Precise Chronology Of Differentiation Of Developing Human Primary Dentition And Odontogenic Differentiation Of Dental Epithelial Cell

Tooth regeneration using stem cells as a potential source of biological material has already become a research hotspot in tissue engineering recently, and the differentiation of stem cells is the focus research problem. Tooth development process is controlled by many genes and proteins, while its many molecular mechanism is unclear. Therefore, through further defined the molecular mechanism of tooth morphogenesis and analysed the key gene and protein during the process and induced adult stem cell into ameloblast seem to be the most significant problems.In this study, we firstly documented precise differentiation timing of the developing human primary dentition. We systematically examined the expression of odontogenic differentiation markers along with the formation of mineralized tissue in each developing maxillary and mandibular tooth from human embryos with well defined embryonic age. Our results provide an accurate chronology of odontogenic differentiation of the developing human primary dentition, which could be regarded as a standard base for future studies of human tooth development.Secondly the dental epithelial cells were separated from the tooth germ. We had established a relatively perfect system of culture of dental epithelial cells. The cells were grown in keratinocyte serum-free media and characterized by morphology and immunohistochemistry. Our results show the successful culture of d dental epithelial cells, and lay a foundation for use of these cells to further understand ameloblast biology with application to tooth enamel tissue engineering.Finally the present study attempted to examine whether dental epithelial cells can differentiate into ameloblasts and regenerate tooth when combined with dental germ mesenchyme. Bioengineered tooth germs were prepared with these cells and E13.5fetal molar mesenchymal tissues and implanted under kidney capsule for30days. Our results indicated that some oral epithelial cells possess the capability to differentiate into ameloblasts, while the highest rate of dental formation of recombinant is nearly70%. PCR and immunohistochemistry analysis of these cells, we considered that FGF8、PITX2were the most significant factor for the induction.