Background: Periodontitis and inflammatory bowel disease (IBD) share similarities in their aetiopathogenesis and patients with IBD are reported to have more often severe periodontitis. Conversely, recent studies have suggested that periodontitis also impacts IBD activity. In this study we used two distinct IBD-populations to assess whether the presence of periodontitis is associated with increased IBD activity, disability, and severity.

Methods: Identical questionnaire-based surveys were conducted in Sweden and Denmark, distributed by the respective patient-organisations. The survey included self-reported oral health as well as IBD-related characteristics. Oral health was assessed by the Periodontal Screening Score (PESS), which is a validated instrument to screen for severe periodontitis (indicated by a score ≥5), and by the number of remaining teeth, as tooth loss is the ultimate outcome of untreated periodontitis. Disease activity in patients with ulcerative colitis (UC) was assessed by the Simple Clinical Colitis Index (SCCAI), and in Crohn’s disease (CD) by the Harvey & Bradshaw’s Activity Index (HBI). Disease related disability was assessed by the Inflammatory bowel disease disability index (IBD-DI).

Results: In total, 1,879 IBD patients, encompassing 898 patients (47.8%) with UC and 981 patients with CD (52.2%), completed the questionnaire. In both UC and CD, severe periodontitis was significantly associated with a higher level of current disease activity [OR 1.51 (1.18;1.93); p=0.001] based on SCCAI/HBI, increased IBD disability score [Coef. 3.62 (1.46;5.79); p=0.001], and increased disease activity in the last 12 months (defined as number of episodes of disease activity in the last 12 months) [OR 1.50 (1.20;1.87); p=<0.001]. Tooth loss (<20 remaining teeth) was associated with both an increased disease activity in the last 12 months [OR 1.36 (1.05;1.76); p=0.018] as well as IBD disability score [Coef. 4.15 (1.66; 6.65); p=0.001]. Tooth loss also showed a tendency to be associated with current disease activity (SCCAI/HBI), although this was not significant [OR 1.31 (0.99;1.75); p=0.062]. IBD severity (a composite parameter of history of IBD-related surgery and/or treatment with biological therapy) was neither associated with severe periodontitis [OR 1.17 (0.90;1.54); p=0.241], nor tooth loss [OR 1.30 (0.95;1.78); p=0.100].

Conclusion: In this questionnaire-based study with responses from 1,879 IBD patients from two countries, we found the presence of periodontitis and tooth loss to be closely associated with both increased disease activity and disability in IBD patients. These findings emphasize the need for an increased focus on the oral health of patients with IBD.