title: Ozone therapy as an adjuvant for endondontic protocols: microbiological - ex vivo study and citotoxicity analyses.
abstract: OBJECTIVE
  This study evaluated the antimicrobial efficacy of ozone therapy in teeth contaminated with Pseudomonas aeruginosa, Enterococcus faecalis, and Staphylococcus aureus using a mono-species biofilm model. Parallel to this, the study aimed to evaluate the cytotoxicity of ozone for human gingival fibroblasts. Material and Methods: One hundred and eighty single-root teeth were contaminated with a mono-species biofilm of Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus. Groups were formed: Group I - control; Group II - standard protocol; Group III - standard protocol + ozone gas at 40 µg/mL; and Group IV - standard protocol + aqueous ozone at 8 µg/mL. In parallel, human gingival fibroblasts were submitted to the MTT test. Cells were plated, then ozone was applied as follows: Group I (control) - broth medium; Group II - aqueous ozone at 2 µg/mL; Group III - aqueous ozone at 5 µg/mL; and Group IV - aqueous ozone at 8 µg/mL. Data were submitted to the Kruskal Wallis test and Bonferroni post hoc analyses to assess microbiology and cytotoxicity, respectively (p<0.05%).
  
  
  RESULTS
  The results revealed antimicrobial efficacy by Group IV with no CFU count. The cytotoxicity assay showed Groups III and IV to be the most aggressive, providing a decrease in cell viability at hour 0 from 100% to 77.3% and 68.6%, respectively. Such a decrease in cell viability was reverted, and after 72 hours Groups III and IV provided the greatest increase in cell viability, being statistically different from Groups I and II.
  
  
  CONCLUSIONS
  According to the applied methodology and the limitations of this study, it was possible to conclude that ozone therapy improved the decontamination of the root canal ex vivo. Ozone was toxic to the cells on first contact, but cell viability was recovered. Thus, these findings suggest that ozone might be useful to improve root canal results.
authors.affiliation: - Universidade de São Paulo, Faculdade de Odontologia, Departamento de Endodontia, São Paulo, SP, Brasil.
authors.forename: Carlos Goes
authors.initials: CG
authors.lastname: Nogales
authors.affiliation: - Universidade de São Paulo, Faculdade de Odontologia, Departamento de Endodontia, São Paulo, SP, Brasil.
authors.forename: Marina Beloti
authors.initials: MB
authors.lastname: Ferreira
authors.affiliation: - Instituto de Pesquisas Tecnológicas do Estado de São Paulo - IBL Núcleo de Bionanomanufatura, São Paulo, SP, Brasil.
authors.forename: Antonio Fernando
authors.initials: AF
authors.lastname: Montemor
authors.affiliation: - Instituto de Pesquisas Tecnológicas do Estado de São Paulo, Departamento de Biotecnologia , São Paulo, SP, Brasil.
authors.forename: Maria Filomena de Andrade
authors.initials: MF
authors.lastname: Rodrigues
authors.affiliation: - Universidade de São Paulo, Faculdade de Odontologia, Departamento de Endodontia, São Paulo, SP, Brasil.
authors.forename: José Luiz
authors.initials: JL
authors.lastname: Lage-Marques
authors.affiliation: - Universidade de São Paulo, Faculdade de Odontologia, Departamento de Endodontia, São Paulo, SP, Brasil.
authors.forename: João Humberto
authors.initials: JH
authors.lastname: Antoniazzi
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D015169:Colony Count, Microbial; D003786:Dental Pulp Cavity / Q000187:drug effects / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000187:drug effects*; D005347:Fibroblasts / Q000187:drug effects*; D005881:Gingiva; D006801:Humans; D010126:Ozone / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D015203:Reproducibility of Results; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000277:Adjuvants, Pharmaceutic; D000890:Anti-Infective Agents; D010126:Ozone; D012973:Sodium Hypochlorite