title: Singlet oxygen production by combining erythrosine and halogen light for photodynamic inactivation of Streptococcus mutans.
abstract: BACKGROUND
  Photodynamic inactivation of microorganisms is based on a photosensitizing substance which, in the presence of light and molecular oxygen, produces singlet oxygen, a toxic agent to microorganisms and tumor cells. This study aimed to evaluate singlet oxygen quantum yield of erythrosine solutions illuminated with a halogen light source in comparison to a LED array (control), and the photodynamic effect of erythrosine dye in association with the halogen light source on Streptococcus mutans.
  
  
  METHODS
  Singlet oxygen quantum yield of erythrosine solutions was quantified using uric acid as a chemical-probe in an aqueous solution. The in vitro effect of the photodynamic antimicrobial activity of erythrosine in association with the halogen photopolimerizing light on Streptococcus mutans (UA 159) was assessed during one minute. Bacterial cultures treated with erythrosine alone served as negative control.
  
  
  RESULTS
  Singlet oxygen with 24% and 2.8% degradation of uric acid in one minute and a quantum yield of 0.59 and 0.63 was obtained for the erythrosine samples illuminated with the halogen light and the LED array, respectively. The bacterial cultures with erythrosine illuminated with the halogen light presented a decreased number of CFU mL(-1) in comparison with the negative control, with minimal inhibitory concentrations between 0.312 and 0.156mgmL(-1).
  
  
  CONCLUSIONS
  The photodynamic response of erythrosine induced by the halogen light was capable of killing S. mutans. Clinical trials should be conducted to better ascertain the use of erythrosine in association with halogen light source for the treatment of dental caries.
authors.affiliation: Dentistry Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Fracalossi
authors.affiliation: Endodontic Department, Federal University of Sergipe, Avenida Marechal Rondon, S/n - Jardim Rosa Elze, Largarto, São Cristóvão, SE, Cep 49100-000, Brazil. Electronic address: jynagata@gmail.com.
authors.forename: Juliana Yuri
authors.initials: JY
authors.lastname: Nagata
authors.affiliation: Chemistry Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil.
authors.forename: Diogo Silva
authors.initials: DS
authors.lastname: Pellosi
authors.affiliation: Dentistry Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil.
authors.forename: Raquel Sano Suga
authors.initials: RS
authors.lastname: Terada
authors.affiliation: Chemistry Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil. Electronic address: nhioka@uem.br.
authors.forename: Noboru
authors.initials: N
authors.lastname: Hioka
authors.affiliation: Physics Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil. Electronic address: mlbaesso@gmail.com.
authors.forename: Mauro Luciano
authors.initials: ML
authors.lastname: Baesso
authors.affiliation: Physics Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil.
authors.forename: Francielle
authors.initials: F
authors.lastname: Sato
authors.affiliation: Department of Physiological Sciences, School of Dentistry of Piracicaba, University of Campinas, Avenida Limeira, 901 - Bairro Areião, Piracicaba, SP, Cep 13414-903, Brazil. Electronic address: rosalen@fop.unicamp.br.
authors.forename: Pedro Luiz
authors.initials: PL
authors.lastname: Rosalen
authors.affiliation: Chemistry Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil.
authors.forename: Wilker
authors.initials: W
authors.lastname: Caetano
authors.affiliation: Dentistry Department, State University of Maringá, Avenida Colombo, 5790 - Jardim Universitário, Maringá, PR, Cep 87020-900, Brazil. Electronic address: mfujimaki@uem.br.
authors.forename: Mitsue
authors.initials: M
authors.lastname: Fujimaki
mesh_terms: D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D055117:Curing Lights, Dental; D004203:Disinfection / Q000295:instrumentation / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004359:Drug Therapy, Combination / Q000379:methods; D004923:Erythrosine / Q000008:administration & dosage*; D006801:Humans; D008027:Light; D008029:Lighting / Q000295:instrumentation* / Q000379:methods; D010778:Photochemotherapy / Q000295:instrumentation* / Q000379:methods; D017319:Photosensitizing Agents / Q000008:administration & dosage; D026082:Singlet Oxygen / Q000008:administration & dosage* / Q000528:radiation effects; D013295:Streptococcus mutans / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D016896:Treatment Outcome
chemical_list: D017319:Photosensitizing Agents; D026082:Singlet Oxygen; D004923:Erythrosine
keywords: Erythrosine; Photodynamic therapy; Singlet oxygen; Streptococcus mutans