A root canal is performed when a tooth has an infected nerve or tooth pulp. This infection may be due to a large cavity that has reached the nerve, a tooth fracture or even traumatic injury that leads to nerve damage.
Root canal pain due to infection often manifests as a dull, aching, continuous pain that can lead to bubbles on the gums that are called abscesses. During the root canal procedure the tooth infection is cleaned out by opening the tooth and using files as well as irrigation solutions to disinfect the canals. The canals are then sealed with an appropriate filling material. After root canal treatment the tooth may become weakened and may require a dental crown to give it more strength.