Faculdade de Odontologia de Araraquara, Universidade Estadual Paulista, Araraquara, São Paulo, Brazil.
Am J Orthod Dentofacial Orthop. 2011 Sep;140(3):e123-8. doi: 10.1016/j.ajodo.2011.03.020.
The purpose of this study was to use photoelastic analysis to compare the system of forces generated by retraction T-loop springs made with stainless steel and titanium-molybdenum alloy (TMA) (Ormco, Glendora, Calif) with photoelastic analysis.
Three photoelastic models were used to evaluate retraction T-loop springs with the same preactivations in 2 groups. In group 1, the loop was constructed with a stainless steel wire, and 2 helicoids were incorporated on top of the T-loop; in group 2, it was made with TMA and no helicoids.
Upon using the qualitative analysis of the fringe order in the photoelastic model, it was observed that the magnitude of force generated by the springs in group 1 was significantly higher than that in group 2. However, both had symmetry for the active and reactive units related to the system of force.
Both springs had the same mechanical characteristics. TMA springs showed lower force levels.
本研究旨在通过光弹性分析比较不锈钢和钛钼合金（TMA）（Ormco，Glendora，加利福尼亚）制成的 T 型环拉簧回缩系统产生的力系，用光弹性分析进行比较。
使用三个光弹性模型在两组中评估具有相同预激活的 T 型环拉簧。在第 1 组中，环由不锈钢丝制成，T 型环顶部有两个螺旋体；在第 2 组中，它由 TMA 制成，没有螺旋体。
使用光弹性模型的条纹级数定性分析，观察到第 1 组弹簧产生的力的大小明显高于第 2 组。然而，两组的主动和被动单元与力系的关系都具有对称性。
两种弹簧均具有相同的力学特性。TMA 弹簧的力水平较低。
