Amalgam four or more surfaces, primary or permanent. Mercury forms alloys with almost all other metals, except iron, tungsten, tantalum, and platinum. In dentistry, an amalgam of silver and tin, with minor amounts of copper and zinc, is used to fill teeth a sodium amalgam is formed during the. The food and drug administration fda and other public health organizations have investigated the. Dental amalgam is a liquid mercury and metal alloy mixture used in dentistry to fill cavities caused by tooth decay. Pdf in recent years, there have been many attempts to improve the properties of dental amalgam. Moreover, it is soft enough to adapt to the size and shape of the tooth cavity, yet hardens sufficiently fast to make it practical. People who might be concerned about dental amalgam because it contains mercury can be reassured that credible scientific studies show no cause for alarm. Dental amalgam or silvercolored filling is a durable metal alloy comprised of silver, copper and tin, in addition to mercury, which binds these components into a hard, stable substance. Advantages and disadvantages of amalgam dental materials. The safety of dental amalgam and alternative dental restoration materials for patients and users by the scientific committee on emerging and newly identified health risks, and the environmental risks and indirect health effects of mercury in dental amalgam by the scientific committee on.
Compliance with the epa final rule on amalgam separators is recommended. The primary constituents are ag, sn, cu, and sometimes. Dental amalgam has served as an excellent and versatile restorative material for many years, despite periods of controversy. Adverse health effects from mercury exposure can be. Prepared by the international academy of oral medicine and toxicology iaomt. Amalgam, alloy of mercury and one or more other metals. Dental amalgam apparently was first used by the chinese. An update article pdf available in journal of conservative dentistry 4. Currently, major components of the alloy are silver, tin, and copper. The original particle is an alloy of ag, sn, cu, andsometimeszn.
Dental amalgam fillings american dental association. It is an alloy composed of a mixed powder of approximately 46% to 57% silver, tin, copper and, in some cases, smaller amounts of zinc, palladium or indium bound by approximately 43% to 54% of elemental liquid mercury. Amalgam is a mixture of two or more metals alloy with mercury which has been purified first by distillation to remove impurities. Highcopper dental amalgam highcopper alloys exhibit properties of high strength, less corrosion and tarnish, less creep and minimal sensitivity to handling variables producing longterm clinical results. Both metallographic and xray diffraction techniques have been used. 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. Dental amalgam is the product of the amalgamation between mercury and an alloy containing silver, tin, often copper, and sometimes other elements combined in. There are indications that dental amalgam was used in the first part of the tang dynasty in china 618907 a. Approximately 50 million amalgam restorations are placed each year. Public health and the environment july 2016 issue summary dental amalgam is an alloy made by combining silver, copper, tin and zinc with mercury. Lowcopper amalgam commonly consists of mercury 50%, silver 2232%, tin 14%, zinc 8% and other trace metals dental amalgams were first documented in a tang dynasty medical text written by su gong in 659, and appeared in germany in 1528. Study after study shows amalgam is safe and effective for filling cavities. The objective of this report is to provide a summary of the results and progress achieved through the implementation of the notice regarding pollution prevention planning in respect of mercury releases from dental amalgam waste the notice.
Dental amalgam is an alloy used as a filling restorative material for tooth cavities caused by either decay, trauma, or other factors, and is composed of mercury, silver, tin, and copper, along with other metallic elements added to improve physical and mechanical properties ada, 2011. Dental amalgam is a mixture of metals, consisting of liquid elemental mercury and a powdered alloy composed of silver, tin, and copper. These controversies are often referred to as amalgam wars. Rigidity moe of high copper amalgam is 55 gpaclose to enamel. It is called a direct restoration because the material used to repair the tooth undergoes its hardening process while in direct contact with the tooth and inside the mouth. Amalgam is an efficient and effective restorative material.
Bothdental4 andmetallographic litera tures810 were surveyed to find an etch suitable for. When amalgam fillings are placed in or removed from teeth, they can release a small amount of mercury vapor. Of the dental amalgam constituents, mercury is of greatest concern to human health because it is a persistent bioaccumulative toxic chemical. Su kung 659 ad mentioned the use of a mixture in the material medica.
Most researchers nowpresume that dental amalgam consists mainly of three phases. The materials properties and guidelines for placement were well. Biological properties of dental materials 1 authorstream. Improvement of dental amalgam properties by increasing.
Dental best management practices for amalgam waste handling and disposal include use of chairside traps, use of iso 11143compliant amalgam separators, regular inspection and cleaning of traps, and use of appropriate commercial waste service to recycle andor dispose of collected amalgam. Amalgams are crystalline in structure, except for those with a high mercury content, which are liquid. Dentists will continue to use it in the foreseeable future, although its use continues to gradually decline. Approximately 50% of dental amalgam is elemental mercury by. Dental amalgam has been in widespread use for over 150 years, and is one of the oldest materials used in oral health care.
