Objective The aim of the present study was to investigate PG0717 gene of Porphyromonas gingivalis （P.gingivalis） in subgingival plaque of the chronic periodontitis patients and periodontal healthy subjects, and to find out the relationship of detection rate of PG0717 and periodontal clinical parameters. Methods A total of 540 subgingival plaque samples were collected from 180 subjects including chronic periodontitis（CP） patients（n=90） and periodontal healthy individuals（n =90）. The periodontal clinical parameters including probing depth（PD）, clinical attachment loss（CAL）, and bleeding on probing（BOP） were estimated by Florida probe. The extracted DNA samples of P.gingivalis positive was amplified with the sequence specific primers designed to obtain the PG0717 gene. Results In subgingival plaque of P.gingivalis positive, the detection rate of PG0717 in CP group was significantly higher than that in periodontal healthy subjects（56.22% versus 41.27%, 掊2=4.50, P＜0.05）. The detection rate of PG0717 in CP group showed the increasing tendency in accordance with the depth of PD and CAL. A higher detection rate of PG0717 was observed in the sites of BOP positive than that in BOP negative（57.73% versus 14.29%, 掊2=42.01, P＜0.01）. Conclusion The findings suggest that the PG0717 gene may influence the virulence of P.gingivalis.
