Quartz 4

L2 Introduction to Trios Scanning

9 min read

2026-01-15

Intraoral Scanners Induction 20261

Robert Nedelcu DDS (Sweden), PhD, BC Oral Prosthetics (Sweden)

Evolution of Intraoral Scanners2

==Intraoral scanners (IOS) have been part of dental technology for approximately 40 years. The first commercial system, the Cerec machine, was released in 1985.==

  • ==Early Systems: These relied on capturing individual static images from various angles to build a 3D mesh. The fit was often poor, requiring large amounts of cement, and the hardware was industrial-sized (weighing up to 40kg).==

  • ==Modern Systems: Today’s scanners are powered by advanced Graphics Processing Units (GPUs) developed for gaming and cryptocurrency mining, allowing for high-speed, real-time 3D rendering. Current iterations, such as the 3Shape Trios 5, are wireless, handheld, and significantly more accurate.==

  • 2008: 3M Lava COS

  • 2010: 3M Lava COS

  • 2018: 3Shape Trios Wireless

Technology3

  • Triangulation LED

  • Triangulation RGB

  • Confocal Microscopy

  • Parallel Confocal

  • ==Triangulation: The scanner shoots multiple light beams at the tooth surface. The sensor measures the angle and time of the reflection to calculate specific points in 3D space.==

  • ==Point Clouds and Meshes: The scanner captures thousands of points. Algorithms average these points to create a polygon mesh, which is then rendered with artificial light and shadows to provide a 3D visual representation.==

IOS Market Penetration4

  • UWA DMD4 research: Liam Meinema, David Hora, Peter Nguyen

  • ==Australia: Recent research indicates a 63% market penetration in Australia, with Western Australia showing high adoption rates.==

  • ==Global: In Nordic and some European countries, penetration exceeds 80%.==

  • ==Clinical Reality: Most modern clinics now utilize scanners, though older units may sit idle due to a lack of clinician training or “digital literacy.”==

3shape5

Trios 3 – Modded
CSSL		Trios 4
student clinics		Trios 5
student clinics
  • ==Trios 3 (Aqua): A well-documented “workhorse” scanner. While slightly slower than newer models, it is highly accurate and used for training.==
  • ==Trios 4: Features a wired, integrated screen that can be wiped with gloves. It is self-calibrating for measurements but may require color calibration.==
  • ==Trios 5: The latest wireless iteration. It features an “air mouse” for screen navigation and is fully self-calibrating for both geometry and color.==

scanning | speed6

==An experienced operator can scan a full arch in approximately 15–20 seconds.==

  • ==Human Factor: Proficiency is a “pilot-dependent” skill. It may take roughly 100 scans for a clinician to become truly proficient.==
  • ==Consistency: The key to speed and accuracy is a smooth, consistent movement across the arch rather than rapid, jerky motions.==

resolution789

The detail an image holds101112

Resolution refers to the density of the polygon mesh (the number of triangles).

  • Higher resolution allows for better detail, particularly at the margins.
  • While hardware has reached a plateau (similar to smartphone iterations), software improvements now focus on AI and tissue differentiation.

Finish line distinctness

What you see is what you get

If a clinician cannot see the preparation clearly with the naked eye (due to blood, saliva, or tissue), the scanner cannot "see" it either.

Artifacts

Errors can occur during the "stitching" process. If the scanner loses its place, it may create "double layers" of teeth. Operators must magnify the scan on-screen to check for these artifacts before finishing.

Finish line distinctness and accuracy in 7 intraoral scanners versus conventional impression: an in vitro descriptive comparison13141516171819

Robert Nedelcu , Pontus Olsson , Ingela Nyström , Andreas Thor

**”It is imperative that clinicians critically evaluate the digital impression, being aware of varying technical limitations among IOS, in particular when challenging subgingival conditions apply.”

Monochrome View

==It is recommended to review preparations in monochrome mode rather than color, as color “bleeding” can obscure the actual margin.==**

subgingival finish line20

  • → you want finish +
  • emergence profile
  • L root surface
  • anatomy
  • scan quickly!
  • reduces artifacts from unstable tissues

Limitations

Scanners cannot "see" through tissue or fluids. If a margin is more than 0.5mm to 1.0mm subgingival, a conventional impression may be more reliable. Subgingival margins remain the greatest challenge for IOS.

Emergence Profile

To create a restoration with proper contour, the scanner must capture not just the finish line, but a small portion of the root surface below it.

Accuracy and precision of 3 intraoral scanners and accuracy of conventional impressions: A novel in vivo analysis method212223242526

R Nedelcu ^1^, P Olsson ^2^, I Nyström ^3^, J Rydén ^4^, A Thor ^5^

“**Intraoral scanners can be used as a replacement for conventional impressions when restoring up to ten units without extended edentulous spans

  • ==In Vivo vs. In Vitro: Laboratory tests often overestimate scanner accuracy. In the mouth, factors like tongue movement, saliva, and limited opening reduce precision.==
  • ==Span Length: Accuracy is high for single units and short bridges (up to ~10 teeth). For full-arch reconstructions, conventional impressions or specialized digital protocols are often still superior due to cumulative “stitching” errors.==.**”

Suitable cases27

  • Diagnostics & Treatment planning
    • Virtual
    • Model (3D printed)
  • Splints
  • Onlays
  • Crowns
  • Implants: Ideal, as there are no subgingival margins to "retract."
  • Custom Trays: Scanning a difficult edentulous ridge to 3D print a custom impression tray.
  • Special cases…

3Shape scan strategy28

Maxilla

The recommended scanning path consists of three swipes: occlusal, buccal, and palate.

