Abstract: Objective: To observe the changes of serum IL-18(interleukin18) and sTREM-1(striggering receptor1 expressedon myeloid cells, TREM-1) levels before and after the foundation treatment in rats with periodontitis and explore the relationship between serum IL-18, sTREM-1 levels and response to treatment. Methods: 30 healthy 2 -month-old male Wistar rats were randomly divided into three groups (n=10). The rats with no other processing as the normal controls (Group A). The second premolars of group B and group C were ligated with silk, fed with a periodontitis recipe. After the success of modeling, we removed the silk of C group and then gave basic treatment. After two weeks, abdominal aortic blood and rats were killed, the level of IL-18 and sTREM-1 in serum were measured by ELISA. Results: In untreated periodontitis group the level of IL-18 and sTREM-1 in serum were significantly higher than the control group and the treatment of periodontitis -based group (P<0.05) and the level of IL-18 and sTREM-1 in serum of the treatment of periodontitis-based group was higher than the control group. Conclusion: The level of IL-18 and sTREM-1 in serum significantly increased in periodontitis groups, and obviously reduced after basic treatment. This indicated that the IL-18 and sTREM-1 levels could provide guidance for the diagnosis and prognosis of periodontitis, provide accurate and useful information for clinical workers, also could provide new therapeutic targets for clinical treatment.

Key words: Rat periodontitis , IL-18 , sTREM-1