Effect of Two Different Irrigation Protocols and Activation Techniques on Postoperative Pain in Single-visit Endodontic Retreatment: Prospective Randomized Clinical Trial

Inclusion Criteria: * o Patients aged 18-60 years who are classified as medically healthy (ASA I or II), * Mature, single-rooted and canal teeth that had root canal treatment at least four years ago, * Teeth with previous root canal obturation 2-4 mm short of the apex, * Teeth that do not need periodontal and prosthetic treatment and whose periapical index score (PAI) is between 2 and 4 , * Teeth with single root and canal diagnosed with asymptomatic apical periodontitis, * Teeth suitable for rubber dam isolation. Exclusion Criteria: * o Patients who had taken analgesics, antibiotics, or corticosteroids within two weeks before root canal retreatment, * Teeth exhibiting periodontal attachment loss, * Presence of vertical root fractures, external root resorption, or perforations, * Teeth with retained broken instruments, * Non-restorable teeth, * Patients in the pregnancy and breastfeeding period.