Loss of Alloy in the Fabrication of Metal Ceramic Crowns

While gold alloys are well accepted for metal ceramic restorations, the increasing cost of gold has limited their use. This study investigated the loss of a noble alloy during the fabrication of metal ceramic crowns. Weight losses resulting from (1) the casting process and cleaning of the casting, (2) sprue removal, (3) seating of the casting onto the die, and (4) preparation for porcelain addition were investigated using 323 crowns. The percentage weight losses were 8.92%, 17.59%, 34.03%, and 39.46%, respectively. Weight losses were generally higher for maxillary restorations, but metal ceramic restorations on anterior teeth registered significantly higher losses than those for premolars and molars.