Role of viruses in periodontitis: An extensive review of herpesviruses, human immunodeficiency virus, coronavirus-19, papillomavirus and hepatitis viruses

Figure 1 Possible mechanisms of interaction between periodontitis and coronavirus disease 2019 infection. (1) Periodontal pocket act like a reservoir for severe acute respiratory syndrome coronavirus 2 and an entrance into the blood stream; (2) Periodontitis as a source for increased direct inoculation of periodontopathic bacteria into the respiratory system in coronavirus disease 2019 (COVID-19) patients; and (3) Periodontitis as a source for increased systemic inflammation and priming the immune system in COVID-19 patients. (Created at BioRender.com)