根管再治疗的上颌磨牙根管数目和牙根变异情况的研究

Clinical study of the variations of root canal of maxillary molars treated by root canal retreatment

目的:结合锥形束CT检查在手术显微镜下观察行根管再治疗术的上颌磨牙根管数目和变异情况。方法:选择因上颌磨牙根管遗漏需再治疗的患者142例共197个患牙,结合CBCT在显微镜下找寻遗漏根管,对所有根管行根管再治疗术。记录根管数目、牙根变异情况,并评价术后1年疗效。结果:上颌第一磨牙近颊第二根管(MB2)遗漏率最高(81.3%),其次是近颊根(MB,12.5%);第二磨牙远颊根(DB)和MB2遗漏率较高,分别为36.6%和34.7%。第一磨牙4根管的发生率最高(83.3%),第二磨牙3根管的发生率较高(49.5%),其次是4根管(35.6%);两者5根管以上的发生率分别为7.3%和11.9%,大多为牛牙症(21.3%)和额外根(1.5%)。术后1年复查,成功率96.4%。结论:上颌磨牙根管变异大,治疗中易遗漏根管,采用显微镜结合CBCT有助于再治疗时找寻遗漏根管,提高治疗成功率。

AIM： To investigate the root canal variations of maxillary molars treated by root canal retreatment. METHODS： 197 maxillary molars in 142 patients underwent root canal retreatment were observed by using dental operating microscope（ DOM） and cone-beam computed tomography（ CBCT）,root canal variations and preliminary treatment effects were analyzed. RESULTS： The second mesiobuccal roots（ MB2） of maxillary first molars had the highest missing rate（ 81. 3%）,followed by the mesiobuccal roots（ MB,12. 5%）. 36. 6% of the distal buccal roots（ DB） and 34. 7% of the MB2 had been missed in the second molars. 83. 3% of the maxillary first molars had 4 canals and 49. 5% of the second molars had 3 canals. The incidences of 5 canals were 7. 3% in the first and 11. 9% second morlars respectively,most of which（ 21. 3%） were taurodontisms and with additional roots. The success rate of the retreatment of 1 year follow-up was 96. 4%. CONCLUSION： The variations of maxillary molars are large and the root canals are easily missed. DOM and CBCT scans show advantages in the improve ment of endodontic retreatment outcome.