This article focuses on the use of noble and precious metals for biomedical applications. These include gold, platinum, palladium, ruthenium, rhodium, iridium, and osmium. The physical and mechanical properties of noble and precious metals are presented in tables. A brief discussion on the ancient history of noble and precious metal use in dentistry is provided. The article discusses the use of direct gold dental filling materials, direct silver dental filling materials, traditional amalgam alloys, high-copper amalgam alloys, and gallium alloys in biomedical applications. It also provides information on gold coatings and iridium oxide coatings for stents.

This article describes dental alloy compositions and its properties. It discusses the safety and efficacy considerations of dental alloy devices. The article defines and compares interstitial fluid and oral fluid environments. Artificial solutions developed for the testing and evaluation of dental materials are summarized. The article examines the effects of restoration contact on electrochemical parameters and reviews the concentration cells developed by dental alloy-environment electrochemical reactions. The composition and characterization of biofilms, corrosion products, and other debris that deposit on dental material surfaces are discussed. The article evaluates the types of alloys available for dental applications, including direct filling alloys, crown and bridge alloys, partial denture alloys, porcelain fused to metal alloys, wrought wire alloys, soldering alloys, and implant alloys. The effects of composition and microstructure on the corrosion of each alloy group are also discussed. The article concludes with information on the tarnishing and corrosion behavior of these alloys.

Precious metals are of inestimable value to modern civilization. This article discusses the resources and consumption, trade practices, and special properties of precious metals and its alloys, including ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold, and tabulates the industrial applications of precious metals. It provides information on the commercial forms (wire, rod, sheet, strip, ribbon, and foil) and uses of precious metals, including semifinished products, precious metal powders, industrial uses, coatings, and jewelry.

This article reviews friction and wear of various dental materials that have been studied by fundamental wear measurements, simulated service wear measurements, and clinical measurements. The materials include dental amalgam, composite restorative materials, pit and fissure sealants, dental cements, porcelain and plastic denture teeth, dental feldspathic porcelain and ceramics, endodontic instruments, periodontal instruments, and orthodontic wires. The article describes the correlations of properties such as the hardness, fracture toughness, and wear. It provides information on wear mechanism such as the sliding adhesive wear, two-body abrasion, three-body abrasion, erosion, and fatigue.

Biomaterials are the man-made metallic, ceramic, and polymeric materials used for intracorporeal applications in the human body. This article primarily focuses on metallic materials. It provides information on basic metallurgy, biocompatibility, chemistry, and the orthopedic and dental applications of metallic biomaterials. A table compares the mechanical properties of some common implant materials with those of bone. The article also provides information on coatings, ceramics, polymers, composites, cements, and adhesives, especially where they interact with metallic materials.

Precious metals include gold, silver, and six platinum-group metals, namely, platinum, palladium, ruthenium, rhodium, osmium, and iridium. This article focuses on the consumption, trade practices, properties, product forms, and applications of these metals and their alloys.

This article discusses the chemical composition, fabrication characteristics, applications, mechanical properties, mass characteristics, thermal properties, electrical properties, optical properties, and chemical properties of precious metals, namely, silver, gold, platinum, and palladium and their corresponding alloys.

Electrogravimetry is the oldest electroanalytical technique in which the element of interest is deposited electrolytically onto an electrode and weighed. This article discusses the principles involved in determining the electrolysis rate of the solution, and describes different methods for the separation of ion in the electrolyte and their corresponding instrumentation. Furthermore, it explores the various types of analysis, such as the separation and quantitative determination of metal ions and internal electrolysis, and provides a detailed account of the applications of electrogravimetry with examples.

This article describes mechanical/electrochemical phenomena related to in vivo degradation of metals used for biomedical applications. It discusses the properties and failure of these materials as they relate to stress-corrosion cracking (SCC) and corrosion fatigue (CF). The article presents the factors related to the use of surgical implants and their deterioration in the body environment, including biomedical aspects, chemical environment, and electrochemical fundamentals needed for characterizing CF and SCC. It provides a discussion on the use of metallic biomaterials in surgical implant applications, such as orthopedic, cardiovascular surgery, and dentistry. It addresses key issues related to the simulation of an in vivo environment, service conditions, and data interpretation. These include the frequency of dynamic loading, electrolyte chemistry, applicable loading modes, cracking mode superposition, and surface area effects. The article explains the fundamentals of CF and SCC, and presents the test findings from laboratory, in vivo, and retrieval studies.

This article provides information on biomedical aspects such as active biological responses and the chemical environment characterizing the internal physiological milieu, as well as electrochemical fundamentals needed for characterizing corrosion fatigue (CF) and stress-corrosion cracking (SCC). It discusses some of the mechanical and electrochemical phenomena related to the in vivo degradation of materials used for biomedical applications. These materials include stainless steels, cobalt and titanium-base alloy systems, and dental amalgam. The article addresses key issues related to the simulation of the in vivo environment, service conditions, and data interpretation. The factors influencing susceptibility to CF and SCC are reviewed. The article describes the testing methodology of CF and SCC. It also summarizes findings from laboratory testing, in vivo testing and retrieval studies related to CF and SCC.

