两种往复运动镍钛锉根管中心定位能力的研究

Central positioning capability of two reciprocating instruments in simulated curved canal preparation

目的:评价2种往复运动镍钛锉对弯曲根管的中心定位能力。方法:将20个树脂模拟弯曲根管(23~25°)随机分为2组,每组10个,分别使用M3系列之W-one和Reciproc预备根管。采集术前、术后图像。使用Photoshop和Caxa绘出根管外形线和中心线,测量分析工作长度、弯曲角度的变化值及中心线偏移量。结果:工作长度、弯曲角度变化值:W-one组小于Reciproc组(P<0.05)。中心线偏移量:在根尖孔和距根尖孔1 mm,8 mm,9 mm,10mm和11 mm位点,2组偏移量均无统计学差异。2 mm,4 mm,5 mm,6 mm和7 mm位点,W-one组偏移量小于Reciproc组;3 mm位点,W-one组偏移量大于Reciproc组,以上差异均有统计学意义(P<0.05)。结论:W-one和Reciproc 2种镍钛器械均可较好地保持树脂弯曲根管的原始形态,W-one在根管弯曲中段部分具有较好的中心定位能力。

Objective： To evaluate the central positioning capability of two reciprocating instruments in simulated curved canal preparation. Methods： Twenty resin blocks with simulated curved canal（ 23 ～ 25°） were divided into two groups randomly,and prepared by W-one in M3 serial and Reciproc respectively. Black ink or red ink was injected into curved canals before or after instrumentation. Pre-and postoperative images were obtained by a digital camera system and superimposed using Photoshop software. The center line of canal was drawn using CAXA software. The working length,central axis positions and curvature degree were measured before and after preparation and were analyzed. Results： Reductions of working length and curvature changes after preparation of group W-one were significantly less than group Reciproc（ P〈 0. 05）. At the 0 mm and 1 mm,8 mm,9 mm,10 mm and 11 mm points,the center line offsets were not significantly different between the two groups. At the 2 mm,4 mm,5 mm,6 mm and 7 mm points,the offsets of group W-one were significantly less than group Reciproc（ P〈 0. 05）. At the 3 mm point,the offset of group W-one were significantly more than group Reciproc（ P〈 0. 05）.Conclusion： Both W-one and Reciproc can maintain the original canal curvature. W-one exhibits superior centering capability in the middle part of the canal.