Effect of Ozone Treatment on Interleukin Levels in Dental Pulp

Objective: To determine whether therapeutic levels of ozone stimulate production of the inflammatory cytokines interleukin-2 (IL-2) and interleukin-6 (IL-6) in healthy teeth. Methods: Participants (9- 17 years old) with healthy teeth requiring extraction for orthodontic reasons were recruited. The teeth were cleaned with pumice and water and randomly assigned to test or control groups. Test teeth were exposed to 40 seconds of ozone treatment via an ozone generating machine (KaVo HealOzone); 20 seconds occlusally and 20 seconds buccally. The teeth were extracted either one day or one week later, and placed in chilled phosphate–buffered saline. The pulp was removed within 30 minutes of extraction and stored at -80°C until assayed. Pulpal concentrations of IL-2 and IL-6 were measured by ELISA (R & D systems). Results: 32 pulps from nine participants were collected, weighed and anaylsed. In the one day extraction group (24 pulps), the mean concentration of IL-6 in the test group was 0.011 ± 0.007 pg/mg of pulp material, compared to 0.014 ± 0.008 pg/mg in the control group (p= 0.039; one-tailed paired t-test). The one week extraction group (eight pulps) showed a mean of 0.007 ± 0.002 pg/mg in the test group and 0.006 ± 0.002 pg/mg in the control group with no statistical difference (p= 0.216). IL-2 was below the level of detection (<7 pg/ml) in all tested pulps. Conclusion: From the experiment, there was no evidence that ozone treatment stimulated an increase in the levels of IL-6 and IL-2 in healthy dental pulp. This suggests that ozone elicits negligible inflammatory responses (if not reduces levels of inflammation) when applied to healthy teeth, and may have potential for prophylactic treatment of patients with high caries risk. This work was supported by the Sir John Walsh Summer Studentship.