Shaping ability of progressive versus constant taper instruments in simulated root canals.
Shaping ability of progressive versus constant taper instruments in simulated root canals.
复制标题
渐进式与恒定锥度器械在模拟根管中的成形能力。
DOI：
10.1111/j.1365-2591.2006.01151.x
复制
发表时间：
2006
影响因子：
5
通讯作者：
Hongle Wu
中科院分区：
文献类型：
--
作者：
Guobin Yang;Xiao;H. Zhang;Hongle Wu
目标
在模拟根管中比较渐进式和恒斜度型根管器械的成形能力。
方法论
分别用ProTaper(渐进式锥度仪)和高弹性旋转642(Hero642)(恒锥度)器械(每例10个根管)模拟制作L和S形树脂根管。采用IMAGE PRO PLUS 5.0软件，记录预备前后的图像，完成对根管形态的评估。在9个测量点测量去除树脂的宽度。记录根管畸形发生率、器械折断情况、预备时间和工作长度变化。此外，还评价了弯曲度和定心能力的变化。数据采用学生t检验或Fisher精确检验进行统计学分析。
结果
在两种类型的根管中，Hero 642器械预备根管的速度比ProTaper器械更快(P<；0.01)，并且保持工作长度的准确性显著高于ProTaper器械(P<；0.05)。在用Hero 642器械预备的根管中，弯曲度变化较小。ProTaper根管预备后，根尖向L形弯曲根管的外侧移动，根尖向S弯曲的根管向内侧移动。Hero 642器械在根管的根尖部分有较好的对中能力，但其形状的锥度较差。
结论
ProTaper和Hero 642器械预备弯曲根管迅速，保持工作长度良好，相对安全，不会造成穿孔和危险区。在两种类型的根管中，Hero 642器械都较好地保持了原有的根管弯曲度，并且由于其恒定的锥度设计，在弯曲的根管中具有更好的定心能力。Hero 642器械在根管冠部准备的锥度普遍较差。
AIM
To compare the shaping ability of progressive versus constant taper shaft designed instruments in simulated root canals.
METHODOLOGY
Simulated L- and S-shaped resin canals were prepared by ProTaper (progressive taper) and high elasticity in rotation 642 (Hero 642) (constant taper) instruments (n = 10 canals in each case). The pre- and post-instrumentation images were recorded and assessment of the canal shape was completed with image pro plus 5.0. The width of resin removed was measured at 9 measuring points. Incidence of canal aberrations, instrument fracture, preparation time and change of working length were recorded. In addition, the change of curvature and centring ability were also assessed. The data were analysed statistically using Student's t-test or Fisher's exact-test.
RESULTS
In both canal types, Hero 642 instruments prepared canals more rapidly (P < 0.01) and maintained working length significantly more accurately than ProTaper instruments (P < 0.05). In canals prepared with Hero 642 instruments, there was less change in curvature. Instrumentation with ProTaper results in transportation towards the outer aspect of the L-shaped curved canals in the apical part and the inner aspect of the S-shaped canals at the curve. Hero 642 instruments had a better centring ability in the apical part of the canal, but resulted in shapes with a poor taper.
CONCLUSIONS
ProTaper and Hero 642 instruments prepared curved canals rapidly, maintained working length well and were relatively safe without creating perforations and danger zones. In both canal types, Hero 642 instruments maintained the original canal curvature better, and had a better centring ability in curved canals because of its constant taper design. The taper prepared by Hero 642 instruments in the coronal part of the canal was generally poor.