title: [Detection of Porphyromonas gingivalis in the subgingival plaque of puberty gingivitis].
abstract: OBJECTIVE
  To detect the presence of Porphyromonas gingivalis (Pg) in the subgingival plaque of puberty gingivitis and to investigate its relationship with gingival health.
  
  
  METHODS
  The subjects of 14- to 17-year-old children in this study were divided into two groups, puberty gingivitis group and gingival healthy group, with 36 in each group. Periodontal parameters were recorded. A 16S rRNA-based polymerase chain reaction (PCR) detection method was used to determine the prevalence of Pg in the subgingival plaque samples. The AVG of positive band in the agarose gel electrophoresis was analyzed using the automatic gel documentation and image analyzer software. The relative quantity of Pg was determined. The data were statistically analyzed using SPSS11.5 software. Chi-square test was used to compare the prevalence of Pg in the two groups. Wilcoxon rank sum test was used to analyze the relative quantity of Pg and the severity between the Pg-positive and the Pg-negative subjects. Spearman correlation analysis was used to test the relationship between the relative quantity of Pg and periodontal parameters.
  
  
  RESULTS
  The prevalence of Pg in the puberty gingivitis group and gingival healthy group was 47.22% and 25.00%, respectively (P<0.05). The relative quantity of Pg in the two groups was 48.02% and 21.46%, respectively(P<0.01). In all the Pg-positive subjects of puberty gingivitis group, there was positive correlation between the relative quantity of Pg and the gingival index (GI),sulcus bleeding index (SBI) and the probe depth (PD). There were statistically differences between them. The GI and SBI index of the Pg-positive subjects were statistically higher than that of the Pg-negative subjects in the puberty gingivitis group (P<0.01).
  
  
  CONCLUSIONS
  Periodontal pathogens can colonize in the subgingival plaque in puberty subjects and colonization of Pg is relevant to the status of gingival health.
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, China Medical University, Shenyang 110002, Liaoning Province, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.forename: Xue-bin
authors.initials: XB
authors.lastname: Xu
authors.forename: Ya-ping
authors.initials: YP
authors.lastname: Pan
authors.forename: Yan-jun
authors.initials: YJ
authors.lastname: Li
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D003773:Dental Plaque / Q000382:microbiology*; D005881:Gingiva / Q000382:microbiology*; D005891:Gingivitis / Q000382:microbiology; D006801:Humans; D016966:Porphyromonas gingivalis / Q000302:isolation & purification*