Gum disease and tooth loss associated with COVID-19 severity: Results of a new study

Dec. 2, 2021
Patients with alveolar bone loss are more likely to experience severe COVID-19 than patients with normal amounts of bone. Dr. Scott Froum looks at the latest research into this association.
Scott Froum, DDS, Editorial Director

The study

A new retrospective cohort study examining 133 patients diagnosed with COVID-19 found that patients with gum disease (alveolar bone loss) and tooth loss were more likely to experience severe COVID-19 than patients who did not have those oral diseases.1 This study included patients who were confirmed to have the SARS-CoV-2 virus (the virus that causes COVID-19) by RT-PCR and had visited a dental clinic to take a panoramic radiograph. The severity of the gum disease was diagnosed by the alveolar bone loss and tooth loss on the panoramic radiograph.

The study found that patients with alveolar bone loss were 5.6 times more likely to be admitted to the intensive care unit or die from COVID-19 than patients with normal amounts of bone. In addition, for every tooth that was lost, a patient had 4.2% higher odds of experiencing severe COVID-19 symptoms versus mild symptoms. Because of the confounding variables between gum disease and COVID-19—e.g., diabetes, smoking, cardiovascular disease, and obesity—this study could not label periodontal disease and tooth loss as independent risk factors for COVID-19 severity.

Related reading: Can periodontal disease be a contributing factor for COVID-19 severity?

How can gum disease be associated with COVID-19 severity?

Since COVID-19 was first described in 2019, there have been many articles that have discussed the potential relationship between gum disease and COVID-19 severity.

  • Bacterial superinfection: Bacteria found in patients with alveolar bone loss can lead to viral superinfections that increase the severity of COVID-19.2
  • Heightened inflammation: Gum disease increases the number of inflammatory markers, especially cytokines such as IL-6, IL-8, and TNF alpha, that have been shown to increase the chances of patients developing COVID-19 cytokine storm and severe symptoms.3
  • Poor nutrition: Evidence has shown that poor nutritional status and diets high in carbohydrates have been linked to COVID-19 severity.4 Poor nutrition has also been linked to oral diseases such as caries and periodontal disease.
  • Similar risk factors: Common risk factors have been identified as contributing to both severity in COVID-19 and gum disease, such as diabetes, smoking, obesity, hypertension, immune dysregulation, cardiovascular disease, and respiratory diseases.5

Related reading: The importance of periodontal treatment in post­–COVID-19 dentistry


This study highlights the significance of the mouth-body connection. Oral diseases influence the systemic health of a patient. The same bacteria implicated in gum disease and tooth loss have been found to cause diseases throughout the body. In addition, the inflammation caused by oral diseases can affect systemic inflammation throughout the body, causing harm to tissues and organs. The relationship between gum disease, tooth loss, and COVID-19 severity is just another example of the oral-systemic connection and the importance of periodontal treatment in a post–COVID-19 world.


  1. Donders HCM, van der Sleen JM, Kleinbergen YJ, Su N, de Lange J, Loos BG. Alveolar bone loss and tooth loss are associated with COVID-19 severity but are not independent risk factors. An explorative study. Advances in Oral and Maxillofacial Surgery. 2022;5:100223.
  2. Botros N, Parvati I, Ojcius DM. Is there an association between oral health and severity of COVID-19 complications? Biomed J.2020;43(4):325-327. doi:1016/
  3. Sahni V, Gupta S. COVID-19 & periodontitis: the cytokine connection. Med Hypotheses.2020;144:109908. doi:1016/j.mehy.2020.109908
  4. Abdulah DM, Hassan AB. Relation of dietary factors with infection and mortality rates of COVID-19 across the world. J Nutr Health Aging.2020;24(9):1011-1018. doi:1007/s12603-020-1434-0
  5. Pitones-Rubio V, Chávez-Cortez EG, Hurtado-Camarena A, González-RascónA, Serafín-Higuera Is periodontal disease a risk factor for severe COVID-19 illness? Med Hypotheses. 2020;144:109969. doi:10.1016/j.mehy.2020.109969 

Editor’s note: This article originally appeared in Perio-Implant Advisory, a chairside resource for dentists and hygienists that focuses on periodontal- and implant-related issues. Read more articles and subscribe to the newsletter.

About the Author

Scott Froum, DDS | Editorial Director

Scott Froum, DDS, a graduate of the State University of New York, Stony Brook School of Dental Medicine, is a periodontist in private practice at 1110 2nd Avenue, Suite 305, New York City, New York. He is the editorial director of Perio-Implant Advisory and serves on the editorial advisory board of Dental Economics. Dr. Froum, a diplomate of both the American Academy of Periodontology and the American Academy of Osseointegration, is a volunteer professor in the postgraduate periodontal program at SUNY Stony Brook School of Dental Medicine. He is a PhD candidate in the field of functional and integrative nutrition. Contact him through his website at or (212) 751-8530.