Does periodontal treatment improve glycaemic control in periodontitis patients with diabetes mellitus?

Data Sources: The electronic databases Cochrane Oral Health's Trials Register, Cochrane Central Register of Controlled Trials, MEDLINE Ovid, Embase Ovid, CINAHL EBSCO, LILACS BIREME Virtual Health Library from inception to September 2021, along with trial registers and journals (hand searching) were searched to identify the randomized controlled trials (RCTs).

Study Selection: Two reviewers independently identified and selected RCTs of at least three months' duration, comparing the effectiveness of subgingival instrumentation relative to no active intervention or usual care (oral hygiene instruction, education, or supportive interventions, and/or supragingival scaling) in the reduction of glycated haemoglobin (HbA1c) in periodontitis patients with type 1 or 2 diabetes mellitus.

Data Extraction And Synthesis: Data extraction and risk of bias assessment were performed by two reviewers independently. Data were synthesized quantitatively with meta-analyses using a random-effects model, and pooled outcomes were expressed as mean differences with 95% confidence intervals. In addition, subgroup analysis, heterogeneity assessment, sensitivity analyses, summary of findings, and assessment of the certainty of the evidence were performed.

Results: Out of 3109 identified records, 35 RCTs were included for qualitative synthesis, and amongst them, 33 studies were included for meta-analysis. Meta-analyses showed that periodontal treatment with subgingival instrumentation, compared to usual care or no treatment, led to a mean absolute reduction of 0.43% in HbA1c at 3 to 4 months, 0.30% at six months, and 0.50% at 12 months. The certainty of the evidence was assessed to be moderate.

Conclusions: The authors concluded that periodontitis treatment by subgingival instrumentation improves glycaemic control in diabetic patients. However, there is insufficient evidence about the effect of periodontal treatment on quality of life or diabetic complications.