下颌前磨牙C形根管的诊断和治疗

The diagnosis and treatment of mandibular premolars with C-shaped canal system

目的:探讨下颌前磨牙C形根管的发现率及其诊治方法。方法:选取需要根管治疗的下颌前磨牙300个,拍摄术前正位和偏位X线牙片。多根管牙插诊断丝摄片。结合C形根管的诊断标准,诊断为C形根管的患牙,记录髓室底形态和X线影像类型。所有患牙使用镍钛机动根管器械预备,侧方加压法充填根管。根据术前、术中和术后X线片评价根管预备和充填效果。结果:第一和第二前磨牙C形根管的发现率依次为5.56%和2.50%。髓室底以C2型多见,X线影像以尖部融合型多见。治疗中无根管堵塞等并发症的发生。根管充填效果,13例C形根管中有5例超充,8例恰充。结论:髓腔探察和插诊断丝拍片是诊断下颌前磨牙C形根管的有效方法。

Objective： To investigate the morphological characteristics of C-shaped canal system in mandibular first premolars. Method： A total of 300 mandibular first premolars were treated endodontically. Two preoperative radiographs were taken respectively, using straight projection and eccentric projection. After access opening, the files were placed in the canals and two other radiographs were taken. The root canal morphology of the premolars with c-shaped system were classfied and recorded. The teeth were shaped using NiTi rotary instruments and obturated with lateral condensation method. The efficiency of preparation and obturation was analyzed with radiographs before, during and after operation. Result：The incidence of c-shaped canal system was 5.5% in mandibular first premolars and 2.5% in mandibular second premolars. Type C2 and the type which canals mercied in apical were the most common in c-shaped system of mandibular premolars. There were no transportation, and apical blockage in all cases. In 13 cases of C-shaped canal system, 8 teeth were filled well, 5 were slight over-filling. Conclusion：The mandibular first premolars had a high frequency C-shaped canal system. Using Exploring and radiographs with file is a useful way in judging the canal categories.