Patients in this group will receive traditional syringe and needle irrigation during root canal treatment. An open ended irrigation needle will be used to deliver 2.5% sodium hypochlorite into the root canal system. The needle will be placed 1-2 mm short of the working length, and irrigation will be performed intermittently during canal instrumentation. No additional activation method will be used.

Patients in this group will receive sonic activation of the irrigant using the EndoActivator device during root canal treatment. After instrumentation and irrigation with 2.5% sodium hypochlorite, the irrigant will be activated using the EndoActivator with a medium-sized (25/04) polymer tip. The device will operate at sonic frequencies (~6000 cycles/min) for 30 seconds per canal to enhance irrigant penetration and cleaning efficacy, particularly in the apical third and lateral canals.

Patients in this arm will receive traditional syringe and needle irrigation using a 30-gauge side-vented needle. 2.5% sodium hypochlorite will be used as the irrigant, delivered 1-2 mm short of working length intermittently during root canal instrumentation. No activation device will be used.

Assessment of postoperative pain intensity using a Visual Analog Scale (VAS) ranging from 0 (no pain) to 10 (worst possible pain).

Number of analgesic tablets (e.g., ibuprofen/paracetamol) consumed by patients within the first 48 hours post-treatment.