How COVID-19 Complications Can Start in the Mouth

How Covid-19 Complications can start in the mouth s

Ever since COVID-19 reached the United States in late 2019, researchers have been trying to learn as much as possible about this novel coronavirus, as well as the new variants. There are a number of studies that suggest the SARS-CoV-2 virus travels through the air on respiratory droplets and can be transmitted through inhalation. It then travels through the upper respiratory system to settle in the lungs. As a result, the CDC recommended social distancing measures and the use of masks that cover the nose and mouth. 

Recently, however, another study has been published that hypothesizes the virus enters the bloodstream in the mouth and travels through the bloodstream to the lungs. The hypothesis also attributes the presence of periodontitis as a possible indicator of complications with the virus. This hypothesis was recently published in the Journal of Oral Medicine and Dental Research and is titled, The COVID-19 Pathway: A Proposed Oral-Vascular-Pulmonary Route of SARS-CoV-2 Infection and the Importance of Oral Healthcare Measures. 


The study asserts that the SARS-CoV-2 virus can accumulate in the saliva, making the mouth a reservoir for the virus. Previous studies have also noted that human viruses such as human immunodeficiency virus, herpesvirus, Epstein-Barr virus, cytomegalovirus, and Zika virus have been found in gingival crevicular fluid, which is produced as a result of inflammation caused by periodontal disease. Researchers found that 64% of COVID positive patients showed the virus as being present in gingival crevicular fluid. It is important to note that people with healthy gums have very little GCF. 

One key feature of periodontal disease is the presence of periodontal pockets, which form when the gums start to pull away from the teeth due to inflammation. In the simplest terms, a periodontal pocket is a space between the tooth and soft tissue. Unfortunately, plaque and bacteria often accumulate in these pockets. This study has also noted that the SARS-CoV-2 virus can also migrate into the periodontal pockets, where it can survive and replicate. 

Past studies have shown that it is possible for excess bacteria to overwhelm the mouth’s immune defenses in order to enter the bloodstream. This is why periodontitis can lead to other health problems such as endocarditis, respiratory infections, and even pregnancy complications. It is now being postulated that the SARS-CoV-2 virus can also enter the bloodstream in the same way. After entering the bloodstream, the virus will then travel through the veins of the neck and chest into the heart, where it will then be pumped into the pulmonary circulation. This is how the virus is said to reach the lungs. 

how COVID reaches the lungs from the mouth
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The article then explains the relationship between periodontitis and the severity of COVID-19 infection. Another case study was mentioned which noted periodontitis was associated with death, intensive care admission, and the need for ventilation. One theory as to why this happens is because the reservoir of the virus in the mouth allows for the virus to be constantly delivered to the lungs, which constantly maintains or raises the total viral load. 

After considering this hypothesis, the article urges people to prioritize their oral health as a way of decreasing the risk of COVID complications. Periodontitis has a number of oral and overall health consequences and is generally caused by too much bacteria in the mouth along the gum line. Therefore, it is more important than ever to brush twice a day, floss daily, and visit your dentist every six months for a professional teeth cleaning. 

Dr. Sam Sadati wearing black suite portrait

Dr. Sadati possesses extensive experience in all aspects of advanced restorative dentistry, with an emphasis in cosmetic and implant dentistry.  He has attained Accredited Fellow status in the American Academy of Cosmetic Dentistry (AACD), the most rigorous, demanding credentialing process in the world. He is the only AACD Accredited Fellow in South Florida.