Periodontal treatment significantly decreased the values of periodontal parameters, including the plaque control record, bleeding on probing, probing depth, clinical attachment level, and percentage of patients with severe periodontitis (P < 0.001 for all parameters), as well as the DAS28-CRP and percentage of patients with moderate RA activities (P = 0.02 and P = 0.04) (Table 3). This evidence concerns the gene CRP and periodontitis.