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Crown design

Write the prescription, attach the arches in the workbench, then design the restoration through to an exported file.

Order a crown as a prescription, design it in the browser

A crown case starts as a prescription rather than an upload. You chart the teeth you are restoring, give each one a material, and create the case with no files attached. The arches come afterwards, as the workbench's first step, which is the same split a lab draws between its order book and its CAD application.

From there it is a crown designer that runs on your own machine: the geometry is computed in your browser, while the case, the project and the credit live on our servers. That is why the design responds immediately and why a stronger workstation feels quicker.

The material numbers the module ships are generic engineering defaults, not manufacturer instructions for use. Check them against the guidance for the material you actually mill or print, and verify the finished restoration before clinical use.

Design a case from prescription to export

  1. Write the prescription

    Chart each tooth and pick its material. A material is required and there is no default. Finish line, seating and emergence sit behind one disclosure and are already set: change nothing and you get Standard seating, an unset finish line and a standard emergence profile. One order can carry up to 32 charted teeth, and a newly charted tooth starts from the settings of the one before it. Joined units, meaning bridges, cannot be ordered today.

  2. Attach the arches on the Scans step

    The workbench opens on two arch slots. The arch carrying the charted teeth is required. The opposing arch is optional for designing, and you can add it part way through without losing work, but it is required for export, because occlusion has to be measured against an opposing scan before the case can leave the workbench.

  3. Orient the scene

    Set which way the occlusal surface faces. Everything after this reads that frame, so it is worth a second look on a scan that arrived at an odd angle.

  4. Place the margin

    Put the finish line (the margin, the curve where the crown meets the preparation) on the die. Detection follows the sharpest ridge it can find, and you correct it point by point. Every later step is built on that curve.

  5. Set the insertion axis

    The path of draw decides the fitting surface. It is solved for you, and you can reset it from the current camera view when the solved axis is not the one you want.

  6. Build the crown bottom

    This step shapes the fitting surface (the intaglio, the inside face that seats on the die) and blocks out undercuts along the path of draw. Cement gap runs 0 to 1 mm in 0.01 mm steps and starts at the material's own value. Seal gap at the margin runs 0 to 1 mm from 0 mm, the seal band 0 to 3 mm from 0.5 mm, the gap ramp 0.05 to 3 mm from 0.5 mm, blockout size 0 to 2 mm from 1 mm, and draft 0 to 10 degrees from 0.

  7. Seat the library tooth

    Place a library tooth on the preparation, position it, and crimp it onto the finish line so the outer surface meets the margin you drew.

  8. Sculpt the crown

    Adjust the outer anatomy by hand where you want to. The brush size runs 0.2 to 5 mm and starts at 1.2 mm; brush strength runs 0.02 to 1 mm and starts at 0.18 mm. This step also measures the wall and can thicken a thin spot in place.

  9. Check contacts and occlusion

    The contact view paints the measured distance in millimetres between the crown and the opposing tooth, with penetration at the loaded end. Its colour scale is a display range from 0.05 to 2 mm and sits at 0.5 mm unless you change it, so widening it flattens the colours and narrowing it exaggerates them. It is a distance scale, never a force reading.

  10. Pass the checks, then export

    The last step measures the thinnest wall, the occlusal clearance and the functional contacts, then closes the outer surface and the fitting surface into one solid. Export writes the file and spends 1 credit at that moment; exporting the same case again is free.

Know what each material asks for

MaterialMinimum thickness and cement gap
ZirconiaAt least 1 mm occlusally, 0.8 mm axially and 0.5 mm at the margin. Cement gap starts at 0.05 mm.
Lithium disilicateAt least 1.5 mm occlusally, 1 mm axially and 0.8 mm at the margin. Cement gap starts at 0.06 mm.
Resin temporaryAt least 1 mm occlusally, 0.8 mm axially and 0.6 mm at the margin. Cement gap starts at 0.08 mm.
Seating choicePassive sets the cement gap to 0.08 mm and Tight to 0.04 mm. Standard, the default, leaves the material's own value in place. You can still type a value between 0 and 1 mm in the workbench.
Where the numbers come fromGeneric engineering defaults, not manufacturer instructions for use. Confirm them against the guidance for your material before clinical production.

Answers before you start designing

None to create it, because the order is a prescription and takes no upload. In the workbench you attach the arch carrying the charted teeth, and the opposing arch.

You can design, but you cannot export. Wall thickness and occlusion both have to be measured before export unlocks, and occlusion needs an opposing scan. Attach it at any point, including part way through; nothing you have already done is lost.

At export, once, on the finished restoration. Creating the case and designing it cost nothing, and re-exporting a case you have already exported is free.

Yes. The project is saved to the case as you work and kept in this browser as well, so reopening the case resumes the design rather than starting over. Undo and redo are on Ctrl+Z and Ctrl+Shift+Z, or the Cmd equivalents on a Mac.

Export is gated on measurements rather than judgement. Everything the case needs has to be present and current, the checks have to pass with no open errors, and the merged solid has to be watertight, must not break through the fitting surface, and must meet the material's minimum wall. The step names which one failed, and a measurement that was never taken never counts as a pass.

The geometry is computed in your browser, while the case, the project and the credit live on our servers.

Not today. An order carries single crowns, up to 32 of them, each with its own material. Pontics and connectors exist in the workbench for cases that already carry them, but they cannot be ordered.

Work through a design that fights back

Why it happens

Detection follows the sharpest ridge it can find, so a torn, blurred or over-polished finish line sends it somewhere plausible but wrong.

What to do

Drag the points back onto the finish line where it wandered, rather than running detection again on the same scan. If the preparation itself is unreadable in the scan, re-scan the die. If it persists, send us the case number.

Why it happens

Both arches are drawn exactly where the scans put them, with nothing in between correcting them, so a bad registration shows up here instead of being hidden.

What to do

Re-export both arches from the same scan session and attach them again. A pair that never shared a registration will not occlude here either. If it persists, send us the case number.

Why it happens

Only the preparation arch was attached, so there is no antagonist to design against and occlusion cannot be measured.

What to do

Go back to the Scans step and attach the opposing arch. Doing it part way through is expected and keeps the work you have already done.

Why it happens

Editing the margin or the insertion axis invalidates what was built on top of it, on purpose: the alternative is a crown seated on a curve that has since moved. Editing the scan itself invalidates more, including the proof that the two arches are registered.

What to do

Re-run the steps it marked. The ones it left alone stay as they were, and nothing is deleted. If a step keeps going stale without you editing anything, send us the case number.

Why it happens

One of the manufacturability checks failed: the outer surface and the fitting surface did not close into one watertight solid, they intersect somewhere, or the measured wall is below the material minimum.

What to do

Read which check failed, then fix that one thing. A wall that is too thin can be thickened in place, while an unclosed solid usually traces back to the margin. If it repeats on a case that looks right, send us the case number.