The researchers noted that the coronavirus could pass into people’s lungs from saliva with the virus moving directly from mouth to bloodstream — particularly if individuals are suffering from gum disease.
Evidence shows that blood vessels of the lungs, rather than airways, are affected initially in Covid-19 lung disease with high concentrations of the virus in saliva and periodontitis associated with an increased risk of death.
The researchers propose that dental plaque accumulation and periodontal inflammation further intensify the likelihood of the SARS-CoV-2 virus reaching the lungs and causing more severe cases of infection.
Experts say this discovery could make effective oral healthcare a potentially lifesaving action — recommending that the public take simple, but effective, daily steps to maintain oral hygiene and reduce factors contributing to gum disease, such as the build-up of plaque.
Initial observations of lung CT scans from patients suffering from Covid-19 lung disease led to a collaboration between medical and dental researchers on the potential entry route into the bloodstream.
“This model may help us understand why some individuals develop Covid-19 lung disease and others do not,” said study co-author Iain Chapple, Professor at the University of Birmingham in the UK.
“It could also change the way we manage the virus — exploring cheap or even free treatments targeted at the mouth and, ultimately, saving lives,” Chapple said.
The researchers noted that gum disease makes the gums leakier, allowing microorganisms to enter into the blood.
Simple measures — such as careful toothbrushing and interdental brushing to reduce plaque build-up, along with specific mouthwashes, or even salt water rinsing to reduce gingival inflammation — could help decrease the viral concentration in saliva.
This can also help mitigate the development of lung disease and reduce the risk of deterioration to severe Covid-19, according to researchers.
The new model is based on the mouth providing a breeding ground for the virus to thrive, with any breach in oral immune defenses making it easier for the virus to enter the bloodstream.
Moving from blood vessels in the gums, the virus would pass through neck and chest veins — reaching the heart before being pumped into pulmonary arteries and small vessels in the lung base and periphery, the researchers said.
“Studies are urgently required to further investigate this new model, but in the meantime, daily oral hygiene and plaque control will not only improve oral health and wellbeing but could also be lifesaving in the context of the pandemic,” Chapple added.