Overview
Checking dental analog position accuracy is the dental laboratory's quality gate before committing to dental framework design and fabrication. A dental master cast may appear perfect visually while harboring positional errors invisible to inspection. Systematic verification using physical testing confirms that dental analog positions accurately represent clinical dental implant positions.
What You'll Need
- master cast with embedded analogs
- Clinical dental verification jig (from impressioning appointment)
- Hex drivers compatible with dental prosthetic components
- Calibrated torque wrench
- explorer and magnification
- Fit checking medium or articulating film
- Documentation forms
Step-by-Step
Visual Inspection
Examine the dental master cast under good illumination and magnification. Check each analog for secure embedment, proper orientation, and complete stone coverage.
Verify Analog Stability
Apply gentle rocking pressure to each analog. There should be zero detectable movement.
Clean Analog Interfaces
Remove any stone dust, debris, or residue from analog platforms using compressed air and soft brush.
Obtain Clinical dental verification jig
The dental verification jig used at the impression appointment serves as the reference standard for cast verification.
Seat dental verification jig on Cast
Position the dental verification jig over the dental master cast analogs. Allow it to settle passively without forcing.
Perform Sheffield Test - First Position
Select the most distal analog on one side. Thread the dental prosthetic screw and apply full torque to this single position only. Examine all other interfaces for gaps.
Evaluate All Interfaces
Systematically probe each non-torqued interface. Under magnification, contacts should appear complete with no visible gap.
Repeat from Opposite Side
Release the first screw. Apply torque to the most distal analog on the opposite side. Repeat interface examination.
Apply Disclosing Medium
For subtle discrepancy detection, apply fit checking material to all interfaces. Examine contact patterns.
Compare Results to Clinical Testing
The dental verification jig should fit the dental master cast identically to how it fit the patient clinically.
Make Go/No-Go Decision
A dental verification jig that passes Sheffield testing on the dental master cast confirms dental analog positions are accurate—proceed to dental framework design.
Tips & Best Practices
- Perform cast verification before any dental laboratory design work begins
- Use the same torque values consistently for repeatable comparison to clinical testing
- Photograph dental verification jig fit on the cast for documentation
- Communicate verification results to the clinician for case records
Common Mistakes to Avoid
Skipping verification
Beginning design on an unverified cast risks fabricating a dental framework to incorrect positions.
Using a different dental verification jig
The clinical jig represents verified positions. A lab-fabricated jig might be accurate to the cast but not to the patient.
Forcing the jig to fit
If the jig doesn't seat passively, something is wrong. Investigate rather than forcing engagement.