Study on the use of an ozone gel for endodontic therapy

—Bactericidal and cytotoxic effects—

Abstract

Abstract : The purpose of this study was to examine any bactericidal and/or cytotoxic effects stemming from an ozone gel and from this determine whether it is possible to incorporate ozone into glycerin for intracanal treatment. When 100 ppm of an ozone gel prepared immediately after thawing was applied for 10 minutes to root canals containing bacteria, the number of viable bacteria decreased below a detectable limit for three species ; E. coli K-12, S. aureus, and L. casei (excluding E. faecalis). A ninety-eight percent glycerin solution did not show any bactericidal effects. With regard to any bactericidal effects of an ozone gel prepared 28 days after thawing, it was observed that the number of viable bacteria decreased from 10⁷ to 10² cfu/mL. With regard to any bactericidal effects from bacteria in quasi-infected root canals, it was observed that the number of viable bacteria decreased below a detectable limit after application of an ozone gel in four of the five root canals in which E. coli K-12 was applied, or in three of those canals in which E. faecalis was applied. Twenty-four hours after application, the number of viable bacteria decreased below a detectable limit in two of the root canals in which E. coli K-12 or E. faecalis were applied, respectively. With regard to any cytotoxicity of the ozone gel, it was observed that when the volume of the medium was 2.0 mL, there was no significant difference between the experimental and control groups. When the volume of the medium was 100 μL, a significant difference was observed between the experimental and control groups (p<0.01). These results suggest that ozone gel may be useful as an intracanal medication for the treatment of infected root canals.