Abstract
Purpose: Recently, laser welding has gained wide acceptance as a dental laboratory technique for bonding metals. We have previously reported a new technique for installing a magnetic keeper in the overdenture abutment coping using laser welding. In the present study, the influence of this technique on the attractive force and corrosion were evaluated.
Methods: A commercially-available magnetic keeper and dental casting Au-Ag-Pd alloy were used. Specimens were prepared by one of the following procedures: original magnetic keeper only, conventional cast-on technique and laser welding technique. Attractive force between thedental magnetic assembly and magnetic keeper was measured using a self-made measuring device. The results were analyzed using the one-way ANOVA test. The external and inner surface of magnetic keepers and cross sections of specimens were observed using metal and stereoscopic microscopes before and after immersion of the specimens in 0.9% NaCl solution for 21 days.
Results: There was no significant difference of attractive force between the conventional cast-on technique and laser welding technique. All of the specimens using the cast-on technique rusted in the corrosion test. Half of the specimens using the laser welding technique changed less, and no oxidized layer or corrosion was observed on the surface.
Conclusions: Installation of magnetic keepers using laser welding is useful for increasing both attractive force and corrosion resistance.
