Root canal treatment is an option to repair and save a damaged or infected tooth instead of removing the tooth from the mouth. The space inside the tooth where the nerve tissue was present is cleaned and a filling is put in its place. Root canal treatment can be done by a general dentist or by a root canal specialist, called an endodontist. 

The nerve of the tooth (dental pulp) can be damaged by decay that extends into the pulp, trauma from falls or accidents, or cracks that extend nearby the pulp leading to bacteria in the area. Root canal treatment is only suitable for certain teeth, ask your dentist if this is an option for your tooth.