ObjectivesSince the peptidyl arginine deiminase of Porphyromonas gingivalis is able to citrullinate peptides and proteins, various studies have suggested the species as a possible link between periodontal disease (PD) and rheumatoid arthritis (RA). This systematic review including meta-analysis was aimed to evaluate whether differences in terms of antibody titers against P. gingivalis exist between RA patients and systemically healthy individuals with and without PD.