Root canal treatment is used to save a tooth which is very decayed. It involves the removal of damaged or infected nerves and tissue from the root of the tooth.
The roots usually become infected due to a large cavity which eventually infects the pulp in the tooth and then the tissue inside the roots. The dentist cleans out the roots, before applying a filling. As a result, the tooth is “dead” but it can continue to function. Dead teeth may turn grey, and the dentist may recommend a crown or post and core treatment.