Researchers have found that “people who have both gum disease and rheumatoid arthritis can relieve both conditions by treating their mouth infection”, BBC News reported. It said that patients who improved their oral hygiene and had treatments such as scaling had a reduction in arthritis symptoms.

This news report is based on a small randomised controlled trial which found that treating gum disease can improve the symptoms of rheumatoid arthritis. This study is not the first to have made the connection between the two conditions and supports previous research. In addition, the study confirmed that the improvement in arthritis symptoms occurred regardless of whether medication (anti-TNF-α drugs) was being taken for these symptoms.

There is a plausible link between periodontitis (gum disease) and rheumatoid arthritis. Both are inflammatory conditions and gum disease is more common in people with rheumatoid arthritis. Oral hygiene is important to general health regardless of its possible link to arthritis and patients with the condition may benefit from having good oral hygiene.

Where did the story come from?

The research was carried out by Dr P Ortiz and colleagues from Case Western Reserve University in Cleveland and King Abdulaziz University in Jeddah, Saudi Arabia. The study was funded by the Department of Periodontics at Case Western Reserve University and was published in the peer-reviewed Journal of Periodontology.

What kind of scientific study was this?

The researchers say that gum disease is common in people with rheumatoid arthritis, an autoimmune disease where the joints become painful, swollen and inflamed leading to tissue damage. They say the diseases have similar characteristics as both involve the destruction of hard and soft tissues. They also say that some studies have suggested a link between the two conditions, with indications that rheumatoid arthritis could have a negative effect on the gums.

This small randomised controlled trial was conducted in people with both rheumatoid arthritis and gum disease. The researchers investigated the effects of treating gum disease on levels of TNF-α in blood. TNF-α is a compound involved in inflammation and a marker of the severity of rheumatoid arthritis.

Forty people from University Hospitals of Cleveland were enrolled. The patients were aged 30 or over and had active rheumatoid arthritis and severe chronic periodontitis (gum disease), with more than 20 teeth present. Twenty patients were receiving DMARDs (disease modifying antirheumatic drugs) for their rheumatoid arthritis and the remaining 20 were receiving a combination of DMARDs and anti-TNF-α drugs. Both groups were randomly split in half to make four groups and were given either periodontal treatment or no further treatment (control).

Those given periodontal treatment were instructed in oral hygiene and underwent full-mouth scaling and/or root planing (removal of tartar and plaque from the teeth and smoothing irregularities on the root surface to discourage plaque build-up). Those assigned to the control group did not receive any gum treatments until after the six-week study period.

Participants were assessed at the beginning of the study and then six weeks later. Several measures of gum health were taken at each follow-up, including whether the gums bled when probed, severity of plaque and number of teeth present. The severity of rheumatoid arthritis was assessed by determining the number of tender and swollen joints and through a disease activity score (DAS28). TNF-α levels were determined through blood tests at each visit. Statistical analyses were used to compare the effects of periodontal treatment on the severity of rheumatoid arthritis across the groups.

What were the results of the study?

The study found that the rheumatoid arthritis of the patients given periodontal treatment was less severe and they had a reduction in TNF-α levels in their blood. Patients who were not given periodontal treatment did not show a similar reduction in the severity of their arthritis. Gum health was improved more in the groups receiving anti-TNF-α therapy. However, the researchers note that in the group that only received anti-TNF-α therapy (and no periodontal treatment), there was no improvement in gum health.

What interpretations did the researchers draw from these results?

The researchers say their study demonstrates that non-surgical periodontal therapy has a beneficial effect on the signs and symptoms of rheumatoid arthritis, “regardless of the medication used to treat this condition”.

What does the NHS Knowledge Service make of this study?

This small randomised controlled trial has confirmed what other studies have found: there is a link between rheumatoid arthritis and gum health and that treatment for gum disease has a beneficial effect on symptoms of rheumatoid arthritis. As demonstrated in other studies, this research also confirms that anti-TNF-α therapy (for rheumatoid arthritis symptoms) reduces the severity of gum disease.

This was a small study, with only 10 people in each compared group, and there is a possibility that some of the findings are due to chance. If the same results were found in larger studies with a similar design, a greater confidence could be had that treating gum disease can reduce the severity of rheumatoid arthritis. In addition, all the participants had severe chronic gum disease, so the findings may not apply to people with rheumatoid arthritis and healthy gums or milder gum disease.

However, this finding does support what other studies have found: a link between gum disease and rheumatoid arthritis. Oral health is important and, until proven otherwise, patients with arthritis may benefit from following a regular routine of good oral hygiene.

Analysis by Bazian
Edited by NHS Website