Dental amalgam is a dental filling material used to fill cavities caused by tooth decay. It has been used for more than 150 years in hundreds of millions of patients around the world. Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper.
Why to not use amalgam?
- Pregnant women and their developing fetuses;
- Women who are planning to become pregnant;
- Nursing women and their newborns and infants;
- Children, especially those younger than six years of age;
- People with pre-existing neurological disease;
- People with impaired kidney function; and
What metals does amalgam contain?
The main ingredient in amalgam is mercury, which accounts for about 50% of the complete filling. The other ingredients are silver, copper, tin, zinc and occasionally nickel. It has been shown that mercury is continuously relieved from mercury dental fillings in the form of mercury vapor and abraded particles.
What do metals make amalgam?
How do you make amalgam? Dental amalgam is produced by mixing liquid mercury with an alloy made of silver, tin, and copper solid particles. Small quantities of zinc, mercury and other metals may be present in some alloys. This combination of solid particles is known as amalgam alloy. Click to read further detail.
What are the characteristics of amalgam?
Amalgam remains soft for a brief time period so it is possible to fill it into any irregular volume and then a hard compound is formed. Amalgam has greater longevity when compared to other direct restorative materials, like composites. Sodium amalgam has been used in organic chemistry as a powerful reducing agent, which is much safer than sodium.
What is the composition of amalgam alloy?
A conventional dental amalgam alloy will contain between 67% and 74% silver, with 25-28% tin, and up to 6% copper, 2% zinc and 3% mercury. The so-called dispersion type amalgam alloys have around 70% silver, 16% tin and 13% copper.
What is the main metal in amalgam?
Amalgam is a mixture of two or more metals (alloy) with mercury which has been purified first by distillation to remove impurities. Currently, major components of the alloy are silver, tin, and copper.
What is the mixture of amalgam?
An amalgam is an alloy of mercury with another metal. It may be a liquid, a soft paste or a solid, depending upon the proportion of mercury.
What are the different types of amalgam?
Currently, three types of dental amalgam alloys are available: lathe cut, spherical and admixed (Figure 6.6). Their handling characteristics are all very different and it is important that they are manipulated correctly when used in the clinic for optimal performance of the set product (see pp.
What is the formula of amalgam?
Amalgam Mineral DataGeneral Amalgam InformationChemical Formula:Ag2Hg3100.00 %Empirical Formula:Ag2Hg3Environment:Base metal ore deposits with oxidisable mercury sulfides.56 more rows
What is the chemical formula of amalgam?
Sodium amalgamPubChem CID9837419Molecular FormulaHgNaSynonymsSodium mercury amalgam Sodium amalgam 11110-52-4 mercury;sodium sodium-amalgam More...Molecular Weight223.58Component CompoundsCID 5360545 (Sodium) CID 23931 (Mercury)3 more rows
What is called amalgam?
: an alloy of mercury with another metal that is solid or liquid at room temperature according to the proportion of mercury present and is used especially in making tooth cements.
What is amalgam and examples?
A mixture or an alloy of mercury with a number of metals such as sodium, zinc, gold and silver as well as with some non-metals is known as amalgam. Dental amalgam is mixture of mercury and silver tin alloy. Was this answer helpful?
What is use of amalgam?
Dental amalgam is a dental filling material used to fill cavities caused by tooth decay. Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper.
What are the 5 types of filling?
5 Types of tooth filling materialsSilver amalgam fillings. This is a popular filling. ... Composite fillings. Composite fillings are created from plastic and resin material. ... Ceramic fillings. They are created using porcelain material, which makes it both durable and cosmetically appealing. ... Glass ionomer fillings.
Why is mercury used in amalgam?
Dental amalgam is a mixture of liquid (elemental) mercury and a powdered alloy made up of silver, tin and copper. Elemental mercury makes up about 50% of dental amalgam by weight and reacts with and binds together the other metal particles to form the strong amalgam.
What are the advantages of amalgam?
Advantages of Amalgam They are very durable and capable of lasting for over a decade or more with proper care. Due to their strength, they can fill fairly large cavities within the teeth. The lower expense of amalgam fillings can be a relief to patients on a budget.
Why is tin used in amalgam?
