Long-term effect of non-surgical periodontal treatment on glycaemic control in patients with diabetes with periodontitis: a systematic review and meta-analysis protocol

INTRODUCTION: Non-surgical periodontal therapy consisting of scaling and root planning has been shown to be effective in the improvement of glycaemic control in patients with diabetes with periodontitis for up to 3 months. However, questions remain about this beneficial effect over a longer period of time. This systematic review and meta-analysis aims to determine the long-term effect (at least 6 months from the therapy) of non-surgical periodontal therapy with or without adjuvant on glycaemic control of patients with diabetes with periodontitis. METHODS AND ANALYSIS: This systematic review will include randomised control trials with a follow-up period of at least 6 months after initial therapy, with measurement of glycated haemoglobin as the primary endpoint. A literature search will be conducted in MEDLINE, CENTRAL, EMBASE, CINAHL, The Cochrane Oral Health Group Trials Register, and the US National Institutes of Health Trials Registry: ClinicalTrials.gov, from inception to 30 June 2020. Selection of studies, data extraction and bias assessment will be conducted independently by two reviewers. A DerSimonian-Laird random-effect meta-analysis will be conducted to pool studies deemed to be homogeneous. A subgroup analysis will be conducted in case of substantial heterogeneity. Egger’s test and observation of the funnel plot will be used to assess publication bias. The statistical analysis will be done using R V.4.0.0 software. ETHICS AND DISSEMINATION: Since primary data are not collected, ethical approval is not required. The final report will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42020192635.