In vitro corrosion behaviour and microhardness of high-copper amalgams with platinum and indium

Samples prepared from Luxalloy(R), GS-80(R), Permite-C(R) and Logic(R) and polished after 24 h by traditional methods were stored in polypropylene tub es containing phosphate-buffered saline solutions (pH3.5 and 6.5) and disti lled water. The amounts of mercury, silver, tin, copper, zinc, platinum and indium in the test solutions were determined at the first, second, eighth, 52nd and 78th week by atomic absorption spectrometry. At the end of the ei ghth week the amalgam samples were removed from solutions and evaluated by Rockwell Super Scial Microhardness tester. Statistically significant low am ounts of metal ions were measured for Permite-C(R) containing Indium and Lo gic(R) containing platinum. The microhardness test results showed that ther e were statistically significant increases Ln the microhardness of Permite- C(R) and Logic(R). As a result it was shown that the amalgam samples were a ffected from corrosion conditions to different degrees. Sample of the Logic (R) group that was stored in distilled water, showed smoother surface prope rties than other amalgam samples containing high copper. However, it was ob served that samples of Permite-C(R) group had the smoothest surface propert ies.