Once upon a time, if you had a tooth with a diseased nerve, you'd probably lose that tooth. Today, with a special dental procedure called a root canal therapy you may save that tooth. Inside each tooth is the pulp, which provides nutrients and nerves to the tooth; it runs like a thread down through the root. When the pulp is diseased or injured, the pulp tissue dies. If you don't remove it, your tooth gets infected and you could lose it. After the dentist removes the pulp, the root canal is cleaned and sealed off to protect it. Then your dentist places a crown over the tooth to help make it stronger.