b. Gingival cells:
The major cellular elements in the gingival connective tissue include:
Fibroblasts, macrophages, mast cells, osteoblasts and osteoblast precursor cells, cementoblasts and cementoblast precursor cells, osteoclasts and odontoclasts, assorted inflammatory cells, and cells that make up vascular channels and nerves. Inflammatory cells include polymorphonuclear leucocytes, lymphocytes and plasma cells. Under normal circumstances they may be found in small numbers, as isolated cells. In the presence of inflammation they can be found in large numbers, often as dense cellular aggregates that have replaced the fibrous elements in the connective tissue. The connective tissue also contains undifferentiated ectomesenchymal cells that serve as a replacement source for more differentiated cells, primarily fibroblasts.
Fibroblasts are irregularly shaped cells responsible for the synthesis of various connective tissue fibers and the ground substance in which they are imbedded. They are also responsible for the removal of these structural elements. Therefore these cells play a key role in the maintenance and remodeling of the connective tissue.
Fig. 33: Portion of a gingival fibroblast showing collagen fibers within digestive
vacuoles (CV). Since fiber assembly during collagen synthesis is an extracellular
event, it is likely that the presence of assembled fibers within the cells is not part of
collagen synthesis. Instead, internalized fibrils result from a phagocytic process
that takes fibers from the extracellular compartment into the cell for degradation by lysosomal enzymes in digestive vacuoles.
