"silver" mercury amalgam filling was introduced by the Crawcours
brothers first to England and then to the United States in the 1830's.
With the introduction of the mercury filling, patients now had another
choice with which to get a cavity fixed.
Previously, the patient had two options. The first was extraction
of the tooth with no anesthesia (in the 1830's local anesthesia had
not yet been invented). The second was a long appointment in which
hot gold would be hammered into the tooth. The new third choice
was the Crawcours' "silver" filling which they claimed would fill
the tooth cavity painlessly in minutes.