Oltjen J M, Duncanson M G, Ghosh J, Nanda R S, Currier G F
University of Oklahoma, College of Dentistry, Department of Orthodontics and Dental Materials, Oklahoma City 73190, USA.
Angle Orthod. 1997;67(3):209-18. doi: 10.1043/0003-3219(1997)067<0209:SDBOSO>2.3.CO;2.
Treatment of horizontal and vertical tooth discrepancies requires wires of low stiffness to produce forces as the teeth are leveled and aligned. In this investigation, the stiffness characteristics of several solid and multistrand nickel-titanium and stainless steel orthodontic wires were determined at selected clinically relevant deflections. Twenty specimens of 24 different wires were tested in both three-point and three-bracket bending modes. The unloading force deflection plot of each wire was described by a polynomial regression from which wire stiffnesses were obtained by mathematical differentiation. Graphs of the functional relationship between stiffness and deflection are presented. The results of this investigation show that wire stiffness can be altered not only by changing the size, but also by varying the number of strands and the alloy composition. An equally important finding was the dependence of stiffness on deflection for most of the wires measured. Comparisons were also made between the stiffness values obtained in three-point bending and the three-bracket bending systems.
治疗水平和垂直牙齿差异需要低刚度的弓丝，以便在牙齿排齐整平过程中产生矫治力。在本研究中，测定了几种实心和多股镍钛及不锈钢正畸弓丝在选定的临床相关挠度下的刚度特性。对24种不同弓丝的20个样本进行了三点弯曲和三托槽弯曲模式测试。通过多项式回归描述每根弓丝的卸载力-挠度曲线，并通过数学微分从中获得弓丝刚度。给出了刚度与挠度之间函数关系的图表。本研究结果表明，弓丝刚度不仅可以通过改变尺寸来改变，还可以通过改变股数和合金成分来改变。一个同样重要的发现是，对于大多数被测弓丝，刚度取决于挠度。还对三点弯曲和三托槽弯曲系统中获得的刚度值进行了比较。
