One of the most essential parts of endodontic practice is the management of postoperative pain and discomfort, which patients regularly complain after receiving endodontic treatment(1). Postoperative pain is unpleasant and is described as discomfort experienced by patients; it has a high incidence rate ranging between 3% - 58%, and tends to worsen between the initial 6 - 12 hours after treatment, peaking at around 40% in 24 hours and then declining to 11% in one week (2,3). The likely causes of postoperative discomfort may be mechanical, chemical, and/or microbiological damage to the periradicular tissues (2). This sometimes causes periapical irritation, also known as flareup.

Cryotherapy, often known as cold therapy , where the surrounding temperature of tissues is being lowered to relive pain. It has been widely used in sports injuries and surgical operations to reduce pain and provide postoperative care (12, 13). (2)Cryotherapy has been shown to reduce inflammation, oedema, pain, and reduces the recovery time in short-term orthopedic, abdominal, gynecological, and hernia procedures. (1) Low temperatures cause vasoconstriction, also it reduces pain by blocking nerve terminals [11]. (2) Vasoconstriction , decreases the release of inflammatory enzymes, it slow down the cell metabolism, lowering oxygen demand and limiting free radical generation in tissues (22).

In dentistry, cryotherapy has already been adopted by professionals, especially for postoperative pain control after surgical procedures. . (4)The temperature of the outer surface of the root can be reduced more than 10 C by using cold saline (2.5 C) for 5 min and has an anti-inflammatory effect on the periradicular tissue. (3)The first clinical investigation on the use of intracanal cryotherapy in pain control was undertaken by Al-Nahlawi et al., (10) using cold saline (2- 40 C), and observed considerable pain reduction.

Although the effectiveness of cryotherapy has been well established in the literature, there is no standardization of the type or volume of the cryoagent used, mode of application, or duration to identify an ideal protocol for this treatment. Therefore, the purpose of this study was to evaluate the effect of dual volume irrigation as a final irrigant following biomechanical preparation of root canals on postoperative pain in patients with irreversible pulpitis.