Comparative analysis of subgingival microbiota between individuals with chronic periodontitis affected or not by type 2 diabetes mellitus

Background & Aim: The aim of this study was to compare the prevalence and bacterial load of six main periodontal pathogens among chronic periodontitis patients with or without type 2 diabetes mellitus. Methods: After selecting 20 diabetic patients (test group), a retrospective trial has been developed with a group ratio 1:1, using as matching variable the extension and severity of periodontal damage. Data were obtained from the Dental Clinic database of the Bologna University. The microbiological data were recorded during the first visit and obtained by means of a quantitative real‐time PCR. The bacterial load of each species, the total bacterial load (tbl) of the single periodontal site, and the percentage of pathogens compared to the total load were analyzed. The bacterial pathogens examined were: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis (Pg), Prevotella intermedia, Treponema denticola (Td), Fusobacterium nucleatum and Tannerella forsythia (Tf). The study protocol was previously approved by the Bologna‐Imola Ethics Committee. Results: The 2 groups resulted balanced in terms of demographic and clinical parameters, except for suppuration. The diabetic patients were 9 Female and 11 Male with a mean age of 56.5 ± 9 years while nondiabetic patients (10 female, 10 male) had a mean age of 49.5 ± 14 years. In the microbiological test sites (4 for each patient) the mean probing pocket depth was 6.33 ± 1.62 mm in diabetic patients and 6.42 ± 1.77 mm in nondiabetic patients. All diabetics were subjected to a metabolic control regime (metformin, insulin and/or diet control). Table show that diabetic patients had significantly greater amount of TBL, red complex (Pg, Td and Tf) and Fn (p < 0.05). Comparing to the TBL, only Tf maintained its prevalence in diabetic patients (p = 0.0001). Single‐species loads and total bacterial loads of the two study samples. DM2 NDM p Pg 3.1 × 104 1.7 × 104 0.031 Td 7.8 × 104 4.3 × 104 0.030 Tf 1.9 × 104 3.2 × 103 0.0001 Fn 1.4 × 104 7.6 × 103 0.392 TBL 2.9 × 106 1.8 × 106 0.001 Conclusion: This retrospective study supports the hypothesis that microbiological differences exist between periodontal subjects affected and not by diabetes mellitus.