Methods: The data was obtained from sixty patients that had consented to be participants in the study. Elastic separators were inserted at the proximal contacts of upper right and left first molars, and CO2 laser was irradiated for one minute at the left side only. After 6, 12 hours, and 1, 2, 3, 4, 5, 6 or 7 days of insertion of elastics, a questionnaire survey by Visual Analog Scale (VAS) was obtained. The pain immediately after the insertion of the elastics was determined as 50% of pain.
Results: Fifty patients out of 60 had felt pain after the insertion of the elastics. The pain was reduced in 70% of the patient by the CO2 laser. The mean VAS of the pain at the control and experimental side in these patients were, 50 and 35%, 60 and 37%, 75 and 40%, 84 and 43%, 74 and 35%, 63 and 34%, 35 and 17% at immediately after, 6, 12 hours, 1, 2, 3, 4, days after of the insertion of elastics, respectively. There was statistically significant difference until four days (p<.0001) . There was no significant difference between the right and left in the patients without irradiating CO2 laser.
Conclusion: Statistically significant reduction in pain until 4 days by irradiating CO2 laser was clearly demonstrated in the present study. It was suggested that the CO2 laser has a strong potential to effectively reduce pain during orthodontic tooth movement.