Untreated periodontitis and COVID-19: What is the evidence? Part 2 of 3

By Casey Hein, MBA, BSDH, RDH

Casey Hein, MBA, BSDH, RDH, examines the second biological mechanism that may increase the risk for COVID-19 complications—how bacterial pathogens in the respiratory tract may predispose to influenza and other viral infections.

If only the periodontal microbiota could talk

Presented in Part 2 of this three-part series is a second biological mechanism I hypothesize may increase the risk for COVID-19 and/or its complications, namely how bacterial pathogens in the respiratory tract may predispose to influenza and other viral infection. To reiterate what I wrote in Part 1, this is a hypothetical link; it has never been studied, and it is ripe for scientific investigation.

In their 2018 review, Shi and colleagues explored how bacteria and viruses impact each other, particularly during the infectious process. They describe how mucosal surfaces harbor diverse microbial communities in complex ecosystems and how the bacterial portion of the microbiota influences the outcomes of many diseases, including infectious illnesses. In other words, the bacterial component of the resident microbiota plays a pivotal role in determining the outcome of an encounter with a new infectious organism. This evidence provides a compelling rationale for eliminating or reducing periodontal disease activity.

The oral microbiota is a reservoir for microorganisms implicated in respiratory infections, and anaerobic bacteria of the oral cavity have been identified in aspiration pneumonia and lung abscesses. We must acknowledge the large body of evidence that demonstrates that periodontitis increases the risk of pneumonia, especially in high-risk populations, such as the institutionalized elderly, patients hospitalized for extended lengths of time, and those undergoing long-term ventilation, all of which are akin to the demographic hardest hit by COVID-19. In addition, periodontitis has been implicated in risk for chronic obstructive pulmonary disorder (COPD)—a known risk factor for COVID-19 infection. Data from Wuhan reported that 7% of nonsurvivors had predisposing COPD.


Originally published in RDH, Nov. 1, 2020


Casey Hein, MBA, BSDH, RDH, is an internationally recognized speaker and extensively published author with over 40 years’ experience as a dental hygienist in private practice, public health, education, and government. She first began speaking about periodontal-systemic links in 2003 and founded the first publication on oral-systemic science, called Grand Rounds in Oral-Systemic Medicine. She is a pioneer in implementation of periodontal-systemic science, medical-dental collaboration, and providing primary-care services traditionally delivered by physicians and nurses in dental offices.

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