Apical Patency, Periapical Lesion Volume, and Postoperative Pain After Root Canal Treatment

This prospective clinical study evaluated whether maintaining apical patency during single-visit root canal treatment influences postoperative pain in adults with single-rooted maxillary anterior teeth and chronic apical periodontitis. Participants were systematically allocated in consecutive order to treatment with apical patency or treatment without apical patency. The study also evaluated the relationship between baseline periapical lesion volume measured on clinically indicated cone-beam computed tomography images and postoperative pain.

Inclusion Criteria: * Adult patients. * Systemically healthy and not using regular systemic medications. * A single-rooted maxillary anterior tooth requiring primary root canal treatment. * Diagnosis of chronic apical periodontitis in the study tooth. * The tooth was restorable. * Absence of root fracture or crack. * Absence of internal or external resorption. * Root canal negotiable to the apical region with a small hand file. * Ability to establish a reliable working length. * Availability of a CBCT scan of the relevant maxillary anterior region, previously obtained for clinical purposes or indicated during the treatment process. Exclusion Criteria: * Pregnancy or breastfeeding. * Previous endodontic treatment of the study tooth. * Severe canal calcification. * Suspected root fracture or crack. * Internal or external root resorption. * Periodontal probing depth of 5 mm or greater. * Previous surgical intervention in the relevant region. * Inability to negotiate the root canal. * Inability to establish a reliable working length.