摘要
目的研究磁性附着体、精密附着体和半精密附着体在体外反复脱位后其固位力的变化情况。方法将磁性附着体(Magfit EX 600W型)、精密附着体(Mini-SG附着体)和半精密附着体(太极扣附着体)分别连接和固定于模具制备试件模型,采用万能材料试验机进行垂直向拉伸测试,测量初始固位力。以每日摘戴3次模拟使用2年的附着体,将各试件模型置于自制的循环拉伸试验机上以2次/s的速度进行循环反复拉伸,分别于拉伸第500、1 000、1 500和2 000次时进行固位力测试。观察和分析不同附着体固位力的衰减情况。结果磁性附着体、Mini-SG附着体和太极扣附着体的初始固位力分别为2.67、7.30和40.20 N;在2 000次的循环拉伸试验中,磁性附着体的固位力变化呈现一水平直线,无显著变化;Mini-SG附着体的固位力变化曲线较为平缓,呈现逐渐变小趋势;太极扣附着体的固位力在最初的500次拉伸试验时即迅速下降,之后逐渐趋于平缓。磁性附着体、Mini-SG附着体和太极扣附着体的固位力分别衰减0.75%、45.75%和69.95%。结论磁性附着体固位力基本不受脱位次数的影响。Mini-SG附着体的初始固位力及其衰减率均小于太极扣附着体。本实验为临床医师和患者对附着体的选择提供了参考依据。
Objective To investigate the changes of retention strength of magnetic attachment,precise attachment and semi-precise attachment after repeated dislocation in vitro.Methods Magnetic attachment(Magfit EX 600W),precise attachment(Mini-SG attachment) and semi-precise attachment(ERA attachment) were fixed on universal material test machine respectively.The retention strength of each attachment was measured initially and after repeated stretching(500 times,1 000 times,1 500 times and 2 000 times of stretching) with the speed of two times per second.The attenuation of retention strength of each attachment was observed and analysed.Results The initial retention strength of magnetic attachment,Mini-SG attachment and ERA attachment was 2.67 N,7.30 N and 40.20 N respectively.There was no significant change in retention strength of magnetic attachment during 2000 times of stretching.The curve of retention strength of Mini-SG attachment was relatively smooth,and the retention strength exhibited a downward trend.The retention strength of ERA attachment decreased significantly during the first 500 times of stretching,and the curve of retention strength turned to be smooth later.The attenuation rates of retention strength of magnetic attachment,Mini-SG attachment and ERA attachment were 0.75%,45.75% and 69.95% respectively.Conclusion The retention strength of magnetic attachment may not be influenced by times of dislocation,and the initial retention strength and attenuation rate of Mini-SG attachment were smaller than those of ERA attachment.The results of this experiment provide reference for attachment selection for both dentists and patients.
出处
《上海交通大学学报(医学版)》
CAS
CSCD
北大核心
2011年第6期813-816,共4页
Journal of Shanghai Jiao tong University:Medical Science
关键词
磁性附着体
精密附着体
太极扣附着体
固位力
衰减
magnetic attachment
precise attachment
ERA attachment
retention strength
attenuation