Good oral health may prevent severe COVID-19 progression
LEIPZIG, Germany: Given that little time has passed since the outbreak of SARS-CoV-2, it comes as no surprise that only sparse data on COVID-19 is available and many factors remain uncertain. Now, the German Society of Dentistry and Oral Medicine (DGZMK) has stressed the importance of dental prevention and the systemic relevance of dentistry, especially in times of the pandemic. Recent studies have indicated that maintaining good oral health may prevent a severe course of the disease.
“In the context of the COVID-19 pandemic, dentistry has a particularly important role to play in keeping the oral cavity healthy. Dental prophylaxis strengthens the immunocompetence at the point of entry of the virus and helps to avoid infection or to mitigate its course,” said Prof. Roland Frankenberger, president of the DGZMK, in a press release.
A healthy oral cavity acts as a barrier against all kinds of diseases, and according to Frankenberger, this is also true for COVID-19. He explained that there is data showing that, in areas where the lack of oral hygiene causes diseases such as caries or periodontitis, there are also more fatal courses of COVID-19. Upon request from Dental Tribune International, the expert provided information about three studies which focus on the oral cavity with regard to COVID-19.
Improved oral hygiene may reduce risk of complications
A study published in the British Dental Journal highlighted the importance of improved oral hygiene during a SARS-CoV-2 infection in order to reduce the bacterial load in the mouth and the risk of a bacterial superinfection. Those patients who were reported to have a severe form of COVID-19 (20%) had associated higher levels of inflammatory markers and bacteria. Therefore, the author of the study recommended that poor oral hygiene be considered as a risk factor for COVID-19 complications, especially in patients with diabetes, hypertension or cardiovascular disease. Those comorbidities are associated with altered oral biofilms and periodontal disease.
“[The intra-oral status] is not to be neglected under any circumstances”
Frankenberger also addressed the topic of periodontitis: “A patient suffering from periodontitis has subgingival periodontal disease. This means that he or she has—often unnoticed—an open wound of about 40 cm2 in the oral cavity. It is quite clear that this leaves the door wide open to a disease like COVID-19.”
Saliva as protective shield against SARS-CoV-2
Hyposalivation as a potential risk factor for a SARS‐CoV‐2 infection was discussed in an article published in Oral Diseases. Human saliva is a very complex fluid and plays a crucial role in the prevention of viral infections and protection against them, since it contains a large number of proteins and peptides with antiviral effects. Previous studies have documented the antiviral effects of some of those proteins against other coronaviruses. In addition, such proteins have been reported to inhibit the replication of other coronaviruses. According to the authors, it is therefore reasonable to assume that the protective effect of these salivary proteins against SARS-CoV-2 might be similar.
Another previous study has suggested that hyposalivation could lead to acute respiratory infection, because the reduced saliva secretion may impair the oral and airway mucosal surface and may result in a decreased secretion of antimicrobial proteins and peptides. Thus, hyposalivation may expose patients to a higher risk of contracting SARS‐CoV‐2. However, the study authors acknowledge that further studies on this topic are needed to prove this hypothesis.
Is mucosal immunity more important?
Although several knowledge gaps about SARS-CoV-2 exist, it is clear that a vaccine is urgently needed to prevent infection and possible reinfection in the long term. A study published in Expert Opinion on Biological Therapy has addressed the question of whether mucosal SARS-CoV-2 vaccines would be more effective than parenteral vaccines. Owing to their genetic similarity, the development of MERS-CoV and SARS-CoV-1 vaccines in recent years has provided important insights for the development of SARS-CoV-2 vaccines. In an experimental series of SARS-CoV-1/MERS-CoV vaccines, mucosal vaccination resulted in attractive protective correlates—even higher than with parenteral vaccines. Thus, the research of mucosal vaccine candidates should be encouraged for developing effective SARS-CoV-2 vaccines, “especially when considering that the ocular, airway, and mouth mucosae are the main port of entry for this pathogen”, stated the study authors.
Emphasising the importance for patients to be immunologically prepared for COVID-19, Frankenberger concluded by warning: “Intra-oral status is a fundamental part of this. This is not to be neglected under any circumstances.”