Each tooth in the mouth contains four different tissues that serve different functions: The teeth are made up of two major parts: The crown and the root. The crown of the tooth is what is visible in the mouth. The root of the tooth is the portion which normally is not visible in the mouth and is anchored within the bone. Within each tooth, the four different tissues that are present are the enamel, the dentin, the pulp and the cementum.
Dr. James L. Johnson