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Research Into Non-Mercury Containing Metallic Alternatives



F Eichmiller


Many attempts have been made over the years with varying degrees of success to develop metallic alternatives to dental amalgam. Much of the difficulty in achieving success is the inability to meet the physical, mechanical and clinical criteria for an ideal alternative. An additional requirement for any new material is that it be environmentally friendly, both from a manufacturing standpoint and in use. Gold foil has been on of dentistry's most successful direct filling materials, but it is only used by few select clinicians and is largely considered a lost art. Metal-modified glass ionomers have achieved some success as crown buildup materials and direct restoratives in the primary teeth of children, but these are slowly being displaced by improved composites. Several attempts have been made to develop metal-filled composites, but only one product is available for use as a crown buildup material. There is a long history of attempts at formulating an acceptable gallium alloy. Early nickel-gallium formulations resulted in severe tumorgenicity in animal trials. Palladium-gallium-tin alloys were less toxic, but still exhibited high latent expansion and severe soft tissue inflammation around implants and tissue-embedded particles. More recent attempts to formulate silver-copper-gallium-indium-tin alloys resulted in better biocompatibility, but clinical trials showed corrosion and latent expansion to be too severe for general clinical acceptability. Studies of consolidated silver materials have resulted in the development of a direct restorative system with favorable properties and biocompatibility, but no human trials have yet evaluated the material's clinical performance. The demands in today's market for esthetics and regulatory pressures to reduce heavy metals in wastewater have resulted in less interest in metallic alternatives for amalgam. Future development will likely focus on improving polymeric composites in an attempt to meet the call for an amalgam alternative.
Operative Dentistry
Supplement 6




Eichmiller, F. (2001), Research Into Non-Mercury Containing Metallic Alternatives, Operative Dentistry (Accessed June 21, 2024)


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Created August 1, 2001, Updated February 17, 2017