Effect of tip design of nickel-titanium and stainless steel files on root canal preparation
Effect of tip design of nickel-titanium and stainless steel files on root canal preparation
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DOI：
10.1016/s0099-2399(97)80345-7
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发表时间：
1997-12-01
影响因子：
4.2
通讯作者：
Walker, WA
中科院分区：
文献类型：
--
作者：
Kuhn, WG;Carnes, DL;Walker, WA
本研究的目的是评价改良和未改良的不锈钢和镍钛根管手锉尖端设计对根管预备的影响。采用四分之一转拔技术制备下颌磨牙近中根根根管。实验设计允许比较单独的镍钛合金结构或锉尖修饰的效果，以及将这两个因素合并到单个锉设计中的效果。使用改良的Bramante技术评估运输、定心率和牙本质去除。镍钛锉，无论尖端设计如何，与不锈钢锉相比，25尺寸的镍钛锉仍能保持明显的居中移动，并且显示出更少的根尖移动。当器械继续到根尖尺寸40并后退时，根尖或冠状部分的运输没有显著差异。然而，在用步进法测量到40尺寸时，与其他锉设计相比，改良刀尖和镍钛合金的组合产生了更多的运输和牙本质去除，并且在根中水平与中心的偏差更大。因此，在本研究评估的锉设计参数中，镍钛结构在确定根尖区域小锉尺寸的根管构型时最重要。虽然镍钛结合改良的尖端设计导致根中区域更大锉尺寸的更多运输，但这种管形的改变在临床上可能不太重要。尽管如此，建议其他因素，如触觉和仪器技术，应考虑合金类型或尖端设计同样重要。
The purpose of this study was to evaluate the effect of modified and non-modified tip designs of both stainless steel and nickel-titanium endodontic hand files on root canal preparation. Root canals of mesial roots of extracted mandibular molars were prepared using a quarter-turn-pull technique. The experimental design permitted comparison of the effects of nickel-titanium alloy construction or file tip modification alone, with effects when these two factors were incorporated into a single file design. Transportation, centering ratio, and dentin removal were evaluated using a modified Bramante technique. Nickel-titanium files, regardless of tip design, remained significantly move centered and demonstrated less apical transportation than stainless steel files at size 25. When instrumentation was continued to size 40 apically with step-back, there were no significant differences in transportation in the apical or coronal sections. However, during instrumentation to size 40 with step-back, the combination of modified tip and nickel-titanium alloy produced significantly more transportation and dentin removal, as well as greater deviation from the center at the mid-root level than did other file designs. Thus, of the file design parameters evaluated in this study, construction from nickel-titanium was most important in defining canal configuration at small file sizes in the apical region. Although the combination of nickel-titanium and modified tip design resulted in more transportation at larger file sizes in the midroot region, such alterations in canal configuration may be of little importance clinically. Nonetheless, it is suggested that other factors, such as tactile sensation and instrumentation technique, should be considered as important as the type of alloy or tip design.