“…Chronic periodontitis is a complex condition outlined by chronic inflammation and the subsequent damage of soft collagen-rich tissues progressing to periodontal ligament and alveolar bone loss as well as a gradual increase in tooth mobility [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. It is typically initiated by an infection with oral anaerobic bacteria followed by inflammatory and immune response in the gingival and periodontal microenvironment [ 1 , 2 , 3 ]. Autoantigens generated during citrullination induced by peptidylarginine-deaminase enzyme produced by Porphyromonas gingivalis (P. gingivalis), the keystone pathogen in the oral microbial biofilm, break the immune tolerance with induction of anti-citrullinated protein antibodies (ACPA) and promote chronic inflammatory response in both periodontal and synovial/articular tissues [ 1 , 3 , 4 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”