Pagavino G, Pace R, Pierleoni P
Istituto di Odonto-Gnato-Stomatologia, Università degli Studi di Firenze.
Minerva Stomatol. 1991 Jul-Aug;40(7-8):455-65.
Many researches agree in maintaining that all the membraneous structure visible in the most external parts of the dental tubules must be considered not ad cytoplasmatic membranes of the odontoblastic processes but as an extracellular organic matrix which in certain conditions may appear detached from the internal wall of the tubule and simulated a superimposable aspect like that of an odontoblastic extension. The aim of this study was to examine at the SEM the state of this organic component in normal conditions and after demineralization with citric acid. Therefore the entire teeth of young people were fixed in formalin and dissected by fracturing. Some of the samples were demineralized with a citric acid solution. All the samples were dehydrated and metallized for the observation at SEM. Demineralization made the peritubular dentine disappear and expose inside every tubule a sheet-like structure which extended all along the tubules. The samples which were not demineralized did not demonstrate a similar structure because of their tight adhesion to the internal wall surface. This kind of formation which other researchers calls "lamina limitans" because of its high content of glycosaminoglycans might be a key factor in controlling the formation of peritubular dentine and tubular sclerosis and it will surely lead to further interesting research.
许多研究一致认为，在牙本质小管最外层可见的所有膜状结构不应被视为成牙本质细胞突起的细胞质膜，而应被视为一种细胞外有机基质，在某些情况下，它可能会从牙本质小管的内壁分离，并呈现出与成牙本质细胞延伸部分相似的叠加外观。本研究的目的是通过扫描电子显微镜（SEM）检查这种有机成分在正常条件下以及用柠檬酸脱矿后的状态。因此，将年轻人的整颗牙齿用福尔马林固定，通过折断进行解剖。部分样本用柠檬酸溶液脱矿。所有样本均进行脱水和金属化处理，以便在扫描电子显微镜下观察。脱矿使管周牙本质消失，并在每个牙本质小管内部暴露出一种沿小管全长延伸的片状结构。未脱矿的样本由于与内壁表面紧密粘连，未显示出类似结构。这种其他研究人员因其高含量的糖胺聚糖而称为“限制板”的结构可能是控制管周牙本质形成和牙本质小管硬化的关键因素，并且肯定会引发进一步有趣的研究。
