Study hypothesizes biologic mechanism of how gum disease could increase risk of Sars-CoV-2 access to the lungs. Interesting, but evidence points to aerosolized route as major source for contagion.

Medical Mythbusting Commentary for May 10, 2021

Source:
And now, some good news: Brushing your teeth may reduce risk of COVID-19
(article found in the middle of the post)

Reference:
The COVID-19 Pathway: A Proposed Oral-Vascular-Pulmonary Route Of SARS-CoV-2 Infection And The Importance Of Oral Healthcare Measures