Written and maintained by CASRAI Editorial Board
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General product and regulatory information only. This page is not medical or dental advice and does not describe clinical technique.
Short answer
A dental amalgam capsule is the container in which silver alloy is intended to be mixed with mercury to form dental amalgam. Under 21 CFR 872.3110 it is a Class I (general controls) device, exempt from premarket notification subject to the limitations in 21 CFR 872.9, and FDA files it under product code DZS (checked 2026-10-31).
Definition and scope
The federal regulation titled “Dental amalgam capsule” says: “A dental amalgam capsule is a container device in which silver alloy is intended to be mixed with mercury to form dental amalgam.” The regulated device is therefore the container. The amalgam it produces is a different thing, and so are the instruments used around it, such as the amalgam carrier and the amalgam condenser.
FDA describes the material the capsule leads to as a mixture of metals: liquid elemental mercury and a powdered alloy of silver, tin and copper. About half (50%) of dental amalgam is elemental mercury by weight.
How it is used in practice
FDA’s consumer page on dental amalgam fillings states that the dentist, under appropriate safety conditions, mixes the encapsulated powdered alloy with the liquid mercury to form an amalgam putty used for the filling. That is the only role the capsule has in this description: it keeps the alloy and the mercury in one enclosed unit until they are combined.
Because the mixture contains elemental mercury, FDA notes that amalgam releases low levels of mercury in the form of a vapor that can be inhaled and absorbed by the lungs. This is why capsule handling sits alongside waste and mercury-capture topics, covered in the guide to the dental amalgam separator.
What the regulatory record says
| Field | Entry | Source |
|---|---|---|
| Regulation title | Dental amalgam capsule (21 CFR 872.3110) | eCFR / Cornell LII, checked 2026-10-31 |
| Regulation part and subpart | Part 872, Dental Devices; Subpart D, Prosthetic Devices | eCFR / Cornell LII, checked 2026-10-31 |
| Classification | Class I (general controls) | 21 CFR 872.3110(b) |
| Premarket notification | Exempt from the procedures in subpart E of part 807, subject to the limitations in 21 CFR 872.9 | 21 CFR 872.3110(b) |
| FDA product code and device name | DZS, “Capsule, Dental, Amalgam” | openFDA device classification, checked 2026-10-31 |
| Review panel and specialty | Dental | openFDA device classification, checked 2026-10-31 |
| Implant flag; life-sustaining or life-supporting flag | N; N | openFDA device classification, checked 2026-10-31 |
How to read it: the regulation number (872.3110) and the product code (DZS) are the two identifiers that tie a capsule listing to this classification. The classification covers the container. It does not classify the amalgam, the amalgamator or hand instruments, which have their own entries.
Capsule, material and instruments are separate things
The amalgam versus composite comparison lists the capsule’s product code and class in one row of its table. The distinctions below separate the three.
- Capsule: the container device defined in 21 CFR 872.3110.
- Dental amalgam: the resulting mixture of mercury and a silver, tin and copper alloy, about half mercury by weight (FDA).
- Handling instruments: the carrier and condenser are discussed in their own guides linked above, not in the capsule regulation.
Where it matters for labs, clinics and supply decisions
- Classification documentation: a Class I, 510(k)-exempt device still carries general controls. The regulation text is the citable basis for describing a capsule’s class, rather than a catalogue’s own wording.
- Patient and staff communication: FDA advises that mercury exposure may pose a greater health risk in certain groups, including pregnant women and their developing fetuses, women planning to become pregnant, nursing women and their newborn infants, children under six, people with neurological disease or impaired kidney function, and people with a known heightened sensitivity to mercury or the other metals in amalgam. FDA also states that the majority of evidence shows exposure to mercury from dental amalgam does not lead to negative health effects in the general population.
- Waste and mercury capture: mercury-containing material is a waste-stream topic for any practice that places amalgam; see the separator guide above.
Common misunderstandings
- “The capsule is the filling.” It is not. The regulation defines the capsule as a container in which alloy and mercury are mixed.
- “Class I means no mercury concern.” Class I is a device classification for the container under 21 CFR 872.3110. FDA’s separate guidance on dental amalgam addresses mercury vapor and the groups for whom caution is advised.
- “The mercury is the same as in fish.” FDA states that the form in dental amalgam is elemental mercury, which releases vapor mainly absorbed by the lungs, while fish contain methylmercury, mainly absorbed through the digestive tract, and the body handles them differently.
Frequently asked questions
What is in a dental amalgam capsule?
Under 21 CFR 872.3110 the capsule is a container in which silver alloy is intended to be mixed with mercury. FDA describes the resulting amalgam as about half elemental mercury by weight, with the rest a powdered alloy of silver, tin and copper.
Is a dental amalgam capsule a Class I device?
Yes. 21 CFR 872.3110(b) classifies it as Class I (general controls) and exempts it from premarket notification, subject to the limitations in 21 CFR 872.9. The openFDA classification record for product code DZS lists device class 1 (checked 2026-10-31).
What is FDA product code DZS?
DZS is the FDA product code for “Capsule, Dental, Amalgam”, assigned to regulation number 872.3110 in the Dental panel (openFDA, 2026-10-31).
What is the difference between the capsule and the carrier?
The capsule is the container defined in the regulation. The carrier is a hand instrument covered in the separate amalgam carrier guide.
Sources
- 21 CFR 872.3110, Dental amalgam capsule, eCFR (ecfr.gov) and Cornell LII copy. Checked 2026-10-31.
- openFDA device classification, product code DZS (open.fda.gov). Checked 2026-10-31.
- U.S. FDA, Dental Amalgam Fillings (fda.gov). Checked 2026-10-31.
