Alloys dental amalgam

Density gradient Dental alloys Dental amalgam Dental amalgams Dental caries... 

Dental amalgams, mainly silver—tin—mercury alloys, have been used as fillings for many years (see Dental MATERIALS). The most common alloy contains 12 wt % tin. 

Composition. The composition of powdered alloys used in preparing dental amalgams usually includes 66.7—75.5% silver 25.3—27.0% tin ... 

Gallium-Based Alloys. A gaUium-based alloy has been kitroduced commercially ki Japan as a substitute for dental amalgam, but similar alloy types have previously been associated with abnormal cellular reactions and are not much used elsewhere nickel— gallium alloys have produced carckiomas ki rats (139). The corrosion resistance of the gallium alloys is also marginal. 

Sodium, potassium, mercury and silver do not alloy with tantalum even at high temperatures 5 attempts to prepare alloys with arsenic, antimony, lead, zinc and tellurium have also failed, but the formation of an alloy with silver, copper and tin for making a dental amalgam with mercury has recently been claimed.6... 

An alloy that is made of a metal dissolved in mercury is called an amalgam. A traditional dental amalgam, used to fill cavities in teeth, contains 50% mercury. Due to concern over the use of mercury, which is toxic, dentists now use other materials, such as ceramic materials, to fill dental cavities. 

Platinum occurs in the following alloys used in the preparation of dental amalgams 4 ... 

Dental amalgam (SEDA-10,210) (SEDA-15,233) (14,15) is still used for about 75-80% of single-tooth restorations. The modern amalgam consists of a metalhc alloy (silver, tin, and copper, sometimes with small amounts of zinc, indium, and/or palladium) mixed with mercury in a percentage of 40-54% mercury by weight. The resultant plastic mass sets and hardens over a period of 8-24 hours. 

Small amounts of silver are used in a variety of other products. For example, it is used in dental amalgams. An amalgam is an alloy in which mercury is one of the metals used. Silver amalgams work well for filling decayed teeth. They are non-toxic and do not break down or react with other materials very readily. Silver is also used in specialized batteries, cell phone covers, circuit boards, and Radio Frequency Identification Devices (RFIDs). 

Hultman P, Johnasson U, Turley SJ, et al. 1994. Adverse immunologicol effects and autoimmunity induced by dental amalgam and alloy in mice. FASEB J 8(14) 1183-1190. 

This relationship between allergy and metallic biomaterials has also been confirmed for alloys used in dentistry Ni, Cr and Co in non-precious alloys (Hildebrand et al. 1989a, 1989b), and Hg and Ag in dental amalgams (Veronetal. 1986 Horsted-Bind-slev et al. 1997 Sandborgh-Englund et al. 

Precious, semi-precious, most Pd-base alloys, Ti-base alloys and stainless steel also produce excellent biological responses with a survival rate of 98% to 70% for the highest concentration. Two semi-precious alloys with high Ag-content reflect the cytotoxic effect of pure silver (Figure 5.1). Ni-Cr alloys (14% and 23%) induce a strong cytotoxic action, and dental amalgams produce total cell death at very low concentrations. 

The MGC test confirmed the quasi-perfect cytocompatibility of the of Pd, Au, Ti powders and of alloys containing respectively these metals, since the number of MGC in exposed cultures was identical to that in control cultures (Table 5.4 Figures 5.3 and 5.4). However, cultures exposed to pure Ni, Co, Ag and to Ni-rich alloys and dental amalgams developed eight- to ten-fold increases of MGC with respect to control cultures (Table 5.4 Figures 5.3 and 5.5). The inflammatory effect of silver is confirmed in the Ag32Pd57 alloy. Stainless steel without a major influence on cell viability induces inflammatory reactions comparable to those produced by Cr. 

Fig. 5.5 Typical feature of LI 32 cells grown in the presence of powders of pure Ni or Co, dental amalgam, Ni-Cr containing alloys or alloys with high amounts of Ag. Note the presence of a large number of multi-nucleated giant cells, indicating an inflammatory reaction.

Mahler DB (1997) The high-copper dental amalgam alloys. J Dent Res 76 537-541. 

Some of these binary and ternary phases have been studied to a larger extent because of special physical and/or mechanical properties. Of particular interest are the Cu phases CuZn, Cu j +1, 3,Zn i 2.3,Al, and (Cu,Ni)3Al, on which the Cu-Zn-Al and Cu-Al-Ni shape memory alloys are based and which are the subject of the following sections. In addition, the Cu-Au phases CU3AU and CuAu and the Cu-Sn phases Cu3Sn and Cu Snj will be addressed, which are important constituents of Cu-Au alloys and amalgams for dental restorative applications. 

Mercury forms solutions or alloys with many different metals, called amalgams. The dental amalgam used to fill cavities in teeth contains mercury, silver and tin. During chewing, it has been suggested... 

Amalgams are alloys of mercury with other metals used extensively as chemical reagents and catalysts. The proportion of mercury dictates whether the amalgam is solid or liquid. They include sodium amalgam (Na Rgy), used to manufacture sodium hydroxide, and dental amalgams (alloys of mercury with some combination of silver, copper, tin, gold, or silver) used to fill dental cavities. 

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