Surface Treatment of Mercury Free Alloys

Published

October 12, 2021

Author(s)

S B. Geiger, D Gurbatov, M P. Dariel, F Eichmiller, R Liberman, M Ratzker

Abstract

Finishing and polishing methods were examined for two metallic direct restorative materials being proposed as possible alternatives to amalgam, namely a gallium alloy and a consolidated silver alloy. The polished surfaces were compared to a conventional spherical amalgam (Tytin^TM). After initial surface treatment with a 12-fluted tungsten carbide bur in a high speed dental handpiece, three polishing methods were evaluated: slow-speed polishing burs, rubber polishing points, and polishing discs (Soflex^TM). Each of these methods was followed by an additional surface treatment in which a pumice-flour/water slurry was applied with a rotary brush and a final surface treatment with a zinc-oxide/ethanol slurry that was applied with rotary rubber cups. The surface roughness was evaluated by profilometric measurements and light microscopy. The results showed that the smoothest surfaces for all metals were achieved with rotary finishing and polishing discs. The rubber points resulted in surfaces that were statistically similar to the disc-polished surfaces on all three materials. The polished surface of gallium alloy was consistently slightly rougher than that of amalgam. The consolidated silver also presented a consistently rougher surface than did amalgam, although these differences were not statistically significant. The additional polishing with pumice and zinc oxide improved the luster, but did not significantly improve the measured surface smoothness in any of the restorative materials studied.

Citation

Operative Dentistry

Pub Type

Journals

Keywords

amalgam polishing, consolidated silver finishing, silver polishing, surface finishing of fillings

Citation

Geiger, S. , Gurbatov, D. , Dariel, M. , Eichmiller, F. , Liberman, R. and Ratzker, M. (2021), Surface Treatment of Mercury Free Alloys, Operative Dentistry (Accessed December 18, 2025)