Porcelain fused to metal.
Metal-ceramic has the longest clinical record of anything on the Rx form, and it still solves problems the all-ceramic options do not. Tick P.F.M under Type of Crown.
Where PFM is still the right answer
Long-span fixed bridgework, where a metal substructure carries load ceramic cannot. Cases requiring a soldered connection or an attachment. Restorations under an existing removable partial framework needing rests, guide planes or clasp seats. And preparations that are less than ideal in taper or retention.
In each of those the metal is doing something no ceramic alternative does as reliably.
It is also the option with decades of behaviour behind it, which counts for something in a restoration expected to last.
Alloy selection is a real decision
The Rx form separates ceramic alloy from full metal alloy, and offers yellow high gold, white high gold, white low gold and white non-precious for ceramic work.
High noble alloys cast well, are kind to the tissues, burnish, and behave predictably at the oxide layer. Non-precious alloys are stiffer, allow thinner copings and longer spans with less flexure, and cost considerably less — at the price of a darker oxide that is harder to mask and the need to know a patient's nickel sensitivity.
Record any known metal sensitivity on the prescription. Alloy identification certificates are provided for your records. Understanding PFM covers the metal-ceramic bond in more detail.
Margin design
The form offers metal, combination and porcelain butt for the labial margin. A metal collar is mechanically excellent and marginally accurate but visible if the tissue recedes. A porcelain butt margin removes the metal display at the gingival third at the cost of a more technique-sensitive fabrication.
Both are legitimate. The decision depends on lip line, tissue biotype and how the margin is placed clinically — and it belongs on the prescription rather than being left to the laboratory to infer.
Space
Between coping, opaque layer and veneering porcelain, a metal-ceramic restoration needs more total reduction than monolithic zirconia to achieve a comparable result.
Under-reduced PFM preparations force a choice between overcontouring and a thin, high-value, opaque restoration. Both are visible, and neither is what anyone intended.
In multi-unit work, connector dimension governs. Adequate cross-section, correctly positioned occlusogingivally, is what carries the span.
Working with existing removable prostheses
One of the situations where metal-ceramic remains the clear answer is a crown that has to serve as an abutment under an existing partial denture.
Those cases need more than a material and a shade. Rest seats, guide planes, survey lines, clasp positions and undercut requirements all have to be designed into the crown, and none of that can be inferred from a die.
Send the prosthesis with the case wherever possible. Partial dentures covers what the laboratory needs to coordinate the two.
Occlusal relief and internal fit
The Rx form offers occlusal as positive or foil relief, with a number of foils. That is the cement space specification, and it matters more than it appears.
A restoration made to fit the die with no relief will not seat clinically, because cement needs somewhere to go. How much relief is appropriate depends on the cement — a filled resin cement needs more room than a thin-film luting cement, and a restoration relieved for one and cemented with the other will either sit high or fit loosely.
If you have a strong preference, state it. Otherwise the laboratory applies its standard.
What to put on the prescription
Tick P.F.M and select the ceramic alloy. Choose the labial margin — metal, combination or porcelain butt. Give the shade with the guide named and the antagonist.
For bridgework, mark the abutments and pontics on the design chart and select the pontic form: modified, ridgelap, cone or hygienic.
If the case involves attachments, rests, guide planes or an existing partial denture, that information has to travel with the case in full — ideally with the prosthesis itself.
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Digital scans and conventional impressions are both accepted. Cases move by UPS and Purolator, and Fairmont works with practices throughout British Columbia and across Canada.