Exclusion criteria
PD, RA
SYSTEMIC DISEASE
(1) Pregnancy or lactation; (2) any known systemic disease other than RA for groups 1 and 3; (3) previous periodontal treatment (surgical or non-surgical) in last 6 months; (4) antibiotics in the past 3 months; (5) previous intra-articular drug injections; (6) smoking; (7) biological DMARD therapy; (8) abnormal body mass index (more than 29.9 kg/mOne rheumatologist (S.A.) did the rheumatologic examination and synovial fluid sampling and one periodontist (Z.S.) did the periodontal examination and GCF sampling; both examiners were blinded from each other for the rheumatologic, periodontal conditions and study groups. Calibration exercises for probing measurements were performed in five patients before the study, with a 0.82 k value for PD and 0.76 for CAL. Laboratory analysis was conducted by O.S. who was blinded to the study groups.