锥形束CT结合手术显微镜在上颌磨牙颊侧根管口下方分叉患牙治疗中的应用

Clinical appliance of cone-beam computed tomography and dental operating microscope in treating maxillary molars containing bifurcative canals buccally

目的探讨锥形束CT检查结合显微根管技术治疗上颌磨牙颊侧根管口下方分叉病例的临床效果。方法选取需进行根管治疗的上颌磨牙304颗(上颌第一磨牙159颗,上颌第二磨牙145颗),开髓后记录髓室底根管口数目及位置,对术前X线片怀疑为颊侧根管口下方分叉的患牙,先在肉眼下探查疏通根管,再根据牙科锥形束CT结果在根管显微镜下在根管口深处寻找疏通根管,确定根管工作长度后逐步深入技术预备根管,冷牙胶侧方加压技术完成根管充填。根据术前、中、后X线片评价根管治疗效果。结果 304颗磨牙中,髓室底两根管口者为51颗,其中颊侧为单一根管口、下方又分为近、远中侧根管者为30颗(上颌第一磨牙8颗,上颌第二磨牙22颗)。牙科锥形束CT结果示根管分叉位于颊侧髓室底根方3～8 mm处。30颗磨牙中,7颗磨牙的根管通过常规操作技术可定位疏通;22颗磨牙的根管通过锥形束CT结合根管显微镜下操作可疏通至根尖区,术中、术后X线片示根管预备、充填良好;8颗磨牙因近颊根第二根管开口于根管中下段或根管钙化而未能疏通。结论牙科锥形束CT检查结合显微根管技术可精准地定位手术区域,是治疗此类疑难根管的有效方法。

Objective To evaluate the effect of using cone-beam computed tomography（CBCT） and dental operating microscope（DOM） in treating maxillary molars containing bifurcative canals buccally.Methods 304 endodontically treated maxillary molars（159 maxillary first molars and 145 maxillary second molars） were included.After preparing access to pulp chamber,the number of canal orifices and location in the pulp chamber floor of each tooth were recorded. For those teeth with bifurcative canals buccally confirmed by preoperative radiographs,the root canals were negotiated by naked eyes firstly,then under DOM according CBCT results.Following working length determination,the root canals were prepared by step-down technique and obturated with cold lateral condensation technique.The efficiency was eva-luated with radiographs before,during and after operation.Results In 304 maxillary molars,51 molars were found to have two canal orifices（buccal one and palatal one） in the pulp floor,30 bifurcative canals buccally（8 upper first molars and 22 upper second molars） were found.CBCT information indicated the level of bifurcation in buccal canals were 3-8 mm under the pulp chamber floors.In 30 maxillary molars,7 teeth treated by X-rays and eyes could be negotiated,22 teeth treated by CBCT and DOM could be negotiated and were well instrumented and filled by evaluating with radiographs during and after operation,8 teeth with deep divergent MB2 canals or calcified canal could not be negotiated.Conclusion Operative field can be located precisely by CBCT and dental operating microscope that could be effective method in treating these sort of canals.