Ibe D M, Segner D
J Orofac Orthop. 1998;59(1):29-38. doi: 10.1007/BF01321553.
Recently archwire materials have become available which are claimed to be capable of exerting different force levels within one arch. Such orthodontic archwires are of importance because the forces they exert are supposed to be better adapted to different physiological force levels as required by teeth with different root surface areas. Undesired side effects such as root resorptions and pain should thus be minimized. The purpose of this study was to test these types of wires and to evaluate whether and, if so, to what degree the claimed properties are present. Load-deflection curves of 6 superelastic nickel-titanium orthodontic wires by 4 manufacturers were recorded using a simple beam bending test at mouth temperature. Activation-deactivation cycles with varying maximum deflection were achieved using a computer controlled stepper motor. Each archwire was tested at 4 different points on the wire. The resulting forces were evaluated metrically and graphically. Great differences were found between the superelastic properties claimed by the manufacturers and the observations of this study and also between the different products. Only 2 of the tested wires showed superelastic properties on a force level that seems adapted to the needs of the teeth to be moved.
最近，已有一些弓丝材料问世，据称这些材料能够在一根弓丝内施加不同水平的力。这种正畸弓丝很重要，因为它们施加的力理应能更好地适应不同牙根表面积的牙齿所需要的不同生理力水平。这样一来，诸如牙根吸收和疼痛等不良副作用就应减到最小。本研究的目的是测试这些类型的弓丝，并评估所宣称的特性是否存在，若存在，程度如何。通过在口腔温度下进行简单的梁弯曲试验，记录了4家制造商生产的6种超弹性镍钛正畸弓丝的载荷-挠度曲线。使用计算机控制的步进电机实现了具有不同最大挠度的激活-去激活循环。每根弓丝在其上的4个不同点进行测试。对所产生的力进行了测量和图形评估。发现制造商所宣称的超弹性特性与本研究的观察结果之间存在很大差异，不同产品之间也存在很大差异。在测试的弓丝中，只有2根在似乎适合待移动牙齿需求的力水平上显示出超弹性特性。
