LAUSR

AIM to investigate the changes in the biomarker levels related to inflammation and tissue destruction in the periapical exudate of mandibular premolar teeth with asymptomatic apical periodontitis after receiving intracanal cryotherapy, to compare cryotherapy and control groups in terms of analgesic intake, interappointment, and postoperative pain, and evaluate the correlation between biomarker levels and interappointment pain. METHODOLOGY Mandibular premolar teeth of 44 patients aged 18-35 years, diagnosed with asymptomatic apical periodontitis, were root canal treated in two visits (registered as NCT04798144). Baseline periapical exudate samples were obtained, and the patients were assigned to either control or intracanal cryotherapy group according to the final irrigation with distilled water either at room temperature or 2.5°C. The canals were dressed with calcium hydroxide. In the second visit, the calcium hydroxide was removed with passive ultrasonic irrigation, and the periapical exudate was sampled again. IL-1β, IL-2, IL-6, IL-8, TNF-α, PGE2 and MMP-8 levels were determined with ELISA. Postoperative pain levels were recorded for six days following both visits using a visual analogue scale. Data were analysed using t-test, Mann-Whitney U, and correlation tests. RESULTS There was a significant correlation between the pain scores reported after first visit and IL-1β and PGE2 levels (p < .05). IL-1β, IL-2, and IL-6 levels showed no significant difference in the cryotherapy group (p > .05), while they significantly increased in the control group (p < .05). There was a decrease in IL-8, TNF-α, PGE2 , and MMP-8 levels, however, the difference was not significant (p > .05). Pain scores were significantly lower in the cryotherapy group for the first three days (p < .05), except for 24th hours (p > .05). CONCLUSIONS The positive correlation between interappointment pain and IL-1β and PGE2 levels might indicate that these biomarker levels can be used to predict the severity of postoperative pain. Intracanal cryotherapy was effective in reducing postoperative pain in the short term in teeth with asymptomatic apical periodontitis. Cryotherapy prevented an increase in IL-1β, IL-2, and IL-6 levels compared to the control group.