微焦点计算机断层扫描术评价根管再治疗中不同器械根管清理效果的研究

摘要

Objective To establish the three-dimensional model of human permanent premolars based on Micro-computed tomography (Micro-CT) data, and evaluate the efficiency quantitatively of two different instrumentations for root canal retreatment. Methods Forty extracted permanent premolars for the reason of orthodontic treatment were collected, prepared by using ProTaper Ni-Ti files and filled by cold gutta pertscha lateral condensation technique. The subjects were scanned by Micro-CT. Forty teeth were randomly divided into two groups and retreated by K-Flexo files and ProTaper Universal retreatment system respectively. Then all subjects were scanned again, and the mean percentage of remaining filling materials and the scores of remaining filling materials presented in upper, middle and apical 1/3 of the canal were calculated. Results Mean percentage of the remaining filling materials by K-Flexo files was lower than that by ProTaper Universal retreatment system (P=0.005). The scores demonstrated that K-Flexo files had greater efficiency than ProTaper Universal retreatment system when retreating the apical 1/3 of canal (P<0.05). Conclusion This study shows that both techniques could not remove filling materials completely.%目的 基于微焦点计算机断层扫描术(Micro-CT)数据建立人前磨牙三维模型,定量评价根管再治疗过程中2种根管预备系统根管清理的效果.方法 选择因正畸治疗拔除的前磨牙40颗,采用ProTaper机用镍钛锉进行根管预备,冷牙胶侧方加压法充填根管.随机分为2组,以弹性K锉和ProTaper Universal再治疗系统分别进行根管二次预备.分别于根管充填及二次预备后进行Micro-CT扫描,计算根管内剩余充填物比例,分别对根管冠1/3、中1/3和下1/3的根管内剩余物进行评分,评价2种器械对根管充填物的清理效果.结果 使用弹性K锉进行根管二次预备的平均根管内剩余物比例低于ProTaper Universal再治疗系统(P=0.005)；弹性K锉组根尖1/3清理效果优于ProTaper Universal 再治疗系统组(P＜0.05).结论 弹性K锉和Pro[per Universal再治疗系统均不能完全清除根管内充填物.