Abstract
The magnetic characteristics of various magnetic systems utilizing a Sm-Co magnet were examined. The attractive force became significantly larger by pairing two magnets or housing the magnet with ferromagnetic yoke. As the gap between the magnet and keeper increased however, the attractive force was rapidly decreased, and when the gap exceeded 0.5mm, it became almost the same as those of the single magnet systems or unhoused magnets. Although the housing effect of the half-shallowed yoke was reduced by half when no gap existed, the attractive force with this yoke became larger than that of the full-size yoke when the gap was 0.2mm or more.
The magnetic systems composed of a pair of magnets or a magnet housed with the full-size yoke may be superior when the system components are closely arranged, while the use of the shallower yoke may be more favorable in retention and ease of clinical application, when a larger gap is inevitably introduced.
