Research on Dental Pulp Stem Cells and Pulpal Healing Process

我们研究了牙齿损伤后牙齿发育和牙髓愈合过程中的细胞动力学，以及牙齿组织中的成体干细胞，得出了以下结论。结论：1.热休克蛋白(HSP)-25蛋白在牙齿发育过程中可能是细胞增殖和细胞终末分化的转换点。我们提出了一个新的概念，即产生各种牙科后代的永恒牙芽是在持续生长的牙齿的顶端形成的，并提出了一个新的术语“顶芽”来表示这种特化的上皮结构。我们阐明了牙髓对CrTmEr：YAG和CaAlAs激光照射的反应。GaAlAs激光可能通过影响成牙本质细胞的分泌活性来诱导三级牙本质的形成。然而，较高的能量可能会对牙髓造成不可逆转的变化，通常会导致牙髓内骨样组织的形成。TRAP和CK阳性细胞的出现可能参与了牙髓骨组织的诱导形成。此外，缺乏合适的含氧液对成牙本质细胞系细胞的存活具有决定性作用，而手术中和/或手术后的咬合力使这些细胞的命运恶化。我们使用自体牙齿移植到舌下区的实验研究支持了成牙本质细胞和成骨细胞系细胞存在于牙髓中的观点。老化的牙髓组织仍然具有防御能力，根据个体牙本质小管和/或成牙本质细胞突起状态的不同，可能会发生各种反应。

We investigated the cell dynamics in the process of tooth development and pulpal healing after tooth injuries and the adult stem cells in the dental tissue, and reached the following conclusion.1. Heat-shock protein (HSP)-25 protein was suggested to act as a switch between cell proliferation and terminal cyto-differentiation during odontogenesis.2. We proposed a new concept that the eternal tooth bud producing various dental progeny is formed at the apical end of continuously growing teeth, and a new term "apical bud" for indicating this specialized epithelial structure.3. We clarified pulpal responses to CrTmEr : YAG and CaAlAs laser irradiation. The GaAlAs laser may induce the formation of tertiary dentin by influencing the secretory activity of odontoblasts. However, higher energies may cause irreversible changes to the pulp, often leading to the formation of an intra-pulpal bone-like tissue.4. The appearance of TRAP-and CK-positive cells may be involved in the induction of bone tissue formation in dental pulp. Furthermore, the lack of proper oxygenated medium is quite decisive for the survival of odontoblast-lineage cells and that the occlusal force during and/or after the operation make the fate of these cells worse.5. Our experimental study using autogenic tooth transplantation into the sublingual region supported the notion that odontoblast-and osteoblast-lineage cells reside in the dental pulp.6. Aged pulp tissue still, possesses the defense capacity, and a variety of reactions could occur depending on the difference in the status of dentinal tubules and/or odontoblast processes in individuals.