Cementum covers the roots of teeth and serves to anchor gingival and periodontal fibers of the periodontal ligament by the fibers to the alveolar bone (some types of cementum may also form on the surface of the enamel of the crown at the cementoenamel junction (CEJ)).
HERS is a collar of epithelial cells derived from the apical prolongation of the enamel organ.
[2] The cementoblasts then disperse to cover the root dentin area and undergo cementogenesis, laying down cementoid.
During the later steps within the stage of apposition, many of the cementoblasts become entrapped by the cementum they produce, becoming cementocytes.
These cementoblasts can form subsequent layers of cementum if the tooth is injured.