Abstract Objective : To confirm the role of a new drug-"Gu Chisan" in the treatment of adult periodontitis (AP). Methods : This study investigated 130 AP patients. In which, 100 cases constituted the experimental group and 30 cases were control group. Two weeks after basic periodontal treatment, the AP patients began to use the drug, twice a day, for 30 days. The clinical parameters were recorded at study 0 day, 30day and 90day. At the same time, investigated the side effects of Gu Chisan in 20 AP patients. Results: The use of Gu Chisan for 30 days, effected improvement in the extent of tooth mobility (TM) and in the bite force (BF). In the experimental group the results were significantly greater than in the control group (P<0.001), and these results maintained at 90 days. 30 days after treatment, the BF in experimental group was higher 2.26 Kg/tooth than in the control group. 60 days after discontinuation of drug therapy, the BF in experimental group was still higher 1.02 Kg/tooth than in the control group. During the study, Gu Chisan had no significant side effects to the heart、liver、kidney and blood system; and there were no visible changes on mucosal membrane. Conslusion: Gu Chisan was a safe and effective new drug to treat adult periodontitis.

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