Department of Endodontics, School of Health and Bioscience, Pontifical Catholic University of Paraná, Curitiba, Brazil.
Department of Endodontics, La Sapienza University, Rome, Italy.
J Endod. 2017 Oct;43(10):1716-1719. doi: 10.1016/j.joen.2017.05.012. Epub 2017 Jul 20.
The purpose of this study was to evaluate in vitro the efficacy of both the electronic apex locator (EAL) and auto apical reverse (AAR) functions of the endodontic motor MM Control (Micro-Mega, Besançon Cedex, France) compared with Root ZX II (J Morita, Tokyo, Japan).
After cervical preflaring, the actual lengths (ALs) of 36 single-rooted teeth were obtained up to the apical foramen. The EAL measurements at the marks "APEX" and "0.5" of both devices were obtained using an alginate model. The teeth were divided randomly into 2 groups (n = 18), and root canal preparation was performed with rotary instruments using the AAR function (0.5 mark) of each motor. The length provided by the AAR was compared with the visual length after preparation (AL2). The differences between the electronic lengths and the respective visual measurements were assigned as negative for lower or positive when higher. The means of the absolute values and the percentages of distribution of the electronic measurements between devices were compared.
There was no difference between the devices in terms of the means of the EAL measurements or AAR length (analysis of variance, P > .05). However, the EAL function of MM Control presented a greater percentage of measurements >1.01 mm longer than AL (chi-square, P < .01). The AAR function provided an acceptable apical limit in 83.3% of the cases for Root ZX and 77.8% of the cases for MM Control.
The AAR function of both MM Control and Root ZX II provided an adequate apical limit of preparation in vitro. However, the use of only the EAL function of MM Control resulted in significantly more cases of overextended readings.
本研究旨在评估根管马达 MM Control（Micro-Mega，Besançon Cedex，法国）的电子根尖定位仪（EAL）和自动根尖反向（AAR）功能与 Root ZX II（J Morita，东京，日本）的体外疗效。
在颈预扩孔后，通过糊剂模型获得 36 颗单根牙到达根尖孔的实际长度（AL）。使用两种设备的“APEX”和“0.5”标记获得 EAL 测量值。将牙齿随机分为 2 组（n=18），使用每个马达的 AAR 功能（0.5 标记）进行根管预备。比较 AAR 提供的长度与预备后的视觉长度（AL2）。将电子长度与各自的视觉测量值之间的差值指定为负值表示较低，指定为正值表示较高。比较设备之间的电子测量值的绝对值平均值和分布百分比。
在 EAL 测量值或 AAR 长度方面，两种设备之间没有差异（方差分析，P>.05）。然而，MM Control 的 EAL 功能呈现出更大比例的测量值比 AL 长 1.01 毫米以上（卡方检验，P<.01）。在 Root ZX 情况下，AAR 功能为 83.3%的病例提供了可接受的根尖极限，在 MM Control 情况下为 77.8%的病例提供了可接受的根尖极限。
MM Control 和 Root ZX II 的 AAR 功能在体外提供了足够的预备根尖极限。然而，仅使用 MM Control 的 EAL 功能会导致明显更多的读数超出延伸。
