镍钛手用锉与不锈钢手用锉对弯曲根管成形能力的对比研究

Shaping ability of nickel-titanium and stainless steel hand-files in simulated curved root canals

目的 :对比镍钛手用锉 (NiTiFLEX)与不锈钢K型锉 ,K Flex锉预备塑料块中的弯曲管的成形能力。方法 :3 6个内含相似弯曲根管的塑料块分为 3组 :( 1)镍钛手用锉组 ;( 2 )不锈钢K Flex锉组 ;( 3 )不锈钢K型锉组。均以逐步后退法预备根管 ,叠加根管预备前后的扫描图像 ,分析根管弯曲部分的形态变化。结果 :( 1)组基本维持原根管曲线 ,根尖 1/3平均角度偏移为 ( 1.2 8°± 0 .73°) ,( 2 )组、( 3 )组根管直化较明显 ,根尖 1/3平均角度偏移分别为 ( 10 .76°± 1.17°)和 ( 12 .5 8°± 1.0 9°) ,与 ( 1)组比较差异有显著性 (P <0 .0 1) ,( 2 )组与 ( 3 )组比较差异亦有显著性 (P <0 .0 1)。根管轴心偏移在弯曲部分向内 ,在根尖区向外 ,偏移量 ( 1)组最小 ,( 2 )组次之 ,( 3 )组最大 ,( 1)组与另两组间差异有显著性 (P <0 .0 1) ;除根尖处外 ,( 2 )组较 ( 3 )组的偏移量差异亦存在显著性 (P <0 .0 1)。 ( 2 )组、( 3 )组预备后的根管较 ( 1)组显著增宽 ,两组间只在距根尖 4mm差异有显著性 (P <0 .0 5 ) ,且均有根尖拉开和肘部形成。 ( 1)组无根尖拉开及肘部形成。结论 :镍钛手用锉较不锈钢手用锉能保持原根管曲线 。

Objective:To compare the shaping ability of nickel titanium hand files with that of stainless steel K Flexofiles and K files in simulated curved canals.Methods:A total of 36 canals were prepared by using either NiTiFlex files,K Flexofiles or K files in a stepback technique.Preinstrumental and postinstrumental images were taken,and assessment of the canal shapes was completed with a computer image analysis program.Results:Less transportation occurred with NiTiFlex files compared to K Flexofiles or K files( P< 0.01),and Average angle deviations of canal apical prepared with NiTiFlex files,K Flexofiles and K files were 1.28°±0.73,10.76°±1.17 and 12.58°±1.09,respectively.K Flexofiles and K files but NiTiFlex files created significantly greater width of canals,apical zips and elbows.Conclusion:NiTiFlex files produce more appropriate canal shapes than stainless steel hand files. [