30 January 2026

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Faculty Member’s Research Advances Link Between Gum Disease and Rheumatoid Arthritis

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A University of Michigan School of Dentistry faculty member is part of a new study that advances understanding of the links between gum disease and rheumatoid arthritis.

Dr. Purnima Kumar, professor and chair of the Department of Periodontics and Oral Medicine, is the senior and corresponding author of the study published in the Journal of Clinical Periodontology.

While the connection between periodontitis and rheumatoid arthritis (RA) has long been established, data from the new study supports a “vicious cycle” model, where periodontitis and (RA) have a complex, mutually reinforcing relationship that can increase inflammation not just in the oral cavity but throughout the body.

In a Q&A interview with the University of Michigan News Service, Kumar said the presence of an unhealthy community of bacteria living under the gumline appears to worsen autoimmune responses in RA, while RA itself can make the oral environment more prone to dysbiosis, an imbalance in the different types of microscopic organisms living in the body. The study showed that RA patients who received deep cleanings for their serious periodontitis demonstrated improvement of their RA status.

Kumar notes that the study reinforces research on the interconnectedness of the body and the relationship of oral health to overall health. “This study really highlights that fact, since patients with RA exhibit detrimental changes to the oral bacterial communities that normally protect them. Once they get gum disease, this virulent community and the inflammation it creates spills out of the mouth into the blood stream. … This makes it vital for clinicians to integrate dental and rheumatological care for affected patients.”

Source: https://dent.umich.edu/