Figure 4-6. - Tissues of the teeth.
Cementum is the bonelike tissue that covers the roots of the teeth in a thin layer (fig. 4-6).
It is light yellow in color, slightly lighter than dentin.
The cementum is composed of approximately 55% organic material and 45% inorganic material.
(The inorganic components are mainly calcium salts.) The cementum joins the enamel at the cervix of the tooth.
The point at which they join is called the cementoenamel junction (CEJ). In most teeth the cementum overlaps the enamel for a short distance.
In some, the enamel meets the cementum in a sharp line.
In a few, a gap may be present between the enamel and the cementum, exposing a narrow area of root dentin.
Such areas may be very sensitive to thermal, chemical, or mechanical stimuli.
The main function of cementum is to anchor the teeth to the bony walls of the tooth sockets in the periodontium.
This is accomplished by means of the fibers of the periodontal ligament or membrane.
Cementum is formed continuously throughout the life of the tooth to compensate for the loss of tooth substance because of occlusal wear, and to allow for the attachment of new fibers of the periodontal ligament to the surface of the root.
The dental pulp, (figure 4-7), is the soft tissue of the tooth, which develops from the connective tissue of the dental papilla. Within the crown, the chamber containing the dental pulp is called the pulp chamber.
The pulp contains blood vessels and nerves that enter through the apical foramen. The coronal pulp is within the crown.
Within the root is the radicular pulp.
Figure 4-7. - Dental pulp.Continue Reading