Baima G, Marruganti C, Sanz M, Aimetti M, Romandini M. Periodontitis and COVID-19: Biological Mechanisms and Meta-analyses of Epidemiological Evidence. J Dent Res 2022; DOI: 10.1177/00220345221104725. Online ahead of print.

Periodontitis was associated with a more than sevenfold increased odds of death due to COVID-19 complications.

This study critically appraised the recent research discoveries linking periodontitis to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to severe COVID. SARS-CoV-2 main receptors and co-receptors are overexpressed in periodontal tissues of periodontitis patients, with inflammation, periodontal pathogens and damage-induced pyroptosis triggering a positive feedback loop. Periodontitis may worsen clinical COVID-19 courses through direct and indirect pathways, including damage to lower airways due to aspiration of periodontal pathogens, exacerbation of the cytokine storm via the low-grade chronic systemic inflammation, and SARS-CoV-2 dissemination through the ulcerated gingival epithelium with consequent induced pulmonary vessels vasculopathy. Meta-analyses of epidemiological studies indicated that periodontitis subjects are more likely to experience a more severe course of COVID-19. Periodontitis was associated with fourfold increased odds of hospitalisation, sixfold of requiring assisted ventilation, and more than sevenfold of death due to COVID-19 complications.