2种机用镍钛器械根管成形效果的对比研究

Comparative study on the shaping ability of canals with 2 new nickel-titanium rotary instruments

目的:比较2种不同类型机用镍钛根管预备器械Mtwo、K3的根管成形效果。方法:选择36个离体上颌第一磨牙的近中颊侧根管,根据其弯曲度分成A(弯曲度≥20°)、B(弯曲度<20°)2组,每组再随机分成2个亚组,分别采用镍钛锉Mtwo和K3进行根管预备。预备前后,分别向根管内注入造影剂并拍摄数字X线片,利用合作研制的计算机图像分析软件生成预备前根管几何中心线并投影至预备后根管,测定根管偏移量(几何中心线偏移量)及根管弯曲度的变化。所有数据用SPSS11.0软件包进行统计学分析。结果:各组样本经t检验分析,根管弯曲度≥20°时,根管弯曲起始处的根管偏移量Mtwo组显著小于K3组(P<0.05);根管弯曲度减小量Mtwo组显著小于K3组(P<0.05)。根管弯曲度<20°时,Mtwo、K3组间根管偏移量及根管弯曲度减小量均无显著性差异(P>0.05)。结论:Mtwo、K3根管预备时均能良好维持原始根管的中心位置;预备弯曲度大于20°根管时,Mtwo可更好维持原始根管弯曲度及走向。

PURPOSE： To compare the shaping ability of two nickel -titanium rotary systems： Mtwo and K3. METHODS：Thirty-six mesio-buccal root canals of maxillary first molars were divided into two groups： group A （≥20°） and group B （〈20°）,according to the angle of the canal. Then, each group was randomly divided into two subsets and prepared by Mtwo,K3, respectively. All root canals were injected with the contrast medium and digital images of all canals were recorded before and after instrumentation. The computer assistant analyze image software was used to form the geometrical central line of pre-instrumented canals. Then the central line was imaged to the post-instrumented canals. The canal transportation and the decrease of curvature were measured. All the data was analyzed with SPSS11.0 software package. RESULTS： Difference between groups was compared using t test.When the curvature of canal ≥20°,the transportation at the beginning of the curvature and the decrease of curvature of Mtwo were significantly less than those of K3 （P 〈0.05）.When the curvature of canal 〈20° ,there was no significant difference between Mtwo and K3 in the transportation and decrease of curvature（P〉0.05）. CONCLUSIONS： Both Mtwo and K3 systems show good preservation of the original geometry of the root canals;the Mtwo system can better preserve original curvature of canals,when the curvature of canal is larger than 20°.