Periodontal disease is an inflammatory disease which affects the tissues that surround and support the teeth. Periodontal disease involves progressive loss of the bone around teeth which may lead to loosening and eventual loss of teeth if untreated.
An Australian study involving 130 participants, 65 of which had rheumatoid arthritis (RA), found that those with RA were 2 times as likely to have periodontal disease with moderate to severe jawbone loss than those without RA. In fact, the rheumatoid arthritis group had an average of 11.6 missing teeth compared to 6.7 missing teeth in the non-RA group.
Scientists differ on the underlying reasons for these results. Some suggest that the immune system and chronic inflammation play a role in both rheumatoid arthritis and periodontal disease. Others suggested that the impact of rheumatoid arthritis on mobility, range of motion, and manual dexterity make it difficult to brush and floss properly which would contribute to poor oral hygiene. The study showed however that there was no difference in plaque deposits on the teeth of rheumatoid or non-rheumatoid study participants.
In another study, conducted at The University of Sao Paulo, Brazil, researchers evaluated periodontal disease in 39 rheumatoid arthritis patients and 22 healthy individuals. They found that the patients with rheumatoid arthritis had fewer teeth, a larger number of sites with dental plaque and more teeth with advanced attachment loss.
Other studies have compared periodontal disease in healthy people to juvenile arthritis patients and found that the juvenile arthritis patients experienced more periodontal attachment loss even though the levels of plaque and bleeding were similar. This demonstrates that the relationship between periodontal disease and RA exists in young patients as well.
Alternately, another study found that patients with more bone loss related to periodontal disease also had more rheumatoid arthritis disease activity in terms of swollen joints, health assessment questionnaire scores, and CRP levels & sedimentation rates, which are indicators of inflammation. The relationship between rheumatoid arthritis and periodontal disease may have to do with an anomalous, underlying problem with unregulated inflammation.