Tin may cause setting contraction whereas copper improves strength, minimizes corrosion and tarnish, brings down creep and brings down cases of marginal leakage.
Why is mercury used in amalgam?
Dental amalgam is a mixture of liquid (elemental) mercury and a powdered alloy made up of silver, tin and copper. Elemental mercury makes up about 50% of dental amalgam by weight and reacts with and binds together the other metal particles to form the strong amalgam.
What is called amalgam?
: an alloy of mercury with another metal that is solid or liquid at room temperature according to the proportion of mercury present and is used especially in making tooth cements.
What type of metal is alloy?
alloy, metallic substance composed of two or more elements, as either a compound or a solution. The components of alloys are ordinarily themselves metals, though carbon, a nonmetal, is an essential constituent of steel. Alloys are usually produced by melting the mixture of ingredients.
What is amalgam made of?
Amalgam is any alloy that contains mercury. Copper, silver, and tin are the major components in dental amalgam but it may also contain zinc, indium, gold, platinum, and palladium. 2, 11, 12 Amalgamation is the name given to the process of mixing liquid mercury (approximately 42 to 50% by weight) with the other alloys to form a highly plastic material that hardens following precipitation. 2 The American National Standards Institute/American Dental Association (ANSI/ADA) standard specifies only the use of precapsulated alloy and mercury, which is triturated by an amalgamator (i.e., a mechanical triturator), to minimize mercury vapor leakage. 12
How much mercury is released from amalgam?
Amalgam restorations release mercury vapor equivalent to approximately 0.2 to 0.4 µg/day for each amalgam-filled to oth surface. 34, 35 These values are below the EPA established reference dose of 0.1 µg/kg/day 25 (approximately 5.8 µg/day for a 130-pound person).
How to avoid mercury spills?
To avoid potential occupational exposure to mercury, FDI recommends 1) avoiding direct skin contact with mercury or freshly mixed amalgam and 2) avoiding exposure to potential sources of mercury vapor (e.g., during placement and condensation of amalgam, during polishing or removal of amalgam, or from malfunctioning or leaky equipment). 15 FDI recommends use of high-volume evacuation systems fitted with traps or filters when polishing or removing amalgam as well as following best practices for amalgam waste (please see the ADA Oral Health Topic, “ Amalgam Separators and Best Waste Management ” for more information about amalgam waste). Phillips’ dental materials textbook also recommends the use of suction and water spray when amalgam is being ground. 2 Use of a dental dam when placing or removing amalgam may have some utility in reducing mercury exposure, but the data on this are limited and any effect seen may be small in magnitude and of transient duration. 16-18
What is the ADA policy for amalgam?
Placement considerations. Current ADA policy (see “ADA Policies on Amalgam as a Dental Restorative Material” below) calls for the elimination of bulk mercury and that dentists only use precapsulated amalgam alloy. 14 The use of precapsulated amalgam formulations reduces waste and mercury vapor leakage and provides a more consistent mercury/alloy ratio, 2, 12 and is consistent with both ADA policy and EPA regulations. A very grainy mix indicates undertrituration, whereas overtrituration will result in a shinier, softer mixture that can stick to the wall of the capsule; overtriturated amalgam has a shorter working time and higher setting contraction. 2
When is the final rule for amalgam separators?
The rule requires that dental offices that release wastewater into public water treatment systems and that place or remove amalgam install an ISO 11143-compliant amalgam separator by July 14, 2020, or if exempt, submit a one-time compliance report. Visit our Oral Health Topic on Amalgam Separators and Waste Best Management for more information, or the Legal and Regulatory Amalgam page for in-depth insight and compliance information.
Is amalgam a good material for restorative dentistry?
For more than 150 years, dental amalgam has served as a safe, durable and affordable material in restorative dentistry. 1 Dental amalgam is a mixture of metals: liquid (elemental) mercury and a powdered alloy mostly composed of silver, tin, and copper. The fact that its formulation includes mercury has raised potential health and environmental concerns.
Is dental amalgam a good material?
Dental amalgam is a safe, affordable and durable restorative material.
What is dental amalgam?
Dental amalgam is a dental filling material used to fill cavities caused by tooth decay. Dental amalgam is a mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper.
How does amalgam work?
