Lesson 3: Tooth Structures


Dr. Lee to John: "John, show us that big smile again."

Enamel is the hard, white, protective material that covers the outside of the crown of the tooth. Enamel is the hardest substance in the human body. We can see that the enamel is the outer covering of his teeth.

Dentin, (dentine outside the U.S.), is the sensitive, calcified tissue underneath the enamel. Dentin forms the bulk of tooth structure and surrounds the pulp.

Pulp is the soft mass of tissue in the center of the tooth that is surrounded by dentin. The pulp contains nerves and blood vessels that nourish the tooth. Pulp is located in the center of the tooth and resides in both the crown and root.

Cementum is the thin, calcified bone-like tissue that covers the roots of John’s teeth. It provides an attachment point for periodontal fibers within the periodontal ligament.

John’s teeth are surrounded by supporting structures collectively known as periodontium. These tissues include the gingiva, cementum, periodontal ligament, and alveolar bone.

The periodontal ligament, also called the periodontal membrane, attaches to the cementum, which covers the root of each tooth. This connects John’s teeth to the underlying alveolar bone. The alveolar process is the thickened ridge of the alveolar bone that contains the tooth sockets.

Each tooth is nourished by blood vessels and innervated by nerves that pass through the root canal into the pulp.

Image: The supporting structures collectively known as periodontium.