The main objectives of root canal therapy are to achieve long-term comfort, function, and aesthetics for the patients and prevention of reinfection of tooth. These objectives are provided through complete cleaning, shaping, and obturation of canals of affected teeth .~Some patients may report moderate-to-severe pain and/or swelling following root canal treatment .~This is detrimental for both patient and dentist and may entail an unscheduled emergency visit by patients to relieve their symptoms.~Postoperative pain is considered a clinical outcome that exhibits the multifactorial nature of patients' responses to variables among treatment procedures such as maintaining the working length to the apical constriction, finishing the endodontic treatment in single visit or multiple visit, instrumentation technique and the type of endodontic sealer used for obturation .~Such pain occurrence is mainly due to mechanical, chemical or microbial injury to the periapical tissues .~Trauma of periapical tissue or bacterial extrusion and root canal sealer specifically, extrusion of root canal sealer can disrupt periodontal tissues and cause inflammatory reactions. The intensity of this reaction depends on the composition of the sealer .~Root canal sealers can play a crucial role in this regard by coming in contact with the periapical tissues through apical foramen and lateral canals causing a localized inflammation with a direct influence on the degree of inflammation based on the composition of the sealer in turn influencing postoperative pain levels .~Silicone is inert and biocompatible and has been widely used in medicine as an implant material Silicone-based root-canal sealers are also available. However, there are no data on the clinical performance of this type of material in endodontic treatment .
The aim of this randomized clinical trial is to evaluate and compare the incidence and intensity of post-operative pain after obturation using resin and silicon-based sealers.