The effect of periodontal therapy on glycemic control and fasting plasma glucose level in type 2 diabetic patients: systematic review and meta-analysis

Background: Diabetic mellitus and periodontal disease have bilateral associations. However, there is a dilemma on the effect of periodontal therapy on glycemic control and/or fasting plasma glucose level in type 2 diabetic patients with periodontitis. Therefore, this review aimed to assess the effectiveness of periodontal therapy versus no periodontal therapy on glycated hemoglobin (HbA1c) and fasting plasma glucose level in type 2 diabetic patients. Methods: Article searching was done using four databases (MEDLINE, Cochrane library (CENTRAL), EMBASE and CINAHL) and a manual search (until December 2015). We included randomized controlled trials testing the effectiveness of periodontal therapy on glycated hemoglobin and fasting plasma glucose level in patients with type 2 Diabetes mellitus with periodontal disease. Studies published in English between 2005 and 2015 were included. Risk of bias was assessed regarding randomization, allocation sequence concealment, blinding, incomplete outcome data, selective outcome reporting, and other biases. Results: After the article selection process, seven Randomized controlled trials involving 940 participants with a primary outcome of change in glycated hemoglobin and/or fasting plasma glucose and having a minimum of 3 months follow-up were included. There was a reduction of glycated hemoglobin 0.48(95 % CI: 0.18-0.78) after 3 months follow-up and 0.53 (95 % CI: 0.24-0.81) at the end of the intervention period. There was also a significant reduction of fasting plasma glucose level, 8.95 mg/dl (95 % CI: 4.30-13.61) in the intervention group after the end of the intervention. The pooled analysis showed that patients with adjunctive antibiotic therapy and mouth wash had effect size of 0.51(0.03, 1.00, p = 0.04) and it was 0.53 (95 % CI: 0.19, 0.87; p = 0.002) in patients without adjunctive therapy. The publication bias of the studies was 0.066 according to Egger's test. Conclusion: In this systematic review and meta-analysis, there is a significant reduction of Glycated hemoglobin and Fasting plasma glucose level on type 2 diabetic and periodontal patients with non-surgical periodontal therapy.