Chapter 1: Introduction: Why Scan Quality Matters
An intraoral scan can make the digital dental workflow faster, cleaner, and more predictable. But the scan itself is only as useful as the clinical data it captures.
For dental laboratories, the quality of the scan directly affects restoration design, margin accuracy, contact strength, occlusion, turnaround time, and remake risk. A clear digital impression allows the lab technician to design confidently. A rushed or incomplete file creates uncertainty, delays, and sometimes a restoration that cannot be fabricated without requesting a rescan.
Below are 5 mistakes we see in the intraoral scan workflow, why they matter, and how dentists can avoid them before submitting files to the lab.
Chapter 2: 5 Critical Mistakes in the Intraoral Scan
Mistake 1: Poor Moisture and Soft Tissue Control
The biggest risks to intraoral scanning are saliva, blood, glare, and soft tissue obstruction.
When the scanning area is not dry enough, or when the gums, cheeks, or tongue obscure the preparation margins, the scanner cannot accurately read the tooth surface. This is especially common in the subgingival margin, proximal areas, and posterior teeth.
Potential consequences:
– Unclear margins;
– Incomplete scan data;
– Inaccurate restoration margin design;
– Laboratory needs to reconfirm or request a rescan;
– Increased risk of rework.
How to solve it:
Before the final scan, ensure proper suctioning, drying, moisture isolation, and soft tissue retraction. Use gingival retraction wire or other gingival management techniques if necessary to ensure complete exposure of the preparation margins.
Mistake 2: Incomplete Margin Capture
Margin clarity is one of the most important parts of any crown or bridge case. If the margin is not visible in the intraoral scan, the technician must guess where the restoration should end, which increases the risk of poor fit.
In traditional impressions, impression material may physically displace soft tissue. In digital impressions, the scanner only records what it can see. If the tissue is covering the finish line, the scanner cannot capture it.
How to solve it:
Use appropriate tissue retraction before scanning. For subgingival or equigingival margins, consider retraction cord or other gingival management methods. After scanning, zoom in and inspect the margin from all angles before submitting the case.
Mistake 3: Moving Too Fast or Following an Inconsistent Scan Path
Modern scanners are fast, but speed should not replace control. Moving too quickly can cause missed surfaces, stitching errors, distorted anatomy, or incomplete data.
Another common issue is an inconsistent scan path. If the scanner loses tracking and repeatedly jumps between areas, the final model may contain inaccuracies even if it looks visually complete at first glance.
How to solve it:
Follow the digital intraoral scan workflow recommended by your scanner manufacturer and digital dental lab suggestion. Slow down around critical areas such as preparations, margins, proximal contacts, implant scan bodies, and occlusal surfaces. A smooth, controlled scan is usually better than a fast scan that requires multiple corrections.
Mistake 4: Inaccurate Bite Registration
A beautiful preparation scan can still lead to problems if the bite scan is inaccurate. Bite registration helps the lab design the occlusion. If the bite is incomplete, distorted, or captured in the wrong jaw position, the final restoration may require chairside adjustment or even remaking.
Incorrect bite data can cause high occlusion, poor functional contact, reduced comfort, or extra adjustment time during seating.
How to solve it:
Capture enough buccal bite data on both sides when needed. Ask the patient to close fully and naturally. After the bite is processed, review the occlusal relationship on-screen rather than assuming the software alignment is correct.
Tip for Avoiding over-scanning during bite registration
When capturing a bite scan, more data does not always mean better data. Repeatedly scanning the same buccal area may introduce overlapping or inconsistent information, which can affect the accuracy of the bite alignment. To capture a reliable bite scan, follow these rules:
– Ask the patient to close fully and naturally before starting the bite scan.
– Make sure the patient maintains the same bite position during scanning.
– Use one slow, steady, and controlled scan instead of repeatedly scanning the same area.
– Review the occlusal relationship on-screen after the bite is processed.
Mistake 5: Not Reviewing the Scan Before Submission
One of the most avoidable mistakes is sending the scan without reviewing it. Many scan problems are visible immediately if the file is checked before submission.
Common issues include missing distal surfaces, holes around margins, incomplete opposing arches, poor bite alignment, unclear scan body data, or soft tissue blocking the preparation.
Once the file reaches the lab, any missing information may delay the case. The lab may need to contact the clinic, request clarification, or ask for a rescan.
How to solve it:
Build a short review step into every digital impression workflow. Before sending the intraoral scan, check the preparation, margin, contacts, bite, opposing arch, and case instructions.
