Morphology of Malassez's epithelial rest-like cells in the cementum: transmission electron microscopy, immunohistochemical, and TdT-mediated dUTP-biotin nick end labeling studies.
Morphology of Malassez's epithelial rest-like cells in the cementum: transmission electron microscopy, immunohistochemical, and TdT-mediated dUTP-biotin nick end labeling studies.
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DOI：
10.1111/j.1600-0765.2006.00871.x
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发表时间：
2006-08
影响因子：
3.5
通讯作者：
M. Suzuki;K. Matsuzaka;S. Yamada;M. Shimono;Y. Abiko;T. Inoue
中科院分区：
文献类型：
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作者：
M. Suzuki;K. Matsuzaka;S. Yamada;M. Shimono;Y. Abiko;T. Inoue
背景与目的众所周知，在牙根形成过程中，上皮岛嵌入牙骨质，但这一过程的细节尚不清楚。本研究的目的是研究牙骨质马拉塞氏上皮静止细胞在猪体内牙根形成过程中的动态特性。材料与方法选用6月龄猪第一磨牙。标本在石蜡包埋前进行脱钙处理。使用tdt介导的dutp -生物素缺口末端标记（TUNEL）、免疫组织化学和超微结构技术对石蜡切片进行研究。结果Malassez的上皮休息细胞位于牙周韧带顶端三分之一的根面附近，在牙周膜中有时观察到被明显的椎板包围的上皮团簇。仅在牙骨质中检测到tunel阳性细胞。牙周韧带的马拉塞氏上皮休息细胞完全被基底膜包围，而牙骨质中的上皮团簇只是间歇性地被基底膜包围。骨水泥上层的细胞角蛋白阳性细胞通过骨水泥细胞和桥粒样结构直接连接。而角蛋白阳性的骨水泥基质细胞中细胞器较少，骨水泥基质沉积在细胞内。结论碎片化的Hertwig根鞘大部分留在牙周韧带内，部分连接成骨水泥细胞的细胞嵌入到牙骨质中并发生凋亡。
BACKGROUND AND OBJECTIVE It is known that epithelial islands are embedded in the cementum during tooth root formation, but details of this process remain unknown. The purpose of this study was to investigate the dynamic characteristics of Malassez's epithelial rest cells in the cementum during tooth root formation in pigs in vivo. MATERIAL AND METHODS The first molars of 6-mo-old pigs were used in this study. Specimens were decalcified before being embedded in paraffin. Paraffin sections were investigated using TdT-mediated dUTP-biotin nick end labeling (TUNEL), immunohistochemical, and ultrastructural techniques. RESULTS Malassez's epithelial rest cells were located close to the root surface at the apical one-third of the periodontal ligament, and epithelial clusters surrounded by distinct lamina cementia were sometimes observed in the cementum. TUNEL-positive cells were detected only in the cementum. Malassez's epithelial rest cells in the periodontal ligament were completely surrounded by basement membranes, but epithelial clusters in the cementum were only intermittently surrounded by such membranes. Cytokeratin-positive cells in the superstratum of the cementum were directly connected by cementocytes and by desmosome-like structures. However, organelles were scarce in the cytokeratin-positive cells in the substratum of the cementum, and the matrix of the cementum was deposited in the cells. CONCLUSION These results suggest that the majority of the fragmented Hertwig's root sheath remains in the periodontal ligament and that some cells, which are connected to cementoblasts, are embedded in the cementum and progress to apoptosis.