Abstract: Objective: To investigate the expression of stem cell factor (SCF) on fibroblasts (FBs), endothelial cells (ECs) and macrophages (m) in the periapical tissues of human chronic periapical diseases, and to analyze the role of CD334-SCF double positive FBs, CD31-SCF double positive ECs and CD14-SCF double positive m in the pathogenesis of periapical diseases. Methods: A total of 50 specimens, including healthy control (n=20), periapical cyst (n=15), and periapical granuloma (n=15) were involved. The tissue samples were fixed in formalin, embedded in paraffin, and then stained with hematoxylin and eosin for histopathology. Double immunofluorescence was employed to identity CD334-SCF double positive FBs, CD31-SCF double positive ECs and CD14-SCF double positive m . Results: Compared with healthy control, the densities of CD334-SCF double positive FBs, CD31-SCF double positive ECs and CD14-SCF double positive m were significantly higher (P <0.01). The densities of CD334-SCF double positive FBs and CD31-SCF double positive ECs in periapical cyst group had no significant difference with those in periapical granuloma group. The densities of CD14-SCF double positive m in periapical granuloma group were significantly higher than those in periapical cyst group (P＜0.01). Conclusion: The results suggest that the CD334-SCF double positive FBs, CD31-SCF double positive ECs and CD14-SCF double positive m may play important roles in the initiation, development and pathogenesis of the human chronic periapical diseases.

Key words: Chronic periapical diseases, Stem cell factor , Fibroblasts , Endothelial cells, Macrophages