Protozoa and oral health: a systematic review.

Gingivitis and periodontitis (GP) are the main diseases of the oral cavity. The ethiology of GP have never been completely understood, however, loss of balance between the host immune system and the microbial virulence of GP pathogens may be considered the trigger of GP. 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 GP. The first studied and the most common parasite in the oral cavity is Entamoeba gingivalis. A possible link between E. gingivalis and GP has never been demonstrated completely, however E. gingivalis is infrequently found in people without GP. In addition, there is evidence that E. gingivalis could favour the onset and progression of GP. In conclusion, we can assert that E. gingivalis and GP may be correlated. This relationship can open new therapeutical approaches for treating GP, particularly in cases refractory to therapy.