Abstract:

Objective The purpose of this study was to establish an indirect co-culture system of rat apical toot germ-conditioned medium（APTG-CM） and periodontal ligament cells（PDLCs）. Methods PDLCs were isolated and cultured through the method of enzyme-digestion. Vimentin and cytokeratin（CK） were used to demonstrate the cells’ mesenchymal derivation. Co-culture system of APTG-CM and PDLCs for 28 days, osteocalcin（OCN）, collagen typeⅠ （COL Ⅰ） and bone sialoprotein（BSP） were detected in PDLCs by immunocytochemistry. Morphological changes were observed by inverted microscope. With building a transplant by dental tube, periodontal ligament cell sheet and ceramic biologic bone（CBB） in vitro, then, the combinations of dental tube and PDLCs incubated by APTG-CM were implanted subcutaneously into athymic mice for 8 weeks. Results This study demonstrated that cellular cementum-like tissue formed along the dentin surface and CBB, with fibrous tissue adjacent or inserted into CBB in vivo. PDLCs were grown better in the CBB than in dentin tubes. And the vertical fibers can’t embed in the control. Conclusion PDLCs, embedded within this APTG-CM, exhibite several phenotypic characteristics of cementoblast lineages. Thereby it contributes to the main processes of periodontal tissue regeneration with rat APTG-CM.

Key words: apical tooth germ cell, apical tooth germ-conditioned medium, periodontal ligament cell, extracellular matrix, microenvironment