Anatomy of a Tooth
How much do you know about your teeth?
For one thing, they’re surprisingly strong. The incisors can exert 30 to 50 pounds of pressure, and the molars can bear down with more than 200 pounds of force.
The part of the tooth visible above the gum line, known as the crown, is covered with a hard, whitish material called enamel. Enamel is a substance composed of calcium and phosphorous. It’s the hardest substance in the body, so it’s ideal for biting, chewing, and resisting decay. The enamel ends at the tooth neck (also called the cervix), where the root, the largest portion of the tooth, begins. A tooth has one to three roots, depending on its size and the amount of chewing pressure it has to endure. The root of the tooth is covered with a thin layer of pale yellow bonelike material called cementum. Cementum is more vulnerable to decay if the gum line recedes enough to expose it.
Inside the tooth are two other types of dental tissue: dentin and pulp. Dentin is harder than cementum but softer than enamel. It constitutes the largest portion of the tooth. At the core of the tooth is a chamber extending from the crown into the root. Inside this chamber is the pulp, the only part of the tooth not hardened with calcium deposits. It consists of loose connective tissue laced with blood vessels that bring nourishment to the dentin. A network of nerves that runs through the pulp communicates pain when the pulp is damaged or infected. The nerves also respond to heat, cold, electricity, and some chemicals. The periodontal ligaments, bands of fibrous tissue that connect the cementum to the bone, secure the teeth.
Source: Dental Health for Adults: A Guide to Protecting Your Teeth and Gums. Copyright © by Harvard University. All rights reserved.