Embedment of Sharpey's fibers in human cellular cementum.

本研究通过光镜和电镜观察了人类前磨牙的细胞牙骨质，以阐明Sharpey纤维是如何被固有纤维嵌入的。扫描电镜采用koh -胶原酶法去除除细胞外的元素。在Sharpey纤维致密的地方，成胶细胞有环绕主纤维的翅膀状突起。在面向骨骨质一侧，翼状突起被分割成与骨骨质表面平行的指状突起。在Sharpey纤维少或不存在的地方，成水泥细胞只有少量或没有翼状突起，但在面向水泥的一侧有手指状突起。主要结果表明：成水泥细胞分为两种。一种是指状突与翅膀状突相联系，并从指状突分泌固有纤维，以结合主要纤维。第二种是指状突起，与翅状突起无关，这种类型是指状突起分泌固有纤维来调节骨质厚度。在大鼠脱细胞骨水泥中，骨水泥形成细胞具有环绕主要纤维的翼状突起。指状突向骨质方向延伸。指状突起的排列可能导致不含内在纤维的脱细胞骨质的形成。

This study observed cellular cementum in human premolars by light and electron microscopy to elucidate how Sharpey's fibers are embedded by the intrinsic fibers. For scanning electron microscopy, KOH-collagenase method was applied to remove elements other than cells.Where Sharpey's fibers were dense, cementoblasts had wing-like processes encircling the principal fibers. On the cementum-facing side, wing-like processes were segmented into finger-like processes in parallel with the cementum surface. Where Sharpey's fibers few or absent, cementoblasts had only a few or no wing-like processes, but had finger-like processes on the cementum-facing side. The main results suggest that : there are two kinds cementoblasts. One has finger-like processes associated with wing-like processes and secrete intrinsic fibers from the finger-like processes to incorporate the principal fibers. The second type has finger-like processes not associated with wing-like processes, this type secretes intrinsic fibers from the finger-like processes to adjust the cementum thickness.In rat acellular cementum, cementum-forming cells had wing-like processes encircling the principal fibers. Finger-like processes extended toward the cementum. The arrangement of finger-like processes may result in the formation of acellular cementum containing no intrinsic fibers.