Objective To investigate the expression of interleukin-10（IL-10） mRNA in gingival tissue of active and stable stage in patients with adult periodontitis. Methods 12 patients with acute abscesses of the periodontium, 12 patients after periodontal initial treatment and 6 periodontal healthy patients having extraction of impacted wisdom tooth were randomly divided into group A（active stage group）, group B（stable stage group） and the control group. Biopsies of gingival tissues were collected from every subject of three groups. Technique of in situ hybridization was applied to observe the expression of IL-10 mRNA in the biopsies from three groups semi-quantitatively. Results IL-10 mRNA was positively expressed in lymphocytes, macrophages and fibroblasts. The quantity of IL-10 mRNA of group A was the lowest in the three groups and was significantly lower than that of control group and group B respectively（P＜0.01）. The quantity of IL-10 mRNA of group B was the highest in the three groups and was significantly higher compared with the control group and group A（P＜0.01）. Conclusion The quantities of IL-10 mRNA expression are closely related with various clinical states of periodontitis.
