SUMMARY TITLE: "Effect of endodontic treatment on inflammatory markers, disease activity and periapical healing in rheumatoid arthritis patients with apical periodontitis"

RATIONALE: Chronic inflammation plays a pivotal role in rheumatoid arthritis as subjects present with elevated serum levels of numerous cytokines such as IL-1, IL-6, 1L-12, IL-17, tumour necrosis factor-alpha, RANK and RANK Ligand. Periodontal and pulpal inflammation are two major low grade chronic inflammatory diseases of the oral cavity. Apical periodontitis extends from the chronic inflammatory process that originated in the dental pulp to surround the apex of the tooth. Thus Rheumatoid arthritis and apical periodontitis converge upon common pathway of inflammation. The scientific literature has also shown to provide potential link between endodontic infection and rheumatoid arthritis. The evidence of increased prevalence of apical periodontitis in subjects of rheumatoid arthritis is provided mainly by cross-sectional and case control studies. Interventional studies have been performed in subjects with rheumatoid arthritis and periodontal disease, with results depicting beneficial effect of periodontal therapy in patients of rheumatoid arthritis. To best of our knowledge no interventional study has been performed to assess the healing pattern of apical periodontitis in subjects of rheumatoid arthritis and subsequently effect of endodontic intervention on inflammatory profile and disease burden in the same.

Inclusion Criteria:

• 1. Age of patients 30-65 years 2.Definite diagnosis of Rheumatoid arthritis based on ACR/EULAR 2010 criteria[28] i.e a score of 6 or greater out of 10 from the individual scores in four domains: number and site of involved joints (range 0-5), serological abnormality (range 0-3), elevated acute-phase response (range 0-1) and symptom duration (two levels; range 0-1) 3. The periapical index (PAI) will be used to evaluate the periapical status patients with PAI >or=3 as given by Orstavik[29] will be included 4. Presence of total teeth >/= 12

Exclusion Criteria:

1. Patients with periodontitis, pocket depth and CAL>5mm (stage 3, 4) will be excluded.
2. Pregnancy; lactation & contraceptives
3. Patients with any other systemic disease other than Rheumatoid arthritis i.e Diabetes, HIV, Chronic Liver Disease, Chronic Kidney disease and Cardiovascular disease

5. Conditions known to alter systemic inflammatory markers i.e orthopaedic trauma, surgery and viral infections 6. Patients with BMI >/= 30 7. Medications (during last 3 months) known to affect systemic inflammatory markers (systemic steroids, immunosuppressants, hormone replacement therapy, contraceptives and systemic antibiotics) 8. Smoking

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ender matched healthy control participants to the same gender rheumatoid arthritis individuals will be analyzed.