Wu M-K, van der Sluis L W M, Wesselink P R
Department of Cariology, Endodontology, Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, the Netherlands.
Int Endod J. 2003 Mar;36(3):218-24. doi: 10.1046/j.1365-2591.2003.00646.x.
To evaluate the capability of two hand instrumentation techniques, namely balanced force and circumferential filing, to remove the inner layer of dentine in oval canals.
Thirty mandibular incisors with a single oval canal were selected and divided into two equal groups on the basis of their radiographic bucco-lingual internal diameters measured at a level 5 mm from the apex. Two different hand instrumentation techniques, i.e. balanced force and circumferential filing, were used in each group. A modification of the Bramante muffle mould was used to examine the root canal before and after instrumentation at a level 5 mm from the apex. The two images of the root cross-section before and after instrumentation were superimposed on one another. The perimeter of the canal and the length of the arc where the inner layer of dentine had been removed by the instrumentation were measured by means of an image analysis program. The percentage of this arc was calculated.
The balanced force method removed the inner layer of dentine from 38.6% of the circumference of the canal wall, as opposed to 57.7% using circumferential filing. The difference was not statistically significant (P = 0.101).
In oval canals, both the balanced force and circumferential filing techniques left large portions of the canal wall uninstrumented.
评估两种手动根管预备技术，即平衡力法和逐步深入法，去除椭圆形根管内牙本质内层的能力。
选取30颗具有单个椭圆形根管的下颌切牙，根据根尖上方5mm处的影像学颊舌径将其平均分为两组。每组分别采用两种不同的手动根管预备技术，即平衡力法和逐步深入法。使用改良的Bramante muffler模具在根尖上方5mm处检查根管预备前后的情况。将根管预备前后的根管横截面图像相互叠加。通过图像分析程序测量根管周长以及器械去除牙本质内层的弧长。计算该弧长的百分比。
平衡力法去除了根管壁周长38.6%的牙本质内层，而逐步深入法为57.7%。差异无统计学意义（P = 0.101）。
在椭圆形根管中，平衡力法和逐步深入法均使大部分根管壁未得到预备。