The aim of this chapter is to describe the properties of the dental amalgam and demonstrates how cavity is prepared for amalgam in classes i. Epa regulation on dental amalgam waste fair and reasonable 617. In obtaining its initial set, or hardness, amalgam allows time for condensing and carving. Jul 31, 2016 amalgam is used to restore many different types of carious lesions and tooth fractures. Amalgam has been studied and tested more than any other restorative. Panel members also acknowledged that the present state of knowledge on chronic health effects was well covered in the white. Dental amalgam is a very strong and durable dental filling material. The ada works with lawmakers, regulators, public health officials, and others to safeguard patient access to the safest. Amalgam four or more surfaces, primary or permanent dental.
A filling is a direct dental restoration used to repair decayed, chipped, cracked or otherwise damaged teeth. When dental amalgam is washed down drains at dental clinics, it travels through municipal sewer systems to wastewater treatment plants, or directly to waterways. Addendum to the white paper to the dental amalgam to. Click here for briefing on dental amalgam pdf history 1833. The safety of dental amalgam and alternative dental. In addition, the chemical reactivities of the phases vary greatly. At times, amalgam is used for small cingulum pits in the lingual of anterior teeth. Addendum to the white paper to the dental amalgam to 2006. Some singlecomposition alloys contain small amounts of indium and palladium. Moreover, those who oppose amalgam for possible health reasons should remember that other substances have not received extensive scrutiny in this regard. Even if dentists completely stopped using amalgam for new fillings, the removal of old amalgam will continue to generate amalgam waste.
Amalgam restorations account for a significant portion of all dental restorations. However, concerns have been voiced about possible harmful effects of the mercury present. Mechanical properties one of the most important properties of dental materials of dental materials is the ability to withstand the various mechanical forces placed on them during use as restoration, impression, models, appliances and tools. Although manyetch ing solutions have been proposed in the literature, each has a shortcoming which limits its use. As defined by the dictionary 2, amalgam amalgam is 1. In view of the specific properties of dental amalgam and alternatives. Dental amalgam visit the ada center for professional success to find out what you need to do to comply with the epa amalgam recycling rule learn more ada president. Flow and creep are characteristics that deal with an. Feb 03, 2012 thermal properties lcte of amalgam is 2. The answers to these questions are a faithful summary of the scientific opinion produced in 2008 by the scientific committee on emerging and newly identified health risks scenihr.
According to the centers for disease control and prevention, there is scant evidence that the health of the vast majority of people with amalgam is compromised. Amalgamchemical composition, mechanical properties and common applications. Dental amalgam has high compressive strength, which is 380mpa for lowcopper amalgam and 414mpa for highcopper amalgams. Key uses of amalgams are in dentistry, gold extraction, and chemistry. Amalgam is a metal alloy of which one of the elements is mercury hg. The principles and physicalchemical properties of dental amalgams are. Dental amalgam is made from a combination of metals that include mercury, silver, tin, and copper. Food and drug administration fda considers dental amalgam fillings safe for adults.
An amalgam restoration needs to be strong enough so as to resist the biting forces of occlusion. More recently, other materials, such as composite resins, have provided dentists. Dental amalgam is used in all surfaces of posterior teeth and occasionally in the lingual pits of anterior teeth. The composition of the alloy powder is controlled by iso standard for dental amalgam alloy iso 1559 to control the properties of amalgam. Dental amalgam is the product of the amalgamation between mercury and an alloy containing silver, tin, often copper, and sometimes other elements combined in varying amounts. Materials engineering, university of babylon, babylon, iraq. Brief summary of amalgam properties authorstream presentation. Again, amalgam is a very costeffective restorative material and is used to restore class i, ii, v and vi carious lesions. The powdered metal is called an amalgam alloy and is predominantly silver ag and tin sn. Dental amalgam is made by mixing approximately equal parts by weight of a powdered metal alloy with liquid mercury. The elemental mercury in dental amalgam is the least potentially harmful of all forms of mercury. Pdf mechanical properties improvement of dental amalgam.
Improvement of dental amalgam properties by increasing copper. Physical properties of dental silvertin amalgams with high. Improvement of dental amalgam properties by increasing copper content dr. In europe, johannes stokers, a municipal physician in ulm, germany, recommended amalgam as a filling material in 1528. Dental amalgam is widely used as a restorative material even though it is not esthetic and there. Amalgamchemical composition, mechanical properties and. It has an acceptable crushing strength and is recognized as having a long life as a restoration. Amalgam properties compressive strength mpa % creep tensile strength 24 hrs mpa amalgam type 1 hr 7 days low copper1 2. The strength of an amalgam is determined primarily by the composition of the alloy, the amount of residual mercury remaining after condensation, and the degree of porosity in the amalgam restoration. An amalgam is formed when an alloy of two or more metals is mixed with mercury. Dental amalgam american college of prosthodontists.
