不同投照角度X线根尖片诊断下颌前牙、前磨牙多根管的临床评价

Clinical evaluation of the effect of angulation apical X-rays and the X-rays with file in diagnosing multiple canals in mandibular anterior teeth and premolars

目的 探讨不同角度X线投照技术对发现下颌前牙、前磨牙多根管及提高其临床治疗率的作用。方法 选取临床上需要进行下颌前牙、前磨牙根管治疗的患者214例，共247颗患牙。每颗患牙均需拍摄术前X线正、偏位投照片及诊断丝X线正、偏位投照片。依据两种X线影像特点（根管位置和走向不在牙根中心、较粗大的根管在根管上1／3、中1／3突然消失或模糊）判断是否为可疑多根管。采用冠向下法预备，冷侧压法根管充填后将根管分为Ⅰ～Ⅴ型并与X线结果对应。结果 在87颗X线诊断的多根管患牙中，临床证实多根管为60．92％；26．44％为扁根管。诊断丝X线偏位投照片的多根管X线诊断灵敏度为93．0％，4例术后发现有遗漏根管。247颗下颌前牙、前磨牙临床治疗多根管57颗，多根管临床治疗率分别为：中切牙9．43％、侧切牙38．33％、尖牙15．90％、第一前磨牙加．38％、第二前磨牙2．63％。结论 不同角度的术前及诊断丝X线根尖片有助于临床医师发现下颌前牙、前磨牙多根管，其中以诊断丝X线偏位投照发现的多根管最多。

Objective To investigate different angle projection technique for the clinical detection and treatment of multiple canals in mandibular anterior teeth and premolars. Methods Two hundred and forty-seven in vivo mandibular anterior teeth and premolars were selected from two hundred and fourteen patients. Four kinds of radiographs were taken for each tooth. The radiograph was taken at a horizontal angles of 0, 20-30 degrees from the mesial or distal of the tooth with and without files in canal. If a radiolucent line or files was present mesial or distal to the main canal, an additional canal was suspected. If the tooth appeared to have one large canal in the cervical or middle third of the root which disappeared or constricted as it traveled in an apical direction, an additional canal was suspected. The root canals were instrumented with ProTaper in crown-down mode and filled with laterally condensed gutta-percha and paste, the root canal configurations were classified into Types Ⅰ-Ⅴ. Results 60. 92% multiple canals and 26. 44% long oval canals were detected and treated from suspected multiple canals. The sensitivity of angle projection technique with file in X-ray diagnosing of multiple canals was 93.0%, and second canal was missed in four cases. The multiple canals in the 247 mandibular anterior teeth and premolars were present in central incisors ： 9. 43% （5 of 53） ;lateral incisors：38. 33% （23 of 60） ; canines ：15. 90% （7 of 44）, first premolar： 40. 38% （ 21 of 52 ） ; second premolar： 2. 63% （ 1 of 38 ）. Conclusions The different angle projection technique will assist the clinician in the detection and treatment of multiple canals in mandibular anterior teeth and premolar, and angle projection technique with file detected more multiple canals.