摘要
目的:测量静磁场下帽状型和三明治型口腔磁性附着体的磁体和衔铁之间的漏磁量,为临床上正确地使用磁性附着体提供依据。方法:在三坐标测量仪上精确模拟磁体和衔铁之间的对位、垂直分离和水平错开3种方式,采用特斯拉计检测磁性附着体的磁体上面、衔铁下面、附着体侧面3个位点的漏磁量,以对位方式漏磁量为基线数据,采用方差分析,比较对位、垂直分离和水平错开时漏磁量的差异性(检验水平α=0.05)。结果:MD800和EX600在垂直分离和水平错开时侧面位点的漏磁量均数都接近或超过了20 mT,尤其是在垂直分离方式下,EX600漏磁量超过了60 mT。在3种磁体和衔铁的接触方式中,对位接触与垂直分离和水平错开的漏磁量相比最小(P<0.05)。无论磁体和衔铁之间为何种接触方式,EX600的漏磁量均大于MD800,且两者之间的差异具有统计学意义。结论:在闭合磁路情况下,两种磁性附着体都存在着不同程度的漏磁现象。对位接触方式的漏磁量比较最小,因此临床上将磁性附着体精确对位是有效解决漏磁的关键。
Objective. To measure the flux leakage of static magnetic fields between the magnet and keeper of the cap and sandwiches types of dental magnetic attachments. Methods. The three modes as correct contraposition, vertical detachment and horizontal slide between the magnets and keepers were simulated on the three-COMERO. The flux leakage of three points of the top of magnet, underside of keepers and lateral of the attachment were measured and compared by Tesla meter. The flux leakage of contraposition was a baseline and data were analyzed with two-way analysis of variance （α=0.05）. Results. During the modes of vertical detachment and horizontal slide laterally, the flux leakage by MD800 and EX600 on the lateral all near to or more than 20 mT, especially in the mode of vertical detachment was more than 60 mT. Among the three modes of position between the magnet and keeper, the flux leakage of contraposition was relatively less than that of vertical detachment and horizontal slide laterally （P〈0.05）. In every contact mode, the average flux leakage by EX600 was larger than that of MD800 and the difference was statistically significant. Conclusion： Under closed-field circuit of the two types of magnetic attachments,there were flux leakages of different extent. The flux leakage of contraposition is the least. It is concluded that attaching the keeper and magnet accurately is a critical procedure to reduce flux leakage in clinical application of magnetic attachment.
出处
《武汉大学学报（医学版）》
CAS
2007年第2期185-187,191,共4页
Medical Journal of Wuhan University
基金
福建省科技厅青年基金资助项目(编号:3502Z20024005)
关键词
磁性附着体
静磁场
磁通密度
漏磁
Magnetic Attachment
Static Magnetic Field
Flux Density
Flux Leakage
