Why Accuracy Complaints Persist Despite &ldquo;Good&rdquo; Scans?

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In my years of clinical practice, I&rsquo;ve learned that most scanner-related restorative failures don&rsquo;t announce themselves clearly. The scan loads quickly, margins look defined, and the lab confirms receipt without questions. Yet the crown sits high, the veneer requires adjustment, or the occlusion feels off despite careful bite registration.When this happens repeatedly with a <a href="https://repair.dental/services/intraoral-scanner-repair/dexis-intraoral-scanner-repair">DEXIS intraoral scanner</a>, the instinct is often to blame the canning technique or lab workflow. I&rsquo;ve seen colleagues rescan cases multiple times, change scan paths, or even switch materials&mdash;without realizing the underlying issue isn&rsquo;t visibility or technique, but scanner quality metrics drifting out of tolerance.The real confusion lies in how dentists interpret accuracy. Many assume accuracy is a single value, when in reality it is defined by two separate but equally important measurements: trueness and precision. A scanner can be precise without being true, or true without being precise. Both scenarios create different clinical problems, but they feel similar chairside.As restorative tolerances tighten&mdash;especially for implant dentistry and anterior aesthetics&mdash;understanding how trueness and precision affect DEXIS scanner performance is no longer optional. It directly influences remake rates, chair time, and patient confidence.

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<h2>2. Technical Explanation &mdash; What Trueness and Precision Mean in Real Dentistry</h2>

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<h3>Trueness: How Close Is the Scan to Reality?</h3>

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Trueness measures how accurately a scan represents the actual physical dimensions of the tooth, arch, or implant position. With <a href="https://repair.dental/services/intraoral-scanner-repair/dexis-intraoral-scanner-repair">DEXIS scanners</a>, trueness is evaluated by comparing scan data against calibrated reference models.

Clinically acceptable trueness for single-unit restorations typically falls within &plusmn;30&ndash;50 microns. Once deviation exceeds this range, dentists may notice:

<ul>
	<li>Crowns that appear fully seated digitally but rock clinically</li>
	<li>Veneers requiring unexpected interproximal reduction</li>
	<li>Implant restorations with passive fit issues</li>
</ul>

Trueness degradation usually stems from optical misalignment, not software errors. Over time, vibration, temperature cycling, and routine handling can cause micro-shifts in the sensor-lens-mirror relationship inside the scanner head.

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<h3>Precision: Can the Scanner Repeat Itself Reliably?</h3>

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Precision measures repeatability. If you scan the same preparation five times, precision reflects how similar those five scans are to one another&mdash;not whether they are correct.

A DEXIS scanner with high precision but low trueness will consistently produce the same inaccurate result. This is why dentists often hear labs say, &ldquo;The scans are consistent, but something feels off.&rdquo;

Precision is influenced by:

<ul>
	<li>Sensor stability</li>
	<li>Frame stitching algorithms</li>
	<li>Mechanical rigidity of the scanner housing</li>
	<li>Thermal stability during prolonged scanning</li>
</ul>

From a dentist&rsquo;s chair, poor precision presents as inconsistent margins, variable occlusion, or scan stitching errors during full-arch cases.

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<h3>Why Dentists Confuse the Two?</h3>

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The reason this distinction is missed is simple: both problems look similar clinically. Misfit restorations, occlusal discrepancies, and aesthetic mismatches don&rsquo;t immediately reveal whether trueness or precision is at fault. Only structured testing can separate the two.

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<h3>How Trueness and Precision Are Tested in DEXIS Scanners</h3>

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Professional evaluation uses:

<ul>
	<li>Dimensional deviation mapping</li>
	<li>RMS error calculations</li>
	<li>Multi-orientation scan overlays</li>
	<li>Reference calibration blocks</li>
</ul>

Deviation beyond &plusmn;100 microns across repeated scans almost always indicates internal alignment issues rather than user error.

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<h2>3. Repair vs Replace &mdash; Making the Right Clinical Decision</h2>

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When scanner accuracy issues surface, dentists usually move through predictable stages: denial, frustration, workaround, and then decision.

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<h3>Repair: When It Makes Sense</h3>

<ul>
	<li>Scanner is less than 6&ndash;7 years old</li>
	<li>Consistent deviation patterns</li>
	<li>No catastrophic sensor failure</li>
</ul>

Typical repair restores 95&ndash;98% of original factory accuracy.

