The periodontium is all of the supporting tissues of the tooth. Here are the key terms to better understand what your teeth are made of.

The periodontium is the part that supports your teeth.

It is made up of 4 different hard or soft tissues: 

. the gums

. cement

. the periodontal ligament

. the alveolar bone

As for your teeth, they are made up of a crown (visible part) and a root, the region between the crown and the root being called the neck.

The crown is made up of:

the enamel that covers the entire crown

the dentin which, being visible by transparency under the enamel, gives its color to the tooth

the pulp, the living part of the tooth due to its wealth of nerves and blood vessels.

The root also includes  dentin and pulp but is covered by cementum.

The gums

The gingiva is part of the oral mucosa and is the visible part of the periodontium. It surrounds the neck of the teeth and covers the alveolar bone. The edge of the gum covers the enamel without being attached to the tooth (it is fixed by simple adhesion) thus leaving a space between the tooth and the gum called the gingivo-dental space.


The cementum is part of both the tooth and the periodontium. It is an essential element allowing the anchoring of the tooth. The cement also protects the roots. It looks like bone but has no vessels or nerves.

The periodontal ligament (alveolo-dental ligament or periodontium)

The ligament guarantees the fixation of the tooth in the alveolus (hollow in which the tooth is located) by junction tissue which surrounds the root.
The periodontal ligament is inserted on the one hand into the alveolar bone and on the other hand into the cementum. In this way, the tooth is not fused to the bone.

The alveolar bone

The alveolar bone surrounds and holds the tooth in place. When the tooth is no longer there, the alveolar bone will gradually remodel and resorb. The alveolus (hollow in which the tooth is located) exists only by the presence of the teeth that it surrounds.