title: Antimicrobial efficacy of ozonated water, gaseous ozone, sodium hypochlorite and chlorhexidine in infected human root canals.
abstract: OBJECTIVE
  To determine the antimicrobial efficacy of ozonated water, gaseous ozone, sodium hypochlorite and chlorhexidine in human root canals infected by Enterococcus faecalis.
  
  
  METHODS
  Thirty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. Eppendorf tubes were connected to the coronal portion of the teeth. Urethane hoses were attached to the tubes and to the entrance of a peristaltic pump. The exit of the apparatus corresponded to the apical portion of the root canals. The test irrigating solutions were ozonated water, gaseous ozone, 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine that circulated at a constant flow of 50 mL min(-1) for 20 min. Samples from the root canals were collected and immersed in 7 mL Letheen Broth (LB), followed by incubation at 37 degrees C for 48 h. Bacterial growth was analysed by turbidity of the culture medium and subculture on a specific nutrient broth. A 0.1 mL inoculum obtained from LB was transferred to 7 mL of brain heart infusion and incubated at 37 degrees C for 48 h. Bacterial growth was checked by turbidity of the culture medium carried out in triplicate.
  
  
  RESULTS
  No solution used as an irrigant over a 20-min contact time demonstrated an antimicrobial effect against E. faecalis.
  
  
  CONCLUSIONS
  The irrigation of infected human root canals with ozonated water, 2.5% NaOCl, 2% chlorhexidine and the application of gaseous ozone for 20 min was not sufficient to inactivate E. faecalis.
authors.affiliation: Department of Endodontics, Federal University of Goiás, Goiânia, GO, Brazil. estrela3@terra.com.br
authors.forename: C
authors.initials: C
authors.lastname: Estrela
authors.forename: C R A
authors.initials: CR
authors.lastname: Estrela
authors.forename: D A
authors.initials: DA
authors.lastname: Decurcio
authors.forename: A C B
authors.initials: AC
authors.lastname: Hollanda
authors.forename: J A
authors.initials: JA
authors.lastname: Silva
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology; D015169:Colony Count, Microbial; D003788:Dental Pulp Diseases / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D008826:Microbial Sensitivity Tests; D009391:Nephelometry and Turbidimetry; D010083:Oxidants, Photochemical / Q000494:pharmacology; D010126:Ozone / Q000494:pharmacology; D012388:Root Canal Irrigants / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000494:pharmacology; D014867:Water / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000891:Anti-Infective Agents, Local; D010083:Oxidants, Photochemical; D012388:Root Canal Irrigants; D014867:Water; D010126:Ozone; D012973:Sodium Hypochlorite; D002710:Chlorhexidine