Nonprecious alloys for use in fixed prosthodontics: a literature review

The physical properties of nonprecious alloys can differ significantly from those of alloys containing a high percent of gold. Relationships among constituents, physical properties, and handling characteristics of base metal alloys were surveyed. Toxicity of nickel, beryllium, and their compounds was discussed with attention given to the dental environment. Allergic contact dermatitis appears to be a health risk to certain patients from nickel-containing prostheses. Beryllium dust is apparently not a hazard in properly ventilated and exhausted grinding and polishing areas. Lack of data on nickel-related health problems in dental laboratory workers should be interpreted with caution. This article also reviewed research on porcelain bonding and corrosion of nonprecious alloys. Although this research cannot yet predict an alloy's porcelain bonding behavior in mouths, little or no porcelain bond problems have been reported. A few controlled clinical studies report little corrosion in up to 4 years.