as the recruitment rate was very low, a futility study was conducted and it was decided to discontinue inclusions

Rheumatoid arthritis and periodontitis are two inflammatory diseases that share many pathophysiological similarities as some inflammatory mediators like TNF-alpha, IL-1, Il-6, Il-17, Il-12 et Il-17, RANK-L, or OPG The most severe or progressive forms of rheumatoid arthritis require in 10-30% of cases, the use of biotherapies such as anti-TNF-alpha, anti CD-20 and anti-lL-6. All these treatments results in, among other things, an increased risk of infection, both viral and bacterial.

These new biotherapies could have an impact on periodontal status

• either by favouring sub gingival colonization of root surfaces by periodontal pathogenic bacteria and initiate periodontitis or exacerbate pre-existing periodontitis,
• or a positive modulation of the host response by inhibiting bone resorption of the alveolar process.

To date, very few studies have been conducted on this subject which is really a translational research, involving several medical specialties.

Inclusion Criteria:

• patient over 18 years presenting a rheumatoid arthritis and for which an anti IL6 biotherapy treatment is prescribed.
• At least 18 permanent teeth in the mouth at least 3 teeth with a healthy periodontal status
• Having expressed their written free and informed consent

Exclusion Criteria:

• Hypersensitivity to any of the following components : tocilizumab, saccharose, polysorbate 80, phosphate disodique dodécahydrate, phosphate monosodique dehydrate
• Severe or active infections
• Systemic Pathology affecting the immune system including Sjögren's syndrome
• Surgery in the previous month
• HIV positive
• Alcoholic
• Toxicoman
• Antibiotic treatment in the last 2 months
• Legally protected patients