Retentive force and Magnetic flux leakage of new magnetic attachment

Chihiro　Nagoya^*,Yoshitada Umekawa^*,**,Tomohiko Ishigami^*,** ,Osamu Kujirai^***,

Hitoshi Toyoma^*,**Masaaki Takamura^*,Masuko Tsuyumu^*,Shigeki Endo^*

*Department of Partial Denture Prosthodontics, Nihon University School　of Dentistry

**Division of Clinical Research, Dental Research Center, Nihon University School　of Dentistry

^***GC　Corporation

Abstract

Magnetic attachment is useful choice for dental attachment. However some clinical situations require smaller keeper and stronger attractive force to apply the magnetic attachment to abutment tooth. GIGAUSS C800(C800)is a new production of GC. This minor axis of keeper is 0.2 mm smaller keeper than the corresponding magnetic assembly.

This study evaluated the retentive force and magnetic flux leakage of C800, as compared with D800.

Retentive force was measured 5 times at crosshead speed of 5 mm/min in a universal testing machine. Magnetic flux strength was measured using a Hall Effect Gaussmeter. Data was statistically analyzed using a one-way ANOVA, and Tukey’s HSD post hoc test(α＝0.05).

The mean retentive force of C800 (719.1 gf) was significantly higher than D800 (700.0 gf) (p＜0.05).The magnetic flux leakage of C800 was significantly lower than D800 at the points of bottom of the keeper and attached side of the keeper and magnetic assembly(p＜0.05).

Nevertheless, C800 has smaller keeper than D800, these results show C800 has stronger attractive force and is lower magnetic flux leakage than D800. Therefore this now attachment GIGAUSS C800 is useful to apply for a lot of clinical situations.