The digital x-ray images are gradually becoming the main trend in dental practice which enable the doctor to “zoom in” on a specific area through post-processing ofthe image and provides less radiation, environmental pollution and a film-less dental clinic. However, among studies in root morphology and canal configuration：vertical sectioning, horizontal sectioning, microscopic investigation were most usedmethods.Some people studied canal configuration by traditional film-based radiographs.The purpose of this study is to investigate the working length and tapering configuration of the canals in Taiwanese anterior teeth through digital X-ray images and offers clinicians the reconsideration of canal cleaning and shaping in endodonitc therapy.A total of 120 extracted teeth were divided into four groups as maxillary, mandibularcentral incisors； maxillary cuspids and mandibular cuspids. All the teeth were rinsedand cleaned and placed in alignment with Rinn cone indicator. Radiovisiographs weretaken (“Poo Yee” X-ray Unit; Model: PY-70C; Dentsply Gendex visilux II)from anteroposterior and proximal view. The whole images were stored and processedby Dentsply Gendex VixWin 2000 v1.9. Measurements including the total tooth length,the major diameter and minor diameter of root canals, the tapering angle drawn fromthe apex to both apical third and cervical line crosses the root canals. The results oftooth length in Taiwanese are coincided to Asian population. The ratio of Max/minor diameter is 1.2-1.8. The tapering angle of each tooth from the apex to apical thirdless than 6% angulations in A-P view, but a nearly 12% angulations found in proximalview in mandibular incisors. The preliminary data reveals that the lower incisors mayrequire No. 30 and at least 0.12 tapered files instrumentation in order to obtain circumferential cleaning and shaping of the canals in Taiwanese teeth. Further studyand evaluation should be needed.
