DOCTOR · CLINICAL GUIDE
Digital scan quality
Great aligner results start with great records. This guide covers accurate digital scans, the scanning workflow and the checks to make before a case moves into planning.
WHY IT MATTERS
Why accuracy matters
Your scan is the foundation your entire case is built on. Distortions, voids or missing margins lead to ill-fitting aligners and avoidable refinements, so getting records right the first time saves time for everyone. Review the scan at the chair before sending it to avoid missing records and delays.
PRINCIPLES
Principles of a good record
Capture the full arch with clean margins and accurate occlusion. Keep the field dry, work methodically, and review your capture before the patient leaves the chair. We need every tooth present, clear gingival margin, no holes or distortion, and a true bite matching the patient’s natural bite.
Full arch, all anatomy
Capture every tooth, including at least half of the 8’s where they are present, with nothing cut off at the ends of the arch.
Clear gingival margin
Show 2 to 4mm of gingival tissue around the teeth so the margin reads cleanly and tooth and gum stay distinct.
A true bite
Capture the patient’s natural bite accurately and check the clinical bite on both sides. If the patient has a natural edge-to-edge bite, capture it as it is.
DIGITAL SCANS
Digital scan technique
Technique and attention to detail make a digital scan dependable. For a scan, make sure all anatomy is visible, including at least half the 8’s if they are visible, and that there are no holes in the scan. Capture 2 to 4mm of gingival tissue, and capture the patient’s natural bite accurately, including a natural edge-to-edge bite where present.
Watch for debris. If debris is picked up during the scan, make sure it is not attached to any anatomy, otherwise the scan is rejected and you will need to rescan. A clean, complete, hole-free scan with a true bite is accepted first time.
- Make sure all anatomy is visible, including at least half the 8’s if they are visible
- Make sure there are no holes in the scan
- If debris is picked up during the scan, ensure it is not attached to any anatomy, otherwise the scan is rejected and you will need to rescan
- Capture 2 to 4mm of gingival tissue
- Accurate natural bite, checked against the clinical bite on both sides
SCAN STRATEGY
Why scan strategy matters
Scan strategy directly affects the accuracy and dimensional stability of a full-arch scan, because it determines how individual images are stitched together in the scanning software. Think of drawing a 5-metre line using only a 15cm ruler. Small errors accumulate over each segment, and over a longer distance the deviation grows. Full-arch scanning is similar. As the scanner head moves across a surface, images are stitched rapidly, and on longer spans errors add up and cause deformation. Sufficiently deformed upper and lower arch scans also make it hard for the software to superimpose the buccal bite scan and find the best fit, which is a common cause of unreliable bite registration. A guided, sequence-based scan strategy is what avoids this.
For a worked example, our Dentsply Sirona scan strategy guide covers the recommended Omnicam and Primescan sequences in full, working distances, the four-part occlusal, buccal, lingual and approximal approach, buccal bite registration, and how to export to the lab.
FAILURE MODES
What gets a record rejected
Most rejections come down to a short list of avoidable faults. Knowing what they look like means you can catch them at the chair rather than after it has been sent to the lab. Inspect every record against the points below before you send it.
On a digital scan
- Holes in the scan
- Missing anatomy or 8’s not captured
- Debris attached to anatomy
- Too little gingival margin captured
- A bite that does not match the patient’s natural bite (check the clinical bite on both sides)
- Deformation from a poor scan sequence
SUBMISSION
Submitting your records
Once your record reads cleanly, submit a clean, full-arch digital scan, capturing clear margins and a true bite. Pair the record with a complete prescription stating your treatment goals and any specific instructions, and the standard clinical photo set. The clearer the brief, the closer the proposed plan will be to what you want.
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