Taking an impression for an implant crown captures the exact three-dimensional position of the implant so a lab can build a crown that fits passively on the abutment. The process differs from a standard crown impression because you’re recording the implant’s position below the gumline rather than the shape of a prepared tooth. Two main approaches exist: a traditional impression with physical materials and trays, or a digital scan using an intraoral scanner and scan bodies. Both can produce accurate results when executed carefully.
Open-Tray vs. Closed-Tray Technique
The two conventional methods are named after the type of tray used. In the open-tray (pick-up) technique, the impression coping stays embedded in the impression material when you remove the tray from the mouth. In the closed-tray (transfer) technique, the coping stays on the implant and is later reinserted into the impression. Open-tray is generally preferred for multi-unit cases or angled implants because it avoids the small repositioning errors that can occur when reinserting a closed-tray coping. For a single implant crown in a straightforward position, either technique works.
Open-Tray Steps
Screw the open-tray impression coping onto the implant and hand-tighten it to roughly 10 Ncm, following the manufacturer’s recommendation. Then try in the custom tray to confirm it seats passively with enough clearance around the coping where it projects through the access hole. If vertical stops on the tray are insufficient, add small composite resin stops to control seating depth and ensure adequate material thickness.
Syringe light-body impression material directly around the impression coping while loading the tray with heavy-body material. Seat the tray carefully, watching the coping’s screw head emerge through the access hole. Covering the hole with a sheet of occlusal indicator wax before seating prevents heavy-body material from flooding over the screw head, keeping it accessible. Hold the tray stable until the material fully sets, then loosen the coping screw with the appropriate driver, and remove the tray. The coping lifts out embedded in the impression.
At the bench, thread the implant analog onto the coping, apply a silicone gingival mask material around the analog to simulate the soft tissue, and pour the impression in dental stone.
Closed-Tray Steps
The closed-tray approach uses a transfer coping that screws onto the implant but remains in the mouth when you pull the tray. After the impression sets and the tray is removed, you unscrew the coping from the implant, attach the analog, and place the assembly back into the impression in the void the coping left behind. This method is simpler and doesn’t require a custom tray with access holes, but the reinsertion step introduces a small chance of positional error.
Custom Trays vs. Stock Trays
Custom trays have long been considered the gold standard because they provide a uniform thickness of impression material, which reduces distortion. However, research comparing the two shows that the accuracy difference between custom and rigid stock trays is not statistically significant for implant impressions, particularly when using polyvinyl siloxane (PVS) material with the open-tray technique. Metal or rigid plastic stock trays outperform flexible plastic ones. If you use a stock tray, choose a rigid option and confirm it allows proper clearance around the impression coping.
Choosing an Impression Material
The two most common elastomeric options for implant impressions are polyvinyl siloxane (PVS) and polyether. PVS monophase material tends to reproduce the master model most accurately in lab comparisons, while polyether is the most predictable in terms of consistency from one impression to the next. PVS putty-wash combinations, by contrast, show the least reliability for implant cases. All impression materials produce some degree of distortion, and those small errors can accumulate through the casting process, so material selection matters more for long-span cases than for single crowns.
For a single implant crown, a medium or monophase PVS material syringed around the coping and backed by a heavier tray material is a reliable combination. Polyether is a strong alternative, especially if you prefer a single-viscosity approach, though it’s stiffer on removal and can be harder to retrieve in deep undercuts.
Splinting Copings for Multi-Unit Cases
When restoring multiple implants with a single prosthesis, connecting the impression copings to each other before taking the impression dramatically improves accuracy. In one study of full-arch implant cases, 12 out of 13 splinted impressions produced casts with accurate prosthesis fit, compared to only 6 out of 13 nonsplinted impressions. The splinted group performed on par with the original fabrication casts.
The standard splinting method uses acrylic resin or pattern resin to join the copings with a rigid bar. Because acrylic shrinks as it cures, the common protocol is to section the splint after it sets, then reconnect the segments with a fresh mix of resin. This breaks the shrinkage chain and yields a more dimensionally stable splint. For a single implant crown, splinting isn’t necessary.
