影响生物牙根再生的关键因素

The key factors which affect the bio-root regeneration

牙齿缺失是口腔颌面部的常见病,目前临床的修复方式均为义齿等赝复体修复,很难再现天然牙的组织形态和完整功能,随着干细胞及组织工程技术的不断发展,牙再生将成为未来牙齿缺失的治疗方向.牙根是牙齿作为器官行使功能的基础,在咀嚼过程中支持牙冠,承载并传导力,因而牙根再生是实现牙齿功能再生的关键.目前对生物牙根的研究已取得初步成效,但生物牙根再生的成功率仍较低,限制了其转化应用,因此生物牙根要想临床转化应用必须提高生物牙根再生的成功率.研究显示诸多因素影响间充质干细胞成牙分化功能,进而影响生物牙根再生的成功率,包括种子细胞来源、支架材料、生长因子及再生微环境等.生物牙根在颌骨中生长,颌骨的骨髓微环境更倾向于诱导干细胞成骨向分化,而干细胞牙向分化的潜能决定了最终牙再生的效果.因此,如何促进干细胞在颌骨微环境中的牙向分化,抑制骨向分化,是提高生物牙根再生成功率的关键.

The morbidity of tooth missing is the highest one among all the human organ diseases. The present restorations used in clinic, including fixed bridges, removable dentures and implant prosthetics, all exhibit their own defects, and hardly to restore the whole tooth structure and function. With the development of stem cells and tissue engineering, as an alternative, tooth regeneration, aiming at the generation of a structure like nature tooth, will be the therapeutic orientation to restore the lost tooth. The dental root, which supports the crown and occlusal force, is the fundamental part for tooth function. Based on the theory of tissue engineering, bio-roots were successfully generated by using mesenchymal stem cells （MSC） in miniature pigs. But the success rate of bio-root is not too high, is urgent to be improved for future clinic application. MSC mediated bio-root regeneration is depended on the dentinogenic differentiation regulation of MSC. Up to now, many factors affect the directed differentiation of MSC and further for the success rate of bio-root, including seeding cells, scaffold, growth factors and microenvironmental niche, etc. Microenvironmental niche is the key factor for affecting the MSC characteristics and special tissue regeneration. Basically, the bio-root is regenerated in jaw, while the jaw microenvironmental niche is prone to induce MSC for osteogenic differentiation, instead of dentinogenic differentiation. How to improve the dentinogenic differentiation of MSC in jaw microenvironmental niche is the key issue for increasing the success rate of bio-root.