Sahara N, Okafuji N, Toyoki A, Ashizawa Y, Deguchi T, Suzuki K
Department of Oral Histology, Matsumoto Dental College, Shiojiri, Nagano, Japan.
Acta Anat (Basel). 1993;147(1):24-34. doi: 10.1159/000147477.
In the later stage of exfoliation in human deciduous teeth, odontoclastic resorption takes place at the pulpal surface of the coronal dentin. However, this resorption does not continue until the teeth are shed, and the resorbed pulp chamber wall is usually repaired by cementum-like tissue deposition. In this study, we examined the formation and characteristics of the cementum-like hard tissue on the resorbed dentin surface in the pulp chamber of deciduous teeth prior to shedding. The site and degree of deposition of newly formed cementum-like tissue on the resorbed pulp chamber wall varied from tooth to tooth. Furthermore, they also showed compositional and structural variations. Generally, however, the matrix of the cementum-like tissue was composed of intrinsic collagen fibers, acellular or cellular. There was a tendency for acellular cementum-like tissue to be deposited on small and shallow resorption bays, whereas the cellular type was found on larger and deeper ones. In both cases, the surface of the deposited cementum-like tissue on the resorbed dentin surface usually became flat. However, unlike the cementum repair of resorbed areas on the root surface, no acellular extrinsic fiber cementum-like tissue was found on the resorption pulp chamber wall. Although the role of the repair of the resorbed pulp chamber wall with cementum-like tissue deposition just before shedding is unknown, it might play some role in the retention of deciduous teeth until shedding.
在人类乳牙脱矿的后期，破牙细胞性吸收发生在冠部牙本质的牙髓表面。然而，这种吸收在牙齿脱落之前不会持续进行，并且吸收后的髓腔壁通常会通过类牙骨质组织沉积进行修复。在本研究中，我们检查了乳牙脱落前牙髓腔中吸收的牙本质表面类牙骨质硬组织的形成和特征。新形成的类牙骨质组织在吸收的髓腔壁上的沉积部位和程度因牙而异。此外，它们还表现出成分和结构上的差异。然而，一般来说，类牙骨质组织的基质由固有胶原纤维组成，有无细胞的或有细胞的。无细胞类牙骨质组织倾向于沉积在小而浅的吸收凹处，而细胞型则见于大而深的吸收凹处。在这两种情况下，沉积在吸收牙本质表面的类牙骨质组织表面通常会变平。然而，与根面吸收区域的牙骨质修复不同，在吸收的髓腔壁上未发现无细胞外源性纤维类牙骨质组织。尽管在脱落前用类牙骨质组织沉积修复吸收的髓腔壁的作用尚不清楚，但它可能在乳牙保留至脱落过程中发挥一定作用。
