Amalgam Flashcards
What is dental amalgam?
Dental amalgam is an alloy that results when mercury is combined with solid metals like silver, tin, copper, and sometimes zinc to form a plastic mass.
What is a dental amalgam alloy?
A dental amalgam alloy contains solid metals, including silver, tin, copper, and sometimes zinc, before being mixed with mercury.
What is amalgamation or trituration?
Amalgamation or trituration is the mixing process of a dental alloy with liquid mercury to form dental amalgam.
What device is used for amalgamation?
A mechanical device called an amalgamator or triturator is used for the mixing process.
What metals are included in dental amalgam alloy?
Dental amalgam alloy includes silver, tin, copper, and sometimes zinc.
Who invented the mercury-based dental amalgam filling and when?
The mercury-based dental amalgam filling was invented by English chemist Bell in 1819.
When and where was the dental amalgam mercury filling first used?
It was first used in 1826 in England and France.
Who introduced amalgam to the US, and what was it made of?
The Crawcour brothers introduced amalgam to the US in 1830, made by mixing powdered silver coins with mercury, which expanded on setting.
What happened in 1840 regarding amalgam?
The American Society of Dental Surgeons denounced the use of amalgams, marking the first amalgam war.
What ended the first amalgam war in 1859?
The ADA (American Dental Association) supported the use of mercury-based amalgams, ending the first amalgam war.
What did G.V. Black contribute to dental amalgam in 1895?
G.V. Black developed the modern formula for amalgam alloy:
• 67% silver
• 27% tin
• 5% copper
• 1% zinc
This formula overcame the expansion problem.
Why is amalgam used in dentistry?
• Inexpensive
• Ease of use
• Proven track record for over 100 years
• Familiarity among clinicians
• Resin-free, causing fewer allergies than composite
• Toughness and wear resistance
• Ability to seal margins effectively
What are the basic components of amalgam?
• Silver
• Tin
• Copper
• Mercury
What are the additional components in amalgam?
• Zinc
• Indium
• Palladium
What is the role of Silver (Ag) in amalgam?
• Increases strength
• Increases expansion
What is the role of Tin (Sn) in amalgam?
• Decreases expansion
• Decreases strength
• Increases setting time
What is the role of Copper (Cu) in amalgam?
• Ties up tin to reduce gamma-2 formation
• Increases strength
• Reduces corrosion and marginal breakdown
What is the role of Mercury (Hg) in amalgam?
• Activates the reaction
• Only pure metal liquid at room temperature
What is the role of Zinc (Zn) in amalgam?
• Decreases oxidation of other elements (sacrificial anode)
