Effectiveness of periodontal treatment to improve glycemic control: an umbrella review

Aim The aim of the present umbrella review was to systematically assess existing evidence on the effect of non-surgical periodontal therapy, both per se' and with adjuvants, on glycemic control in patients with type 2 diabetes and periodontitis and to combine quantitative data with a meta-analysis. Materials and methods A detailed study protocol was registered on PROSPERO (CRD42021222279). Four electronic databases (Medline via Pubmed, EMBASE, Cochrane Database of Systematic Reviews and Scielo) were searched independently and in duplicate to identify potentially eligible systematic reviews up to March 2022. Two pre-calibrated independent reviewers performed study selection, data extraction and quality assessment with two checklists (AMSTAR 2 and PRISMA). Moreover, general characteristics of primary studies included in each systematic review were abstracted, and JADAD scale was used to assess the risk of bias for included randomized controlled trials. Data from the individual studies included in each meta-analysis were analyzed, using both fixed and random effect model. The statistical heterogeneity was calculated using the Q test and the I-2 index. The publication bias was evaluated using a funnel plot and Egger's linear regression method. Results Sixteen systematic reviews, published between 2010 and 2021, were included for qualitative synthesis. From these systematic reviews, a total of 27 studies were included in the meta-analysis: all of them were randomized clinical trials, except 1 controlled clinical study. A statistically significant mean difference of - 0.49% and of - 0.38% HbA1c reductions was seen respectively at 3- and 6-month post-treatment, favoring the treatment group (non-surgical periodontal therapy alone) compared to the control group (no treatment). The effect of periodontal treatment with the adjunctive use of antibiotics or laser on the glycemic control was not statistically significant compared to non-surgical periodontal therapy alone. Conclusions The findings of the present study, within its limitations, indicated that non-surgical treatment of periodontitis is an efficacious therapy for improving the glycemic control in type 2 diabetes mellitus patients, both at 3- and 6-month follow-up.