Dental clean

Dent Clin N Am 48 (2004) 499–512

Casting alloys
John C. Wataha, DMD, PhD*, Regina L. Messer, PhD
Medical College of Georgia School of Dentistry, Augusta, GA 30912-1260, USA

Dental casting alloys play a prominent role in the treatment of dental disease. This role has changed significantly in recent years with the improvement of all-ceramic restorations and the development of more durable resin-based composites. However, alloys continue to be used as the principal material for fixed prosthetic restorations and will likely be the principal material for years to come. No other material has the combination of strength, modulus, wear resistance, and biologic compatibility that a material must have to survive long term in the mouth as a fixed prosthesis. The compositions and types of casting alloys available to the dental practitioner have changed significantly over the past 25 years. Before the deregulation of the price of gold in the United States in the early 1970s, gold-based alloys, with gold comprising over 70 weight percentage (wt %) of the composition, were virtually the only type of alloy used for fixed prostheses, with or without ceramic veneers [1]. Fluctuations in the price of gold in the early 1980s (and more recently palladium) and the need for superior modulus and strength have since spurred the development of alternative alloys. Initially, these newer alloys were primarily gold based with less gold (35–50 wt %). However, today’s practitioner may select from alloys based on palladium, silver, nickel, cobalt, and titanium, among others [1]. Furthermore, alloys within each of these groups are diverse, and the practitioner faces a bewildering array of choices. Because of the long-term role these materials play in dental treatment, the selection of an appropriate alloy is critical from technical, ethical, and legal perspectives. Although uses for pure metals such as gold foil and platinum foil exist in dentistry, the main role for metals in dentistry has