ABSTRACT
PURPOSE: To explore the correlation between gingipain K (Kgp) and inflammatory reaction of gum in the process of orthodontic treatment, and analyse the role of Kgp in the development of gingivitis during orthodontic treatment. METHODS: Totally 45 orthodontic healthy teenagers were randomly chosen for the study. The subgingival plaques were collected simultaneously before orthodontic treatment and 3 months after treatment. 16S rDNA PCR technique was used to detect Porphyromonas gingivalis (P.g) and Kgp. SPSS17.0 software package was used for statistical analysis. RESULTS: The detection rate of Kgp was 35.71% before orthodontic treatment and 67.86% after treatment. Positive correlation (P<0.05) was observed between Kgp and gingival inflammation. CONCLUSIONS: Fixed orthodontic appliances cause plaque accumulation, accordingly slight gingiva inflammation and the increament of P.gingivalis in the early stage.