<b>Conclusions</b>: This study shows that non-surgical periodontal therapy (NSPT) is followed by longitudinal changes in IRS2 and SOD1 expression at the mRNA and protein levels in individuals with T2DM+P (poorly/well controlled) and periodontitis, reinforcing the clinical relevance of periodontal treatment in the systemic context of T2DM. Here, IRS2 is linked to type 2 diabetes mellitus.