Cementoblast

Overview
A cementoblast is a biological cell that forms from the follicular cells around the root of a tooth, and whose biological function is cementogenesis, which is the creation of cementum (the hard tissue that covers the root of the tooth). Cementoblasts lay down the organic matrix of cementum which later gets mineralised by minerals from oral fluids. Thus the cementoblasts lay down collagen and secrete osteocalcin and sialoprotein. They possess all the organelles associated with protein synthesis such as RER and Golgi apparatus.

The mechanism of differentiation of the cementoblasts is controversial but circumstantial evidence suggests that an epithelium or epithelial componenet may cause dental follicle cells to differentiate into cementoblasts, characterised by an increase in length. The initially formed cementum in coronal two-thirds of the root is acellular, but when the cementoblasts get trapped in lacunae in their own matrix like bone cells, the cementum is called cellular or secondary cementum and is present only in the apical third of the root. Once in this situation, the cementoblasts lose their secretory activity and become cementocytes.

セメント芽細胞