New high-palladium casting alloys: 1. Overview and initial studies.
High-palladium alloys for metal ceramic restorations, based on the Pd-Cu-Ga and Pd-Ga systems, were introduced to the dental profession during the past decade. These alloys have become increasingly popular because they are much less expensive than the gold-based alloys, and recently marketed high-palladium alloy compositions have excellent mechanical properties. A summary of the important melting and casting considerations for these somewhat technique-sensitive alloys is presented together with an overview of important dental materials science aspects and the results of a dental laboratory survey. A maxillary central incisor coping was chosen as the clinically appropriate specimen shape, and the gas-oxygen torch melting technique was found to produce castings with clinically acceptable levels of marginal sharpness and little evidence of microporosity. The etched as-cast high-palladium alloys exhibited fine-scale multiphase microstructures, and a noteworthy finding was that relative proportions of the microstructural constituents frequently varied for thin versus thick sections of the cast specimens.
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Section of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, Columbus 43210-1241.
Brantley
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D003442:Crowns; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry*; D003735:Dental Casting Technique; D004553:Electric Conductivity; D006244:Hardness; D008422:Materials Testing; D010165:Palladium / Q000737:chemistry*; D013499:Surface Properties; D011795:Surveys and Questionnaires; D013718:Tensile Strength
D003722:Dental Alloys; D010165:Palladium