The Study Of Correlation Between Suspected Periodontal Pathogens And Chronic Periodontitis By 16S RRNA Real-time PCR

Purposes: Through detection and quantification of Porphyromonas gingivalis (Pg), Tannerella forsythus (Tf) and Treponema denticola (Td) in subgingival plaque by 16S rRNA DNA TaqMan real-time fluorescence quantitative PCR, the correlation between the three factors was studied as follows: the changes of the three bacteria in chronic periodontitis before and after initial periodontal therapy, and the relationship of bacteria detection rate, quantity and periodontal clinical indicators.Methods: Subgingival plaque samples were collected by standard paper tip from 50 sites from 12 patients with chronic periodontitis, and then recorded the clinical indicators. Four weeks after initial periodontal therapy, samples were collected and the clinical indicators were recorded again. The three target genes of the standard plasmid were cloned respectively to establish a quantitative assay; The TaqMan real-time fluorescence quantitative PCR was chosen to detect Pg, Tf and Td in subgingival plaque.Results: The detection rates of Pg, Tf in chronic periodontitis were 84%, 98%, after initial periodontal therapy they were decreased as 48%, 48%; the detection rate of Td is 84%, then after treatment it was 96%; There were no statistically significant difference the detection rates before and after treatment. The quantity of bacteria is converted by the logarithmic, Pg and Tf have statistically significant difference between before and after initial therapy, but Td hasn't. The clinical indicators of probing depth (PD), plaque index (PLI), sulcus bleeding index (SBI), clinical attachment loss (CAL) improved significantly (P<0.05). The bacteria in chronic periodontitis were related to PD and BI; three bacteria were related to each other. Conclusions: TaqMan real-time fluorescence quantitative PCR offers a sensitive, efficient and reliable approach to quantify; the volumes of Pg, Tf and Td are related to PD and BI. After initial periodontal therapy, the clinical indicators improve significantly, along with the change of the volume of Pg, Tf and Td in subgingival plaque.