Effects of Intracanal Cryotherapy on Biomarkers and Postoperative Pain in Apical Periodontitis

This randomized controlled clinical study will evaluate the effects of intracanal cryotherapy during root canal treatment in patients with asymptomatic apical periodontitis. The study will investigate whether the temperature of the final irrigation solution influences the biological inflammatory response and postoperative pain. Participants will be randomly assigned to one of three groups according to the temperature of distilled water used for final root canal irrigation: 2-4°C, 8-10°C, or 22-24°C. Periapical tissue fluid samples will be collected before and after the intervention and analyzed for inflammatory and tissue-response biomarkers, including IL-1β, TNF-α, RANKL/OPG, PGE2, TGF-β, and MMP-9. Postoperative pain and analgesic use will also be recorded during the first 7 days after treatment. The study aims to determine whether intracanal cryotherapy can reduce the inflammatory response and postoperative pain associated with root canal treatment and whether these effects vary according to the temperature of the irrigation solution.