Tabletting spherical dental amalgam alloy

Abstract

A process is provided for tabletting spherical dental amalgam alloy. The process comprises treating the particles of spherical alloy by contacting them with a hydrochloric acid solution of cupric chloride, separating the acidic cupric chloride solution from the spherical alloy particles, washing the spherical alloy particles with water, drying the spherical alloy particles to remove residual water and then compacting the treated spherical alloy particles into a solid form such as a tablet.

I claim: 
     
       1. The process for treating spherical alloy particles to enable them to be tabletted in a compacting press comprising: contacting spherical dental amalgam alloy particles .Iadd.  having a composition within the range of 59.1 to 59.7% silver, 26.5 to 27.6% tin, 12.9 to 14.3% copper and 0.01 to 0.05% zinc .Iaddend.with a hydrochloric acid solution of cupric chloride for a time sufficient to react with the alloy surface and grow cubical crystals containing copper thereon said hydrochloric acid ranging in concentration from about 10 volume percent to about 30 volume percent concentrated hydrochloric acid and said cupric chloride ranging in concentration from about 0.1 grams to about 1 gram per 100 milliliters of hydrochloric acid solution;   separating the hydrochloric acid solution of cupric chloride from the spherical alloy particles;   washing the separated spherical alloy particles with water to remove the residual hydrochloric acid solution of cupric chloride;   drying the washed spherical alloy particles to remove residual water; and finally   compacting the dried spherical alloy particles into a solid form.   
     
     
       2. The process of claim 1 in which the compacting is done by a tabletting machine. .[.3. The process of claim 1 in which the spherical alloy 
     
     
        particles are a silver, tin, copper and zinc alloy..]. 4. The process of claim 1 in which the hydrochloric acid solution of cupric chloride is in contact with the spherical alloy particles for a period ranging from about 
     
     
        10 minutes to about 40 minutes. 5. The process for treating spherical alloy particles to enable them to be tabletted in a compacting press comprising: contacting spherical dental amalgam alloy particles .Iadd.  having a composition within the range of 59.1 to 59.7% silver, 26.5 to 27.6% tin, 12.9 to 14.3% copper and 0.01 to 0.05% zinc .Iaddend.with a hydrochloric acid solution of cupric chloride for a time sufficient to react with the alloy surface and grow crystals containing copper thereon said hydrochloric acid ranging in concentration from about 10 volume percent to about 30 volume percent concentrated hydrochloric acid and said cupric chloride ranging in concentration from about 0.1 grams to about 1 gram per 100 milliliters of hydrochloric acid solution;   separating the hydrochloric acid solution of cupric chloride from the spherical alloy particles;   washing the separated spherical alloy particles with water to remove the residual hydrochloric acid solution of cupric chloride; and   drying the washed spherical alloy particles to remove residual water. .[.6. The process of claim 5 in which the spherical alloy particles are a   
     
     
        silver, tin, copper and zinc alloy..]. 7. The process of claim 5 in which the hydrochloric acid solution of cupric chloride is in contact with the spherical alloy particles for a period ranging from about 10 minutes to about 40 minutes.