The short answer
Dental amalgam is not pure silver: it combines mercury with an alloy containing silver, tin, and copper. FDA advises against unnecessary removal of sound amalgam fillings and recommends additional caution when selecting new restorations for higher-risk groups.
The familiar name hides the mixture
The phrase silver filling describes the appearance of dental amalgam, not its purity. FDA explains that amalgam is prepared from elemental mercury and an alloy powder containing silver, tin, and copper. Roughly half of the resulting material is mercury by weight. The silver is real, but the finished restoration is not a piece of fine silver placed inside a tooth.
Mercury's chemical role is to bind the alloy particles into a material that hardens. This is a different use of silver from a coin, an electrical contact, or a topical dental liquid. Similar color does not establish similar composition, performance, or exposure.
Composition and risk must be explained together
Amalgam can release small amounts of mercury vapor, which can be inhaled. FDA reports that the available evidence does not establish adverse health effects in the general population, while also identifying uncertainties and people who may be more susceptible. Neither calling amalgam harmless for everyone nor assuming that every existing filling is poisoning its owner reflects that guidance.
FDA's patient information identifies pregnancy or planned pregnancy, breastfeeding, childhood, particularly under six, neurological impairment, kidney dysfunction, and sensitivity to mercury or other amalgam components as reasons for additional caution. For people in higher-risk groups who need a new filling, the agency favors non-amalgam materials when possible and appropriate.
Those qualifications matter. A suitable restoration depends on the tooth and the person's health circumstances. The list is not a self-diagnosis tool, and a description of a material cannot decide which restoration an individual should receive.
New fillings and existing fillings are different decisions
FDA explicitly discourages removing or replacing sound amalgam fillings without a medical reason. Removal can sacrifice healthy tooth structure and temporarily increase exposure to mercury vapor. That caution also applies to people in the higher-risk groups; identifying a reason to prefer another material for a new filling is not an instruction to remove an intact one.
The useful fact for a silver enthusiast is therefore both chemical and practical: dental amalgam contains silver, but it is a multimetal restorative material. Decisions about an existing filling belong in a dental assessment, not in conclusions drawn from its nickname or from a general fact card.
About this edition
Original source and editorial notes
Adapted from original material by Rich Silver. Original source card: Silver fact: supplied original card (publication date not established).
Reviewed 2026-11-04. Corrected aren't silver to not pure silver, since amalgam does contain silver. Used FDA's approximate 50% mercury-by-weight description rather than an unsupported universal range. Omitted the separate dental-gold classification claim to keep this fact focused. Added the FDA's higher-risk groups and explicit warning against unnecessary removal of intact fillings. This is U.S. guidance, not a worldwide regulatory summary or individual medical advice. No graphic, card publication date, or unverified card URL is reproduced.