镍钛拉簧和弹力链力值衰减的体外实验研究  

In Vitro Experimental Study of Strength Reduction of NiTi Tension Spring and Elastic Chain

作　　者：金福[1] 李志华[2] JIN Fu;LI Zhihua(Jiangxi Provincial Maternal and Child Health Care Hospital,Nanchang 330006,China)

机构地区：[1]江西省妇幼保健院,江西南昌330006 [2]南昌大学附属口腔医院,江西南昌330006

出　　处：《现代医院》2018年第9期1315-1318,共4页Modern Hospitals

基　　金：江西省卫生计生委科技计划项目(20155539)

摘　　要：目的通过试验,对口腔环境和牙齿移动条件进行模拟,分析镍钛拉簧和弹力链在实际应用中的力值衰减情况,旨在揭示牙齿正畸过程中,镍钛拉簧和弹力链的受力情况,为临床应用提供参考。方法选择3种不同品牌的镍钛拉簧和2种品牌的弹力链,利用Instro 2343万能材料力学实验机拉伸至150 g和250 g,在力学装置上进行固定,然后放置在35. 5℃人工唾液中,模拟冷热循环。以每周为单位,进行螺丝紧固,将两端距离缩小0. 35 mm,模拟牙齿移动。对拉簧及弹力链在拉伸4 h、8 h、24 h等时间点的剩余力值进行测量,计算与初始力的百分比,做好结果统计分析。结果在模拟牙移动过程中,镍钛拉簧和弹力链在不同时间点均表现出力值衰减的特性,不同品牌的镍钛拉簧和弹力链,于不同时间点,剩余力值差别有统计学意义(P <0. 05);镍钛拉簧在模拟牙齿移动过程中的剩余力值较弹力链大,镍钛拉簧显示出更好的超弹性。结论在4～24 h内,弹力链力值衰减迅速,24 h后力值持续衰减,但保持平缓;与之相比,在各时间点,镍钛拉簧的力值衰减更加平缓,因此,临床牙齿正畸中,应该优先选择镍钛拉簧。Objective To simulate the oral environment and tooth movement conditions through experiments, and to analyze the decay- of force value of NiTi tension spring and elastic chain in practice. The aim is to reveal the relationship be- tween NiTi tension spring and elastic chain Of the force situation, provide a reference for clinical application. Methods Three different brands of NiTi tension spring and two kinds of elastic chain were selected and stretched to 150 g and 250 g using Instro 2 343 universal mechanics test machine. The mechanical strain was fixed on the mechanical device and then placed in 35.5 ~C artificial saliva. Simulate hot and cold cycles. Weekly as a unit, the screw fastening, will narrow the dis- tance between the ends 0.35 mm, simulation of tooth movement. Residual force values of tension spring and elastic chain at the time of 4 h, 8 h, 24 h and so on were measured, the percentage of initial force was calculated, and the result was statisti- cally analyzed. Results In the process of simulated tooth movement, NiTi tension spring and elastic chain showed the decay of force value at different time points. Different brands of NiTi tension spring and elastic chain, at different time points, the residual force difference was statistically （ P 〈 0. 05 ）. The residual force value of NiTi tension spring in simulated tooth move- ment is larger than that of elastic force, NiTi tension spring shows better superelasticity. Conclusion Within 4 h to 24 h, the strength of the elastic chain decays rapidly, and the force continuously decay-s after 24 h, but remains flat. Compared with that, the strength of the NiTi extension spring attenuates more smoothly at each time point. Therefore, Orthodontic, NiTi Ten- sion should be preferred.

关 键 词：镍钛拉簧 弹力链 力值衰减 体外实验 

分 类 号：R783.1[医药卫生—口腔医学]