Cementoblast

Martha Somerman and her laboratory played a key role in identifying and characterizing cementoblasts, the cells responsible for forming cementum, a vital mineralized tissue covering tooth roots.

Structure

Thus cementoblasts resemble bone-forming osteoblasts but differ functionally and histologically. The cells of cementum are the entrapped cementoblasts, the cementocytes. Each cementocyte lies in its lacuna (plural, lacunae), similar to the pattern noted in bone. These lacunae also have canaliculi or canals. Unlike those in bone, however, these canals in cementum do not contain nerves, nor do they radiate outward. Instead, the canals are oriented toward the periodontal ligament (PDL) and contain cementocytic processes that exist to diffuse nutrients from the ligament because it is vascularized. The progenitor cells also found in the PDL region contribute to the mineralization of the tissue.

Once in this situation, cementoblasts lose their secretory activity and become cementocytes. However, a layer of cementoblasts is always present along the outer covering of the PDL; these cells can then produce cementum if the tooth is injured (see hypercementosis).