上颌第一前磨牙髓腔壁扫描电镜观测及其临床意义

A scanning electron microscopic investigation of the pulp cavity walls of maxillary first premolar and its clinical significance

目的：揭示在髓腔壁的微细形态学规律，为根管治疗术以及理解牙本质过敏现象提供应用形态学基础。方法：首先采用扫描电镜对２５颗４的髓腔壁进行系统观测，并分区定点摄影，然后对扫描电镜照片进行形态测量。结果：①牙本质小管口分为４型，即圆形、卵圆形、长条形和不规则形。②从髓室自根尖方向，牙本质小管口的直径、密度和相对面积均逐渐减小。③不规则性继发性牙本质最多见于根尖１／３，其次是根中１／３。结论：①牙本质小管口的形态与牙本质小管的走向及其在钙球上的开口的形态与牙本质小管的走向及其在钙球上的开口部位有相关关系。②牙本质小管口的相对面积较单纯的牙本质小管口的直径和密度更能全面地反映不同部位髓腔壁的特征。③不规则性继发性牙本质的出现属于生理现象而并非病理变化。

Objective The purpose of this study is to reveal the micromorphological featare and law of the pulp cavity walls of human premolars and to provide a micromorphological basis for root canal therapy and dentine sensitivity. Methods first, the pulp cavity walls of 25 maxillary premolars were systematically observed and photographed by scanning electron microscopy, then, these photographs were analysed by morphometry. Results ① The shape of the tubular openings was classified into 4 typies: circular, oval, stripform and irregalar. ② From pulp chamber to root apex, the diameter, the density and the mean percentage area of tubular openings all reduced gradually. ③ Irregular secondary dentine was most often seen on the apical third of the root canal wall, then the middle third. Conclusion ①The shape of the tubular openings has a corelation with both the arrangement of the dentinal tubules and their opening sites on the calcospherites. ②Compared with the diameter and the density of tubular opening, the mean percentage tubular opening area reflects the feature of the pulp cavity wall more comprehensively. ③The appearances of irregular secondary dentine is not a pathological change but a physiological feature.