Once upon a time, if the nerve in your tooth was diseased, you'd probably lose that tooth. Today with a special dental procedure called a root canal therapy we save that tooth. Inside each tooth there is a 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.