Entamoeba gingivalis and Trichomonas tenax: Protozoa parasites living in the mouth

Objective: This review article aims to summarize the existing data on the history, biology and potential patho-genicity of Entamoeba gingivalis and Trichomonas tenax in periodontal disease, as well as the available techniques for laboratory diagnosis.Design: A detailed review of scientific literature available up to October 1, 2022 in three databases (PubMed, Scopus and Web of Science) was performed relevant to biology, biochemistry, epidemiology, and experimental studies on infection by E. gingivalis and T. tenax, as well as laboratory techniques for the diagnosis of both protozoa in periodontal diseases.Results: Accumulated evidence over the decades indicates that the protozoa E. gingivalis and T. tenax are able to interact with host cells and induce inflammation in the periodontal tissue by promoting the expression of pro -inflammatory molecules and the recruitment of neutrophils, contributing to the periodontal disease process. Among the available techniques for the laboratory diagnosis, culture and molecular assays seems to be the best tools for detection of both protozoan parasites.Conclusions: E. gingivalis and T. tenax are potentially pathogens that colonize the oral cavity of humans and may cause periodontal disease.