温控型镍钛弓丝力学性能的时效变化  

Study of mechanical properties'secular variation of thermodynamic nickel-titanium archwires

作　　者：范旭升[1] 李志华[2] 刘翔[2] 罗俊[2] 

机构地区：[1]浙江省杭州市第一人民医院口腔科,浙江杭州310006 [2]南昌大学附属口腔医院正畸科,江西南昌330006

出　　处：《上海口腔医学》2012年第1期36-40,共5页Shanghai Journal of Stomatology

摘　　要：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。PURPOSE： To study the changes of mechanical properties of thermodynamic nickel-titanium（NiTi） archwires under 37℃ and in artificial saliva.METHODS： Using a modified partial dental arch bending device,4 types of 0.016-inch in diameter thermodynamic NiTi archwires were tested in 37℃ artificial saliva and at different moments in 8 weeks.An Instron Universal Testing Machine delivered deflections of 3mm in the lateral incisor area.The load-deflection curves were determined from the passive position to deflections of 3mm.The following variables from unloading curves were calculated,the load value at 1.5mm of unloading deflection point（UDP）,stiffness between 0.5mm UDP to 2.5mm UDP after unloading.Statistically significant differences in these variables for different brands and moment were analysed using one-way analysis of variance with SPSS11.5 software package.RESULTS： The load-deflection curves of A,B and D archwires were very similar at 0-week and 4-week,while their loading curves rised obviously at 8-week.The load-deflection curves of C archwire had significant differences at 3 moments.The load value of 1.5mm UDP of A,B and D archwires had insignificant difference at 8-week,the unloading force value of C archwire increased slightly at 8-week.There were a few fluctuations of the unloading stiffness of B and D archwires,while A and C archwires＇s unloading stiffness had a tendency to decrease.CONCLUSIONS： Thermodynamic NiTi archwires always exhibited superelasticity and SME in 8 weeks.Clinically,thermodynamic NiTi archwires can still deliver forces continuously when they are loaded for 2 months even longer.

关 键 词：温控型镍钛弓丝 力学性能 人工唾液 

分 类 号：R783.5[医药卫生—口腔医学]