title: Comparative study of methylene blue and erythrosine dyes employed in photodynamic therapy for inactivation of planktonic and biofilm-cultivated Aggregatibacter actinomycetemcomitans.
abstract: OBJECTIVE
  The proposal of this work was to test the efficacy of photodynamic therapy (PDT) by using methylene blue (MB) and erythrosine (ERY) to inactivate Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), the main pathogen in aggressive periodontitis.
  
  
  METHODS
  A. actinomycetemcomitans was cultivated in planktonic cultures and biofilm by using Tryptic Soy Broth medium. The sensibility (dark toxicity) to MB and ERY was determined, and its ideal concentration for PDT protocols was established. An odontologic resin photopolymerizer was used as the light source. The bacterial viability was determined by CFU (planktonic cultures) and microscopic observation (biofilms).
  
  
  RESULTS
  The results show that ERY is more efficient at killing bacterial cells of A. actinomycetemcomitans in planktonic (75%) and biofilm (77%) culture compared with MB (50% and 54%, respectively).
  
  
  CONCLUSIONS
  PDT using MB or ERY as a photosensitizing agent and odontologic resin photopolymerizer as a light source could be an efficient option for pocket decontamination in aggressive periodontal disease.
authors.affiliation: Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, FFCLRP-USP, Ribeirão Preto, SP, Brazil.
authors.forename: Rosangela de Carvalho
authors.initials: Rde C
authors.lastname: Goulart
authors.forename: Geraldo
authors.initials: G
authors.lastname: Thedei
authors.forename: Sérgio L S
authors.initials: SL
authors.lastname: Souza
authors.forename: Antonio Cláudio
authors.initials: AC
authors.lastname: Tedesco
authors.forename: Pietro
authors.initials: P
authors.lastname: Ciancaglini
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans; D018441:Biofilms / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004923:Erythrosine / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000494:pharmacology*; D008751:Methylene Blue / Q000494:pharmacology*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology*; D010933:Plankton / Q000502:physiology
chemical_list: D005456:Fluorescent Dyes; D017319:Photosensitizing Agents; D004923:Erythrosine; D008751:Methylene Blue