Abstract：
Replacement teeth develop from the successional dental lamina (SDL). Understanding how SDL transitions from quiescence to initiation is crucial for preserving dental lamina stem cells in the jawbone microenvironment and for complete tooth regeneration. Miniature pigs are good models for studying human tooth replacement because of their similarities to humans. However, the molecular mechanisms and cellular composition that initiate SDL development remain unclear. One possible reason for this is the limitations of the current methods for culturing SDL in vitro, such as the inability to directly observe tooth morphological changes during culture and low tissue viability. This study aimed to improve the in vitro culture method for SDL. Using a McIlwain Tissue Chopper, we obtained mandibular slices containing deciduous canine and SDL of permanent canine. The slices were approximately 500 μm thick and were cultured on a Transwell membrane supported with metal grids over medium. The SDL developed into the bud stage on the second day and entered the cap stage on the fifth day in vitro. The expression of proliferation markers, cell death markers, and key odontogenetic genes in vitro was similar to that observed in vivo. In conclusion, we successfully applied a slice culture system to the SDL of miniature pigs. This slice culture method allowed us to directly visualize SDL initiation and further elucidate the molecular mechanisms underlying the initiation of permanent tooth development.
摘要：
替代牙齿从演替性牙层（SDL）发展而来。了解SDL如何从静止过渡到起始对于在颌骨微环境中保存牙层干细胞和完整的牙齿再生至关重要。小型猪是研究人类牙齿替代的好模型，因为它们与人类相似。然而,启动SDL发育的分子机制和细胞组成尚不清楚.一个可能的原因是目前体外培养SDL的方法的局限性，如培养过程中无法直接观察牙齿形态变化和组织活力低。本研究旨在改进SDL的体外培养方法。用McIlwain组织斩波器,我们获得了含有落叶犬和永久犬SDL的下颌切片。切片为约500μm厚,并在培养基上用金属网格支撑的Transwell膜上培养。SDL在体外第2天发育成芽阶段，第5天进入帽阶段。增殖标志物的表达，细胞死亡标记,关键的牙本质遗传学基因在体外与在体内观察到的相似。总之,我们成功地将切片培养系统应用于小型猪的SDL。这种切片培养方法使我们能够直接可视化SDL起始，并进一步阐明了永久牙齿发育起始的分子机制。
