The antibacterial effect of gas ozone after 2 months of in vitro evaluation

The aim of this study was to evaluate the effect of HealOzone on two microorganisms, 4 and 8 weeks after treatment, using a tooth cavity model. Four groups of caries-free third molars (n = 12) were used (A, B, C and D). Three cavities were prepared into each tooth. After sterilization, groups A and B were inoculated with Streptococcus mutans, and groups C and D, with Lactobacillus casei for 48 h. One cavity of each tooth was used to evaluate the infection. After inoculation, groups B and D were treated with ozone (60 s), and groups A and C were used as controls. Then, the two cavities of each tooth were filled with composite, and the teeth were stored in sucrose medium. The restorations were removed after 4 and 8 weeks, respectively; dentin chips were collected, and the amount of microorganisms was determined. Ozone treatment reduced significantly the amount of S. mutans compared to the control group (p ≤ 0.05). This antibacterial effect was able to be seen after 4 (p = 0.0005) and 8 (p = 0.0002) weeks. No significant difference was found between the control and treated group as far as L. casei is concerned (p > 0.05). HealOzone (60 s) can provide some antibacterial treatment against S. mutans even after 8 weeks. However, an elimination of the microorganisms through HealOzone seems not to be possible. L. casei was more resistant to ozone. Although ozone exerts a significant antibacterial effect against S. mutans, it is probably not enough as the only antibacterial method, during the fillings therapy.