A scanning electron microscopic investigation of the pulp cavity walls of maxillary first premolar and its clinical significance
Qin yanjun, Pi Xin. Dep. of Oral Anatomy and physiology, Hubei Medical University, Wuhan 430071
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.