Are periodontitis and rheumatoid arthritis linked?

2016 08 22 14 15 49 958 Danenberg Alvin 400

Periodontitis is a chronic inflammatory disease. Rheumatoid arthritis (RA) also is a chronic inflammatory disease. In addition, both have autoimmune characteristics. Many people who have periodontitis have rheumatoid arthritis. Likewise, many people who have rheumatoid arthritis have periodontitis. Which came first? Current medical research offers a robust discussion.

However, another question may be more basic and important: Could there be a common cause for both diseases?

Chronic inflammation

Alvin Danenberg, DDS.Alvin Danenberg, DDS.

A common cause for periodontitis and rheumatoid arthritis might be chronic systemic inflammation. If that were the case, then the manifestations of periodontitis and rheumatoid arthritis could depend on individual genetic predispositions and host response.

In a healthy situation, when the body is harmed, the immune system creates inflammation to heal the injury. However, if the insult to the body becomes constant, then the body cannot turn off its internal emergency reaction, and the immune system continues to be activated.

When this happens, what used to be normal inflammation becomes chronic. Elements of chronic inflammation begin to destroy healthy tissue throughout the body and manifest into many chronic diseases.

Medical research

Here are some thoughts from three medical reports.

Chronic inflammation may cause many chronic degenerative diseases. In a 2016 paper in Evolution, Medicine, and Public Health (January 2016, Vol. 1:1, pp. 37-51), the authors use the lens of evolution to describe various factors that affect the development of chronic inflammation. They note that if insults, which create acute inflammation, are not removed within three to eight weeks, the body begins a destructive path leading to chronic diseases.

How does this relate to your patients? Dental plaque is made up of many types of microbes, which are in a balanced state when we're in good health. What can cause the plaque to become unhealthy?

“Eliminating all sources of chronic inflammation is essential for a healthy outcome.”

Environmental factors can affect a person's immune system, according to the second study. If the immune system is compromised, then the host response may be altered and become destructive. A compromised immune system and a negative change in the host response can allow various bacteria in dental plaque to overgrow and become extremely pathogenic.

As some of these harmful bacteria in active periodontitis are resistant to the immune system's attempt to kill them, further chronic inflammation develops. In turn, there is damage to the jawbone and potential spread of infection, as well as elements of chronic inflammation to various parts of the body, as described in Nature Reviews: Immunology (January 2015, Vol. 15:1, pp. 30-44).

In the third study, researchers reported that a specific virulent bacterium associated with periodontitis, Porphyromonas gingivalis, uniquely produces an enzyme called peptidylarginine deiminase (PPAD). Research in Nature Reviews: Rheumatology (August 24, 2017) has linked this production of PPAD by P. gingivalis to the creation of specific antibodies, which might cause the development of rheumatoid arthritis. These antibodies can be identified many years before the patient experiences clinical symptoms of RA.

What you can do

Chronic inflammation causes many different types of chronic disease. Specifically, the apparent initial cause of periodontal disease and rheumatoid arthritis is chronic systemic inflammation. Once periodontitis has become active, the production of PPAD and its resulting antibody production may cause the development of rheumatoid arthritis or aggravate existing rheumatoid arthritis. A vicious cycle is at work among periodontitis, rheumatoid arthritis, and chronic inflammation. So, what is a dentist to do?

First and foremost, talk to your patients about eliminating completely whatever is causing the progression of chronic inflammation. If there are foods and chemicals in the diet that are stoking the flames of inflammation, these must be avoided. Other irritating environmental factors need to be identified and removed. If there is damage to the gut lining or an increase in pathogenic microbes in the gut, these must be treated. If there is active gum disease or any other source of active infection, these must be resolved.

Eliminating all sources of chronic inflammation is essential for a healthy outcome. Only treating the symptoms of periodontitis and rheumatoid arthritis would not ensure a healthy outcome.

So, which came first -- periodontitis or rheumatoid arthritis? It could be a toss up, but treatment must eliminate the ultimate and common cause, which is chronic inflammation.

A version of this column first ran on Dr. Danenberg's blog. appreciates the opportunity to reprint it. His book Crazy-Good Living from Elektra Press is available here.

Alvin Danenberg, DDS, practices at the Bluffton Center for Dentistry in Bluffton, SC. He is also on the faculty of the College of Integrative Medicine and created its integrative periodontal teaching module. He also spent two years as chief of periodontics at Charleston Air Force Base earlier in his career. His website is

The comments and observations expressed herein do not necessarily reflect the opinions of, nor should they be construed as an endorsement or admonishment of any particular idea, vendor, or organization.

Page 1 of 7
Next Page