title: Effect of gaseous ozone on Enterococcus faecalis biofilm-an in vitro study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the antimicrobial effect of gaseous ozone compared to conventional methods against Enterococcus faecalis.
  
  
  METHODS
  One hundred twenty-five teeth were infected by E. faecalis and were incubated for 72 h to form biofilm. Teeth were distributed among five groups. In the first group, ozone was used; in the second group, teeth were rinsed with 20 % ethylenediaminetetraacetic acid (EDTA); in the third group, with 3 % sodium hypochlorite (NaOCl). Group 4 combined 20 % EDTA with ozone. NaOCl and ozone were combined in group 5. After treatment, the samples with paper points were taken, followed by dentin samples taken with K-file, and cultured for 24 h. Then bacterial colonies were counted.
  
  
  RESULTS
  All treatments reduced significantly (p < 0.05) the bacteria. Paper points' samples showed 85.38 % reduction after ozone. The highest reduction was observed in NaOCl group (99.98 %). EDTA reduced bacteria by 80.64 %. Combination of NaOCl and ozone eradicated 99.95 % of the bacteria. Combination of EDTA and ozone reduced E. faecalis up to 91.33 %. The dentin chips showed the following: the highest CFU counts were observed in EDTA group, followed by ozone and NaOCl group. The lowest CFU counts were found in NaOCl-ozone group and EDTA-ozone group.
  
  
  CONCLUSIONS
  Ozone reduced E. faecalis, even organised in a biofilm, however, lower than NaOCl. No treatment reduced totally the bacteria.
  
  
  CONCLUSIONS
  Used as an adjuvant, ozone can increase the efficacy of conventional rinsing like EDTA and presents an alternative treatment when NaOCl cannot be used e.g. in teeth with a wide-open apical foramen.
authors.affiliation: Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Hugstetterstraße 55, 79106, Freiburg i. Br, Germany. tanja.boch@uniklinik-freiburg.de.
authors.forename: Tanja
authors.initials: T
authors.lastname: Boch
authors.affiliation: Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Hugstetterstraße 55, 79106, Freiburg i. Br, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Tennert
authors.affiliation: Center for Medical Biometry and Medical Informatics, Institute for Medical Biometry and Statistics, Medical Center-University of Freiburg, Stefan-Meier-Str. 26, 79104, Freiburg, Germany.
authors.forename: Kirstin
authors.initials: K
authors.lastname: Vach
authors.affiliation: Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Hugstetterstraße 55, 79106, Freiburg i. Br, Germany.
authors.forename: Ali
authors.initials: A
authors.lastname: Al-Ahmad
authors.affiliation: Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Hugstetterstraße 55, 79106, Freiburg i. Br, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Hellwig
authors.affiliation: Department of Operative Dentistry and Periodontology, University Medical Center Freiburg, Hugstetterstraße 55, 79106, Freiburg i. Br, Germany.
authors.forename: Olga
authors.initials: O
authors.lastname: Polydorou
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects*; D015169:Colony Count, Microbial; D004492:Edetic Acid / Q000737:chemistry; D013293:Enterococcus faecalis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D010126:Ozone / Q000737:chemistry*; D012973:Sodium Hypochlorite / Q000737:chemistry; D014070:Tooth / Q000382:microbiology*
chemical_list: D010126:Ozone; D004492:Edetic Acid; D012973:Sodium Hypochlorite
keywords: Disinfection methods; Endodontics; Enterococcus faecalis; Ozone; Root canal treatment