Periodontal disease and glycemic control in diabetics.

DATA SOURCES: Medline, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL). This was supplemented by handsearching of the Journal of Clinical Periodontology, Journal of Periodontology, Journal of Dental Research, Journal of Dentistry, Journal of Periodontal Research, International Journal of Periodontics and Restorative Dentistry, Periodontology 2000, Odontology, Clinical Oral Investigations, Annals of Periodontology, Journal of American Dental Association, British Dental Journal, Community Dentistry and Oral Epidemiology, Diabetes, Diabetes Care, Diabetes & Metabolic Syndrome, Diabetes & Metabolism and Annals of Internal Medicine. There were no language restrictions.

STUDY SELECTION: Randomised controlled trials (RCTs) on diabetic patients with periodontal disease that reported glycated haemoglobin (HbA1c) and/or fasting plasma glucose (FPG) modification after treatment, with a minimum of three months follow-up were included. Study quality was assessed independently by two reviewers.

DATA EXTRACTION AND SYNTHESIS: Data extraction was carried out independently by two reviewers. Meta-analysis was carried out to evaluate the effect of non-surgical periodontal treatment on HbA1c and FPG levels. The effect of the adjunctive use of antimicrobials was also assessed.

RESULTS: Fifteen studies were included, five were considered to be at low risk of bias, three at high risk and the remainder at unclear risk. Seven studies (678 patients) contributed to the meta-analysis for HbA1c. At the three-four months follow-up, the weighted mean difference was -0.38% (95% CI -0.23 to -0.53; P < 0.001) and at six months it was -0.31% (95% CI 0.11 to -0.74; P = 0.15), favouring the treatment groups [three studies contributing to meta-analysis]. There was statistically significant heterogeneity for both comparisons. For FPG, five studies presented data for three-four months and two for six months. At the three-four months follow-up, the weighted mean difference was -9.01 mg/dL (95% CI -2.24 to -15.78; P = 0.009) and at six months it was -13.62 mg/dL (95% CI 0.45 to -27.69; P = 0.06).

CONCLUSIONS: Despite the limitations of the present study, it can be concluded that periodontal treatment might be effective in improving metabolic control in terms of reduction of HbA1c and FPG concentrations in patients with diabetes. However, the significance of this improvement is questionable and should be further investigated.