Chapter 3: Case Study
In one recent case, our laboratory received an intraoral scan for a crown restoration. At first glance, the file appeared usable. However, during design review, our technicians found missing surface data around the preparation and inconsistent capture near the margin.
After reviewing the scan file, the likely cause was that the doctor moved too fast during scanning. The scanner had not captured enough stable data in the critical preparation area.
Our solution:
At Triple T Dental Laboratory, we perform quality checks before moving digital cases into production. When scan data is incomplete, we flag the issue early and communicate clearly with the clinic.
Specifically, we take the following steps:
- Initial file inspection
Our technicians first review the intraoral scan file before starting CAD design, checking whether the preparation area, margin, adjacent teeth, opposing arch, and bite registration are complete. - Identify the missing or distorted area
If missing data is found, we mark the exact area affected, such as the preparation margin, proximal surface, distal area, occlusal surface, or gingival margin. - Assess whether the case can proceed
Our team evaluates whether the missing data will affect restoration fit, margin accuracy, contact design, or occlusion. If the risk is low, we may proceed with caution; if the risk is high, we will recommend a rescan. - Communicate clearly with the clinic
We explain the issue to the clinic with a clear description of the affected area and the possible consequences, so the dentist can quickly understand why additional data is needed. - Recommend targeted rescanning
Instead of asking for a full rescan immediately, we first determine whether a targeted rescan of the affected area is enough. This helps save chairside time and reduces inconvenience for the patient. - Recheck the updated file before production
After receiving the corrected or additional scan data, we review the file again to confirm that the margin and key areas are complete before moving the case into production.
This process helps reduce remakes, protects chairside time, and gives both the dentist and patient a more predictable outcome.
Chapter 4: Final Pre-Submission Scan Quality Checklist
Before submitting an intraoral scan to the lab, use this quick checklist:
- Is the preparation margin clearly visible from all angles?
- Is the field dry and free of saliva or blood?
- Is soft tissue blocking any part of the margin?
- Are adjacent contacts fully captured?
- Are occlusal surfaces complete and not distorted?
- Is the opposing arch scanned clearly?
- Is the bite registration complete and correctly aligned?
- Are implant scan bodies fully captured, if applicable?
- Are there holes, missing surfaces, or obvious stitching errors?
- Are the prescription, material, shade, and case instructions complete?
A two-minute review before submission can save days of delay later.
Chapter 5: In Summary: Common Mistakes in the Intraoral Scan
A high-quality intraoral scan is not just a digital file. It is the foundation of the restoration.
The most common mistakes are:
- Poor moisture and soft tissue control
- Incomplete margin capture
- Moving too fast or using an inconsistent scan path
- Inaccurate bite registration
- Submitting the scan without reviewing it
The solution is simple but important: control the field, expose the margin, scan with a consistent path, verify the bite, and review the file before sending it to the lab.
At Triple T Dental Laboratory, we combine digital workflows, CAD/CAM technology, experienced technicians, and quality control to support dentists with predictable dental restorations. Better scan quality helps us design better restorations, reduce remakes, and keep cases moving efficiently.
Need support with digital case submission or scan quality review?
Contact Triple T Dental Laboratory to discuss your next digital case by WhastApp at (852) 9148-2010 or (852) 6801-0826, or email us at info@tttdental.com.hk
FAQ
1. How does digital dentistry improve patient experience?
Digital workflows eliminate bulky impression trays, shorten in-office time, and let patients view a 3D model of their planned restoration. Tip: show a quick 3D preview during consultation to boost acceptance and explain expected results.
2. What role does CAD/CAM technology play in dental practices?
CAD/CAM streamlines the workflow from digital impression to manufactured restoration: design in CAD, produce in CAM. This reduces manual steps, accelerates turnaround time, and improves the precision of crowns, bridges, and dentures.
3. What are the benefits of digital impressions compared to conventional methods?
Digital impressions generally offer faster workflows, immediate quality review, easier electronic transfer to the lab, and improved patient comfort. Studies and reviews indicate comparable accuracy for many restorative cases when scans are performed correctly.
4. What is the typical turnaround time for zirconia or PFM restorations from a digital lab?
By streamlining data transfer through an intraoral scan, Triple T Dental Lab offers a rapid 5-7 day turnaround for restorations. This efficiency allows practices to complete cases faster while maintaining quality and safety.
5. What should I include in a scan submission file?
Quick submission checklist: export STL, PLY, or OBJ files as requested; include separate bite or occlusion files; ensure margins are visible; include the opposing arch and sufficient adjacent teeth; and name files clearly with patient ID, tooth number, and restoration type. Attach margin photos if helpful, and use the Pre-Submission Scan Quality Checklist before sending.