论文部分内容阅读
目的:比较不同品牌温控型镍钛弓丝力学性能的长期变化。方法:利用Instron万能材料力学实验机在37℃人工唾液中对4种品牌温控型镍钛圆丝(直径0.016英寸)在3个时间点(0、4、8周)进行改良部分牙弓弯曲实验,绘制加载、卸载的载荷-挠曲曲线,计算各时间点卸载1.5mm的载荷值、卸载2.5～0.5mm之间的刚度平均值和标准差。采用SPSS11.5软件包对数据进行统计学分析。结果:A、B、D 3种温控型镍钛圆丝0周与4周载荷-挠曲曲线很相近,而在8周时加载曲线明显增高,但卸载曲线无显著变化,C弓丝在3个时间点的载荷-挠曲曲线之间均有显著差异。A、B、D 3种弓丝在所有时间点卸载1.5mm载荷值的波动很小,C弓丝8周时卸载力值有所增大。B与D弓丝不同时间点的卸载刚度波动较小,而A与C弓丝卸载刚度随着时间延长有减小趋势。结论:温控型镍钛弓丝随着加载时间的延长,其力学性能有所变化,但其超弹性及形状记忆性能并未改变。
Objective: To compare the long-term changes of mechanical properties of temperature-controlled NiTi arch wires of different brands. Methods: Four brands of temperature controlled NiTi filaments (0.016 inch in diameter) were modified at 37 ℃ artificial saliva at 3 time points (0, 4, and 8 weeks) using Instron universal mechanical testing machine. Partial dental arch curvature The load-deflection curves of loading and unloading are plotted. The unloading 1.5mm load value at each time point is calculated, and the average value and standard deviation of stiffness between 2.5 and 0.5mm are unloaded. SPSS11.5 software package for statistical analysis of the data. Results: The load-deflection curve of three kinds of temperature-controlled nickel titanium rounds of A, B and D were similar between 0 week and 4 weeks, while the loading curve increased obviously at 8 weeks, but the unloading curve did not change significantly. There was a significant difference between the load-deflection curves at 3 time points. A, B, D three kinds of arch wire at all time unloading 1.5mm load value fluctuations in the small, C arch wire unloading force value increased at 8 weeks. The unloading stiffness of B and D arch wires fluctuated less at different time points, while the unloading stiffness of arch wires A and C tended to decrease with time. CONCLUSION: The mechanical properties of the temperature-controlled Ni-Ti arch wires vary with loading time, but their super elasticity and shape memory properties have not changed.