title: Antimicrobial effect of photodynamic therapy in carious lesions in vivo, using culture and real-time PCR methods.
abstract: BACKGROUND
  The aim of this study was to evaluate the antimicrobial effect of photodynamic therapy (PDT) in carious lesions in vivo by culture and real-time PCR methods.
  
  
  METHODS
  Ten teeth with deep active carious lesions were selected and five portions of carious dentin were removed for each tooth. Two increments were used as control, to represent the superficial and deep dentin, respectively. Methylene blue at 100mg/L was placed in contact with the cavity for 5min, before being irradiated with a halogen light source for 1min. Then, after PDT, other three portions were removed. The samples were processed in laboratory and the number of viable cfu was obtained. The real-time PCR analyses were performed in two increments of carious dentin, removed before and after PDT. The Streptococcus mutans DNA was isolated from carious dentin samples and amplification and detection of DNA were performed with real-time PCR. The cavities were then restored with glass-ionomer cement.
  
  
  RESULTS
  Using conventional culture methods, the results demonstrated that viable bacteria were significantly reduced in all of the agar plates following photosensitization. No difference was found between both groups regarding S. mutans DNA quantification by real-time PCR.
  
  
  CONCLUSIONS
  Although PDT may not affect the number of S. mutans DNA copies immediately after the treatment, clear reduction of the number of cfu was found. Despite its promising use for eliminating bacteria in dental caries treatment, further studies are necessary to establish an effective clinical protocol for the PDT.
authors.affiliation: Restorative Dentistry Department, School of Dentistry-Federal University of Minas Gerais, ODR-FO-UFMG, Avenida Antônio Carlos, 6627, Pampulha, Belo Horizonte, CEP: 31270-901 MG, Brasil. Electronic address: odr@odonto.ufmg.br.
authors.forename: Patricia Valente
authors.initials: PV
authors.lastname: Araújo
authors.affiliation: Department of Oral Surgery and Pathology, School of Dentistry, Federal University of Minas Gerais, Avenida Antônio Carlos, 6627, Pampulha, Belo Horizonte, CEP: 31270-901 MG, Brasil.
authors.forename: Jeane de Fátima
authors.initials: Jde F
authors.lastname: Correia-Silva
authors.affiliation: Department of Oral Surgery and Pathology, School of Dentistry, Federal University of Minas Gerais, Avenida Antônio Carlos, 6627, Pampulha, Belo Horizonte, CEP: 31270-901 MG, Brasil. Electronic address: rsgomez@odonto.ufmg.br.
authors.forename: Ricardo Santiago
authors.initials: RS
authors.lastname: Gomez
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Minas Gerais, Avenida Antônio Carlos, 6627, Pampulha, Belo Horizonte, CEP: 31270-901 MG, Brasil. Electronic address: mlamassara@terra.com.br.
authors.forename: Maria de Lourdes de Andrade
authors.initials: Mde L
authors.lastname: Massara
authors.affiliation: Restorative Dentistry Department, School of Dentistry-Federal University of Minas Gerais, ODR-FO-UFMG, Avenida Antônio Carlos, 6627, Pampulha, Belo Horizonte, CEP: 31270-901 MG, Brasil.
authors.forename: Maria Esperanza
authors.initials: ME
authors.lastname: Cortes
authors.affiliation: Restorative Dentistry Department, School of Dentistry-Federal University of Minas Gerais, ODR-FO-UFMG, Avenida Antônio Carlos, 6627, Pampulha, Belo Horizonte, CEP: 31270-901 MG, Brasil.
authors.forename: Luiz Thadeu de Abreu
authors.initials: LT
authors.lastname: Poletto
mesh_terms: D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial; D003731:Dental Caries / Q000188:drug therapy*; D003804:Dentin; D005260:Female; D006801:Humans; D008297:Male; D008751:Methylene Blue / Q000627:therapeutic use*; D050296:Microbial Viability; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D060888:Real-Time Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000187:drug effects*
chemical_list: D004269:DNA, Bacterial; D017319:Photosensitizing Agents; D008751:Methylene Blue
keywords: Caries; Photodynamic therapy; Quantitative PCR; Streptococcus mutans