摘要
目的比较相同托槽间距下多曲不锈钢方弓丝与相同尺寸国产超弹镍钛方丝加载及卸载过程中的应力/应变.方法用万能材料试验机DCS-5000分别在室温下对两种弓丝进行加载和卸载实验,数据输入Excel软件绘制加载和卸载曲线,并用SPSS10.0软件对每个形变点的力值进行统计分析,最后计算并比较载荷形变率.结果(1)在形变1.0mm的范围内,国产超弹镍钛方丝并没有表现出超弹性,即应力-应变曲线中并未出现"平台区".(2)多曲不锈钢方弓丝与国产超弹镍钛方丝的加载曲线近似呈线性变化,但相同形变下,多曲不锈钢方弓丝的应力值显著小于镍钛方丝,两者的载荷形变率比值为1:1.38,差异有显著性(P<0.05).多曲弓丝卸载曲线与国产超弹镍钛方丝相比更加平缓.结论相同托槽间距下,0.016×0.022英寸多曲不锈钢方弓丝的载荷形变率低于国产超弹镍钛方丝.
Objective To compare the load-deflection characteristics of multiloop edgewise arch （MEAW） with that of . 016× 022-inch superelastic nickel-titanium wire at the uniform interhracket span. Methods The loading and unloading-deflection of the wires were measured by using the mechanical universal testing machine （Shimadazu DCS-5000, Japan） at room temperature. Then, the data were transmitted to the Excell software , and the load-deflection curves and the unload-deflection curves were plotted in the Excell software. Forces produced at every 0. lmm deflections were compared by analysis of independent-samples t test. Results The load-deflection curves of two wires were almost linear. The LDR of the MEAW at the uniform interbracket span was 1 ： 1.38 of the superelastic nickel-titanium wire. Forces produced at every 0. lmm deflections of the MEAW were much lower than that of the superelastic nickel- titanium wire（P〈0. 05）. Conclusion In the uniform interbracket span, the multiloop edgewise arch showed much lower stiffness than the same size superelastic nickel-titanium wire.
出处
《口腔正畸学》
2005年第4期173-176,共4页
Chinese Journal of Orthodontics
关键词
多曲弓丝
超弹镍钛方丝
载荷形变率
Multiloop wire
Superelastic nickel-titanium wire
Load-deflection rate