When placing dental amalgam, the dentist first drills the tooth to remove the decay and then shapes the tooth cavity for placement of the amalgam filling. Next, under appropriate safety conditions, the dentist mixes the encapsulated powdered alloy with the liquid mercury to form an amalgam putty.
What should I know before getting a dental amalgam filling?
Deciding what filling material to use to treat dental decay is a choice that should be made by you and your dentist. As you consider your options, you should keep in mind the following information about dental amalgam fillings.
Why is mercury used in dental amalgam?
Mercury is used to bind the alloy particles together into a strong, durable, and solid filling. Mercury's unique properties (it is a liquid at room temperature that bonds well with the alloy powder) make it an important component of dental amalgam that contributes to its durability.
Why is amalgam called silver?
Dental amalgam fillings are often referred to as "silver fillings" because of their silver-like appearance , although the use of this term in not recommended because the term does not correctly explain the materials in amalgam. When placing dental amalgam, the dentist first drills the tooth to remove the decay and then shapes ...
What is the chemical form of mercury?
There are several different chemical forms of mercury: elemental mercury, inorganic mercury, and methylmercury. The form of mercury associated with dental amalgam is elemental mercury, which releases mercury vapor. The form of mercury found in fish is methylmercury, a type of organic mercury. Mercury vapor is mainly absorbed by the lungs.
Why are amalgams good for teeth?
Benefits of Dental Amalgam: Strong and long-lasting, so they are less likely to break than some other types of fillings. Useful in patients that have a high risk of tooth decay, for large tooth preparations, and where moisture makes it difficult for other materials such as resins to establish a bond to tooth.
How is amalgam made?
Dental amalgam is produced by mixing liquid mercury with an alloy made of silver, tin, and copper solid particles. Small quantities of zinc, mercury and other metals may be present in some alloys. This combination of solid particles is known as amalgam alloy. 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 particles, or a combination of these, suitable for mixing with liquid mercury to produce the dental amalgam. Amalgam is used most commonly for direct, permanent, posterior restorations and for large foundation restorations, or cores, which are precursors to placing crowns.
What is amalgam used for?
Dental amalgam is a liquid mercury and metal alloy mixture used in dentistry to fill cavities caused by tooth decay. Low-copper amalgam commonly consists of mercury (50%), silver (~22–32%), tin (~14%), zinc (~8%) and other trace metals.
How long does it take for an amalgam filling to be strong?
An amalgam restoration develops its strength slowly and may take up to 24 hours or longer to reach a reasonably high value. At the time when the patient is dismissed from the surgery, typically some 15–20 minutes after placing the filling, the amalgam is relatively weak.
What was the first dental amalgam?
It was during the Ming Dynasty that the composition of an early dental amalgam was first published, and a text written by Liu Wentai in 1505 states that it consists of "100 shares of mercury, 45 shares of silver and 900 shares of tin.".
How does a dentist make amalgam filling?
To fabricate an amalgam filling, the dentist uses a mixing device to blend roughly equal parts (by mass) of shavings of a silver-base alloy with mercury until the shavings are thoroughly wetted. The silver alloy is typically 40–70% Ag, 25-29% Sn, 2–40% Cu and 0–2% Zn (when the alloy is formulated Zn is a scavenger and is mostly consumed during melting and lost as oxide). The dentist packs the plastic mass, before it sets, into the cavity. The amalgam expands ≈0.1% over 6–8 hours on setting.
Why is amalgam used in dentistry?
In the 1800s, amalgam became the dental restorative material of choice due to its low cost, ease of application, strength, and durability. In July 2018 the EU prohibited amalgam for dental treatment of children under 15 years and of pregnant or breastfeeding women.
What is low copper amalgam?
Low-copper amalgam commonly consists of mercury (50%), silver (~22–32%), tin (~14%), zinc (~8%) and other trace metals. Dental amalgams were first documented in a Tang Dynasty medical text written by Su Gong (苏恭) in 659, and appeared in Germany in 1528. In the 1800s, amalgam became the dental restorative material of choice due to its low cost, ...
What is amalgam made of?
