Brantley W A, Luebke N H, Luebke F L, Mitchell J C
Section of Restorative and Prosthetic Dentistry, College of Dentistry, Ohio State University, Columbus.
J Endod. 1994 May;20(5):241-5. doi: 10.1016/S0099-2399(06)80286-4.
A laboratory study was performed on Gates Glidden and Peeso drills to determine the incidence of shaft fracture when a bending deflection was superimposed on the rotating drills. Samples of sizes #1 to #6 stainless steel Gates Glidden drills, sizes #1 to #6 stainless steel and carbon steel-type P Peeso drills, and sizes #009 to #023 carbon steel-type B-1 Peeso drills from each of two manufacturers were evaluated with a unique apparatus that applied a 2-mm bending deflection while rotating the instruments. The apparatus did not restrict movement of the bur head during rotation. The test drills were rotated at 2500, 4000, and 7000 revolutions per minute, and the number of revolutions at failure was recorded. Scanning electron microscopic observations established that the stainless steel Gates Glidden and Peeso drills failed by ductile fracture, whereas the carbon steel Peeso drills failed by brittle fracture. Instrument fracture was always near the handpiece shank with this test, and the length of the fractured drills was measured from the working tip. It is recommended that this additional test be adopted to determine fatigue properties of engine-driven rotary endodontic instruments in establishing international performance standards.
对盖茨·格利登钻和皮索钻进行了一项实验室研究，以确定在旋转的钻头上叠加弯曲挠度时杆部骨折的发生率。对来自两家制造商的1号至6号不锈钢盖茨·格利登钻、1号至6号不锈钢和碳钢型P皮索钻以及009号至023号碳钢型B-1皮索钻样本，使用一种独特的装置进行评估，该装置在旋转器械时施加2毫米的弯曲挠度。该装置在旋转过程中不限制牙钻头的移动。测试钻以每分钟2500、4000和7000转的速度旋转，并记录失效时的转数。扫描电子显微镜观察表明，不锈钢盖茨·格利登钻和皮索钻因韧性断裂而失效，而碳钢皮索钻因脆性断裂而失效。在该测试中，器械断裂总是在手用柄附近，断裂钻头的长度从工作尖端开始测量。建议采用这种附加测试来确定发动机驱动的旋转牙髓器械在建立国际性能标准时的疲劳特性。
