The goal of this randomized clinical trial is to learn the effect of using local corticosteroids and maintaining apical patency in reducing post-preparation pain in patients with acute irreversible pulpitis in molar teeth. The main question it aims to answer is: • How effective are using local corticosteroids and maintaining apical patency in reducing post-preparation pain in patients with acute irreversible pulpitis? Participants will be asked to fill a visual analogue scale to record their pain, after receiving a root canal treatment while using local corticosteroids or not as well as maintaining apical patency or not. Researchers will compare the use of corticosteroids and maintaining apical patency in reducing post-operative pain.