If you are among the many dentists who have streamlined their restorative process by adding an intraoral scanner to their practices, you’ve experienced the cost and time savings, convenience, and efficiency that the digital workflow offers. However, the full potential of this technology cannot be unlocked without following the appropriate principles and techniques when capturing a digital impression. This is particularly true when scanning implant sites. It is vital to capture the angulation and orientation of the prosthetic connection with both high accuracy and precision. Intraoral scan bodies, when used correctly, can do just this. To ensure the most accurate implant restoration possible, there are simple digital impression methods and guidelines you can utilize, several of which I’ll outline here.

1. How to Scan Implant Abutments
2. Confirming Complete Seating of the Implant Scan Body
3. Evaluate, Adjust and Capture Accurate Contacts
4. Taking an Accurate Digital Bite Registration

Let us consider a situation where a cement-retained implant restoration is recommended. If the final implant abutment is already seated, the abutment itself can be scanned, as opposed to removing the abutment and utilizing a scan body. This type of digital impression technique is similar to scanning a tooth preparation for a crown.

When taking a digital impression at a site where an abutment is seated, it is important to capture the margins of the abutment. Ideally, the margins of the abutment are situated at or 0.5 mm below the gingival margin, allowing for a more predictable cement cleanup. A custom abutment allows the lab technician to ideally place the margins, and with the abutment margin located close to the gingival margin, the intraoral scanning process is easier.

If the margins of the abutment are covered by the gingiva, then the soft tissue must be retracted to expose the margins. Otherwise, it will be difficult for the dental lab to create an accurate implant crown. To see the importance of tissue retraction, note the difficulty of visualizing the abutment margins in the scan below.

To expose subgingival margins, gently place cord to retract the tissue before the implant site is scanned. After five minutes, remove the retraction cord and immediately scan the implant site. This allows for the creation of digital impressions where the margins are easily identified by both the dental lab and the CAD software used to create crowns. Before digitally submitting the case to the lab, it is important to inspect the post-processing scan to ensure the margin, the body of the abutment, and the adjacent contacts are clear and clean. This ensures the lab has the information needed to create a well-fitting, functional implant restoration.

When the digital impression is taken at the implant level, it is important to make certain that the scan body is completely seated before acquiring the intraoral scan. If the scan body is not completely seated, the resulting restoration will not fit.

When the scan body is connected to the implant, both bond and soft tissue around the implant can hinder the seating of the scan body. Thus, after hand-tightening the scan body into place, it is recommended to acquire radiographic confirmation to ensure it is completely seated.

It is important to note that if you’re not able to fully seat the scan body, the implant restoration will not seat properly either. If complete seating is not possible after multiple attempts, the bone contours surrounding the implant site can be modified using a bone profiler or instrument of choice to scrape away bone around the implant platform. Make sure the cover screw or healing abutment is connected to the implant as you perform this procedure to protect the implant connection.

The scan region of the scan body must be clearly captured in order for the lab to create a restoration that accommodates the position and angulation of the implant. If you encounter problems with clearly capturing this area in your digital impression, Teflon tape can be placed in the screw access channel of the scan body — just make sure that the tape does not interfere with the geometric patterns of the scan area.

To produce a well-fitting restoration, the teeth adjacent to the implant site should be evaluated to determine if the contact areas require modifications. In some cases, an enameloplasty procedure may be needed to ensure broad, parallel contacts. This allows for better distribution of functional forces at the implant site. Broad, parallel contacts are also necessary to ensure a clear path of insertion for the restoration and prevent black triangle formation, limiting interproximal food impaction.

To help visualize the path of draw, the adjacent teeth can be scanned with the scan body in place. It’s important to note that the “auto-fill” feature should not be used, as it will not create an accurate representation of any missing data. If data is being inaccurately captured, make sure the area is thoroughly cleaned and dried before rescanning. After scanning, assess the contact areas in both the color and model or stone mode, ensuring that the contacts are completely captured and are smooth and free of any data scatter. Take the time to review the post-process scans to ensure the scan body and adjacent contacts are accurately captured. If any distortions are noted, it’s important to rescan those segments before sending the patient home.

One of the many benefits of digitally scanning implant cases is that there is no need to take and send in a physical bite registration. Due to the accuracy of intraoral scanning technology, it is easy to capture an accurate bite scan. However, in cases where the scan area of the scan body protrudes above the occlusal table, it can be challenging to capture an accurate digital bite registration. Thus, it may be necessary to remove the scan body and replace it with the healing abutment or provisional restoration prior to taking the bite scan.

Additionally, make sure to inspect the digitally acquired bite registration for accuracy while the patient is still sitting in the chair. If your bite scan is accurate, this ensures the occlusion of the implant restoration will also be accurate, simplifying the final delivery appointment and minimizing the odds that any adjustments will be necessary.

Digital scanning technology is incredibly accurate, but achieving an ideal restorative outcome is contingent upon observing the proper practices and techniques. So long as care is taken to accurately capture all of the data needed to restore your case, you can expect a precise, well-fitting implant restoration.