Backgrounds: To date, there is still no consensus about the clinical efficacy of non-surgical periodontal therapy in rheumatoid arthritis (RA) patients with periodontitis. Therefore, the overall aim of this study was to summarize available data regarding the clinical efficacy of scaling and root planing (SRP) in patients with RA and periodontitis compared to patients with periodontitis alone.Methods: A meta-analysis of existing randomized controlled clinical trials (RCTs) was conducted. The

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... ible RCTs were selected through Embase, PubMed and Cochrane Central Register of Controlled Trials and manual retrieval from the earliest records to March 15, 2020 to extract data. The overall effect size of plaque index (PI), gingival index (GI), attachment loss (AL), probing depth (PD) and bleeding on probing (BOP) were calculated by either a fixed or random-effect model, and subgroup analyses were conducted according to the different time points of follow-up. Cochrane Collaboration's tool was responsible for the evaluation of the literature quality and the inter-study heterogeneity was evaluated by Q test and I2 statistic. The authors applied sensitivity analysis for results with heterogeneity. Publication bias was determined by Begg's test, Egger's test and the trim-and-fill method.Results: Eight RCTs eventually met the inclusion criteria for the study. The overall outcomes concerned PI, GI, PD, Al and BOP were 0.42(95% CI 0.02, 0.81), 0.03(95% CI -0.03, 0.10),-0.06mm (95% CI -0.18, 0.06), 0.16mm (95% CI-0.03, 0.36) and 4.15(95% CI -0.26, 8.55), respectively. In subgroup analysis, a larger BOP reduction at 3 months, PI and AL reduction at 6 months were observed in patients with RA and periodontitis group. The results of sensitivity analyses had no significant effect. No evidence of potential publication bias was tested.Conclusions: The authors conclude that SRP is equally effective in patients with periodontitis and RA than in periodontitis ones. This result suggests RA does not affect the clinical efficacy of non-surgical periodontal therapy.