Pertot W J, Camps J, Damiani M G
Universite D'Aix-Marseille II, Faculté D'Odontologie, Marseille, France.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1995 Apr;79(4):504-9. doi: 10.1016/s1079-2104(05)80136-2.
The purpose of this study was to evaluate and to compare root canal configuration after preparation with three different hand instruments and techniques: the canal master U preparation technique (Brasseler, Savannah, GA.), using stainless steel or nickel-titanium canal master U instruments, and the step-back technique using precurved conventional stainless steel K-type files. Sixty-three simulated curved canals were divided in three groups of 21 each. Each group was prepared using one of the three instruments. Comparison of root canal configuration was evaluated with pre- and postoperative photographs that measured the difference in canal diameter and the mesial and distal transportation of the canal walls at the canal length and at levels 1, 2, 3, 4, 5, 6, 7, and 8 mm coronal to the canal length. Data obtained were analyzed statistically using an analysis of variance. Instrument breakage was also recorded. Results showed that the final diameter of the prepared canals as well as canal transportation were significantly different between both canal master U instruments and the stainless steel K file. Three stainless steel canal master U instruments separated during instrumentation whereas none in the nickel-titanium canal master U and stainless steel K-type file groups separated. The results of this study show that the canal master U instruments and technique provide a better canal configuration than K files using the step-back technique and that the nickel-titanium canal master U and stainless steel K-type file offers a greater safety factor against breakage than the stainless steel canal master U.
根管塑形U形预备技术（Brasseler公司，佐治亚州萨凡纳市），使用不锈钢或镍钛根管塑形U形器械；以及使用预弯常规不锈钢K型锉的逐步后退技术。63个模拟弯曲根管被分为三组，每组21个。每组使用三种器械中的一种进行预备。通过术前和术后照片评估根管形态，测量根管长度以及根管长度冠方1、2、3、4、5、6、7和8 mm处的根管直径差异和根管壁的近中及远中移位。使用方差分析对获得的数据进行统计学分析。同时记录器械折断情况。结果显示，两种根管塑形U形器械与不锈钢K锉之间，预备后根管的最终直径以及根管移位均存在显著差异。在预备过程中，三把不锈钢根管塑形U形器械分离，而镍钛根管塑形U形器械组和不锈钢K型锉组均无器械分离。本研究结果表明，根管塑形U形器械及技术比使用逐步后退技术的K锉能提供更好的根管形态，并且镍钛根管塑形U形器械和不锈钢K型锉比不锈钢根管塑形U形器械具有更高的抗折断安全系数。
