Effect of non-surgical periodontal treatment on glycemic control of patients with diabetes: a meta-analysis of randomized controlled trials

OBJECTIVE: The present study aimed at investigating whether non-surgical periodontal treatment can reduce the Haemoglobin A1c (HbA1c) % level in type 2 diabetic patients. METHODS: A search of the literature on English publications was performed in Cochrane Central, Medline, ISI Web of Knowledge and EMBASE (until 06 February 2014). An RCT was selected if the subject was type 2 diabetic patients diagnosed with chronic periodontitis, and compared HbA1c% change after non-surgical periodontal treatment alone for at least three months of the study duration. Weighted mean difference for pooled data and large sample size strata were calculated. Heterogeneity and publication bias were explored. RESULTS: After the study selection process, only 9 RCTs were suitable. Compared to the control group, the pooled analysis (n=1082) showed −0.27 % (95 % CI:-0.46 % to −0.07 %, p= 0.007) absolute difference in HbA1c % with treatment while studies with sufficient sample size had HbA1c % change of −0.014 % (95 % CI:-0.18 % to 0.16 %, p= 0.87). Publication bias was marginally significant with Egger’s teat (p=0.045) but not with Begg’s test (p=0.72). CONCLUSION: The moderate reduction in HbA1c after the non-surgical therapy in patients with type 2 diabetes is consistent with previous systematic reviews. However, more large scale and high-quality RCTs are necessitated to confirm these results. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-015-0810-2) contains supplementary material, which is available to authorized users.