Anatomy of the Human Tooth

Anatomy of the human tooth

The tooth is complex structure anatomically although it might appear otherwise.

The tooth is basically composed of 4 layers:

• Enamel
• Dentin
• Cementum
• Pulp

Enamel: Enamel is the hardest substance in the human body and forms the outer most layer of a tooth. It is even stronger than bone and attains a maximum thickness of 2-2.5mm. It is required to be hard as the tooth is subjected to lot of stress upon chewing.

Enamel is composed mainly of inorganic substances (96%) and organic substances (4%). Microscopically, enamel is composed of structures called as enamel rods which range in number from 5- 12 million.

Enamel forms a protective covering over the tooth and its loss causes tooth sensitivity.

Dentin: This is present below the enamel. It gives bulk and general form to the tooth. Physically and chemically, the dentin layer tends to be similar to the bone. Dentin is composed of 35% organic matter and 65% inorganic matter. Microscopically, dentin is formed by S shaped dentinal tubules. It is less hard than enamel but harder than cementum.

Cementum: This is a mineralized dental tissue which covers the roots of the tooth. It is less hard than dentin. It forms a point where the tooth can anchored. It also serves as reparative tissue to the root surface of the tooth.

Pulp: The Pulp occupies the center of the tooth and is mainly soft connective tissue. It is divided in to coronal pulp and radicular pulp. It consists of soft connective tissue, blood vessels and nerves.