Silver Alloys in Dentistry
Posted on 09/26/2011
Silver has been used in dentistry as an alloy within amalgam fillings for many years. Its use within dental laboratories grew since the 1980s due to an increased use of palladium as a substitute for gold. Silver-Palladium alloys were for many years the most common crown and bridge alloys that were categorized as "noble metal" or "semi-precious" metal alloys.
Silver has historically been alloyed to either gold or palladium because it offered a number of physical properties that improved gold and palladium's use within dentistry. The advantages of silver include:
- Silver raises the thermal expansion of palladium
- Silver lowers the melting range of gold and palladium
- Silver adds fluidity to casting alloys and solders
- Silver helps to control the strength and harness of crown and bridge alloys
The major disadvantage to silver is that it can tarnish. If not alloyed correctly, silver can turn green and thereby cause porcelains to discolor. However, most alloys that include silver on the dental lab market today are alloyed correctly and will not cause noticeable tarnish or porcelain discoloration.
Silver has historically been alloyed to either gold or palladium because it offered a number of physical properties that improved gold and palladium's use within dentistry. The advantages of silver include:
- Silver raises the thermal expansion of palladium
- Silver lowers the melting range of gold and palladium
- Silver adds fluidity to casting alloys and solders
- Silver helps to control the strength and harness of crown and bridge alloys
The major disadvantage to silver is that it can tarnish. If not alloyed correctly, silver can turn green and thereby cause porcelains to discolor. However, most alloys that include silver on the dental lab market today are alloyed correctly and will not cause noticeable tarnish or porcelain discoloration.
