title: Effectiveness of chemomechanical preparation with alternating use of sodium hypochlorite and EDTA in eliminating intracanal Enterococcus faecalis biofilm.
abstract: BACKGROUND
  The elimination of microorganisms from root canals is a critical step in endodontic treatment. We aimed to evaluate the antimicrobial effectiveness of an alternating irrigation regimen during chemomechanical preparation (CMP).
  
  
  METHODS
  During 21 days, root canals of extracted human teeth were infected with Enterococcus faecalis, and colonization was confirmed by scanning electron microscopy (SEM). Canals were irrigated with saline solution (control group), with 5.25% NaOCl followed by a final rinse with 17% EDTA (conventional irrigation group), or with the alternating use of NaOCl and EDTA (alternating irrigation [AI] group). Samples were taken before treatment (S1), after CMP (S2), and during the following 14 days. Two specimens/group were analyzed by SEM.
  
  
  RESULTS
  The AI group yielded negative agar and liquid cultures from immediately after CMP and from the 5th day on, respectively. SEM confirmed several bacterium-free sites in the AI group.
  
  
  CONCLUSIONS
  The irrigation regimen based on the alternating use of NaOCl and EDTA seems to be a promising endodontic tool because it promoted the elimination of root canal E. faecalis biofilms throughout the experimental period.
authors.affiliation: Department of Dentistry, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, Minas Gerais, Brazil.
authors.forename: Janir Alves
authors.initials: JA
authors.lastname: Soares
authors.forename: Maria Auxiliadora
authors.initials: MA
authors.lastname: Roque de Carvalho
authors.forename: Suelleng Maria
authors.initials: SM
authors.lastname: Cunha Santos
authors.forename: Rafael Mangerotti Castro
authors.initials: RM
authors.lastname: Mendonça
authors.forename: Antonio Paulino
authors.initials: AP
authors.lastname: Ribeiro-Sobrinho
authors.forename: Manoel
authors.initials: M
authors.lastname: Brito-Júnior
authors.forename: Paula Prazeres
authors.initials: PP
authors.lastname: Magalhães
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Santos
authors.forename: Luiz
authors.initials: L
authors.lastname: de Macêdo Farias
mesh_terms: D018441:Biofilms / Q000187:drug effects; D015169:Colony Count, Microbial; D003786:Dental Pulp Cavity / Q000382:microbiology*; D004492:Edetic Acid / Q000009:adverse effects / Q000494:pharmacology; D013293:Enterococcus faecalis / Q000187:drug effects*; D006801:Humans; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000009:adverse effects / Q000494:pharmacology
chemical_list: D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite