弹力链力值衰减体外研究  

In vitro study of force degradation of elastomeric chains

作　　者：李志媛[1,2] 刘奕[1] 郑颖[1] 

机构地区：[1]中国医科大学附属口腔医院正畸科,辽宁省口腔疾病转化医学研究中心,沈阳110002 [2]解放军202医院,沈阳110003

出　　处：《中国实用口腔科杂志》2015年第2期99-102,107,共5页Chinese Journal of Practical Stomatology

基　　金：辽宁省科学技术计划项目(2013225090)

摘　　要：目的通过体外实验在热循环条件下研究连接体类型以及圈数对于弹力链力值衰减的影响。方法本研究于2013年在中国医科大学附属口腔医院中心实验室进行。将4、5、6个圈数的短、中、长距型弹力链按照正交实验设计进行组合,拉伸250 g（1 g=0.0098 N）初始力值,置于37℃人工唾液环境下,每日3次15-55℃热循环;利用电子推拉力仪,测量各组弹力链在加力4、24 h以及7、14、21、28 d的剩余力值大小及各测量时间点的力值衰减百分比。结果在15-55℃热循环条件下,弹力链力值随加力时间逐渐衰减,在最初的4 h内力值衰减急剧,24 h末内衰减最快,24 h至28 d之间各时间点力值衰减百分比增幅不大;各时间点不同连接体类型及圈数对弹力链力值衰减影响的差异均有统计学意义（P〈0.01）;短、中、长距型弹力链力值衰减百分比依次增大,4、5、6个圈数弹力链力值衰减百分比依次减小。结论在15-55℃热循环条件下,弹力链力值在4 h内衰减最快,24 h后衰减趋于稳定;在初始力相同的前提下,连接体越长,圈数越少,弹力链力值衰减越大。Objective To test the influence of the type of filament and the number of loops on force degradation of elastomeric chains under the condition of thermal cycle. Methods The elastomeric chains tested in this study included 3 kinds of filament types ： close, medium and long. Each type of the elastomeric chains were all cutted into four, five and six loops. And various chains were stretched to produce the initial force of 250 g. Then arrange the experiment groups by the orthogonal design, and the stretched length of different groups of chains were maintained respectively in artificial saliva environment of 37-C and thermocyeled between 5℃ and 55℃ for 3 time a day. The remaining force of the elastomeric chains were recorded at different moments in 4 weeks. Then calculate the percentage of remaining force. Results The force of elastomeric chain gradually decayed over time, under the condition of thermal cycle. The force degradation was sharp in the first 4 hours. The force degradation was the fastest within the end of 24 hours. Force decay percentage in- creased slightly between 24 hours to 28 days. Differences among different connection types as well as loops on force deg- radation at each time point were statistically significant. When given the same stretched force, the strerched length of close, medium, large filament types and 4,5,6 loops were increased in sequence. Conclusion The force of elastomeric chain fastest decayed within the initial 4 hours and stabilized after 24 hours under the condition of thermal cycle; while the initial force is the same premise, the longer the connector body, the fewer number of turns, the greater the force degradation of elastomeric chain.

关 键 词：弹力链 力值衰减 热循环 

分 类 号：R78[医药卫生—口腔医学]