Gutierrez J, Nicholls J I, Libman W J, Butson T J
Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, USA.
Int J Prosthodont. 1997 Nov-Dec;10(6):562-7.
Thirty-five implant torque wrenches were tested for torque delivery accuracy. Seven of these drivers had a 10-Ncm value, 12 had a 20-Ncm value, 10 had a 30-Ncm value, and six had a 35-Ncm value. All of the wrenches had been in clinical service for a minimum of 1 month or a maximum of 3 years and were assumed by the clinicians to be fully effective in delivering the required torque values. Torque delivery accuracy was determined using a Tohnichi torque wrench calibrated to +/- 1% of the scale value. All torque wrenches had been subjected to steam sterilization following clinical use. Data collected on all wrenches included (1) age since purchase, (2) number of sterilization cycles to which each wrench had been subjected during the use period, and (3) 10 sequential torque readings using the Tohnichi wrench as the torque reading device. The results of this study showed that there was no significant correlation of delivered torque with (1) age or (2) number of sterilization cycles. Furthermore, in each torque category there were torques both above and below the control values. For the 10-Ncm torque wrenches, the largest value was 455.0% greater than the control, the largest values were 41.6% greater for 20-Ncm wrenches, 17.0% greater for the 30-Ncm torque wrenches, and 58.6% greater for the 35-Ncm wrenches. Corrosion of the spring in the handle of the torque wrench was found to be the reason for the 455.0% value.
对35把种植体扭矩扳手的扭矩传递准确性进行了测试。其中7把扳手的设定值为10 Ncm，12把为20 Ncm，10把为30 Ncm，6把为35 Ncm。所有扳手均已临床使用至少1个月或最长3年，临床医生认为它们在传递所需扭矩值方面完全有效。使用校准至刻度值±1%的东日扭矩扳手测定扭矩传递准确性。所有扭矩扳手在临床使用后均进行了蒸汽灭菌。收集的所有扳手数据包括：(1)购买后的使用时长；(2)使用期间每把扳手经历的灭菌循环次数；(3)使用东日扳手作为扭矩读取装置进行的10次连续扭矩读数。本研究结果表明，传递扭矩与(1)使用时长或(2)灭菌循环次数之间无显著相关性。此外，在每个扭矩类别中，扭矩值既有高于控制值的，也有低于控制值的。对于10 Ncm扭矩扳手，最大值比控制值大455.0%；对于20 Ncm扳手，最大值大41.6%；对于30 Ncm扭矩扳手，大17.0%；对于35 Ncm扳手，大58.6%。发现扭矩扳手手柄内弹簧的腐蚀是导致出现455.0%这个值的原因。