  1. Start the scanner while it rests occlusal on the molar, wait 3-5 clicks.
  2. Move towards the centrals, capturing the occlusal surface.
  3. Continue slowly during the centrals and again continue along the occlusal surface until you reach the last molar.
  4. Turn slowly buccal by rotating the scanner 60-90 degrees at the last molar and complete the buccal swipe taking care of areas where soft tissue may interfere with the scan.
  5. Go along the buccal side until reach the last molar on the opposite side.
  6. Then roll to the palate side and complete the swipe.
  7. If you wish to include the palate in the scan, swipe back to position the scanner behind the incisors and then slowly go from side to side the palate in the distal direction.

Wiggle Technique

In the incisal area, "wiggle" the scanner to capture both buccal and palatal aspects of the thin incisal edges.

Mandible

Lower Scan: The recommended scanning path consists of 3 sweeps: Occlusal, lingual, and buccal. The best scanning method is to start with the molar occlusal surface.

  1. Wait 3-5 clicks, then move towards the incisors.
  2. Slowly wiggle the scanner when passing centrals.
  3. Continue until the last molar.
  4. Remember to move the scanner smoothly without jumping around.
  5. When you reach the last molar, turn slowly lingual, taking care of areas where soft tissue may interfere with the scan.
  6. Roll the scanner 60-90 degrees to the lingual side and use the tip to keep the tongue away.
  7. Go along the lingual surface of the whole arch, until reach the last molar on the opposite side.
  8. Roll to the buccal side and complete the buccal swipe.
  9. Go along the buccal surface of the whole arch.

Retraction

==Use an OptraGate and retraction to keep “moving tissues” (cheeks/tongue) out of the view, as the scanner cannot distinguish between fixed and moving objects. The lingual surface is scanned before the buccal to capture it before saliva pools or the tongue moves.==

3Shape Viewer – DCM file2930313233

  • ==DCM: A proprietary 3Shape file format. It allows clinicians to rotate, zoom, and adjust transparency of the 3D models.==
  • ==Clinical Use: Students should use the viewer to discuss preparations with tutors on a laptop screen rather than relying on physical models.==

STL34

Standard Tessellation Language

Info

The universal file format for CAD/CAM. It is usually monochromatic and used for 3D printing and milling.

PLY

Polygon File Format

Info

A newer format that includes color mapping data. It is more compact than some older formats but less universally used than STL.

Laboratory workflow35

  1. ==Identification: Because the university system uses a shared account, students must put their Name and Student ID in the “Notes” field of the scan.==
  2. ==Paper Slips: A physical paper slip is still required to trigger production or to request that files be exported to the student’s library.==
  3. ==Production: Files are sent to the lab for 3D printing (models) or milling (crowns/splints) using machines like the Ivoclar PM7.==

Footnotes

  1. Original PDF page 1: L2 IOS-Induction-2026, p.1 ↩

  2. Original PDF page 2: L2 IOS-Induction-2026, p.2 ↩

  3. Original PDF page 3: L2 IOS-Induction-2026, p.3 ↩

  4. Original PDF page 4: L2 IOS-Induction-2026, p.4 ↩

  5. Original PDF page 6: L2 IOS-Induction-2026, p.6 ↩

  6. Original PDF page 9: L2 IOS-Induction-2026, p.9 ↩

  7. Original PDF page 10: L2 IOS-Induction-2026, p.10 ↩

  8. Original PDF page 12: L2 IOS-Induction-2026, p.12 ↩

  9. Original PDF page 16: L2 IOS-Induction-2026, p.16 ↩

  10. Original PDF page 19: L2 IOS-Induction-2026, p.19 ↩

  11. Original PDF page 21: L2 IOS-Induction-2026, p.21 ↩

  12. Original PDF page 22: L2 IOS-Induction-2026, p.22 ↩

  13. Original PDF page 23: L2 IOS-Induction-2026, p.23 ↩

  14. Original PDF page 24: L2 IOS-Induction-2026, p.24 ↩

  15. Original PDF page 25: L2 IOS-Induction-2026, p.25 ↩

  16. Original PDF page 26: L2 IOS-Induction-2026, p.26 ↩

  17. Original PDF page 27: L2 IOS-Induction-2026, p.27 ↩

  18. Original PDF page 28: L2 IOS-Induction-2026, p.28 ↩

  19. Original PDF page 30: L2 IOS-Induction-2026, p.30 ↩

  20. Original PDF page 32: L2 IOS-Induction-2026, p.32 ↩

  21. Original PDF page 33: L2 IOS-Induction-2026, p.33 ↩

  22. Original PDF page 34: L2 IOS-Induction-2026, p.34 ↩

  23. Original PDF page 36: L2 IOS-Induction-2026, p.36 ↩

  24. Original PDF page 37: L2 IOS-Induction-2026, p.37 ↩

  25. Original PDF page 38: L2 IOS-Induction-2026, p.38 ↩

  26. Original PDF page 40: L2 IOS-Induction-2026, p.40 ↩

  27. Original PDF page 44: L2 IOS-Induction-2026, p.44 ↩

  28. Original PDF page 46: L2 IOS-Induction-2026, p.46 ↩

  29. Original PDF page 48: L2 IOS-Induction-2026, p.48 ↩

  30. Original PDF page 49: L2 IOS-Induction-2026, p.49 ↩

  31. Original PDF page 50: L2 IOS-Induction-2026, p.50 ↩

  32. Original PDF page 52: L2 IOS-Induction-2026, p.52 ↩

  33. Original PDF page 54: L2 IOS-Induction-2026, p.54 ↩

  34. Original PDF page 55: L2 IOS-Induction-2026, p.55 ↩

  35. Original PDF page 56: L2 IOS-Induction-2026, p.56 ↩

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