口腔锥形束CT在下颌第二磨牙C形根管诊治中的应用

Oral CBCT in the diagnosis of C-shaped canals of mandibular second molars

目的探讨口腔锥形束CT(cone-beam computed tomography,CBCT)在根管治疗中诊断治疗下颌第二磨牙C形根管的临床应用。方法选取初次根管治疗失败的下颌第二磨牙62颗,根尖片不能确定根管解剖形态以及可疑遗漏根管,患牙采用CBCT进行扫描三维重建。结果使用CBCT确定下颌第二磨牙中52颗为C形根管,C形根管发生率达83.87%,C形根管中28颗为C1型变异根管(53.84%),18颗为C2型变异根管(34.62%),6颗为C3型变异根管(11.54%)。52颗患牙除2颗因根管侧穿导致根管治疗失败外,其余50颗患牙通过热牙胶充填与垂直加压技术将软化的牙胶充入不规则的根管系统,达到严密充填根管,根管再治疗后患牙成功治疗的有50颗(96.15%),均无不适症状。CBCT在根管治疗中辅助定位变异根管,定位准确率较高。结论 CBCT影像精密度高,可从三维角度分析根管,在根管治疗中诊断治疗下颌第二磨牙C形根管具有临床指导意义。

Objective To investigate the clinical efficiency of dental cone-beam computed tomography （CBCT） in the diagnosis and treatment of C-shaped canals of mandibular second molars in root canal therapy. Methods 62 mandibular second molars that failed in the first root canal therapy were included in this study. The periapical films could not indicate the anatomic forms of root canals and the suspicious missed canals. The teeth were scanned by CBCT. Results 52 canals （83.87%） were diagnosed as C-shaped ca- nals,among which the numbers of C1 type,C2 type and C3 type were 28 （53.84%） ,18 （34.62%） and 6 （ 11.54% ） ,respectively. Among the 52 teeth with C-shaped canals ,2 teeth failed to receive the root canal therapy due to root canal perforation,and 50 teeth re- ceived gutta-percha filling through warm gutta-percha obturation and vertical condensation to fill the irregular root canal system so as to fill the root canals thoroughly. After endodontic retreatment,50 teeth （96.15%） showed satisfactory outcome with no complications i- dentified. CBCT functioned in positioning the lesioned root canals with a high accuracy. Conclusions CBCT can analyze the configura- tion of root canals in a three-dimensional view,which is of prime importance in the diagnosis and treatment of C-shaped canals of man- dibular second molars.