Deformation and fracture of RaCe and K3 endodontic instruments according to the number of uses.
Deformation and fracture of RaCe and K3 endodontic instruments according to the number of uses.
复制标题
RaCe 和 K3 牙髓器械根据使用次数的变形和断裂。
DOI：
10.1111/j.1365-2591.2006.01119.x
复制
发表时间：
2006
影响因子：
5
通讯作者：
E. P. M. Oliveira
中科院分区：
文献类型：
--
作者：
C. H. Troian;M. V. R. So;J. A. P. Figueiredo;E. P. M. Oliveira
目的
通过扫描电子显微镜评估NiTi RaCe和K3尺寸25、0.04锥形手术工具的变形和断裂。
方法
使用10套来自RaCe和K3 NiTi旋转系统的器械在环氧树脂块中制备100个模拟根管，其具有20或40度曲率，从孔口开始8或12 mm。使用冠下技术，每个器械组用于制备5个模拟根管。使用SEM对25号0.04锥度手术工具进行分析（新的和每次使用后再次进行）。每次使用后，三名观察员对手术工具的图像进行评分，以确定螺旋变形（无变形、一个螺旋变形或一个以上螺旋变形）、磨损（无磨损、轻微、中度或重度磨损）和断裂（是或否）。使用双因素方差分析工具之间的变形和磨损差异; Fisher精确检验寻找与工具断裂相关的差异。
结果
K3手术工具未发生断裂，而RaCe手术工具有6件断裂（P = 0.005）。RaCe和K3器械在螺旋变形和表面磨损方面存在统计学显著差异（P < 0.001）。螺旋扭曲和磨损随着RaCe手术工具的逐步使用而增加，而K3手术工具在第五次使用后仍然相对未损坏。曲率半径较小的模拟根管与RaCe器械断裂呈正相关。
结论
在25号0.04锥度手术工具的变形和断裂方面，发现RaCe和K3之间存在显著差异; K3手术工具的结果更有利。
AIM
To evaluate, by scanning electron microscopy, the deformation and fracture of NiTi RaCe and K3 size 25, 0.04 taper instruments.
METHODOLOGY
Ten sets of instruments from RaCe and K3 NiTi rotary systems were used to prepare 100 simulated canals in epoxy resin blocks with 20 or 40 degree curvatures beginning 8 or 12 mm from the orifice. Each instrument set was used to prepare five simulated canals using a crowndown technique. The size 25, 0.04 taper instruments were analysed by SEM when new and again after each use. Three observers scored images of the instruments after each use for distortion of the spirals (no distortion, distortion of one spiral or distortion of more than one spiral), wear (no wear, small, moderate or severe wear) and fracture (yes or no). Two-way anova was used to analyse differences between instruments for distortion and wear; Fisher's exact test looked for differences related to fracture of instruments.
RESULTS
No fractures occurred with K3 instruments, whereas six RaCe instruments fractured (P = 0.005). A statistically significant difference occurred between RaCe and K3 instruments in terms of distortion of spirals and surface wear (P < 0.001). Distortion of spirals and wear increased with progressive use of RaCe instruments, whereas K3 instruments remained relatively undamaged after their fifth use. The simulated canals with smaller radii of curvature were positively associated with fracture of RaCe instruments.
CONCLUSIONS
A significant difference was found between RaCe and K3 in terms of deformation and fracture of size 25, 0.04 taper instruments; K3 instruments had more favourable results.