EVALUATION OF THE ATTRACTIVE FORCE OF DIFFERENT TYPES OF NEW-GENERATION MAGNETIC ATTACHMENT SYSTEMS

Statement of problem. Rare earth magnets have been used in prosthodontics, but their tendency for corrosion in the oral cavity and insufficient attractive forces limit long-term clinical application. Purpose. The purpose of this study was to evaluate the attractive force of different types of new-generation magnetic attachment systems. Material and methods. The attractive force of the neodymium-iron-boron (Nd-Fe-B) and samarium-cobalt (Sm-Co) magnetic attachment systems, including closed-field (Hilop and Hicorex) and open-field (Dyna and Steco) systems, was measured in a universal testing machine (n=5). The data were statistically evaluated with 1-way ANOVA and post hoc Tukey-Kramer multiple comparison test (alpha=.05). Results. The closed-field systems exhibited greater (P <.001) attractive force than the open-field systems. Moreover, there was a statistically significant difference in attractive force between Nd-Fe-B and Sm-Co magnets (P<.001). The strongest attractive force was found with the Hilop system (9.2 N), and the lowest force was found with the Steco system (2.3 N). Conclusions. The new generation of Nd-Fe-B closed-field magnets, along with improved technology, provides sufficient denture retention for clinical application. (J Prosthet Dent 2011;105:203-207)