五种新型机用镍钛器械在模拟根管内成形的能力

目的：利用树脂模拟根管比较机用ProTaper Next、ProTaper Universal、K3XF、Twisted File和Hyflex CM在弯曲根管内的成形能力。方法：使用机用ProTaper Next、ProTaper Universal、K3XF、TwistedFile和Hyflex CM预备五组模拟树脂根管,预备过程中记录器械变形及分离的发生,预备完成后测量预备前后根管中轴线的变化。结果：根管中轴线的变化量：在根尖部和根中部,K3XF、Twisted File和HyflexCM三组均少于ProTaper Next和ProTaper Universal组（P〈0.05）;在根中部,ProTaper Next组小于ProTaper Universal组（P〈0.05）;在根冠部,Hyflex CM组小于其他各组（P〈0.05）。结论：ProTaper Next、K3XF、Twisted File（TF）和Hyflex CM在预备弯曲根管时,均能够较好地维持根管原始走向,防止根尖偏移,是较理想的弯曲根管预备器械。

Shaping ability of five new Ni-Ti rotary endodontic instruments in simulated root canals

Objective：To compare the shaping ability of five Ni-Ti rotary endodontic instruments,ProTaper Next,ProTaper Universal,K3 XF,Twisted File and Hyflex CM in curved root canal by using simulated resin root canals.Methods：Five groups of simulated resin root canals were prepared by ProTaper Next,ProTaper Universal, K3XF,Twisted File and Hyflex CM respectively.During the preparation,incidences of instrument deformation and separation were recorded.After the preparation was completed,the change in medial axis of the root canals was respectively measured.Results：Changes of medial axis were smaller in the three groups with K3XF,Twisted File and Hyflex CM than the groups with ProTaper Next and ProTaper Universal in the coronal and middle third of the root canals （P〈0.05）.The amount of axis offset were less in ProTaper Next group than ProTaper Universal group in the middle third of the root canals （P〈0.05）.They were less in the Hyflex CM group than the other groups in the coronal third of the root canals （P〈0.05）.Conclusion：ProTaper Next,K3XF,Twisted File and Hyflex CM files can well maintain the original path of root canals during preparation of curved root canals and avoid apical aberration,and therefore are ideal equipments for curved root canal preparation.