Abstract:

Objective    To evaluate the clinical effect of cone beam computed tomography（CBCT）as an adjunctive therapy of endodontic treatment for calcified canals，and discuss the clinical significance. Methods    Three hundred and seventy-four teeth were selected，which needed to get the root canal therapy，and all of them were blocked with calcification completely in x-ray. The 185 calcified canals that could not be negotiated during the conventional root canal therapy were treated under the endodontic microscope combined with ultrasonic instruments. The negotiation rates were calculated. After that，the 46 canals which could not be negotiated continued to be treated with the help of CBCT，and the negotiation rates were calculated. Results    During the conventional root canal therapy，374 teeth were treated；185 root canals were not negotiated. After that，these blocked canals were treated under the endodontic microscope combined with ultrasonic instruments. Totally 139 canals were negotiated and the negotiation rate was 75.14%；27 root canals were seen in the CBCT images，and 19 root canals were not. The former included 11 thin root canals，9 canals whose orifices were blocked and 7 canals whose negotiating direction was deviated. With the help of microscope and ultrasonic instruments，all of the 27 blocked canals were treated successfully. The success rate was improved to 89.72%. Conclusion    CBCT images can assist to locate the root canal orifice，and show the direction of calcified canal and canal morphology. To some extent，it can improve the negotiation rate of the calcified root canals.

Key words: cone beam computed tomography, CBCT；canal calcification；location of root canal orifice

摘要：

目的    评价锥形束CT（CBCT）辅助治疗钙化根管的临床效果，探讨其临床应用价值。方法    选取2010年4月至2015年3月于天津市口腔医院国际诊疗中心就诊患者的根尖片表现为根管完全性钙化且需根管治疗的患牙374颗，对于常规根管治疗不能疏通的185个钙化根管（患牙114颗），在口腔显微镜下使用超声器械进行疏通。对仍未疏通者拍摄CBCT，参照CBCT影像信息，在显微镜下再次超声疏通，统计钙化根管的疏通成功率。结果    185个钙化根管中，显微镜下超声疏通139个，疏通率为75.14%。对未疏通的46个根管拍摄CBCT后，其中27个显示有根管影像，19个未见根管影像。前者包括11个根管细小、9个根管口钙化物未去净及7个根管疏通方向偏离，在镜下调整疏通方向或使用超声器械去除根管上段钙化物，全部疏通，疏通率提高到89.72%。结论             CBCT能够辅助定位钙化根管，显示根管走向，在一定程度上提高治疗钙化根管的疏通率。

关键词: 锥形束CT, 钙化根管, 根管口定位