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The composition of the alloy particles are controlled by the ISO Standard (ISO 1559) for dental amalgam alloy in order to control properties of set amalgam such as corrosion and setting expansion. It is important to differentiate between dental amalgam and the amalgam alloy that is commercially produced and marketed as small filings, spheroid ...
The setting reaction produces an end product called zinc eugenolate, which readily hydrolyses, producing free eugenol that causes adverse effects on fibroblast and osteoclast-like cells. At high concentrations localised necrosis and reduced healing occurs whereas for low concentrations contact dermatitis is the common clinical manifestation.
Improvements in the understanding of the structure of amalgam post-1986 gave rise to copper-enriched amalgam alloys, which contain between 12 wt% and 30 wt% copper and at least 40 wt% silver. [12] The higher level of copper improved the setting reaction of amalgam, giving greater corrosion resistance and early strength after setting.
Thus, amalgam (an alloy of mercury with another metal or metals, from the French word amalgame) was invented. This was further perfected in 1826, when Auguste Taveau of Paris used a silver paste made from mixing French silver-tin coins with mercury, which offered more plasticity and a quicker setting time. [3]
Amalgam is an "excellent and versatile restorative material" [9] and is used in dentistry because it is inexpensive and relatively easy to use and manipulate during placement. It remains soft for a short time so it can be packed to fill any irregular volume, and then forms a hard compound.
Amalgam is a metallic filling material composed from a mixture of mercury (from 43% to 54%) and a powdered alloy made mostly of silver, tin, zinc and copper, commonly called the amalgam alloy. [16] Amalgam does not adhere to tooth structure without the aid of cements or use of techniques which lock in the filling, using the same principles as a ...
Edwards said Blankson's role demands a complex amalgam of skills and passion."You are operating on multiple speeds, across different complex subjects matters with deep personal resonance," she said.
Original versions were also hard for dentists to handle and had a long setting time, but otherwise had few drawbacks. Newer versions replace the bismuth oxide with zirconium oxide, shortening the setting time, and took other measures to shorten the setting time and improve the handling. [3] MTA is relatively expensive. [1]