Sometimes, a crack in the enamel travels through to the nerve in the center of the tooth. This type of cracked tooth may hurt when you bite down or when you stop biting. The crack may be to small to see, but when it opens, the pulp inside the tooth may become irritated. The pulp is soft tissue inside the center of the tooth that contains the nerves and blood vessels. If the crack extends into the pulp, the tooth may become sensitive to extreme heat and cold. A root canal treatment may be needed in addition to a crown to save the tooth. For more information about taking care of your mouth and teeth, visit MouthHealthy.org or call Dr. Hutchins at 1-970-242-7373.