Zirconia crowns.
Zirconia is the option to reach for when clearance is limited, function is heavy, or the field cannot be isolated well enough to bond reliably. Tick Zirconia under Type of Crown on the Rx.
Where zirconia earns its place
Its strength allows thinner sections than any ceramic alternative, which makes it the practical answer for a short clinical crown, a patient unwilling to accept further reduction, or a tooth already heavily restored.
It also does not depend on an adhesive bond to perform. Where a preparation provides retention and resistance form, zirconia can be conventionally cemented with a resin-modified glass ionomer entirely predictably — useful when the margin is subgingival or the field will not stay dry.
For posterior units, evident parafunction, long spans and limited occlusal clearance, it is usually the correct selection.
Translucency and strength trade against each other
Zirconia is a family rather than a single material. Lower-yttria formulations are stronger and more opaque; higher-yttria formulations contain more cubic phase, transmit light better and give up flexural strength for it.
Rather than requesting a generation by number, tell the laboratory what the case needs — the tooth position, the antagonist, whether parafunction is evident, and how demanding the aesthetic result has to be. The formulation follows from that.
The full comparison is set out in monolithic versus layered zirconia.
Bonding, if you are bonding
Zirconia has no glass phase, so hydrofluoric acid does essentially nothing to it. The working protocol is gentle air abrasion with fine alumina followed by a primer containing a phosphate monomer such as MDP.
Restorations are dispatched with the fitting surface prepared appropriately. What undoes it is try-in: saliva contact deposits proteins and phosphates that block the sites the primer needs, and rinsing with water does not reliably remove them. Clean with a dedicated agent or repeat the air abrasion.
Cement selection and surface treatment are covered in cementation considerations.
Adjusting and polishing
Adjust with fine diamonds under copious water and light intermittent pressure. Heat is the main risk — heavy dry grinding damages the surface and locally induces phase change.
Then polish properly, with diamond-impregnated instruments and through the full sequence. Conventional ceramic polishers designed for glass ceramics are softer than zirconia and will burnish rather than cut, producing gloss over the original scratches.
Well-polished zirconia wears opposing enamel considerably less than glazed zirconia does, which is why this step matters more than it appears — see polishing zirconia.
Bridges and longer spans
Zirconia's strength makes it the usual choice for multi-unit fixed work where an all-ceramic result is wanted. Connector dimension governs whether a span survives, and occlusogingival height contributes far more to that than buccolingual width does.
Anything that reduces available height at the embrasure reduces the strength of the bridge directly — insufficient occlusal reduction, a high gingival margin, or an opposing tooth that has over-erupted.
Mark abutments and pontics on the design chart and select the pontic form. Pontic design sets out the options on the Rx, and bridge connector design covers the mechanics.
Preparation the material actually needs
A defined chamfer suits zirconia well. It retains strength in thin section and does not need bulk at the finish line to survive handling and try-in, which is part of why it tolerates conservative preparations.
What it does not tolerate is an undercut or an unreadable margin. Review the insertion axis in your scan software rather than accepting the default view, and confirm the finish line is continuous around its full circumference before the record is taken.
Reduction figures by restoration type are collected in preparation guides.
What to put on the prescription
Tick Zirconia under Type of Crown, and give the shade with the guide you used. Mark the tooth on the design chart.
Then the things that change the design: the antagonist, whether parafunction is evident, how demanding the aesthetic requirement is, and the interproximal contact you want — the form offers normal, broad or point, with tightness normal or tight.
If clearance is tight and you have accepted it deliberately, say so. The laboratory will otherwise raise it, and knowing it was a considered decision changes the conversation.
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