Effects of Ozone and Photo‑Activated Disinfection against <i>Enterococcus faecalis</i> Biofilms <i>In Vitro</i>

Abstract

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 × 10⁸ 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.

Keywords: Biofilm, Ozone, Photo‑activated Disinfection, Root Canal Disinfection