Effect of subgingival periodontal therapy on glycaemic control in type 2 diabetes patients: Meta-analysis and meta-regression of 6-month follow-up randomized clinical trials.

BACKGROUND

Periodontitis worsens the hyperglycaemia in patients with type 2 diabetes mellitus (T2DM). Subgingival instrumentation, with or without surgical access, is the gold-standard treatment for periodontitis. The aim was to summarize the evidence on the effect of subgingival instrumentation (with or without open flap) on the reduction of glycosylated haemoglobin (HbA1c).

METHODS

Nine electronic databases were searched up to 15 February 2023. Twelve randomized controlled trials with at least 6 months of follow-up were included. Studies using systemic or local-delivery antimicrobial therapies were excluded. Meta-analyses were performed using the random-effects model. The sources of heterogeneity were assessed by applying linear meta-regression. Risk of bias was assessed by RoB 2, and certainty of evidence by GRADE.

RESULTS

Eleven studies were included in the quantitative analyses (1374 patients). Subgingival instrumentation resulted in 0.29% lower HbA1c (95% confidence interval: 0.10-0.47; p = .03) compared with non-active treatment.

DISCUSSION: None of the 12 studies were assessed as having low risk of bias. The percentage of females and the time of diabetes diagnosis significantly explained the high level of heterogeneity. Subgingival periodontal therapy results in a significant and clinically relevant improvement in glycaemic control over 6 months in patients with T2DM and periodontitis. The grade of evidence was moderate.