Veterans Administration Cooperative Studies Project No. 147. Part IX: A comparison of the mechanical properties of several alternative metal ceramic alloys cast in clinical and research laboratories.
Comparison of mechanical properties of five metal ceramic alloys cast in clinical and research laboratories resulted in significant differences. Tested alloys included one Au-Pd (control), one Pd-Ag, and three Ni-Cr. Mechanical properties included strength, elongation, and microhardness. Tensile bars were torch cast simultaneously with restorations in the clinical laboratory and induction cast by using a preformed design in the research laboratory. Mechanical properties of most alloys showed larger variations when cast in the clinical laboratory. In the clinical laboratory the Au-Pd alloy showed significantly higher values for all properties. One Ni-Cr alloy was not significantly affected by environment for all properties. The remaining alloys were significantly affected for some properties by environment. The different laboratories had no greater or lesser effect on the base metals as a group than on the noble metals. Variation in handling, spruing, casting, and specimen size may account for some of the differences between laboratories.
D002516:Ceramics; D003722:Dental Alloys; D003799:Dental Stress Analysis; D004548:Elasticity; D006244:Hardness; D013718:Tensile Strength
D003722:Dental Alloys