The ecological catastrophe of oral diseases: a possible link between periodontitis and protozoa.

Periodontal disease (PD) is one of the prevalent diseases in the adult population. The ethiology of PD has never been completely understood, however, loss of balance between the host immune system and the microbial virulence of PD pathogens may be considered the trigger of PD. In fact, the immune system, activated by microbiological agents, attacks the host and not the biofilm bacteria, causing the destruction of periodontal tissue, alveolar bone and loss of teeth. Parasites may play an important role in the pathology of PD. The first studied and the most common parasite in the oral cavity is Entamoeba gingivalis. A possible link between E. gingivalis and PD has never been demonstrated completely, however E. gingivalis is infrequently found in people without PD. In addition, there is evidence that E. gingivalis could favour the onset and progression of PD. In conclusion, we can assert that E. gingivalis and PD may be correlated. This relationship can open new therapeutical approaches for treating PD, particularly in cases refractory to therapy.