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Amalgam filling on first molar. In dentistry, amalgam is an alloy of mercury used to fill teeth cavities. [1] It is made by mixing a combination of liquid mercury and particles of solid metals such as silver, copper or tin.
This could be due to corrosion which may result in "creep" and "ditching" of the restoration. Creep can be defined as the slow internal stressing and deformation of amalgam under stress. This effect is reduced by incorporating copper into amalgam alloys. Some patients may experience local sensitivity reactions to amalgam.
Sometimes, a tooth is planned to be restored with an intracoronal restoration, but the decay or fracture is so extensive that a direct restoration, such as amalgam or composite, would compromise the structural integrity of the restored tooth or provide substandard opposition to occlusal (i.e., biting) forces. In such situations, an indirect ...
Zinc amalgam finds use in organic synthesis (e.g., for the Clemmensen reduction). [3] It is the reducing agent in the Jones reductor, used in analytical chemistry.Formerly the zinc plates of dry batteries were amalgamated with a small amount of mercury to prevent deterioration in storage.
Dental composites. Glass ionomer cement - composite resin spectrum of restorative materials used in dentistry. Towards the GIC end of the spectrum, there is increasing fluoride release and increasing acid-base content; towards the composite resin end of the spectrum, there is increasing light cure percentage and increased flexural strength.
The reaction that occurs at the surface of the amalgam may actually be a hydrogenation rather than a reduction. The presence of water in the solution is reportedly necessary; the electron rich amalgam will oxidize aluminium and generate hydrogen gas from water, creating aluminium hydroxide (Al(OH) 3) and free mercury.
Sodium amalgam is a by-product of chlorine made by mercury cell electrolysis. In this cell, brine (concentrated sodium chloride solution) is electrolysed between a liquid mercury cathode and a titanium or graphite anode. Chlorine is formed at the anode, while sodium formed at the cathode dissolves into the mercury, making sodium amalgam.
The metal may be in the granulated form or as shavings, wool, or powder. The amalgam forms on the surface of the zinc. After washing to remove salts, the amalgam is placed in a long glass tube, similar to a chromatography column, equipped with a stopcock. [1] The amalgam is a more effective reducing agent than zinc metal.