Nabavizadeh Mohammadreza, Abbaszadegan Abbas, Khojastepour Leila, Amirhosseini Mohsen, Kiani Ebrahim
Department of Endodontics, Dental School, Shiraz University of Medical Sciences, Shiraz, Iran;
Department of Radiology, Dental School, Shiraz University Medical Sciences, Shiraz, Iran;
Iran Endod J. 2014 Spring;9(2):117-22. Epub 2014 Mar 8.
Preserving the apical root structure during cleaning and shaping of the canal has always been a challenge in endodontics particularly when the root canals are curved. The purpose of this in vitro study was to compare the apical transportation induced by the Reciproc and BioRaCe rotary systems in preparing the mesiobuccal root canal of the human maxillary molars.
The mesiobuccal canals of sixty extracted maxillary molars with curvature angle of 25˚-35˚ were selected and randomly assigned into two groups. Each canal was prepared by either Reciproc or BioRaCe rotary systems. A double-digital radiographic technique and AutoCAD software were used to compare the apical transportation at 0.5, 1, 2, 3, 4 and 5 mm distances from the working length (WL). The distance between the master apical rotary file and the initial K-file in the superimposed radiographs determined the amount of apical transportation. An independent t-test was used to compare the groups. The statistical significant level was set at 0.05.
Apical transportation of the Reciproc group was significantly greater than the BioRaCe group in all distances (P<0.001). The maximum apical transportation occurred in the Reciproc group at 0.5 mm from the WL (0.048±0.0028 mm) and the minimum occurred for BioRaCe at 5 mm from the WL (0.010±0.0005 mm).
The Reciproc system produced significantly more apical transportation than the BioRaCe, but this fact does not seem to negatively alter the clinical success or quality of root canal treatment.
在根管清理和预备过程中，保留根尖部根管结构一直是牙髓病学中的一项挑战，尤其是当根管弯曲时。本体外研究的目的是比较Reciproc和BioRaCe旋转系统在预备人类上颌磨牙近中颊根根管时所引起的根尖移位情况。
选取60颗弯曲角度为25˚-35˚的拔除上颌磨牙的近中颊根根管，并随机分为两组。每组根管分别用Reciproc或BioRaCe旋转系统进行预备。采用双数字放射照相技术和AutoCAD软件，比较距工作长度（WL）0.5、1、2、3、4和5mm处的根尖移位情况。在叠加的X线片上，主尖锉与初始K锉之间的距离确定根尖移位量。采用独立t检验比较两组。统计学显著性水平设定为0.05。
在所有距离处，Reciproc组的根尖移位均显著大于BioRaCe组（P<0.001）。Reciproc组在距WL 0.5mm处出现最大根尖移位（0.048±0.0028mm），BioRaCe组在距WL 5mm处出现最小根尖移位（0.010±0.0005mm）。
Reciproc系统产生的根尖移位明显多于BioRaCe系统，但这一事实似乎并未对根管治疗的临床成功率或质量产生负面影响。
