Good oral health reduces risk of fatal outcomes from COVID-19

Gum disease linked to increased rates of complications, hospitalization, and death among patients with severe cases of COVID-19
Published: 7 April 2021

Infected and inflamed gums may result in higher rates of complications and more fatal outcomes for individuals diagnosed with the SARS-COV-2 virus, according to a new international study led by McGill researchers recently published in the Journal of Clinical Periodontology. The study suggests that gum disease may be associated with higher risks of complications from COVID-19, including ICU admission and death.

Researchers discovered that COVID-19 patients with gum disease were 3.5 times more likely to be admitted to the intensive care unit, 4.5 times more likely to need a ventilator, and 8.8 times more likely to die when comparing to those without gum disease. Until now, no other research has been published about the destructive effects of gum disease in patients with COVID-19.

“Looking at the conclusions of our study we can highlight the importance of good oral health in the prevention and management of COVID-19 complications,” explains Belinda Nicolau, contributing author and Full Professor in the Faculty of Dentistry at McGill University. “There is a very strong correlation between periodontitis and disease outcome.”

What is periodontitis?

Periodontitis, also referred to as gum disease, is a serious infection of the gums that damages supporting tissues of the teeth and if left unmanaged can lead to bone loss. Gum disease is the most common dental problem in Canadians, with seven out of ten affected to some degree in their lives. However, it is largely preventable by maintaining good oral hygiene through daily brushing and flossing and getting regular dental check-ups.

“Periodontitis has been considered as a risk factor for a number of both oral and systemic diseases,” explains Wenji Cai, co-author and PhD student from Faculty of Dentistry. “It's an invisible pandemic. We need to raise awareness of the disease and make more effort to maintain periodontal health, especially during this global pandemic.”

The study also found that blood levels of biomarkers which indicate inflammation in the body were significantly higher in COVID-19 patients with gum disease, which may explain the higher rates of complications for those patients. “Periodontitis causes inflammation of the gums and, if left untreated, that inflammation can spread throughout the body,” says Cai. “In patients with severe cases of COVID-19, the virus causes an inflammatory response that can lead to complications such as being intubated or even death. Our research shows that periodontitis can exacerbate this.”

This observational study crossed dental records with medical records of patients with severe cases of COVID-19 in Qatar between February and July 2020. “We included 568 patients in our study and took various factors into consideration, such as demographic, medical or behaviour factors, to avoid biases,” adds Cai. “In Qatar the medical and dental records happened to be digitized, which made it possible to collect data and conduct this research swiftly.”

The results of this multi-national study stem from a cooperation between researchers from McGill University, Complutense University of Madrid, Hamas Medical Corporation of Qatar and Qatar University. The research team continues to expand data collection to strengthen the study.

About this study

Association between periodontitis and severity of COVID‐19 infection: A case–control study” by Wenji Cai, Belinda Nicolau and al. was published in the Journal of Clinical Periodontology.

This study was funded by the Hamad Medical Corporation Business Intelligence Center and the Alpha‐Omega Foundation.

About McGill University

Founded in Montreal, Quebec, in 1821, McGill University is Canada’s top ranked medical doctoral university. McGill is consistently ranked as one of the top universities, both nationally and internationally. It is a world-renowned institution of higher learning with research activities spanning two campuses, 11 faculties, 13 professional schools, 300 programs of study and over 40,000 students, including more than 10,200 graduate students. McGill attracts students from over 150 countries around the world, its 12,800 international students making up 31% of the student body. Over half of McGill students claim a first language other than English, including approximately 19% of our students who say French is their mother tongue.

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