Susceptibility of Dental Caries Microcosm Biofilms to Photodynamic Therapy Mediated by Fotoenticine
Maíra Terra Garcia,
Rafael Araújo da Costa Ward,
Nathália Maria Ferreira Gonçalves,
Lara Luise Castro Pedroso,
José Vieira da Silva Neto,
Juliana Ferreira Strixino,
Juliana Campos Junqueira
Affiliations
Maíra Terra Garcia
Department of Biosciences and Oral Diagnosis, Institute of Science and Technology/ICT, São Paulo State University/UNESP, São José dos Campos 12245-000, Brazil
Rafael Araújo da Costa Ward
Department of Biosciences and Oral Diagnosis, Institute of Science and Technology/ICT, São Paulo State University/UNESP, São José dos Campos 12245-000, Brazil
Nathália Maria Ferreira Gonçalves
Department of Biosciences and Oral Diagnosis, Institute of Science and Technology/ICT, São Paulo State University/UNESP, São José dos Campos 12245-000, Brazil
Lara Luise Castro Pedroso
Department of Biosciences and Oral Diagnosis, Institute of Science and Technology/ICT, São Paulo State University/UNESP, São José dos Campos 12245-000, Brazil
José Vieira da Silva Neto
Associate Laboratory of Sensors and Materials/LABAS, National Institute for Space Research, São José dos Campos 12227-010, Brazil
Juliana Ferreira Strixino
Photobiology Applied to Health, Research and Development Institute IP&D, University of Vale do Paraiba/UNIVAP, São José dos Campos 12244-390, Brazil
Juliana Campos Junqueira
Department of Biosciences and Oral Diagnosis, Institute of Science and Technology/ICT, São Paulo State University/UNESP, São José dos Campos 12245-000, Brazil
Photodynamic therapy (PDT) mediated by Fotoenticine® (FTC), a new photosensitizer derived from chlorin e-6, has shown in vitro inhibitory activity against the cariogenic bacterium Streptococcus mutans. However, its antimicrobial effects must be investigated on biofilm models that represent the microbial complexity of caries. Thus, we evaluated the efficacy of FTC-mediated PDT on microcosm biofilms of dental caries. Decayed dentin samples were collected from different patients to form in vitro biofilms. Biofilms were treated with FTC associated with LED irradiation and analyzed by counting the colony forming units (log10 CFU) in selective and non-selective culture media. Furthermore, the biofilm structure and acid production by microorganisms were analyzed using microscopic and spectrophotometric analysis, respectively. The biofilms from different patients showed variations in microbial composition, being formed by streptococci, lactobacilli and yeasts. Altogether, PDT decreased up to 3.7 log10 CFU of total microorganisms, 2.8 log10 CFU of streptococci, 3.2 log10 CFU of lactobacilli and 3.2 log10 CFU of yeasts, and reached eradication of mutans streptococci. PDT was also capable of disaggregating the biofilms and reducing acid concentration in 1.1 to 1.9 mmol lactate/L. It was concluded that FTC was effective in PDT against the heterogeneous biofilms of dental caries.
