What Is Amalgam?

Amalgam is defined as an alloy of two or more metals, one of which is mercury (Hg). Dental amalgams, commonly known as "silver fillings," contain mercury, silver, tin and sometimes copper and zinc. First introduced in North America in 1833, dental amalgam is now estimated to represent 75 percent of all single tooth restorations (fillings). There are several manufacturers of amalgam, each with a slightly different formula.

What's In It?

• Mercury Hg 50%
• Silver Ag 35%
• Tin Sn 13%
• Copper Cu 0-3%
• Zinc Zn 0-1%

Liquid elemental mercury (Hg) is added in equal parts by weight to the other ingredients to produce a mass that is pliable enough to be forced into the prepared cavity. Excess Hg is squeezed out of the amalgam usually by manual pressure. The filling then cures; ideally it hardens in about a day. The final mass contains about 45-50% Hg by weight.

Did you know?

• That over 150 million amalgams are placed annually in the USA alone?
• Most restorations placed in New Zealand are amalgams?
• Amalgams can be polished and do not have to be black?
• Of the amalgam controversy?

Why use Amalgam?

Simple, really - it is both reasonably priced and very effective at what it does! Porcelain and gold restorations of a comparable price is many times more expensive!