The concentration of inorganic salts in the liquid environment in which human oral epithelial cells live is .9%. In this environment, cells can maintain normal morphological structure. Below this concentration, oral epithelial cells will absorb water and swell, while above this concentration, they will lose water and shrink. Therefore, when making temporary tablets of human oral epithelial cells, the purpose of dropping .9% physiological saline is to maintain cell morphology.

So the answer is: √.