Sell dental gold: crowns, bridges and inlays

Crowns, bridges, inlays: what each one is

Dental restorations were cast to fit one person's mouth, and they were chosen for strength and for how they sat against the tooth next door, never for what they were made of. That is why there is no standard alloy and no useful rule of thumb. What there is, is a small number of recognisable shapes.

Full gold crown

A solid metal cap, yellow, shaped like a tooth with a hollow underside. Usually the richest thing in the envelope.

Porcelain-fused-to-metal crown

A tooth-coloured ceramic shell over a thin metal cup. Turn it over and the metal shows at the rim; most of what you can see is not metal at all.

Inlay or onlay

A cast filling, often no bigger than a grain of rice, that sat in the chewing surface of a back tooth.

Bridge

Two or more crowns joined by a solid span, replacing a missing tooth. Sometimes with ceramic on the front face only.

Denture clasp or framework

The metal skeleton of a partial denture, with wire arms. Sometimes precious alloy, more often chrome-cobalt, which is worth nothing as metal.

A crown often comes with a fragment of the tooth it was cemented to still inside it. That is completely normal and it is not something to deal with at home. It stays where it is until you have accepted an offer, with its weight estimated and left out, and it comes out here afterwards, under proper conditions.

Why colour is no guide at all

High-gold dental alloys run from roughly 700 to 900 parts per thousand. Medium-gold alloys sit somewhere between 400 and 700. Both look yellow, and so does a low-gold alloy with a lot of copper in it, because copper is what makes gold look yellow in the first place. A rich alloy with palladium in it can come out almost white.

So a bright yellow crown may be modest and a dull white one may be the best thing in the envelope. White crowns in particular go both ways: some are palladium-rich precious alloys, some are nickel-chromium or cobalt-chromium with no precious metal in them whatever. There is no version of this you can settle by eye, which is why it is settled by testing.

Handling, hygiene and what not to do at home

These were in somebody's mouth. Every dental item is handled with gloves and kept physically apart from jewellery from the moment the parcel is opened. Nothing is cleaned off it before an offer is made, because cleaning alters a piece and clause 4.2 of the terms needs your written consent for that. None of it is something to do at the kitchen table either.

• Rinse the pieces in warm water. That is all the cleaning that is wanted from you.
• Do not pick at cement or tooth with a knife, pliers or a screwdriver. Small pieces of alloy fly, and they are gone.
• Do not try to break the porcelain off a crown. It is taken off here, after you have accepted, and never before.
• Put dental items in their own small sealed bag inside the parcel. An inlay is the size of a grain of rice and it will not survive loose among chains; posting gold and silver safely covers the rest of the packing.
• Send the whole envelope, including the pieces you are sure are plastic or base metal. Sorting them out is the work, not a favour.

Amalgam fillings are the one thing to keep out. They contain mercury, they are clinical waste rather than scrap, and they must be disposed of through a dentist. If there is amalgam in the envelope it is identified and dealt with properly, but it is better not to send it.

What is left out of the weight

Metal and not-metal in common dental items

Scroll sideways for more →

Porcelain can be more than half the weight of a crown you are holding, which is the single biggest reason a figure quoted on the whole thing would mislead you. The ceramic is taken off only after you have accepted the offer. A crown you decline goes back looking exactly as it did when it arrived.

Send the whole envelope, and the box it came in

Dental items come in ones and twos, and a single crown feels too small a thing to bother anybody with. It is not. They also come in quantity: a dental practice clearing a drawer of thirty years of returns, or a family finding a jar their father kept. Both are normal, and the process is the same for one piece as for two hundred.

If this came from someone who has died, there is nothing unusual about selling it. Crowns are often handed back to families by a dentist or a funeral director, and many people are unsure whether it is acceptable to do anything with them. It is, and the same identity questions apply as to any other sale. Probate and estate jewellery covers the paperwork side, and identity and provenance checks explains what is asked for and why.

A photograph is less useful here than anywhere else in this catalogue, because the thing that matters is inside the alloy and no camera can see it. What a photograph can do is rule out the obvious: acrylic dentures, chrome frameworks, ceramic-only crowns with no metal in them at all. If the box is mostly those, you will be told before anything is packed. How it works follows a lot from that first photograph to payment.

What happens to dental items when they arrive

1. Kept separate from the startDental items are booked in apart from jewellery, counted and photographed as they arrived, and handled with gloves throughout.
2. Nothing cleaned offCement and debris stay where they are. Readings are taken where bare metal shows, and cleaning a spot first needs your written consent (clause 4.2), because anything on the surface pulls a reading down.
3. Tested piece by pieceWhere an analyser is available, X-ray fluorescence (XRF) reads gold, palladium, platinum, silver and copper together, which is what a multi-metal casting alloy needs. Readings are taken on bare metal, more than once where the shape allows, and an acid touchstone test is used only with your written consent.
4. Listed with its readingEvery piece appears on the list with what it is, what was left out of its weight and what the tests found. Nothing is averaged into a single line.
5. One offer, then your decisionCeramic removal and anything else irreversible happens only after you have accepted. Decline, and the envelope comes back as it arrived; offers, returns and payment covers each answer you can give.

A small curved crown is one of the harder things to read accurately, and your offer says so where it applies. Melting and re-testing would settle a batch whose readings vary widely, but nothing is melted before you have accepted an offer (clause 4.4). A batch that stays uncertain is priced cautiously on the readings that exist, with their limits written on your offer. The dental gold testing guide goes through the alloy families and where the difficulty lies.

What we buy, and what we leave out

Stopped before anything is treated as scrap

• Laboratory offcuts of a known alloy may do better through the alloy manufacturer's own return scheme, and we say so
• A large batch of one alloy is best settled by melting and assay, which needs a laboratory we have no arrangement with, so a refiner who offers assay may suit it better
• High-palladium white alloys are checked for palladium as well as gold, so the whiter pieces are not written off
• Historic gold dentures and early gold work occasionally interest collectors of dental history
• Anything that turns out not to be dental at all, which happens, is identified and dealt with on its own terms