Tooth decay, trauma or cracks can cause the nerves of teeth to degenerate. When this occurs your tooth can often still be saved with root canal therapy.

You may have symptoms like

Sensitivity to hot and cold food.
Constant throbbing or dull pain.
Pain on chewing.
Discoloration of the tooth.
swelling, drainage and tenderness in the lymph nodes as well as nearby bone and gingival tissues.
Or you may have no symptoms at all.

Whether or not you have symptoms, your tooth will worsen over time and it may eventually have to be removed.

During RCT, The dentist removes the inflamed or infected pulp, carefully cleans and shapes the inside of the canal, a channel inside the root, then fills and seals the space. Afterwards, the dentist will place a crown or other restoration on the tooth to protect and restore it to full function. After restoration, the tooth continues to function like any other tooth.

If treated early, root canal therapy need not be uncomfortable. With modern dental techniques available and  the use of local anesthetics, the entire procedure can be totally painless.