Effects of ozone and photo-activated disinfection against Enterococcus faecalis biofilms in vitro

Niger J Clin Pract. 2015 Nov-Dec;18(6):814-8. doi: 10.4103/1119-3077.163289.


Objectives: The purpose of this study was to compare the antibacterial effects of gaseous ozone (O3) and photo-activated disinfection (PAD) methods against Enterococcus faecalis (E. faecalis) biofilms.

Materials and methods: Sixty-five human mandibular premolars with straight root canals were selected. After root canal preparation, the samples were sterilized and placed into eppendorf tubes with 1 mL brain heart infusion broth containing 1.5×10(8) colony-forming units (CFUs)/mL of E. faecalis. The contaminated samples were then divided into four groups (n=15) according to the disinfection method used: Group 1, Saline (positive control); Group 2, NaOCl (negative control); Group 3, Gaseous O3; and Group 4, PAD. Three non-contaminated teeth were used to control the infection and sterilization process. The CFUs were counted and the data were analyzed statistically.

Results: There was a statistically significant difference between the experimental and control groups (P<0.05). The saline group had the highest number of remaining microorganisms. Complete sterilization was achieved in the 2.5% NaOCl group. There were no statistically differences between PAD and gaseous O3 (P>0.05).

Conclusion: Both PAD and gaseous O3 have a significant antibacterial effect on infected root canals. However, 2.5% NaOCl was superior in terms of its antimicrobial abilities compared with the other disinfection procedures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biofilms / drug effects*
  • Dental Pulp Cavity / microbiology*
  • Disinfection / methods*
  • Enterococcus faecalis / isolation & purification*
  • Humans
  • Ozone / pharmacology
  • Root Canal Irrigants / therapeutic use*
  • Root Canal Preparation / methods*
  • Sodium Hypochlorite / pharmacology


  • Root Canal Irrigants
  • Ozone
  • Sodium Hypochlorite