Objective: To investigate the distribution differences of Porphyromonas gingivalis(Pg) FimA genotypes between periodontitis patients with and without type 2 diabetes for a better understanding of the relationship between diabetes and periodontitis.
Methods: Questionnaires and detailed periodontal examinations(6 sites per tooth) were conducted in 80 subjects with moderate-severe chronic periodontitis in the Department of Periodontology, Peking University School and Hospital of Stomatology. There were 40 type 2 diabetic patients and 40 systemicly healthy patients enrolled respectively. The periodontal parameters including plaque index(PLI), probing depth(PD), bleeding index(BI), attachment loss(AL) by 6 sites per tooth and numbers of missing teeth were also recorded. Pooled subgingival plaque samples using pocket method with Whatman No3 filterpaper were collectedat each of the 6 sites from one incisor and one molar. Pg and its FimA genotype distributions were investigated using DNA extrctedfrom plaque samples by PCR.
Results: Diabetic patients had a significantly higher score of PLI[2.35(0.58) vs 1.64(0.76),P<0.05] , while rest of periodontal indexes observed(PD, BI and AL) did not differ significantly between diabetic patients and systemicly healthy controls(P>0.05). The detection rate of Pg did not show statistically significant difference between the two groups(50% vs 60%,P>0.05). However, the proportion of FimA Ⅱ was significantly higher in diabetic group than systemicly healthy group(80% vs 42%,P<0.05).
Conclusions: Type 2 diabetic patients were prone to be infected by highly virulent strains of Pg: FimA ⅡPg.