Shaping the Gum Before the Impression
A well-contoured emergence profile, the shape of the crown where it transitions through the gum tissue, is critical for a natural-looking result. If the implant was restored with a healing abutment that’s cylindrical, the surrounding tissue will be shaped like a tube rather than mimicking the natural root form. Taking a final impression at that stage captures the wrong soft tissue contour.
The solution is to place a provisional (temporary) crown on the implant first and let the tissue reshape around it over four to six weeks. The provisional is fabricated on a soft tissue cast, with composite resin built up at the base to sculpt the desired gingival contour. After the tissue has matured and harmonized with the adjacent teeth, you remove the provisional and immediately take the final impression before the tissue can collapse. This non-surgical approach reliably produces a natural emergence profile that the lab can replicate in the definitive crown.
Digital Impressions With Scan Bodies
Intraoral scanners offer an alternative that eliminates physical impression material entirely. Instead of an impression coping, you screw a scan body onto the implant. The scan body is a small post with a known geometry that the scanner’s software recognizes, allowing it to calculate the implant’s exact position and angulation digitally.
Scan bodies come in different materials, including titanium and PEEK (a tooth-colored polymer), and must match the specific implant system and connection type. Some systems use a hex connection, others a conical connection, and the scan body must correspond to whichever your implant uses. Like impression copings, scan bodies are hand-tightened to approximately 10 Ncm.
For residual natural teeth adjacent to the implant, intraoral scanners show no significant difference from conventional impressions in capturing anatomy. The digital file is sent directly to the lab or milling center, bypassing the stone model entirely in many workflows. This removes the cumulative distortion that can occur through impression material, stone pouring, and die trimming. The practical trade-off is that digital workflows depend on the scanner’s ability to capture the scan body cleanly, which can be challenging if the scan body sits deep below the tissue or if saliva and blood obscure the field.
Verifying the Impression’s Accuracy
Even a carefully made impression can contain errors that lead to a crown that doesn’t seat passively. For single-unit crowns, the lab typically checks framework fit on the stone model before finishing the restoration. For multi-unit cases, an implant verification jig provides an extra layer of quality control before the prosthesis is fabricated.
A verification jig is a rigid framework, usually made from acrylic resin, that connects the implant analogs on the master cast. After fabrication, it’s tried in the patient’s mouth. If it seats passively on all the implants without rocking or requiring pressure, the cast is accurate. If it doesn’t fit, the jig pinpoints where the error is. The preferred method is to fabricate the jig on the cast, section it between each implant site, then reconnect the sections intraorally with fresh low-shrinkage acrylic resin. After about 17 minutes of initial polymerization, you remove it and assess fit on the master cast under magnification.
When verification reveals a localized mismatch, the implant replica at that site can be repositioned on the master cast using the jig as a spatial reference. A generalized mismatch signals a larger problem with the original impression or cast, and the jig can then be used to retake a splinted open-tray impression to generate a corrected cast.
Common Errors and How to Avoid Them
Voids around the impression coping are the most frequent problem. They occur when blood, saliva, or sulcular fluid prevents the impression material from flowing into contact with the coping surface. Thorough tissue management before the impression, including hemostasis and gentle retraction of the surrounding gum, is essential. Syringe light-body material directly around the coping rather than relying on the tray-loaded material to reach it.
Air bubbles trapped against the coping produce small, well-defined voids that can distort the analog position on the resulting cast. Injecting material from the deepest point and letting it flow upward pushes air ahead of it rather than trapping it underneath. Internal bubbles caused by fluid are larger and less sharply defined. Both types compromise fit.
A “stepped” impression happens when a two-phase (wash) technique is used and the tray doesn’t reseat fully over the first layer, creating a ledge in the material. For implant impressions, this is less common because most clinicians use a single-step, dual-viscosity approach, but if you do reline an impression, make sure the reseating path is unobstructed. When in doubt, retake the impression rather than sending a questionable one to the lab. The time spent on a second impression is far less than the time lost to a poorly fitting crown.
Finally, verify that the impression coping is fully seated on the implant before making the impression. A coping that’s slightly elevated or rotated will transfer the wrong position to the cast. Confirm seating with a periapical radiograph if there’s any question, particularly in posterior sites where visual access is limited.