Amalgam (dentistry)

Lore & Background

The earliest evidence of dental amalgam appears in the Tang dynasty medical text *Xinxiu bencao*, written by Su Gong in 659, manufactured from silver and mercury. Historical records hint that use may date even earlier in the Tang dynasty. In the Western world, amalgam was introduced from 1818 into the 1830s, and in 1833 the Crawcour brothers brought it to the United States, but fled a year later due to malpractices. The American Society of Dental Surgeons declared its use malpractice in 1844, leading to the first dental amalgam war, which ended in 1856 with the disbanding of that association. The American Dental Association, founded in 1859, has since defended amalgam.

Reader's Guide

Dental amalgam has been a significant restorative material for over a millennium, first documented in China in 659 and later adopted in Europe. Its low cost, ease of application, strength, and durability made it the material of choice in the 1800s. However, its mercury content sparked recurrent controversies from its introduction in the Western world, leading to professional disputes and the formation of new dental associations. Metallurgical advances in the 20th century, such as the introduction of Dispersalloy in 1962 and Tytin a decade later, improved marginal integrity by reducing the weak γ2 phase. The composition of amalgam alloy has evolved, with modern standards allowing higher copper content to enhance properties. Despite ongoing debate, amalgam remains in use for posterior restorations and cores, with its properties controlled by ISO Standard 1559.

Did You Know?

• Dental amalgam was first documented in a Tang dynasty medical text written by Su Gong in 659.
• The γ2 phase (Sn8Hg) is the weakest phase in set amalgam and is subject to corrosion.
• Dispersalloy, introduced in 1962, was the first high-copper amalgam alloy, raising copper content from about 5% to 13%.