['To determine if eliminating periodontal infection and gingival inflammation affects the severity of active rheumatoid arthritis (RA) in patients with chronic inflammatory periodontal disease.', "Twenty-nine subjects with confirmed diagnosis of RA and mild-to-moderate chronic periodontitis of at least 3 years' duration were enrolled in the study. The activity of RA was assessed using the disease activity score test (DAS28). Seventeen subjects completing the study received periodontal treatment consisting of scaling/root planing and oral hygiene instruction; 12 subjects completing the study received no treatment. Participants continued their usual disease-modifying medications for RA without any changes in DMARD therapy during the study period. RA measurements, and periodontal indices were recorded at baseline and at 8 weeks for each participant. Mann-Whitney U and chi tests were used to test for significant differences in the severity of RA in the periodontally treated group compared with the untreated groups.", 'Ten of 17 subjects (58.8%) in the treated group and 2 of 12 subjects (16.7%) in the untreated group showed improvement in RA scores. There was a statistically significant difference in DAS28 (4.3 +/- 1.6 vs. 5.1 +/- 1.2) and erythrocyte sedimentation rate (31.4 +/- 24.3 vs. 42.7 +/- 22) between the treatment and the control groups.'] Does control of periodontal infection reduce the severity of active rheumatoid arthritis?