Ultrastructure of early mineral deposition during hyaline layer formation in rat molars
Ultrastructure of early mineral deposition during hyaline layer formation in rat molars
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DOI：
10.1016/s0003-9969(00)00131-x
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发表时间：
2001-04-01
影响因子：
3
通讯作者：
Arana-Chavez, VE
中科院分区：
文献类型：
--
作者：
Tomazela-Herndl, SA;Arana-Chavez, VE
与根牙本质并列的第一个矿化层，即透明层，是各种牙本质还是牙骨质，甚至是上皮起源的组织，目前还没有共识。一些人认为在脱细胞外纤维牙骨质和牙根本质之间没有中间组织。为了研究透明层的形成和矿化，我们用透射电镜观察了10 ~ 13日龄Wistar大鼠上颌磨牙根发育的早期阶段。除了常规处理的材料外，还检查了未脱矿和未染色的切片，这些切片显示了与牙根牙本质矿化表面接触的细矿物晶体的沉积。透明层的早期矿化发生在内基底膜区域，并持续存在于Hertwig上皮根鞘的内细胞层和外矿化根本质之间。当根鞘开始断裂时，来自正在发育的牙周韧带的胶原原纤维开始插入矿化的透明层，这层宽0.5-0.8微米。随着根鞘破裂的增加，更多的胶原原纤维出现在矿化的透明层中。在较晚期，当透明层完全矿化，AEFC开始形成时，就不能再识别透明层了。因此，在牙周发育的早期阶段，透明层是清晰可见的。随后，它被牙骨质和牙本质的混合所掩盖，因此不可能在大鼠磨牙的形成根中检测到它。2001爱思唯尔科学有限公司版权所有。
There is no consensus on whether the first mineralized layer, the hyaline layer, that is juxtaposed to root dentine is a variety of dentine or cementum or even a tissue of epithelial origin. Some suggest that there is no intermediate tissue between the acellular extrinsic fibre cementum (AEFC) and the root dentine. Here, to study hyaline layer formation and mineralization we examined by transmission electron microscopy the early stages of root development in upper molars from 10 to 13 day old Wistar rats. In addition to conventionally processed material, undemineralized and unstained sections were examined, which showed the deposition of fine mineral crystals in contact with the mineralized surface of root dentine. Early mineralization of the hyaline layer occurred in the region of the inner basement membrane, which persisted between the inner cellular layer of Hertwig's epithelial root sheath and the outer mineralized root dentine. When the root sheath began its fragment, collagen fibrils From the developing periodontal ligament began to insert into the mineralising hyaline layer, which was 0.5-0.8 mum wide. As the fragmentation of the root sheath HERS increased, more collagen fibrils appeared intermingled with the mineralising hyaline layer. In more advanced stages, when the hyaline layer had become fully mineralized and the formation of the AEFC began, the hyaline layer could no longer be identified. Thus, the hyaline layer is clearly discernible at early stages of periodontal development. Subsequently, it is masked by intermingling of cementum and dentine and therefore it is not possible to detect it in the formed roots of rat molars. (C) 2001 Elsevier Science Ltd. All rights reserved.