Overview
Taking an accurate dental full arch implant impression is the foundation of every successful implant-supported dental prosthesis. Unlike single-unit restorations, multi-implant cases compound any positional error across all fixtures, making precision critical. A flawed impression leads to dental frameworks that rock, screw holes that don't align, and dental prosthetics destined for the remake pile.
What You'll Need
- Open-tray impression copings compatible with your dental implant system
- Implant-specific hex drivers and torque wrench
- Custom open-tray impression tray with adequate clearance
- Polyvinyl siloxane (PVS) or polyether impression material
- Splinting material (dental floss, acrylic resin, or dental implant verification jig)
- Bite registration material
- Articulating paper
Step-by-Step
Remove the dental prosthesis and Assess Tissue Health
Remove the existing dental provisional or definitive dental prosthesis and evaluate the peri-implant soft tissue. Healthy tissue should appear pink and firm without signs of inflammation or suppuration. Clean around each implant platform with chlorhexidine and dry thoroughly. Document any tissue abnormalities before proceeding.
Connect Impression Copings
Thread impression copings onto each implant, ensuring the anti-rotational hex engages fully. Hand-tighten first, then apply manufacturer-recommended torque (typically 10-15 Ncm). Verify each coping is fully seated by checking that no gap exists between the coping base and implant platform.
Splint the Impression Copings
Rigid splinting prevents individual copings from shifting during impression removal. Connect all copings using your preferred method: dental floss embedded in acrylic resin, light-cured composite bars, or a prefabricated dental implant verification jig. Allow adequate polymerization time and section/relute if using resin to compensate for shrinkage.
Try-In the Custom Tray
Seat your custom open-tray over the splinted copings. Confirm adequate clearance around each coping access hole (minimum 2mm circumferentially). The tray should seat passively without contacting the copings or splint material. Mark any interference points and relieve with an acrylic bur.
Apply Tray Adhesive
Paint a thin, even layer of adhesive specific to your impression material on all internal tray surfaces. Allow the adhesive to dry completely per manufacturer instructions (typically 3-5 minutes). Tacky adhesive prevents impression material from separating from the tray during removal.
Inject and Seat
Syringe light-body impression material around each coping, ensuring complete coverage of the coping-implant interface. Load the tray with heavy-body material and seat with firm, even pressure. Maintain stability throughout the setting time. Avoid any movement that could introduce distortion.
Unscrew and Remove
Once the material has fully set, unscrew each impression coping through the tray access holes. Use the correct hex driver and break torque smoothly to avoid rotating the copings within the impression. Lift the tray straight up in the path of insertion. The copings should remain embedded in the impression material.
Inspect and Verify
Examine the impression for voids, tears, or pulls around each coping. Verify all copings transferred and remain rigidly splinted. Check that analog interfaces are clean and undamaged. Any defect requires remaking the impression—proceeding with a compromised impression guarantees a misfit dental framework.
Tips & Best Practices
- Use open-tray technique exclusively for multi-implant cases; closed-tray introduces unacceptable positional error
- Allow acrylic splint material to cure completely, then section and relute to eliminate polymerization shrinkage
- Take a verification record with the dental master cast to confirm accuracy before dental framework fabrication
- Communicate dental implant system and connection type clearly to your dental laboratory
Common Mistakes to Avoid
Inadequate splinting rigidity
Flexible splints allow copings to shift during impression removal, transferring inaccurate positions to the dental master cast.
Insufficient tray clearance
Copings contacting the tray create stress points that distort the impression upon removal.
Skipping the verification step
Proceeding to dental framework fabrication without verifying dental master cast accuracy leads to costly remakes when the dental framework fails to seat passively.