Madani Zahra Sadat, Goudarzipor Daryoush, Haddadi Azam, Saeidi Akam, Bijani Ali
Department of Endodontics, Dental School, Babol University of Medical Sciences, Babol, Iran;
Department of oral and Maxillofacial Radiology, Dental School, Tehran University of Medical Sciences, Tehran, Iran.
Iran Endod J. 2015 Winter;10(1):44-8. Epub 2014 Dec 24.
Apical transportation changes the physical shape and physiologic environment of the root canal terminus. The aim of the present experimental study was to determine the extent of apical transportation after instrumentation with hand K-Flexofile and K3 rotary instruments by means of cone-beam computed tomography (CBCT).
Forty mesiobuccal root canals of maxillary first molars, with 19-22 mm length and 20-40(°) canal curvature, were selected and assigned into two preparation groups. The first group was prepared with K-Flexofile with passive step-back technique and the second group was prepared with K3 rotary instruments. Pre and post instrumentation CBCT images were taken under similar conditions. The amount of root canal transportation was evaluated by Mann-Whitney U test and the chi-square test was used for the qualitative evaluation.
The amounts of apical canal transportation with the K3 and K-Flexofile instruments were 0.105±0.088 and 0.150±0.127 mm, respectively with no statistically significant differences. In the manual technique, 25% of the canals had no apical transportation; while 30% of the canals in the K3 group were transportation free.
Both systems were able to preserve the initial curvature of the canals and both had sufficient accuracy. Preparation with K3 rotary instruments resulted in apical transportation similar to that of K-Flexofile.
根尖移位会改变根管末端的物理形态和生理环境。本实验研究的目的是通过锥形束计算机断层扫描（CBCT）确定使用手动K-Flex锉和K3旋转器械进行根管预备后根尖移位的程度。
选取40颗上颌第一磨牙的近中颊根根管，长度为19 - 22mm，根管弯曲度为20 - 40°，并将其分为两个预备组。第一组使用K-Flex锉采用被动逐步后退技术进行预备，第二组使用K3旋转器械进行预备。在相似条件下拍摄根管预备前后的CBCT图像。采用曼-惠特尼U检验评估根管移位量，采用卡方检验进行定性评估。
K3器械和K-Flex锉器械导致的根尖根管移位量分别为0.105±0.088mm和0.150±0.127mm，差异无统计学意义。在手动技术组中，25%的根管没有根尖移位；而在K3组中，30%的根管没有移位。
两种系统都能够保持根管的初始弯曲度，并且都具有足够的准确性。使用K3旋转器械进行预备导致的根尖移位与使用K-Flex锉相似。
