Why does a crown sometimes come back from the lab looking acceptable, yet still require heavy chairside adjustment once the patient bites down?

In many digital crown cases, the issue is not always the crown material, CAD design, or lab fabrication. The problem may start earlier, when the bite scan does not accurately capture the patient’s real bite relationship. If the patient closes differently during scanning, if the scan area is too limited, or if the occlusion preview is not checked before submission, the lab may design the crown based on bite data that does not fully match the patient’s actual occlusion.

This article explains the common bite scan mistakes that can affect crown cases, how they appear from the lab side, and what dentists can check before sending a digital crown case to the lab.

Key Takeaways

• An incomplete bite scan can increase chairside adjustment time for crown cases.
• A patient’s resting position, light bite, and true habitual bite may not be the same.
• Dentists should ask the patient to close properly and repeatably before scanning.
• More reliable bite reference points help the software and lab read the bite alignment more accurately.
• Reviewing the occlusion preview before submission can reduce lab-clinic back-and-forth.

The Problem Is Not Always the Crown

When a crown comes back high, it is easy to assume the restoration was designed or made incorrectly. Sometimes that is true. But in a digital workflow, the lab is working from the files submitted by the clinic.

A crown may be designed correctly to the file, while the file itself does not represent the patient’s real bite.

This is why bite registration matters. The bite scan tells the software and the lab how the upper and lower arches relate to each other. If that relationship is shifted, incomplete, or based on an unstable closure, the crown occlusion can be affected before CAD design even begins.

The lab can review the occlusion, opposing arch, contact areas, and crown clearance in the file. But it cannot know whether the patient closed naturally unless the scan and prescription make that clear.

Common Bite Scan Mistakes That Affect Crown Cases

Before looking at individual mistakes, it helps to understand how a chairside issue appears from the lab side.

Chairside Cause	What the Lab May See	Possible Crown Case Result
Bite scan area is too limited	Not enough bite alignment reference points	More chairside adjustment
Patient did not close naturally	One-sided contact or open bite	Crown may feel high or low
Arch scan is unstable	Shifted upper/lower relationship	Crown designed to the wrong model relationship
Soft tissue interference	Incorrect arch matching	Suspicious occlusion preview
Occlusion preview was not checked	Obvious bite issue enters the lab workflow	Delay or rescan request
No occlusal notes	Lab cannot interpret the clinical intention	More back-and-forth communication

Mistake 1: The Bite Scan Area Is Too Small

One of the most common problems is scanning too little bite data. A small buccal scan area may not give the software enough stable landmarks to align the arches.

This matters especially for posterior crowns, multi-unit cases, bilateral cases, and patients with complex occlusion. If the bite scan does not include enough readable buccal surfaces and contact landmarks, the alignment may look completed in the software but still be weak.

Possible result:

• The upper and lower arches may shift slightly.
• The lab has less reliable occlusal data.
• The crown may require more chairside adjustment after delivery.

What dentists can do:

• Do not capture only a tiny buccal segment.
• Include clear buccal surfaces, cusps, fossae, and opposing surfaces.
• For larger or more complex crown cases, capture more reliable bite reference points.
• After scanning, check whether the bite alignment looks stable in the software.

Mistake 2: The Patient Does Not Close Properly Before Scanning

A bite scan records the patient’s closure at that moment. If the patient is confused, tense, biting lightly, avoiding pressure, or being affected by the scanner tip, the recorded bite may not match the patient’s normal bite.

This is one reason a crown can look acceptable in the file but feel high in the mouth.

Possible result:

• The lab designs the crown to the wrong bite relationship.
• The patient feels the crown is high or uncomfortable.
• The dentist spends more time fine-tuning the crown occlusion.

What dentists can do:

• Ask the patient to close a few times before scanning.
• Confirm that the patient is closing into habitual bite or maximum intercuspation when appropriate.
• Avoid blocking closure with the scanner, cotton roll, fingers, or soft tissue.
• If the patient cannot close repeatably, add a note for the lab.

Mistake 3: The Upper or Lower Arch Scan Is Already Unstable

The bite scan depends on the quality of the upper and lower arch scans. If the arch scan has missing data, distortion, or stitching errors, the bite registration may be built on an unstable model, which is why accurate digital impressions for crowns are important before the case is sent to the lab.

Possible result:

• The bite alignment appears complete but is based on distorted arch data.
• Crown occlusion may not match the mouth.
• Chairside adjustment time increases.

What dentists can do:

• Check the prep arch and opposing arch before bite capture.
• Review occlusal surfaces, adjacent teeth, and posterior areas.
• If an arch scan has obvious missing data or distortion, rescan the arch before taking the bite.
• Do not use bite registration to compensate for a poor arch scan.

Mistake 4: Soft Tissue Interference Is Not Removed

Cheeks, tongue, lips, movable tissue, tuberosities, or the retromolar pad can interfere with digital bite registration. Soft tissue may create false reference points, block full closure, or confuse the alignment process.

This is especially common in posterior bite scans, where space is limited and the patient may move during scanning.

Possible result:

• Incorrect bite alignment
• Open bite, overlap, or shifted bite in the software
• The lab may need to pause and ask for clarification or a new scan

What dentists can do:

• Retract cheek and tongue before bite capture.
• Keep the scanner focused on stable tooth surfaces, not movable tissue.
• If the bite alignment looks strange, check whether soft tissue data was included.
• If needed, remove interfering data according to the scanner workflow and rescan the bite.

