Quantification of Periodontal Pathogens Cell Counts by Capillary Electrophoresis

•We proposed a simple method to extract the periodontal pathogens from the periodontal pocket.•We researched the relationship between fluorescence intensity and sample concentration.•We quantified the concentration of periodontal pathogens cell counts in the periodontal pocket by capillary electrophoresis for the first time.

Gingivitis is a highly prevalent periodontal disease around the worldwide. Porphyromonas gingivalis (P.g), Treponema denticola (T.d) and Tannerela forsythia (T.f) were considered to be three important periodontal pathogens related to gingivitis, and research shows that the counts of periodontal pathogen cells in the patients before, during, and after fixed orthodontic appliance therapy were quite different. We proposed a simple method to extract the periodontal pathogens from the periodontal pocket in this work and demonstrated a new approach to determine periodontal pathogen level based on capillary electrophoresis (CE). After polymerase chain reaction amplification of P.g (197 bp), T.d (311 bp), and T.f (641 bp), it shows that they can rapidly identified by CE within 5 min. The peak area in the eletropherogram is linearly related to the concentration of P.g, T.d, and T.f, and the correlation coefficients R2 corresponding to them are 0.993, 0.993, and 0.956, respectively. According to this linearly relationship, the estimated concentration of P.g, T.d, and T.f in gingival crevicular fluid from one volunteer was inferred to be about 9.90 × 102, 1.48 × 103, and 9.01 × 102 cells/μl, respectively.