Digital Dental Impressions: What Labs Need from Your Scanner

Digital impressions have eliminated a lot of the headaches of PVS, no impression material, no tray seating, no shipping a physical model in a padded envelope. But "digital" doesn't automatically mean "better." A bad scan is just as unusable as a bad impression, and labs still see plenty of both. Here's what makes a digital file your lab can actually work with.

Scan strategy: dry, retract, and don't skip

Scanners need clean, dry, well-retracted teeth. Saliva pools, blood, and reflective material throw off the optical sensors and create gaps or noise. The scan path matters too, follow the manufacturer's recommended pattern (usually occlusal first, then lingual, then buccal) without lifting the wand off the tissue. Lifting forces the software to re-register, which introduces stitching errors.

Capture the margin clearly

The margin is the single most important part of the scan. If your lab can't see a clean, continuous margin line on the prep, they can't design a crown that will seat or fit. Use retraction cord, air-dry the prep, and confirm visually in the scanner software that the margin is sharp before sending. Re-scan just the margin if needed, most modern software lets you erase and re-capture a small region.

Capture the bite, both sides if you can

A single bite scan on one side is often enough, but for full-arch cases, complex occlusion, or anterior esthetic work, scan both sides in MIP. The lab uses these to articulate the case digitally, the more reliable bite data, the more accurate the occlusion you receive back.

File formats

STL is universal and works with every lab CAD system. Most labs also accept proprietary formats directly (iTero .iiq, TRIOS .dcm, Medit .gen, Primescan .ply / .dxd), which can preserve color and texture data useful for shade matching.

What to send with the file

• Patient name and case number (matches the lab slip)
• Tooth number(s) being restored
• Material requested
• Shade (VITA Classical or 3D Master), with a photo if anterior esthetic case
• Occlusal scheme notes (group function, canine guidance, anything unusual)
• Special instructions (contacts, occlusion preferences, anatomy tightness)

Common mistakes labs see daily

• Scans with blood or saliva at the margin
• Bite scans taken in a protruded position instead of MIP
• Missing adjacent teeth (we need at least one tooth on either side for contacts)
• Files sent with no Rx, prescription details, or shade information
• Old scans re-sent with a new patient name (please send a fresh scan)

How to send to VDL

We accept files from every major scanner. Upload through our digital case portal, or send via your scanner's direct integration if you've connected to us already. Questions about scanner setup or file format? Call (508) 281-9997 and we'll walk through it.