髓室底穿孔的下颌后牙残冠保存疗法临床观察

目的 探讨穿髓底的下颌后牙经牙体牙髓治疗后的修复方法。方法 随机选择临床建议拔除的穿髓底的下颌后牙残冠病例，经完善的根管治疗后15～30d无症状者，于根分叉处将牙冠切成近、远中两段，修改成两个前磨牙形态，桩核、联冠修复。结果 修复后3年复查，有效率91％，患牙能正常行使咀嚼功能。缝迨穿髓底的下颌后牙残冠经完善的根管治疗后，于根分叉处行冠切联冠修复，可以保存较长时间。

Clinical observation of effect of the combination casting crowns on the mandibular posterior residual crown associated with penetrated pulp floor

Objective To investigate the restorative procedure and the survival period of the mandibular posterior residual crown companied with penetrated pulp floor after complete endodontic treatment.Method 22 patients(26 teeth) with penetrated pulp floor of mandibular posterior residual crowns were selected at random.All the cases were followed up from half a month to a month after excellent root canal therapy and without any uncomfortable symptom.Then,these mandibular residual teeth were separated into medial part and distal one along the root furcation,and modified each part into the shape of premolar by post/core crown ,meanwhile the two post/core crowns of each posterior residual tooth were repaired by combination casting crowns.Result All the patients were followed up for three years after prosthetics treatment .It was found that the valid rate was 91%,and these teeth can performed their mormal function.Conclusion This treatment may be employed as a practical means for the mandibular posterior residual crown with penetrated pulp floor.