. mutans strains, including nine clinical strains and one reference strain (ATCC 35688), were used. Suspensions containing 10 6 cells/mL were prepared for each strain and were tested under different experimental conditions: a) LED irradiation in the presence of rose bengal as a photosensitizer (RB+L+); b) LED irradiation in the presence of erythrosine as a photosensitizer (E+L+); c) LED irradiation only (P-L+); d) treatment with rose bengal only (RB+L-); e) treatment with erythrosine only (E+L-); and f) no LED irradiation or photosensitizer treatment, which served as a control group (P-L-). After treatment, the strains were seeded onto BHI agar for determination of the number of colony-forming units (CFU/mL). The results were submitted to analysis of variance and the Tukey test (p ≤ 0.05). The number of CFU/mL was significantly lower in the groups submitted to photodynamic therapy (RB+L+ and E+L+) compared to control (P-L-), with a reduction of 6.86 log 10 in the RB+L+ group and of 5.16 log 10 in the E+L+ group. Photodynamic therapy with rose bengal and erythrosine exerted an antimicrobial effect on all S. mutans strains studied.