Effect of Casting Conditions on Some Mechanical Properties of Cobalt-Base Alloys

Abstract

The casting of cobalt-base alloys in dentistry is comparatively new in relation to the casting of gold alloys and other restorative procedures. It has been less than thirty years since these alloys were introduced to dentistry, but each year they have become more popular. A survey of the choice of dental alloys for removable partial dentures conducted by Lane ' in 1949 showed that five times as many removable partial den-tures were cast of the cobalt-base alloys as of gold alloys. Today this ratio may be even higher, since cobalt-base alloys are the choice of many dentists and laboratory technicians. Unfortunately, even with such a high demand for this type of alloy in dentistry, little is known by the profession about the physical and mechanical properties of the alloy or about its basic nature. Similar alloys of cobalt are widely used in industry at high temperatures, and consequently more work is done and reported with this type of alloy used at high temperatures than at room temperature. Although acceptable dental techniques for casting these alloys are available, a completely dependable, accurate, and easy-to-apply technique has not yet been developed. Such a technique probably