Prevalence and proportion of P.gingivalis and TM7 in type-2-DM subjects

Diabetes mellitus is an important risk factor for periodontal diseases. Clinically, diabetic subjects have experienced with more probing depth and attachment loss than non-diabetic ones. Differences in prevalence and proportion of relevant microorganisms between the two groups are of interest.

Objective: The aim of this study was to evaluate prevalence and proportion of P.gingivalis and TM7 in Thai type-2-DM and periodontitis patients.

Methods: Volunteers were divided into 4 groups (6 subjects in each group), healthy, periodontitis, type-2-DM and type-2-DM together with periodontitis subjects. After clinical parameters were recorded, subgingival plaque from 89 periodontal pockets (47 sites from depth 1-3mm, 24 sites from 4-6mm and 18 sites from >6mm) were sampled. DNA was prepared by boiling for 10min. Semiquantitative-PCR of the two species together with total bacteria was performed and then amplicons were densitometrically analyzed (BioRad®, Italy). Percentage and prevalence of each organism were statistically calculated.

Results: P.gingivalis counts were significantly different among the four groups (p=0.04), with the highest percentage in the DM-periodontitis one (18.3±28.6%). Levels of P.gingivalis were increased by the depth of periodontal pocket (p=0.002). Of all sites, P.gingivalis was positive 35.8%, especially in the DM-periodontitis group (19.6%). Similarly, among the 4 groups, TM7 was present 16.3% with nearly half of prevalence in the DM-periodontitis group (7.6%). However, there was no significant relation between the numbers of TM7 and clinical parameters.

Conclusions: Data here suggested that P.gingivalis counts may be associated with increased pocket depth and type-2 diabetes. In addition, presence of TM7 may prefer diabetic condition. However, more samples are required to elucidate such association. This work was supported by the grant of Mahidol University, Thailand.