Wesselink P R, Beertsen W, Everts V
Calcif Tissue Int. 1986 Jul;39(1):11-21. doi: 10.1007/BF02555735.
In order to study in detail the processes leading to the resorption and ankylosis of teeth after trauma, the effects of cold application on the periodontal tissues were studied in the mouse. Liquid nitrogen was applied locally to the outer surface of the lower jaw which resulted in a freezing of the incisor and its surrounding tissues. The healing processes in the damaged periodontal ligament and the accompanying phenomena of ankylosis and dental root resorption were investigated histologically at both the light and electron microscopic levels. As a result of cold application, the cells in the periodontal ligament were killed. After a few days, the ligament started to be repopulated with cells like fibroblasts and macrophages. From 3 days on, mineral crystallites were deposited along the cementum covering the lingual, mesial, and lateral surfaces of the incisor, finally resulting in a 4-6 micron thick layer. During the period of 7-12 days following cold application, this layer of mineralized material started to be phagocytosed and degraded, presumably by mononuclear cells. Finally, extensive root resorption and some ankylosis between the tooth and the alveolar bone were observed. In the resorbed areas, cells were seen which could not be distinguished from osteoclasts. In some instances, their ruffled border was in close apposition with each of the three mineralized tissues--dentin, cementum, and alveolar bone. It is hypothesized that the deposition and subsequent phagocytosis of mineralized material along the root surface may be an important factor in the initiation of dental root resorption.
为了详细研究外伤后牙齿吸收和强直的过程，在小鼠中研究了冷敷对牙周组织的影响。将液氮局部应用于下颌外表面，导致切牙及其周围组织冻结。在光学和电子显微镜水平上，组织学研究了受损牙周膜的愈合过程以及伴随的强直和牙根吸收现象。由于冷敷，牙周膜中的细胞被杀死。几天后，韧带开始重新填充成纤维细胞和巨噬细胞等细胞。从第3天开始，矿物质微晶沿着覆盖切牙舌侧、近中侧和外侧表面的牙骨质沉积，最终形成4-6微米厚的一层。在冷敷后的7-12天期间，这层矿化物质开始被单核细胞吞噬和降解。最后，观察到广泛的牙根吸收以及牙齿与牙槽骨之间的一些强直。在吸收区域，可见一些与破骨细胞无法区分的细胞。在某些情况下，它们的褶皱边缘与三种矿化组织——牙本质、牙骨质和牙槽骨中的每一种紧密相邻。据推测，矿化物质沿牙根表面的沉积及随后的吞噬作用可能是牙根吸收起始的一个重要因素。