The safety of dental amalgam and alternative dental restoration materials for patients and users 2 about the scientific committees three independent nonfood scientific committees provide the commission with the scientific advice it needs when preparing policy and proposals relating to consumer safety, public health and the environment. Sources of amalgam in dental wastewater include the placement of and removal of amalgam fillings restorations. Resin composite has replaced amalgam as the material of choice in many clinical situations. Despite its favourable properties, its use has been highly controversial because of concerns about its potential effects on health. An overview of the new epa dental amalgam separator. The objective is to meet a 95% reduction of national mercury releases from dental amalgam waste, from a base year of 2000. Amalgam has been used to restore teeth affected by decay for more than a hundred years.
Sometimes described as silvercolored fillings, dental amalgam has been used by dentists for more than 100 years because it lasts a long time and is less expensive than other cavityfilling materials such as toothcolored composites or gold fillings. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Alloys are metals that are a combination of several elements. Other procedures, such as inlays and onlays, are considered to be indirect restorations because the material used. This increases the longivity of amalgam restoration 24. Amalgam is a metallic filling material composed from a mixture of mercury from 43% to 54% and powdered alloy made mostly of silver, tin, zinc and copper, commonly called the amalgam alloy. Physical properties of dental silvertin amalgams with.
Composition of amalgam conventional amalgam alloys. The properties of set amalgam depends upon the alloy compositionparticle size, shape and. Dental amalgam is a liquid mercury and metal alloy mixture used in dentistry to fill cavities. The safety of dental amalgam and alternative dental restoration materials for patients and users and the environmental risks and indirect health effects of mercury in dental amalgam. The answers to these questions are a faithful summary of two scientific opinions produced in 2008. The safety of dental amalgam and alternative dental restoration.
Lowcopper dental amalgam these were being used in the past and have almost fully been replaced by highcopper amalgams. In the united states, dental amalgam has been used successfully for the restoration of teeth for over 170 years. Mercury can bioaccummulate three to ten times across each trophic level of the food chain. When mercury initially comes into contact with amalgam alloy the particles are wet by the mercury and then begin to absorb it 2. Amalgam, composite resins, longevity, biocompatibility. Vi black rightly concluded that an amalgam with zero change would ideally be best. However, amalgam fillings are more versatile than the newer materials, because they can be used for other dental situations and hold up better over time, especially in teeth that undergo wear and tear from pressure and chewing. This chapter covers the properties and handling of amalgam and mercury hygiene.
Dental amalgam has been used to restore teeth for almost 200 years. Physical properties of dental silvertin amalgams with high and low copper contents. Later, li shihchen 1578 chronicled a dental mixture of 100 parts mercury with 45 parts silver and 900 parts tin. Abstractthe aim of the present investigation is to study the effect of copper content on mechanical properties for of dental amalgam. Amalgam can also release small amounts of mercury vapor during chewing. Dental amalgam and mercury in dentistry working party background 12 working party 12 terms of reference 12 approach to the task progress 14 issues identified 14 1. In addition to toothcolored, composite resin fillings, two other toothcolored fillings exist ceramics and. Explanations are useful to guide through learning process and confirm that the correct answer is indeed correct. Dental amalgam adheres chemically to the walls of the cavity. Strength amalgam is one such material which gained a lot of popularity because the its strengths were adequate for normal situations within the oral cavity for posterior teeth, primary requirement is high tensile and compression strength however, it is weaker in tension than in compression and it is a brittle material. The new high copper single composition alloys offer superior properties but may not offer as good seal as older amalgams. However, concerns have been voiced about possible harmful effects of the mercury present in. Known since early times, they were mentioned by pliny the elder in the 1st century ad.
An overview of the new epa dental amalgam separator regulations 40 cfr parts 403 and 441 effluent limitations guidelines and standards for the dental category regulations are laws, most likely written by lawyers. The first amalgam war began during the first half of the 19th century, when amalgam. The distribution or electronic posting of this pdf file is strictly prohibited. Is the force per unit area induced in a body in response to some externally applied force. Dental amalgam is a combination of mercury with other metals and has been used for over 150 years for the treatment of tooth cavities because it is very strong and durable. Response to 2006 joint advisory panel comments and recommendations, 2009 pdf 10 life sciences research office lsro the life sciences research office is a nonprofit organization of scientists, who contract with outside agencies to analyze issues that arise in biomedicine, healthcare, nutrition. Overview history basic composition basic setting reactions classifications manufacturing variables in amalgam performance click here for briefing on dental amalgam pdf. Dental amalgam dental amalgam is not mercury its important to separate fear from facts. Amalgam restorations and future perspectives longdom. People can absorb these vapors by inhaling or ingesting them. As the cherry on top, amalgam is more budgetfriendly, as it is less costly than other dental materials available.
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