Haïkel Y, Serfaty R, Lwin T T, Allemann C
Department of Endodontics C.R.O., INSERUM U424, University Louis Pasteur of Strasbourg, France.
J Endod. 1996 Dec;22(12):651-6. doi: 10.1016/S0099-2399(96)80058-6.
The cutting efficiency of endodontic instruments was measured using an original experimental technique that incorporates new concepts to simulate clinical conditions. Five designs of #ISO 030 endodontic instruments, K-reamer (Maillefer), Flexofile (Maillefer), Helifile (Micro-mega), K-flex (Kerr), and Unifile (De Trey), were chosen and their cutting efficiency assessed at their full working length of 16 mm on two Plexiglas parallelepipeds tilted to follow the 2% conicity of the instruments. For each instrument, four series of 25 cuts were carried out and each cut made on a new flat, smooth Plexiglas surface with an even hardness of 33 VHN. Instruments were tested under a simulated clinical condition of a quarter clockwise turn ROTARY MOTION followed by a PULL ACTION at 16 mm/s rate, with a fixed load on the instrument of 325 g. Water irrigation at a rate of 85 ml/s was supplied before each procedure. Cutting efficiency was evaluated in terms of mass of Plexiglas cut (using a Mettler analytic balance with accuracy of 3 x 10(-5) g) per unit of energy used by the instrument, i.e. mg/J. Unifile was found to have the best cutting efficiency of 0.80 +/- 0.01 (Mean +/- SD) and lowest cutting efficiency loss followed by Flexofile 0.70 +/- 0.03 then Helifile 0.36 +/- 0.01 then K-flex 0.51 +/- 0.07. K-reamer was found to have the lowest cutting efficiency of 0.16 +/- 0.05.
采用一种结合了新观念以模拟临床状况的原创实验技术，来测量根管治疗器械的切割效率。选取了5种#ISO 030根管治疗器械设计，即K型扩孔钻（迈尔费公司）、Flexofile锉（迈尔费公司）、Helifile锉（微迈格公司）、K-flex锉（克尔公司）和Unifile锉（德瑞公司），并在两个倾斜以遵循器械2%锥度的有机玻璃平行六面体上，于其16毫米的全长上评估它们的切割效率。对于每种器械，进行了4组每组25次的切割，每次切割都在一个新的、平坦光滑且硬度均匀为33维氏硬度的有机玻璃表面上进行。器械在模拟临床状况下进行测试，即顺时针旋转四分之一圈（旋转运动），然后以16毫米/秒的速度进行提拉动作，器械上施加325克的固定负载。在每个操作步骤之前，以85毫升/秒的速率供应水冲洗。根据器械每使用单位能量所切割的有机玻璃质量（使用精度为3×10⁻⁵克的梅特勒分析天平）来评估切割效率，即毫克/焦耳。发现Unifile锉的切割效率最佳，为0.80±0.01（平均值±标准差），且切割效率损失最低，其次是Flexofile锉为0.70±0.03，然后是Helifile锉为0.36±0.01，接着是K-flex锉为0.51±0.07。发现K型扩孔钻的切割效率最低，为0.16±0.05。
