Severe gum disease may raise a coronavirus patient's death risk, research suggests.
Most adults in the UK have gum disease to some extent, which tends to manifest as bleeding gums while brushing.
Over time, this can develop into periodontitis, which affects the tissues that support teeth, ultimately damaging the jaw bone. A patient may then endure recurring abscesses, receding gums and lost teeth.
After analysing more than 500 coronavirus patients, scientists from Qatar University reported those with periodontitis were 3.5 times more likely to be admitted to intensive care and 4.5 times more likely to require a ventilator.
Perhaps most astonishingly, those with advanced gum disease were also nearly nine times more likely to die compared to the patients without periodontitis.
Although unclear, "inflammation in the oral cavity may open the door to the coronavirus becoming more violent", warned the scientists.
Early research suggests the coronavirus is mild in four out of five cases.
Medical conditions like diabetes, cancer and severe asthma have been linked to more serious complications, however, with these patients being prompted to shield and put near the top of the vaccine priority list.
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While it may sound farfetched, research has long linked poor oral health to a higher risk of heart disease.
This may be due to inflammatory molecules in the mouth entering the bloodstream and travelling to the vital organ. Alternatively, people who do not look after their teeth may also neglect other aspects of their wellbeing, like diet and exercise.
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To better understand the impact oral health may have on coronavirus complications, the Qatar scientists analysed the electronic health records of 568 people who tested positive for the infection between February and July 2020.
Of the 258 individuals with periodontitis, 33 experienced severe ill health, compared to seven of the 310 participants without advanced gum disease.
Overall, the study's results – published in the Journal of Clinical Periodontology – link periodontitis to a 3.6 times higher risk of COVID-19, the disease caused by the coronavirus.
When it comes to intensive care admission and ventilator use specifically, the odds were found to increase by 3.5 and 4.5 times, respectively.
Periodontitis was also linked to an 8.8 times higher death risk.
The patients with severe gum disease also had significantly higher levels of so-called C-reactive protein, a marker of inflammation.
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The results remained true after the scientists adjusted for other factors that can influence a person's COVID-19 risk, like old age, being male, obesity, smoking and other medical conditions.
The scientists stressed their study did not prove cause and effect, leading to "clear limitations" and the need to interpret the results "with caution" .
Periodontitis was also only defined as "interdental bone loss", which "may limit the diagnostic accuracy".
Nevertheless, the participants represented a broad sample of the countries they were recruited from – Qatar, Canada and Spain – according to the scientists.
External experts also assessed the patients' radiograph scans, a common method of periodontitis diagnosis.
If a link between periodontitis and coronavirus complications is confirmed, "then establishing and maintaining periodontal health may become an important part of the care of these patients".
Periodontitis-related bacteria may be inhaled, "aggravating" the coronavirus by "inducing the expression" of ACE2; the receptor the virus binds to in order to enter cells.
This inhalation may also trigger an excessive release of inflammatory proteins in the lower airways, known as a cytokine storm. This occurs when the proteins that are meant to fight off an infection mistakenly attack healthy tissue.
Untreated periodontitis can also cause small spaces to open up between the gums and teeth, which may act as "viral reservoirs".
"This may contribute to the deterioration of patients with COVID-19 and raise the risk of death," said study author Professor Mariano Sanz, from the Complutense University of Madrid.
"Hospital staff should identify COVID-19 patients with periodontitis and use oral antiseptics to reduce transmission of bacteria."
Co-author Professor Lior Shapiraf from the Hebrew University-Hadassah Faculty of Dental Medicine in Jerusalem agreed, adding: "The results of the study suggest the inflammation in the oral cavity may open the door to the coronavirus becoming more violent.
"Oral care should be part of the health recommendations to reduce the risk for severe COVID-19 outcomes."
Treating periodontitis has previously been linked to reduced inflammatory markers in the blood.
Gum disease is caused by a build-up of plaque on the teeth, which can be prevented by brushing at least twice a day and flossing regularly. Dental check-ups also enable any hardened plaque to be removed.
In more severe cases, a dentist may recommend a specialist mouthwash. Deep cleans and even surgery are required in some incidences.
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