比较两种镍钛器械在不同运动模式下预备根管后牙根裂纹的发生率

Incidences of root cracks after root canal preparation: A comparison of two nickel-titanium instrumentation with different kinematics

目的:比较Twist File Adaptive(TFA)和Pro Taper Universal(PTU)两种镍钛器械系统分别在自适应运动模式和连续旋转模式下预备根管后牙根裂纹的发生率。方法:收集因正畸减数拔除的100个健康下颌前磨牙,并随机分为5组(n=20)。其中对照组不进行根管预备,4个实验组分别用TFA和PTU两种镍钛器械系统并分别在自适应运动模式和连续旋转模式下预备根管至#25。预备结束后,在各牙根样本距离根尖3、6、9 mm处横断牙面,并在立体显微镜下观察牙根裂纹的发生情况。结果:对照组未观察到牙根裂纹的发生,而各实验组均有不同数目的牙根裂纹发生。PTU在两种不同运动模式下的牙根裂纹发生率均明显高于TFA组(P<0.05);TFA在自适应运动模式下产生的牙根裂纹少于连续旋转模式组(P<0.05);PTU在两种不同运动模式下的牙根裂纹发生率差异无统计学意义(P>0.05)。结论:新型镍钛锉TFA相比于传统锉PTU在根管预备后可产生较少的牙根裂纹。用TFA预备根管时,自适应运动比连续旋转运动产生的牙根裂纹少。

AIM： To compare the incidences of tooth root cracks after root canal preparation using Twist File Adaptive（TFA） and ProTaper Universal system （PTU） with adaptive motion and continuous rotation respectively. METHODS： 100 mandibular premolars were randomly divided into 5 groups（ n = 20）. The roots in control group were unprepared. And the other 80 teeth were divided into 4 experimental groups and the root canals were prepared by TFA and PTU to #25 with adaptive motion and continuous rotation respectively. All the roots were sectioned horizontally at 3, 6, and 9 mm from the apex, and the slices were observed by stereomicroscope. The presence of root cracks was not- ed. RESULTS： No root crack was observed in the control group. The incidences of root cracks in PTU groups were significantly higher than those in TFA groups （ P 〈 0.05 ）. The incidence of root cracks was lower in TFA group work- ing with adaptive motion than that with continuous rotation （P 〈 0.05 ）. There was no statistic difference of root crack incidence between adaptive motion and continuous rotation in PTU groups （ P 〉 0.05 ）. CONCLUSION： The new Twist File Adaptive instruments causes less crack than the traditional ProTaper Universal system. There is less crack using Twist File Adaptive with adaptive motion than that with continuous rotation.