What Is a Tooth Made Of?

A tooth may appear to be a solid object, but in reality it is a complex structure. The tooth consists of several different parts and layers, each performing a unique function for the maintenance and health of the tooth. The four parts of the tooth are the cementum, the dental pulp, the dentin and the enamel.

Cementum

• The cementum is the connective tissue that covers the tooth's root. It essentially holds the tooth in place by attaching the periodontal ligaments to the root of the tooth. This allows the tooth to remain stable, but still maintains a degree of "give" when biting something hard. The cementum continues to grow throughout the life of the tooth, which helps compensate for some degree of tooth wear. The cementum is light yellow, but is mostly hidden from view below the gum-line.

Dental Pulp

• The soft dental pulp occupies the pulp cavity at the center of the tooth. The pulp serves four purposes within the tooth. The most important function is the production of new dentin. Second, the pulp provides nutrients and moisture to the rest of the tooth. The pulp is the part of the tooth that senses pressure, temperature and damage from decay.The pulp also forms a secondary dentin that repairs damaged dentin.

Dentin

• Dentin makes up most of the tooth. It is a hard, mineral substance that relies on the pulp to stay healthy. If the pulp is taken out by a dentist or otherwise dies, the dentin becomes brittle. It is harder than bone or cementum, but not as hard as the thin layer of enamel that covers it. Dentin continues to grow throughout the life of the tooth, and will repair to some degree if injured. The dentin is more yellowish than white.

Enamel

• The enamel is the hard substance that covers the top of the tooth and tapers down the sides. It is extremely brittle, but is supported by the dentin underneath. It is typically grayish-white and gives the tooth a mostly white look. It is almost completely composed of minerals. Tooth decay is caused when the minerals in the enamel are eroded by acid. Enamel will re-mineralize to a small degree, but does not regenerate.