The root is the part of the tooth that is embedded in the alveolar bone, located in the basal bone of the maxilla or the mandible. Topped with the dental crown, the root serves as a pillar for the tooth. It ends in an apex.
A tooth may have one or more roots. The number of roots is generally the same for a given type of teeth, but some variations may exist.
Monoradiculated teeth: incisors, canines
Biradiculated teeth: premolars
Three-rooted teeth: molars
The place where the roots of a tooth separate is called a furcation.
Unlike the crown, the root is not protected by the enamel, but by the much finer cementum. Dentin hypersensitivity is therefore very common when the root is denuded. This can happen either because of periodontal disease or as a result of a gingival recession due to excessive forces exerted on the teeth (bruxism or traumatic brushing).
It also defines the extraction method, among other things.