Overview
Section and relute is the essential technique for rescuing resin dental verification jigs from polymerization shrinkage distortion. By cutting through the cured splint and rejoining the sections, you break the continuous shrinkage vector and allow each dental implant position to return to its true location. This technique transforms a dimensionally compromised jig into an acceptably accurate verification tool, though it requires meticulous execution.
What You'll Need
- Cured resin dental verification jig
- Thin sectioning disc (0.2-0.3mm thickness)
- Slow-speed straight handpiece
- Fresh pattern resin for reluting
- Mixing pad and spatula
- Protective eyewear and mask
Step-by-Step
Confirm Complete Initial Cure
Verify that the original resin splint has fully polymerized. The surface should be completely hard with no tackiness. Incomplete cure means active shrinkage continues—sectioning too early releases some but not all shrinkage stress. Wait the full manufacturer-recommended time, or ideally 10-15 minutes beyond.
Plan Your Section Locations
Identify the midpoint between each adjacent coping pair. Mark these locations with a pencil or marker. You will make one complete cut between each coping pair. For four copings, you need three cuts; for six copings, five cuts. Ensure cuts will not damage the copings themselves.
Stabilize the Jig
Seat the dental verification jig on the implants (or dental master cast analogs) and hand-tighten one coping. This stabilizes the jig during cutting and maintains orientation. The coping closest to your first cut should be the one secured.
Make the First Section Cut
Using a thin sectioning disc, cut completely through the resin at your marked location. Apply light pressure and let the disc do the work to minimize heat generation. The cut must pass entirely through the splint—verify visually that the sections are completely separated.
Observe the Gap
After sectioning, the cut surfaces will have separated slightly. This gap represents the polymerization shrinkage that was pulling that coping out of position. The gap may be 0.5-2mm depending on span length and resin volume. This visible separation confirms shrinkage was present.
Relute the First Section
Mix fresh pattern resin to a thin consistency. Apply a small amount to the cut surfaces and press together gently. Do not force the sections—allow them to approximate naturally while the resin flows into the gap. Use minimal material to reduce secondary shrinkage.
Allow Complete Relute Cure
Wait for the relute material to fully polymerize before proceeding to the next section. Rushing this step introduces movement that distorts the connection. The relute volume is small, so cure time is faster than the original bulk application—but still allow full manufacturer-recommended time.
Repeat for All Sections
Systematically section and relute each connection, working from one end to the other. Complete one relute before making the next section cut. This sequential approach maintains rigidity throughout the process and prevents gross distortion from multiple simultaneous cuts.
Final Verification
After all sections are reluted and cured, perform the Sheffield test. The jig should now seat passively with no detectable gaps at any position. If gaps remain, the jig may need additional section-relute cycles or complete refabrication.
Tips & Best Practices
- Use the thinnest disc that provides structural integrity—narrower kerf means less material to relute
- Cool the disc with air spray during cutting to prevent heat damage to adjacent resin
- Consider performing section-relute twice for maximum shrinkage compensation in critical cases
- Document the pre-section and post-section gap widths to understand your shrinkage patterns
Common Mistakes to Avoid
Incomplete sectioning
Cuts must pass completely through. Any resin bridge maintains shrinkage stress and negates the compensation.
Excessive relute material
Large volumes of relute resin create their own shrinkage problem. Use the minimum amount needed for connection.
Rushing between sections
Each relute must fully cure before the next cut. Simultaneous mobile sections lead to gross positional error.