An amalgam is an alloy of mercury with another metal. It may be a liquid, a soft paste or a solid, depending upon the proportion of mercury. These alloys are formed through metallic bonding, with the electrostatic attractive force of the conduction electrons working to bind all the positively charged metal ions together into a crystal lattice structure. Almost all metals can form amalgams with mercury, the notable exceptions being iron, platinum, tungsten, and tantalum. Silver -mercury amalgams are important in dentistry, and gold -mercury amalgam is used in the extraction of gold from ore. Dentistry has used alloys of mercury with metals such as silver, copper, indium, tin and zinc.
How is amalgam obtained?
Amalgam obtained by either process was then heated in a distillation retort, recovering the mercury for reuse and leaving behind the gold. As this released mercury vapors to the atmosphere, the process could induce adverse health effects and long term pollution.
What is mercury used for in placer mining?
Large amounts of mercury were used in placer mining, where deposits composed largely of decomposed granite slurry were separated in long runs of "riffle boxes", with mercury dumped in at the head of the run. The amalgam formed is a heavy solid mass of dull gray color.
What metals can be amalgamated with?
Almost all metals can form amalgams with mercury, the notable exceptions being iron, platinum, tungsten, and tantalum. Silver -mercury amalgams are important in dentistry, and gold -mercury amalgam is used in the extraction of gold from ore. Dentistry has used alloys of mercury with metals such as silver, copper, indium, tin and zinc.
How does aluminium form?
Aluminium can form an amalgam through a reaction with mercury. Aluminium amalgam may be prepared by either grinding aluminium pellets or wire in mercury, or by allowing aluminium wire or foil to react with a solution of mercuric chloride. This amalgam is used as a reagent to reduce compounds, such as the reduction of imines to amines. The aluminium is the ultimate electron donor, and the mercury serves to mediate the electron transfer. The reaction itself and the waste from it contain mercury, so special safety precautions and disposal methods are needed. As an environmentally friendlier alternative, hydrides or other reducing agents can often be used to accomplish the same synthetic result. Another environmentally friendly alternative is an alloy of aluminium and gallium which similarly renders the aluminium more reactive by preventing it from forming an oxide layer.
What is zinc amalgam?
Zinc amalgam finds use in organic synthesis (e.g., for the Clemmensen reduction ). 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. It is a binary solution (liquid-solid) of mercury and zinc.
How is gold separated from mercury?
The amalgam was scraped off and the gold then separated from the amalgam by heating and evaporating the mercury, which was then recovered by a condenser for reapplication to the plates.
What is amalgam dental?
DEFINITION Dental amalgam is a metal like restorative material composed of a mixture of silver/tin/copper alloy and mercury. 3.
How long has amalgam been used?
3. HISTORY Amalgam has been primary restorative material for more than 150 yrs. Initially, amalgam restorations were made by dentists filing silver coins and mixing the filings with mercury. This was made to a putty like mass that was placed into the defective tooth.
What Is Dental Amalgam?
Mercury Toxicity of Dental Amalgam
- Mercury toxicity is a concern in dentistry because mercury and its chemical compounds are toxic to the kidneys and the central nervous system. Proper handling of mercury will prevent harm to office staff. The most significant danger is from mercury vapor. Mercury has a high vapor pressure and evaporates at room temperature. The lungs absorb most of the mercury vapor in a…
Advantages of Using Dental Amalgam
- Because of its toughness and wear resistance, amalgam is a long-lasting, cost-effective restorative material. In addition, amalgam has the ability to seal its margins during service. As the margins corrode, the tooth/restoration interface fills with corrosion products so that microleakage is reduced. Often, margins of a dental amalgam may look broken down but are actually well seal…
Properties of Dental Amalgam
- Several physical properties of amalgam hold particular interest for the clinician. Proper handling of the material is required for optimum results. 1. Dimensional Changes of Dental Amalgam Minimal change in dimension after condensation is important. 1. Excessive contraction leads to leakage and postoperative sensitivity. 2. Excessive expansion can also cause postoperative sen…
Use of Dental Amalgam
- Amalgam is used to restore many different types of carious lesions and tooth fractures. Again, amalgam is a very cost-effective restorative material and is used to restore Class I, II, V and VI carious lesions. At times, amalgam is used for small cingulum pits in the lingual of anterior teeth. Amalgam is also used as a foundation for a future crown to restore a severely decayed tooth. Th…