Conventional and Nano-Metronidazole Irrigation With/Without Activation in Necrotic Teeth With Apical Periodontitis

This randomized controlled clinical trial evaluates the effect of conventional metronidazole and nano-formulated metronidazole as root canal irrigants, with and without ultrasonic activation, in patients with necrotic single-rooted teeth associated with apical periodontitis. A total of 60 participants will be randomly allocated into six equal groups according to the irrigant used and whether ultrasonic activation is performed. Sodium hypochlorite will be used as the conventional control irrigant. The study will compare the groups regarding post-operative pain and reduction in root canal endotoxin levels. Post-operative pain will be assessed using a Visual Analogue Scale, while endotoxin levels will be measured before and after treatment using an ELISA assay

Inclusion Criteria: * Patients aged between 21 and 50 years. * Patients requiring non-surgical root canal treatment. * Single-rooted permanent teeth with necrotic pulp. * Teeth diagnosed with apical periodontitis. * Teeth with fully formed apices. * Patients medically free or with a controlled systemic condition. * Patients able to understand the Visual Analogue Scale (VAS). Exclusion Criteria: * Patients with systemic diseases affecting healing, such as uncontrolled diabetes or immunocompromised patients. * Patients who received antibiotics or anti-inflammatory drugs within the last 48 hours. * Pregnant or lactating women. * Previously endodontically treated teeth (retreatment cases). * Teeth with root resorption, open apex, root fracture, or severe canal calcification.