Intraoral scan checklist: what the dental lab needs
An intraoral scan checklist from the dental lab: margins, bite, antagonist, pre-op scans, photos and order details that make CAD design quick and remakes rare.
A good intraoral scan makes CAD design quick. A poor one forces the designer to choose between guessing and asking the clinic, and both cost time. This intraoral scan checklist is what I, as the designer receiving the files, would like every clinic to go through before sending a case.
Margins
The margin must be visible all the way around. Retraction, hemostasis and a dry field come first, and the preparation is scanned while the margin is exposed, before the tissue moves back. Look for a continuous, sharp finish line without drag marks, holes or smeared areas. If part of it is unclear, rescan that area while the patient is still in the chair, because the designer can only draw the margin the scan shows.
Preparation
Check that there is enough clearance for the planned material, using the scanner’s clearance tool if it has one. Undercuts that make a single insertion axis impossible should be corrected before scanning. Capture the adjacent teeth as well, including the contact areas.
Antagonist and bite
Scan the whole antagonist arch, since the designer needs more than the single opposing tooth. Scan the bite with no material between the teeth, in maximum intercuspation or in the planned position, and on both sides for larger cases. Complex cases benefit from articulator values or jaw motion data (see exocad virtual articulator).
Pre-op and provisional scans
A pre-op scan taken before preparation helps whenever the original anatomy should be kept or copied. When the patient has already approved a provisional, a scan of it lets the designer reproduce that shape exactly.
Photos and shade
Anterior cases need a retracted frontal photo and a smile photo. Hold the shade tab in the same plane as the teeth and write down which shade was chosen. For translucent materials, add the stump shade.
The order form
State the tooth numbers together with the numbering system (see tooth numbering systems), the restoration type and the material. Implant cases also need the implant system and the planned components (see scan body scanning tips). Add any preferences for contacts, occlusion or emergence profile, and the delivery date.
Exporting and sending the scan
Send color scans in PLY or OBJ instead of grey STL whenever the scanner allows it (see STL vs PLY vs OBJ). Sending through the scanner portal keeps all the files of the case together.
A final look before the patient leaves
Rotate the model once and look at the margin, the clearance, the bite and the contacts. It takes about two minutes, and it is the last moment when a missing detail can be fixed without booking another appointment.
Frequently asked questions
What is the most common problem in intraoral scans sent to labs?
Margins that are not visible because gingiva, blood or saliva cover them. The designer cannot draw a margin the scan does not show.
Should clinics send a pre-op scan?
Yes, whenever the existing tooth shape is useful, for example in anterior aesthetics, when copying anatomy or for provisionals. It takes a minute and often saves a try-in.
Is a single-side bite scan enough?
For a single unit it can be, if the scanner workflow and the occlusion are reliable. For larger cases, scan the bite on both sides to avoid a tilted jaw relation.