Mistake 5: The Occlusion Preview Is Not Checked Before Sending

Many intraoral scan systems provide an occlusion preview, but this step is sometimes skipped when the case appears straightforward. Before sending a digital crown case to the lab, dentists should carefully review the occlusion preview. If the software already shows an open bite, mesh overlap, shifted bite, or unusual one-sided contact, the bite scan should be checked again before submission.

Once a digital bite registration error is detected, the lab may need to pause the case, ask the clinic for clarification, or request a new bite scan. Until the bite relationship is confirmed, crown design or production may not be able to move forward.

Mistake 6: Special Occlusion Is Not Explained in the Prescription

Not every bite is straightforward. Bruxism, crossbite, open bite, implant crowns, temporary crowns, adjusted occlusion, missing posterior stops, and unstable bite patterns can all affect how the lab interprets the case.

If these details are not included, the lab has to rely only on the scan geometry. That may not fully explain the clinical intention.

Possible result:

• The lab may misunderstand the desired occlusal design.
• The crown occlusion may not match the dentist’s expectation.
• The case may require extra communication or adjustment.

What dentists can do:

• Add occlusal notes to the prescription.
• Mention bruxism, crossbite, open bite, implant crown, or unstable bite when relevant.
• For multi-unit, implant, full-arch, or occlusion-heavy cases, consider checking with the lab before submission.
• If the patient’s bite is difficult to reproduce, say so clearly.

When Should You Rescan, Add Notes, or Ask the Lab?

After reviewing the common bite scan mistakes, the next step is deciding what to do before the case is submitted. Not every bite issue requires the same response. Some cases need a new bite scan. Others need a clearer note.

Rescan the bite when:

• Bite alignment is obviously wrong.
• The occlusion preview shows an open bite, overlap, or shifted bite.
• The patient did not close normally during capture.
• Soft tissue interference affected the bite scan.

Rescan the arch when:

• The prep arch or opposing arch has missing data.
• Occlusal surfaces are incomplete.
• The scan shows visible distortion or stitching instability.
• The bite scan is being aligned to a poor-quality arch scan.

Add occlusal notes when:

• The patient has bruxism, crossbite, open bite, or unstable occlusion.
• The case involves an implant crown, multi-unit restoration, or adjusted bite.
• The scan data is usable, but the clinical situation needs explanation.

Ask the lab before proceeding when:

• The case is complex or occlusion-heavy.
• You are unsure whether a single bite scan is enough.
• The scanner platform, file format, or submission method is unclear, especially if your clinic is still refining its dental digital workflow.

Before sending the digital crown case, use the checklist below to confirm that the bite scan, arch scans, and occlusal information are complete enough for the lab to review.

Bite Scan Pre-Submission Checklist

Check Item	Why It Matters	Before Sending
Prep arch	CAD design needs stable preparation data	Check prep, margin, and adjacent teeth
Opposing arch	Needed for crown occlusion	Confirm occlusal surfaces are complete
Bite scan range	Affects bite alignment stability	Do not scan only a very small area
Buccal reference points	Help software align both arches	Capture clear buccal landmarks
Natural closure	Prevents wrong bite relationship	Ask the patient to close normally and repeatably
Soft tissue control	Reduces false alignment	Move cheek and tongue away
Occlusion preview	Catches obvious errors before submission	Check open bite, overlap, and shifted bite
Occlusal notes	Helps the lab understand special cases	Note bruxism, crossbite, implant cases, or unstable bite

Conclusion: Better Bite Scans Mean Fewer Crown Case Surprises

A bite scan is not just the final quick step in an intraoral scan. It is the record that tells the lab how the upper and lower arches relate to each other.

If the bite scan is incomplete, unstable, or captured while the patient is not closing naturally, the crown may need more chairside adjustment even when the restoration itself is well made.

A few extra checks before submission can reduce delays, avoid repeated communication, and help the Triple T dental lab design crown occlusion with better data.

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Email: info@tttdental.com.hk

Website: tttdental.com.hk

FAQ

Why does my crown come back high after an intraoral scan?

A crown may come back high if the bite scan does not match the patient’s natural bite, if the arch scans are unstable, or if the occlusion preview was not checked before submission.

How does an incomplete bite scan affect a crown case?

An incomplete bite scan may provide too few reference points for reliable bite alignment. This can affect crown occlusion and increase chairside adjustment.

Can the lab fix a bad bite scan digitally?

The lab can identify suspicious bite alignment and adjust the design within the limits of the submitted records, but it cannot reliably recreate the patient’s true bite from incomplete or incorrect scan data.

Should bite registration be scanned on one side or both sides?

It depends on the case. A simple single crown may need less bite support than a multi-unit, bilateral, implant, or complex occlusion case. More reliable reference points can help in more demanding cases.

How should I ask the patient to bite before scanning?

Ask the patient to close gently and naturally, then repeat the closure to confirm it is stable. Avoid forcing the patient to bite hard or guiding them into an unnatural position.

Should I rescan if the occlusion preview looks wrong?

Yes. If the preview shows an open bite, mesh overlap, shifted bite, or a relationship that does not match the clinical bite, retake the bite scan before sending the case.

What should I include when sending a digital crown case to Triple T?

Include the digital scan files, prep arch, opposing arch, bite scan, tooth number, material, shade, and any occlusal notes such as bruxism, crossbite, implant crown, adjusted bite, or unstable bite.