Dental alloy for porcelain-fused-to-metal restorations

Abstract

A dental alloy comprises 50-55% by weight gold, 10-20% by weight platinum, 0-10% by weight silver, 15-35% by weight nickel, 0-10% by weight indium, 0-10% by weight tin; and 0.1% by weight grain refiner. The dental alloy may be made by mixing preselected quantities of gold, platinum, nickel and a grain refiner, subjecting the mixture to a heating process until all the metals are brought to a molten state, and thereafter allowing the metals in the molten state to cool and cure in a mold.

1 . An alloy for dental applications comprising gold, platinum, nickel and a grain refiner.  
     
     
         2 . An alloy as claimed in  claim 1  wherein the gold comprises 50-60% by weight of the alloy.  
     
     
         3 . An alloy as claimed in  claim 2  wherein the gold comprises 55% by weight of the alloy.  
     
     
         4 . An alloy as claimed in  claim 1  wherein the platinum comprises 5-20% by weight of the alloy.  
     
     
         5 . An alloy as claimed in  claim 4  wherein the platinum comprises 10-20% by weight of the alloy.  
     
     
         6 . An alloy as claimed in  claim 4  wherein the platinum comprises 10% by weight of the alloy.  
     
     
         7 . An alloy as claimed in  claim 1  wherein the nickel comprises 15-35% by weight of the alloy.  
     
     
         8 . An alloy as claimed in  claim 7  wherein the nickel comprises 20-30% by weight of the alloy.  
     
     
         9 . An alloy as claimed in  claim 7  wherein the nickel comprises 25% by weight of the alloy.  
     
     
         10 . An alloy as claimed in  claim 1  further comprising silver.  
     
     
         11 . An alloy as claimed in  claim 10  wherein the silver constitutes 1-20% by weight of the alloy.  
     
     
         12 . An alloy as claimed in  claim 10  wherein the silver comprises 10% by weight of the alloy.  
     
     
         13 . An alloy as claimed in  claim 1  further comprising indium.  
     
     
         14 . An alloy as claimed in  claim 13  wherein the indium comprises 1-20% by weight of the alloy.  
     
     
         15 . An alloy as claimed in  claim 13  wherein the indium comprises 0.5% by weight of the alloy.  
     
     
         16 . An alloy as claimed in  claim 1  further comprising tin.  
     
     
         17 . An alloy as claimed in  claim 16  wherein the tin comprises 1-10% by weight of the alloy.  
     
     
         18 . An alloy as claimed in  claim 16  wherein the tin comprises 0.25% by weight of the alloy.  
     
     
         19 . An alloy as claimed in  claim 1  wherein the grain refiner comprises a mixture of ruthenium, iridium and rhenium.  
     
     
         20 . An alloy as claimed in  claim 19  wherein the ruthenium, iridium and rhenium are present in substantially equal quantities.  
     
     
         21 . An alloy as claimed in  claim 1  wherein the grain refiner constitutes 0.1% by weight of the alloy.  
     
     
         22 . A method of making an alloy comprising the steps of mixing preselected quantities of gold, platinum, nickel and a grain refiner, subjecting the mixture to a heating process until all the metals are brought to a molten state, and thereafter allowing the metals in the molten state to cool and cure in a mold.  
     
     
         23 . A method as claimed in  claim 22  wherein the metals are mixed in a crucible.  
     
     
         24 . A method as claimed in  claim 23  wherein the grain refiner forms a lowermost first layer within the crucible, the metal having the greatest constituent by weight of the metal alloy forms a second layer, with subsequent layers being formed respectively by metals having a sequentially decreasing constituent proportion by weight in the metal alloy.  
     
     
         25 . A method as claimed in  claim 22  when carried out in a protective environment comprising a substantially noble gas.  
     
     
         26 . An alloy comprising 50-55% by weight gold, 10-20% by weight platinum, 0-10% by weight silver, 15-35% by weight nickel, 0-10% by weight indium, 0-10% by weight tin; and 0.1% by weight grain refiner.  
     
     
         27 . An alloy as claimed in  claim 26  comprising 55% by weight gold, 10% by weight platinum, 10% by weight silver, 25% by weight nickel, 0.5% by weight indium, 0.25% by weight tin, and 0.1% by weight of grain refiner. 
 [The total percentages in  claim 27  slightly exceed 100%. Please reconfigure so that total percentage adds up to 100%].  
 
     
     
         28 . An alloy as claimed in  claim 26 , wherein the grain refiner comprises a mixture of ruthenium, iridium and rhenium.