Hello, Thanks for your query. If the pain after root canal is intense, this could be a sign of complications and possibly of a root canal failure. The most common causes of post root canal pain include: Irritation of periodontal tissues. Hyper occlusion Bruxism Infection - Periapical abscess (concentration of pus and fluid at the tip of the root). The normal post root canal pain can be relieved by taking an over-the-counter pain reliever, usually an anti-inflammatory medicine like Ibuprofen. Sometimes an antibiotic is also prescribed to minimize the risk of a new infection. Follow your dentist’s instructions for post-operative care. Good oral hygiene will help in faster healing. I do hope that you have found something helpful and I will be glad to answer any further query. Take care