A tooth is comprised of the crown and the root, and it has multiple parts. Teeth are the hardest bones in the body and are essential for mastication and speech development, according to WebMD.
The crown is the visible portion of each tooth in the mouth, and the root of each tooth descends into the jaw below the gums. The white outer part of the crown tooth is known as enamel. Enamel is comprised almost entirely of calcium phosphate, a dense mineral that provides teeth their strength, and is formed by ameloblasts, explains Dentalcare.com. Enamel does not grow further or repair itself once it is completely formed, but it does have the ability to remineralize. Since enamel is semi-translucent, the color of teeth takes on the hue of dentin which lies underneath the enamel.
Dentin is formed by odontoblasts and does have the ability for constant growth, notes Dentalcare.com. It is comprised of living cells and creates the main portion of the tooth. Dentinal fibers that are enclosed within microscopic tubules carry nutrition throughout the tooth and transmit pain stimuli.
Within the dentin, pulp is located in the center of the tooth. The pulp cavity is divided into the pulp chamber, which is located in the crown, and the pulp canal, which is located in the root. Pulp is composed of blood and lymph vessels, connective and nerve tissue, and the cells that produce dentin. The pulp chamber is initially large until dentin grows throughout life and the chamber decreases in size. The nerve supply in the pulp canal transmits pain stimuli up through the tooth. Cementum is a thin layer of connective tissue that binds the root of the tooth to the gums and jawbone, according to WebMD.