title: Photodynamic therapy for root canals infected with Enterococcus faecalis.
abstract: OBJECTIVE
  The aim of this study was to investigate the effects of photodynamic therapy (PDT) on endodontic pathogens by evaluating the decrease in numbers of Enterococcus faecalis colonies in the canals of extracted human teeth.
  
  
  BACKGROUND
  Failure in endodontics is usually related to inadequate cleaning and disinfection of the root canal system. This is due to the establishment of microorganisms in areas where the instruments and chemical agents used during root canal preparation cannot eliminate them. PDT is a complementary therapeutic method that could be used to eliminate these remaining bacteria. PDT is a process in which radiation acts on a dye that is applied to the target organism, resulting in bacterial death.
  
  
  METHODS
  Forty-six uniradicular teeth had their canals contaminated with bacteria and were incubated for 48 h at 35 degrees C. After that, the teeth were divided into a control group (CG) and a test group (TG). The 23 CG teeth did not undergo any intervention, whereas in the TG the teeth received a solution of 0.0125% toluidine blue for 5 min followed by irradiation using a 50-mW diode laser (Ga-Al-As) at a wavelength of 660 nm. Bacterial samples were taken before and after irradiation. In each of the samples, the number of colony-forming units (CFU) was counted.
  
  
  RESULTS
  The mean decrease in CFU was 99.9% in the TG, whereas in the CG an increase of 2.6% was observed.
  
  
  CONCLUSIONS
  PDT was effective as a bactericidal agent in Enterococcus faecalis-contaminated root canals.
authors.affiliation: Hospital Heliópolis, São Paulo, Brazil. essencialsaude@yahoo.com.br
authors.forename: Michelle Bernardes
authors.initials: MB
authors.lastname: Fonseca
authors.forename: Paulo Odair Tessare
authors.initials: PO
authors.lastname: Júnior
authors.forename: Raul Capp
authors.initials: RC
authors.lastname: Pallota
authors.forename: Hely Ferreira
authors.initials: HF
authors.lastname: Filho
authors.forename: Odilon Victor Porto
authors.initials: OV
authors.lastname: Denardin
authors.forename: Abrão
authors.initials: A
authors.lastname: Rapoport
authors.forename: Rogério Aparecido
authors.initials: RA
authors.lastname: Dedivitis
authors.forename: João Francisco
authors.initials: JF
authors.lastname: Veronezi
authors.forename: Walter João
authors.initials: WJ
authors.lastname: Genovese
authors.forename: Ana Lucia Franco
authors.initials: AL
authors.lastname: Ricardo
mesh_terms: D003114:Colony-Forming Units Assay; D003786:Dental Pulp Cavity / Q000382:microbiology*; D013293:Enterococcus faecalis; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D066298:In Vitro Techniques; D010778:Photochemotherapy; D018915:Root Canal Preparation / Q000379:methods; D014076:Tooth Diseases / Q000188:drug therapy