E. gingivalis, the mouth amoeba, is found in the tartar or plaque deposited around the bases of teeth and abscesses of gums, throat and tonsils in nearly 70% of human population. Its occurrence is more common in the mouth of persons suffering from pyorrhoea. It was believed in the past that E. gingivalis caused pyorrhoea. However, it is now certain that pyorrhoea is caused by bacterial infection. E. gingivalis, however, aggravates pyorrhoea by destroying the tissues in the gums. It is nonpathogenic.
Its trophozoites measure 12 to 20 microns in diameter. The cytoplasm is divisible into a clear, peripheral ectoplasm, and central, granular, vacuolated endoplasm. The endoplasm contains a nucleus with central endosome, food vacuoles containing bacteria, cellular debris and white blood cells (these arc its food). It produces many broad and rounded pseudopodia. It moves with the help of the pseudopodia.
E. gingivalis does not form cysts. It is directly transmitted from mouth by contact during kissing or while eating or drinking. Maintenance of oral hygiene is necessary to avoid its infection.
It aggravates pyorrhoea by destroying the tissues in the gums.