Homayoon Amin, Hamidi Mahmood Reza, Haddadi Azam, Madani Zahra Sadat, Moudi Ehsan, Bijani Ali
Endodontist, Private Practic , Babol, Iran;
Department of Endodontics, Dental School, Babol University of Medical Sciences, Babol, Iran;
Iran Endod J. 2015 Fall;10(4):263-7. doi: 10.7508/iej.2015.04.011.
Fearless removal of tooth structure during canal preparation and shaping has negative effects on the prognosis of treatment. On the other hand, sufficient pre-enlargement facilitates exact measurement of the apical size. The present in vitro study aimed to compare the efficacy of Gates-Glidden drills, K3, ProTaper, FlexMaster and RaCe instruments in dentin removal during coronal flaring using cone-beam computed tomography (CBCT).
A total of 40 mandibular molars were selected and the coronal areas of their mesiobuccal and mesiolingual root canals were randomly prepared with either mentioned instruments. Pre- and post-instrumentation CBCT images were taken and the thickness of canal walls was measured in 1.5- and 3-mm distances from the furcation area. Data were analyzed using the one-way ANOVA. Tukey's post hoc tests were used for two-by-two comparisons.
At 1.5-mm distance, there was no significant difference between different instruments. However, at 3-mm distances, Gates-Glidden drills removed significantly more dentin compared to FlexMaster files (mean=0.18 mm) (P<0.02); however, two-by-two comparisons did not reveal any significant differences between the other groups.
All tested instruments can be effectively used in clinical settings for coronal pre-enlargement.
根管预备和塑形过程中无畏地去除牙体组织会对治疗预后产生负面影响。另一方面，充分的预扩大有助于精确测量根尖尺寸。本体外研究旨在使用锥形束计算机断层扫描（CBCT）比较Gates-Glidden钻、K3、ProTaper、FlexMaster和RaCe器械在冠部扩管时去除牙本质的效果。
共选择40颗下颌磨牙，其近中颊根和近中舌根根管的冠部区域随机使用上述器械进行预备。在器械操作前后拍摄CBCT图像，并在距根分叉区1.5毫米和3毫米处测量根管壁厚度。数据采用单因素方差分析进行分析。Tukey事后检验用于两两比较。
在1.5毫米距离处，不同器械之间无显著差异。然而，在3毫米距离处，Gates-Glidden钻去除的牙本质明显多于FlexMaster锉（平均值=0.18毫米）（P<0.02）；然而，两两比较未显示其他组之间有任何显著差异。
所有测试器械均可有效地用于临床冠部预扩大。
