title: The photodynamic therapy on Streptococcus mutans biofilms using erythrosine and dental halogen curing unit.
abstract: The purpose of our study was to evaluate the effect of photodynamic therapy (PDT), using erythrosine as a photosensitizing agent and a dental halogen curing unit as a light source, on Streptococcus mutans in a biofilm phase. The S. mutans biofilms were formed in a 24-well cell culture cluster. Test groups consisted of biofilms divided into four groups: group 1: no photosensitizer or light irradiation treatment (control group); group 2: photosensitizer treatment alone; group 3: light irradiation alone; group 4: photosensitizer treatment and light irradiation. After treatments, the numbers of colony-forming unit (CFU) were counted and samples were examined by confocal laser scanning fluorescence microscopy (CLSM). Only group 4 (combined treatment) resulted in significant increases in cell death, with rates of 75% and 55% after 8 h of incubation, and 74% and 42% at 12 h, for biofilms formed in brain-heart infusion (BHI) broth supplemented with 0% or 0.1% sucrose, respectively. Therefore, PDT of S. mutans biofilms using a combination of erythrosine and a dental halogen curing unit, both widely used in dental clinics, resulted in a significant increase in cell death. The PDT effects are decreased in biofilms that form in the presence of sucrose.
authors.affiliation: Department of Pediatric Dentistry, Graduate School, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Lee
authors.forename: Ho-Won
authors.initials: HW
authors.lastname: Park
authors.forename: Ju-Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Hyun-Woo
authors.initials: HW
authors.lastname: Seo
authors.forename: Si-Young
authors.initials: SY
authors.lastname: Lee
mesh_terms: D058491:Bacterial Load / Q000187:drug effects; D001431:Bacteriological Techniques; D018441:Biofilms / Q000187:drug effects*; D055117:Curing Lights, Dental / Q000145:classification*; D004923:Erythrosine / Q000627:therapeutic use*; D006801:Humans; D050296:Microbial Viability / Q000187:drug effects; D018613:Microscopy, Confocal; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D013010:Sonication; D013295:Streptococcus mutans / Q000187:drug effects*; D013395:Sucrose / Q000494:pharmacology; D013997:Time Factors
chemical_list: D017319:Photosensitizing Agents; D013395:Sucrose; D004923:Erythrosine