Controlled-potential coulometry is a highly precise and accurate method primarily used for major constituent analysis of analyte substances such as alloys, compounds, nonmetallic materials and organic compounds. This article illustrates the apparatus required for controlled-potential coulometry, and provides information on its techniques and applications. It contains a table that lists the metals for which accurate methods have been developed and the basic electrochemistry of the procedures. The article explains that gold and uranium are the elements that are determined frequently in various sample types.

Tin is a soft, brilliant white, low-melting metal that is most widely known and characterized in the form of coating. This article discusses the primary and secondary production of tin and explains the uses of tin in coating, namely tinplating, electroplating, and hot dip coatings. It presents a short note on pure (unalloyed) tin and uses of tin in chemicals. The article also covers the compositions and uses of tin alloys which include solders, pewter, bearing alloys, alloys for organ pipes, and fusible alloys. It goes on to discuss the other alloys containing tin including battery grid alloys, type metals, copper alloys, dental alloys, cast irons, titanium alloys, and zirconium alloys. Finally, it presents a short note on the applications of tin powder and corrosion resistance of tin.

This article focuses on the various forms of corrosion that occur in the passive range of aluminum and its alloys. It discusses pitting corrosion, galvanic corrosion, deposition corrosion, intergranular corrosion, stress-corrosion cracking, exfoliation corrosion, corrosion fatigue, erosion-corrosion, atmospheric corrosion, filiform corrosion, and corrosion in water and soils. The article describes the effects of composition, microstructure, stress-intensity factor, and nonmetallic building materials on the corrosion behavior of aluminum and its alloys. It also provides information on the corrosion resistance of anodized aluminum in contact with foods, pharmaceuticals, and chemicals.

This article discusses the corrosion resistance of aluminum and aluminum alloys in various environments, such as in natural atmospheres, fresh waters, seawater, and soils, and when exposed to chemicals and their solutions and foods. It describes the forms of corrosion of aluminum and aluminum alloys, including pitting corrosion, intergranular corrosion, exfoliation corrosion, galvanic corrosion, stray-current corrosion, deposition corrosion, crevice corrosion, filiform corrosion, stress-corrosion cracking, corrosion fatigue, and hydrogen embrittlement. The article also presents a short note on aluminum clad products and corrosion at joints.

Aluminum and its alloys are highly corrosion resistant, protected by a self-healing oxide film that effectively passivates the underlying surface. This article examines the various processes by which the protective layer can be breached and the types of corrosion that can occur. It describes pitting, galvanic, and atmospheric corrosion as well as stress-corrosion cracking, corrosion fatigue, and erosion corrosion. It also covers intergranular, exfoliation, filiform, deposition, and crevice corrosion and special cases of corrosion in soils, seawater, and automotive coolant systems. The article provides an extensive amount of data as well as information on coatings, claddings, and cathodic protection methods; the effects of composition, microstructure, and surface treatments; and the compatibility of aluminum with food and various household and industrial chemicals.

Liquid metal induced embrittlement (LMIE) is the reduction of the fracture resistance of a solid material during exposure to a liquid metal. This article discusses the mechanisms and occurrence condition of LMIE and describes the effects of metallurgical factors, such as grain size, temperature and strain rate, stress, inert carriers, and fatigue, on LMIE. It provides a detailed discussion on LMIE in ferrous and nonferrous metals and their alloys. In addition, the article highlights the ways of preventing embrittlement in metals and alloys.

Cast irons provide excellent resistance to a wide range of corrosion environments when properly matched with that service environment. This article presents basic parameters to be considered before selecting cast irons for corrosion services. Alloying elements can play a dominant role in the susceptibility of cast irons to corrosion attack. The article discusses the various alloying elements, such as silicon, nickel, chromium, copper, and molybdenum, that enhance the corrosion resistance of cast irons. Cast irons exhibit the same general forms of corrosion as other metals and alloys. The article reviews the various forms of corrosions, such as graphitic corrosion, fretting corrosion, pitting and crevice corrosion, intergranular attack, erosion-corrosion, microbiologically induced corrosion, and stress-corrosion cracking. It discusses the four general categories of coatings used on cast irons to enhance corrosion resistance: metallic, organic, conversion, and enamel coatings.

Metal powders are used as fuels in solid propellants, fillers in various materials, such as polymers or other binder systems, and for material substitution. They are also used in food enrichment, environmental remediation market, and magnetic, electrical, and medical application areas. This article reviews some of the diverse and emerging applications of ferrous and nonferrous powders. It also discusses the functions of copier powders and the processes used frequently for copier powder coating.