Objective Quantitative analysis the regional specificity and time dependence of Ciclosporin（CsP） on gingival tissue modality of rats. Methods Eighty SPF grade male Wistar rats of 7 weeks old were randomly divided into experimental group and control group, and each group was divided into 4 subgroups according to the duration of treatment（10, 20, 30 and 40 days）. The experimental objects were given intragastric administration of fresh milk including CsP, and the control ones were given intragastric administration of fresh milk the same as the experimental objects. After giving perfusion 4% paraform trans -heart to internal fixation, the specimens were get and made bucco-lingual paraffin sections at lower first molar and made HE staining. The area of buccal and lingual gingival epithelial and connective tissue, the length of the longest rete pegs were measured with the image analysis system. Data were analyzed by two-way analysis of variance of factorial design. Results The rats of the experimental group took place gingival overgrowth, and the rete pegs of gingival epithelium of attached gingiva approach muco-gingival junction were prolonged. The area of buccal and lingual gingival epithelium and connective tissue, the length of buccal longest rete pegs of the experimental group were significantly higher than that of the control group rats（bucca P＜0.01, lingua 0.01＜P＜0.05）. The length of lingual longest rete pegs of the experimental group were no difference than that of the control group rats. The area of buccal and lingual gingival epithelial, connective tissue, the length of longest rete pegs among experimental groups were no difference. Conclusion CsP may have the regional specificity on the rats′ gingival epithelium of buccal attached gingiva approach muco-gingival junction, but the effect of CsP on the rats′ gingiva was no time dependence.
