Ameloblast Ameloblast Ameloblasts are cells present only during tooth development that deposit tooth enamel, which is the hard outermost layer of the tooth forming the surface of the crown. Each ameloblast is a columnar cell approximately 4 micrometers in diameter, 40 micrometers in length and is hexagonal in cross section. The secretory end of the ameloblast ends in a six-sided pyramid-like projection known as the Tomes' process. The angulation of the Tomes' process is significant in the orientation of enamel rods, the basic unit of tooth enamel.Distal terminal bars are junctional complexes that separate the Tomes' processes from ameloblast proper. Ameloblasts
Human tooth development lengthen and thicken the bundles of fibers. Noncollagenous proteins, such as bone sialoprotein and osteocalcin, are also secreted. Acellular cementum contains a secreted matrix of proteins and fibers. As mineralization takes place, the cementoblasts move away from the cementum, and the fibers left along the surface eventually join the forming periodontal ligaments. Cellular cementum develops after most of the tooth formation is complete and after the tooth occludes (in contact) with a tooth in the opposite arch. This type of cementum forms around the fiber bundles of the periodontal ligaments. The cementoblasts forming cellular cementum become trapped in the cementum