The impact of different states of type 2 diabetes when stratified by baseline HbA1c on the periodontal outcomes of non‐surgical periodontal treatment: A systematic review and network meta‐analysis

Background Type 2 diabetes mellitus (T2DM) has been considered by many studies to have a bidirectional relationship with periodontitis. This systematic review and network meta‐analysis aimed to investigate the impact of different states of T2DM when stratified by baseline HbA1c on the clinical outcomes of non‐surgical periodontal treatment (NSPT). Methods This study followed the Preferred Reporting Items for Meta‐Analyses (PRISMA) guidelines and involved an electronic literature search (from inception to the 2nd of January 2023). The study included at least two groups of patients: chronic periodontitis only (No‐DM) or periodontitis and well‐controlled/poorly controlled type 2 diabetes mellitus (WC/PC‐T2DM). Clinical outcomes included probing depth (PD) reduction, bleeding on probing reduction, and clinical attachment level (CAL) gain. Direct and indirect comparisons between groups were assessed by network meta‐analysis, thus allowing us to establish a treatment ranking. Results Ten prospective cohort studies (11 data sets) were included for qualitative analysis and network meta‐analysis. The data included in this study had high consistency; in addition, a funnel plot and Egger's test showed that the articles had low publication bias. Network meta‐analysis showed that the effect of NSPT in the No‐DM group was significantly better than the WC‐T2DM group [weighted mean difference (WMD) = 0.09, 95% confidence interval (CI) (0.01, 0.18)] and the PC‐T2DM group [WMD = 0.09, 95% CI (0.01, 0.18)] in terms of CAL gain and better than the PC‐T2DM group [WMD = 0.15, 95% CI (0.02, 0.28)] in terms of PD reduction. According to the surface under the cumulative ranking value, the No‐DM group had the highest probability of achieving the best outcome following NSPT. Conclusions Collectively, our analyses show that T2DM exerts significant effects on the outcomes of NSPT.