上颌第一恒磨牙遗漏根管再治疗的临床分析

Clinical analysis of missed canals in endodontically retreated maxillary first molars

目的探讨上颌第一恒磨牙根管治疗中遗漏根管的原因及对策。方法上颌第一恒磨牙再治疗中通过插入小号K锉进行X线片偏移投照技术(近中或远中)及手术显微镜下仔细探查髓室底所确认的遗漏在根管病例9例,记录再治疗中发现遗漏根管的部位,数量及疏通的根管数目并进行分析。结果再治疗中发现上颌第一恒磨牙遗漏一个根管病例8例,遗漏两个根管病例1例;遗漏部位为近烦根管1例,近烦舌侧根管(MB2)根量5例,远颊根管2例,腭侧根管1例;再治疗中可重新疏通的遗漏根管7例。结论上颔第一恒磨牙根管治疗中MB2根管遗漏率较高,遗漏根管的原因主要是根管口钙化及根管结构变异,完全去除髓室顶并仔细探查髓室底及显微超声技术的应用有助于寻找、发现并疏通遗漏根管。术前X线片有助于诊断上颌第一恒磨牙遗漏根管的发生及部位。

Objective To analysis the factors affecting the missed canal of permanent upper first molars. Methods An evaluation of 9 retreated maxillary first molars missed canals which were confirmed by multiple obliquely angled radiographs preoperatively and were reconfirmed by surgical operating microscope was made in an attempt to determine the location and negotiability of missed canal in maxillary first molar. Results Overall, 8 （88.89 % ） cases were found missed one canal, whereas 1 （11.11% ） case was found missed two canals; Of these cases ,the missed canals were 1 mesiobuccal canal, 5 mesiolingual canals, 2 distobuccal canals and 1 palatal canal, respectively ,there were 7 canals could be renegotiated during retreatment. Conclusion Our study suggested that calcified canal orifice and anatomical variation are main causes for missed canal in maxillary first molars, creating complete access and SOM can be available for identifying and negotiating the missed canals, careful radiographic re - examination of the tooth should be done in order to identify possibly missed canals.