Teeth dental amalgam

Dentistry. Mercury is used in dental amalgams for fillings in teeth (see Dental materials). Dental uses have accounted for 2—4% of total U.S. mercury consumption since 1980 and generally 3—6% before that time (3). Dental amalgams used to fill cavities in teeth are approximately 50% mercury by weight. Dental use of mercury can be expected to continue to decrease, in part because of more effective cavity prevention as well as development and increasing use of alternative dental materials such as plastics and ceramics, and increasing awareness of the environmental and health effects of mercury. 

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. 

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). 

The general public is also clearly concerned about the placement of mercury, a substance with demonstrated toxic effects, into their mouths. A survey conducted by the American Dental Association in 1991 demonstrated that nearly half of the 1,000 American adults surveyed believed that health problems could develop as a result of dental amalgam (ADA 1991). Increases in life expectancy and increases in the numbers of older adults who still have their permanent teeth will result in longer mercury exposure durations from dental amalgam, which may result in new or increased severity of effects. 

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... 

In a population with a moderate consumption of fish, dental amalgam is the main factor for the mercury burden. In the mean, more than 10 teeth with amalgam restorations elevates the concentration of inorganic mercury in the human renal cortex, the liver, and the brain by factors of 11, 4, and 2, respectively [15]. 

Dental amalgam silver, tin, copper, zinc, mercury filling cavities in teeth... 

Dental composite materials are now used that have several advantages over traditional amalgams. The composites can be made in a wide range of colors, for example, to match the color of the other teeth. The existing healthy portion of the tooth can be etched with acid, moreover, to create pores into which the composite material can bond. With traditional dental amalgam, the dentist must create indentations in the healthy tooth to hold the amalgam in place. Destroying a portion of the healthy tooth is undesirable and can be avoided with the use of the composite. 

A material used in dentistry must have properties that maximize both patient comfort and the lifetime of the implant. Dental fillings and tooth replacements must be re.sistant to adds, for example, because many foods (such as citrus fruits and soft drinks) contain acids directly. Any food containing carbohydrates can produce acids, though, if traces are left in the mouth because the bacteria that reside there consume carbohydrates, producing acids in the process. These acids eat away at the natural hydroxyapatite in teeth, creating caries (cavities). Materials like dental amalgam, gold, and dental composite resist attack by acids in the mouth. 

Dental amalgam consists of several metals dissolved in an alloy with mercury. Dental composite materials consist of a methacrylate polymer in a silica matrix. The composite can be varied in color to match existing teeth, making the repair more aesthetically pleasing than metallic amalgam. 

The most common oral condition and dental emergency is dental caries, which is a destructive disease of the hard tissues of the teeth due to bacterial infection with Streptococcus mutans and other bacteria. It is characterized by destruction of enamel and dentine. Dental decay presents as opaque white areas of enamel with grey undertones and in more advanced cases, brownish discoloured cavitations. Dental caries is initially asymptomatic and pain does not occur until the decay impinges on the pulp, and an inflammation develops. Treatment of caries involves removal of the softened and infected hard tissues, sealing of exposed dentines and restoration of the lost tooth structure with porcelain, silver, amalgam, composite plastic, gold etc. 

But even as recendy as the mid-20th cenmry, there was relatively litde concern about mercury metal and many mercury compounds. High school chemistry students often played with tiny droplets of mercury in the laboratory. They used mercury to coat pennies and other pieces of metal. Mercury was also widely used in dentistry. It was used to make amalgams, alloys of mercury with other metals, used to fill teeth. Most people even today are likely to have dental fillings that contain a small amount of mercury metal. The question of whether mercury is still safe to use in... 

Teeth with decayed regions have traditionally been restored with metals such as silver amalgam. Metallic restorations are not considered desirable for anterior teeth for cosmetic reasons. Acrylic resins and sihcate cements had been used for anterior teeth, but their poor material properties led to short service life and clinical failures. Dental composite resins have virtually replaced these materials and are very commonly used to restore posterior teeth as well as anterior teeth [Cannon, 1988]. 

Dental composite resins have become established as restorative materials for both anterior and posterior teeth. The use of these materials is likely to increase as improved compositions are developed and in response to concern over long term toxicity of silver-mercury amalgam fillings. 

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