Choosing an alloy.
The Rx form separates full metal alloy from ceramic alloy, and offers different options under each. The choice affects handling, appearance, tissue response and cost, and it is worth making deliberately rather than by default.
The two sections on the form
Under Full Metal Alloy the options are yellow high gold, yellow low gold and white non-precious. Under Ceramic Alloy they are yellow high gold, white high gold, white low gold and white non-precious.
The distinction matters because a metal-ceramic restoration asks something different of its alloy: it has to form a controlled oxide layer that the opaque porcelain bonds to, and its coefficient of thermal expansion has to match the ceramic so the porcelain is not left in tension as it cools.
An alloy that casts and finishes beautifully as a full metal restoration is not automatically the right choice beneath porcelain.
High noble alloys
Substantial gold and platinum-group content makes these forgiving. They cast well, they are kind to the tissues, they burnish, their oxide behaviour is predictable, and their long-term corrosion resistance is excellent.
They are also the most expensive, and the price moves with the metals market — which is why the cost conversation belongs before the case starts rather than at the fee estimate.
For a restoration expected to last decades, for a subgingival margin where tissue response is the primary concern, or for a case where burnishability matters, they remain the reference standard.
Low gold and non-precious
Reduced noble content lowers cost. Non-precious alloys, typically nickel-chromium or cobalt-chromium, are stiffer and stronger, which allows thinner copings and longer spans with less flexure — a genuine structural advantage on extended bridgework.
The trade-offs are a darker, harder-to-mask oxide beneath porcelain, more demanding casting and finishing, and the need to know a patient's nickel sensitivity before proceeding.
Nickel sensitivity is reasonably prevalent, more so in women, and frequently already known to the patient through reactions to jewellery. Ask, and record the answer on the prescription.
White or yellow
For a full metal restoration this is largely an appearance decision, and it is the patient's to make once they understand where the restoration will sit.
Beneath porcelain the choice interacts with masking. A yellow alloy warms the restoration from beneath, which can help in a chromatic case and hinder where high value is wanted. A white alloy is more neutral but darker oxides need more opaque to cover, which consumes space.
Where space is limited and the shade is demanding, that interaction is worth discussing before the tooth is prepared.
Documentation
Alloy identification certificates are provided for your records, so what was used on a given case can be established afterwards. That matters most on restorations that may need matching or replacing years later, and on any patient with a documented sensitivity.
Where a case involves an existing restoration whose alloy is unknown, the material cannot be identified reliably from a die — see frequently asked questions for dentists.
Cost, and how to discuss it
Precious metal content is a significant proportion of the cost of a cast or ceramic-alloy restoration, and the price moves with the metals market rather than staying fixed.
That makes it a conversation to have with the patient before the case is started rather than at the fee estimate. A patient who has chosen a high noble alloy knowingly is a very different situation from one presented with an unexpected figure at delivery.
Pricing for your practice is available on request — see fee guide request.
What to put on the prescription
Tick the correct alloy box for the section that applies — full metal or ceramic — rather than leaving it to be inferred from the crown type.
Record any known metal sensitivity in Special Instructions. If cost is a governing factor for the patient, say so; there is usually a sensible compromise available, and it is better chosen than defaulted to.
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