When a patient has a toothache or infection, a root canal is a recommended procedure to save the tooth. Inside the tooth there is a space filled with nerves called the pulp. A root canal cleans and sterilizes the root system.  

Teeth that require a root canal are not always painful. However, signs you may need a root canal include severe toothache, pain upon chewing or application of pressure, prolonged sensitivity or pain in response to hot and cold temperatures, a dark discoloration of the tooth, and swelling and tenderness in the nearby gums.

Once the root canal is completed, the area around the tooth can finally heal and the toothache will go away. These teeth are typically prone to breakage so a crown is recommended after the procedure.