Cost range: $800&ndash;$1,500 
Downtime: 3&ndash;5 business days

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<h3>Replacement: When It&rsquo;s Necessary?</h3>

<ul>
	<li>Repeated electronic failures</li>
	<li>Severe optical damage</li>
	<li>Obsolete model support</li>
</ul>

Replacement costs for a DEXIS scanner often exceed $25,000, not including training and workflow disruption.

Clinical takeaway: For most practices, professional repair offers the highest return with the least interruption.

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<h2>4. DIY Troubleshooting &mdash; What Dentists Can Safely Check Chairside</h2>

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Before sending a scanner out, there are a few checks every dentist can perform safely.

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<h3>Safe Chairside Steps</h3>

<ul>
	<li>Run factory calibration</li>
	<li>Scan a known reference model twice and overlay the results</li>
	<li>Inspect lens and mirror surfaces for haze or micro-scratches</li>
	<li>Maintain consistent room temperature during scanning</li>
</ul>

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<h3>&nbsp;</h3>

<h3>When to Stop Immediately?</h3>

<ul>
	<li>Identical errors across all scans</li>
	<li>Marginal distortion is unaffected by the technique</li>
	<li>Color inconsistency paired with geometric error</li>
</ul>

Attempting mechanical adjustment without precision tools often leads to permanent damage and voided warranties.

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Clinical Insight: 
&ldquo;In my practice, every case of repeated anterior misfit traced back to internal alignment&mdash;not scanning technique.&rdquo;

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<h2>5. Professional Repair Process for DEXIS Accuracy Restoration</h2>

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At Repair. Dental, restoring scanner accuracy means addressing both trueness and precision, not just recalibration.

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<h3>Diagnostic Phase</h3>

<ul>
	<li>Optical path inspection</li>
	<li>Sensor position verification</li>
	<li>Deviation and repeatability analysis</li>
</ul>

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<h3>Repair &amp; Calibration</h3>

<ul>
	<li>Optical realignment using laser reference tools</li>
	<li>Sensor stabilization and reseating</li>
	<li>OEM-standard calibration routines</li>
</ul>

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<h3>Quality Assurance</h3>

<ul>
	<li>Multi-angle accuracy testing</li>
	<li>Full trueness and precision validation</li>
	<li>Documented verification results</li>
</ul>

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Turnaround: 3&ndash;5 business days

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<h2>6. Cost Transparency &mdash; What Dentists Should Budget?</h2>

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From a business perspective: 
Avoiding just two remakes per month often offsets annual repair costs.

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<h2>7. Prevention &amp; Maintenance &mdash; Protecting Scanner Accuracy</h2>

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<h3>Daily</h3>

<ul>
	<li>Clean optical surfaces</li>
	<li>Handle the scanner cable and head carefully</li>
</ul>

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<h3>Weekly</h3>

<ul>
	<li>Run calibration verification</li>
	<li>Review scan consistency</li>
</ul>

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<h3>Quarterly (High-volume practices)</h3>

<ul>
	<li>Professional inspection</li>
</ul>

Environmental stability matters. Heat, humidity, and sudden temperature shifts accelerate drift and reduce both trueness and precision.

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<h2>FAQs</h2>

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Q1: Can a scanner be precise but inaccurate? 
Yes. Precision reflects repeatability, not correctness.

Q2: Does calibration fix trueness issues? 
Only if the optical path remains aligned.

Q3: Will repair affect diagnostic accuracy? 
No&mdash;professional repair restores factory tolerances.

Q4: How long do repairs last? 
Typically, 2&ndash;4 years with proper care.

Q5: Does professional repair voidthe arranty? 
No, when OEM standards are followed.

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<h2>8. Conclusion:</h2>

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Trueness and precision define whether a <a href="https://repair.dental/services/intraoral-scanner-repair/dexis-intraoral-scanner-repair">DEXIS scanner</a> delivers restorations that seat predictably and consistently. When either metric drifts, the scanner may still &ldquo;look fine&rdquo; while quietly increasing remakes and chairside frustration.Understanding the difference allows dentists to make informed decisions&mdash;repairing when appropriate and restoring accuracy without unnecessary replacement.

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<h3>Schedule Your DEXIS Scanner Repair &ndash; 3 Day Turnaround</h3>

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For more professional dental equipment repair insights, please visit <a href="https://repair.dental/">Repair. Dental</a> or follow us on <a href="https://www.facebook.com/repair.dental">Facebook </a>&amp; <a href="https://www.instagram.com/repair.dental/">Instagram</a>.

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DEXIS scanner trueness and precision directly affect restoration fit. Learn how calibration, wear, and repair restore reliable digital accuracy.

Trueness vs Precision: Understanding DEXIS Scanner Quality Metrics