Most root canals can be done with little or no discomfort and will usually heal uneventfully. Unfortunately, there is an occasional poor soul who has post-operative complications. The most common of the complications is pain. Most pain is caused by inflammation. I always recommend that my patients who have undergone root canal treatment take an NSAID (non-steroidal anti-inflammatory) such as ibuprofen right after the procedure. Getting the anti-inflammatory into the bloodstream before the inflammation sets in is the key to preventing most post-operative pain. Infections can be the other main reason for post-op pain. A root canal is usually done on a tooth that is already infected. Through the root canal process, most of the infectious bacteria are removed. But there is still the possibility that some bacteria could be left at the tip of the root. Normally, the bioburden is greatly reduced from the root canal procedure, however, sometimes the body’s defenses can still be overwhelmed. Most infections can be handled with a single regimen of antibiotics. If you experience pain and/or swelling that is present for more than a couple of days after a root canal, you should contact your dentist immediately.