This study aims to evaluate the efficacy of the GentleWave® System compared to conventional methods in reducing postoperative pain in patients with necrotic pulp or requiring endodontic retreatment.

New irrigation modalities such as the GentleWave® System, which integrates advanced multisonic ultrasound technology, have been developed to overcome limitations and improve root canal treatments success rates, by ensuring comprehensive cleaning while minimizing mechanical instrumentation. This system, featuring CleanFlow technology, optimizes the delivery of irrigants and promotes efficient root canal debridement. Postoperative pain is common, usually peaking within the first 24 hours after treatment and decreasing thereafter.

In the presence of necrosis, microorganisms can colonize anatomical complexities, such as isthmuses, ramifications and dentinal tubules causing symptoms such as pain, inflammation, and in some cases even odontogenic sinusitis. Conventional Syringe Irrigation (CSI), which delivers irrigants (NaOCl, EDTA) through a needle-syringe system, often fails to reach the entire working length and the intricate anatomy of the root canal. This inadequacy can result in residual bacteria and necrotic tissue, potentially compromising treatment efficacy and increasing the risk of treatment failure; furthermore, positive pressure exerted during CSI may cause the extrusion of irrigants beyond the apex, leading to complications.

Inclusion Criteria:

• Male and female patients from 18 years age or older (maximum of 80 years of age), both genders.
• The patients in need of an endodontic intervention.
• All dental groups in both arches were eligible.
• Patients who do or do not experience symptoms after the endodontic intervention.
• Patient-signed informed consent/assent form

Exclusion Criteria:

• Patients< 18 years old.
• fractured teeth.
• Patients who were recommended extraction after the endodontic evaluation.