The periodontist will also take a small measuring instrument called a probe and place it between the teeth and gums to determine the depth of those spaces, known as periodontal pockets; this helps the periodontist assess the health of the gums.
The ground substance of connective tissue is different from all of these fluids; it is the liquid medium through which these other fluid exchanges take place.
Like all connective tissue, dense regular connective tissue is composed of cells, in this case fibroblast cells (fiber producing cells), fibers (elastin and collagen), as well as a jelly-like extracellular matrix called ground substance.