Successful patient outcomes in implant dentistry are contingent upon a thorough comprehension of impression types and, critically, the ability to discern the appropriate application for each method.
Digital scans, closed tray and open tray techniques each present unique advantages and limitations. Understanding these nuances is essential, as specific clinical situations warrant using one method over another.
Obtaining precise and accurate impressions from the outset not only minimizes frustrating setbacks associated with remakes stemming from suboptimal impressions but also empowers clinicians to confidently deliver exceptional care.
This guide clarifies implant impression techniques and answers questions regarding:
- Dental Implant Impression Techniques
- Dental Implant Materials
- Dental Implant Impression Process
- Implant Impression FAQs
- Guidance for Restorative Dentists
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Dental Impression Techniques
Restorative dentists face a pivotal decision when tasked with capturing the final impression: selecting the appropriate method for this task.
A digital scan, closed tray impression, or open tray impression may be preferred or necessary to obtain precise and accurate impressions.
Digital Scan Impressions
Recent advancements in dental technology have revolutionized the way we capture impressions, offering enhanced convenience and efficiency. However, there are limitations to digital scans, particularly when it comes to full-arch restorations.
When to Use Digital Scanning for Impressions
Digital scanning is highly effective for limited-span implant fixed restorations. As a general guideline, we recommend clinicians consider digital impressions for cases spanning half an arch or involving no more than three implants.
Digital Scan Technique
Digital scanning technology captures multiple “snapshot” images of the oral cavity, which are then meticulously stitched together by sophisticated software to create a comprehensive digital model.
However, despite the precision of this process, minor variations introduced during stitching can impact the accuracy of the physical model crafted from the scan. Even deviations as small as a few microns can affect the fit of fixed implant restorations. Digital scans remain a valuable tool in the implant workflow, but we advise you to exercise caution when considering digital impressions for complex implant cases involving more than three implants.
Closed Tray Impressions
The closed tray technique closely mirrors the conventional procedure used to obtain impressions of teeth. Notably, though, it requires that specially designed impression copings (discussed below) be used to accurately capture the vertical and rotational positioning of the implants.
When to Use the Closed Tray Technique
The closed tray technique is particularly suitable for straightforward cases where implants are easily accessible and properly aligned. In such situations, the closed tray technique provides accurate impressions with less risk of complications. It offers simplicity and efficiency, making it a preferred choice for routine implant cases with favourable conditions.
Closed Tray Impression Copings
In preparation for a closed-tray impression, healing abutments are removed from implants, and impression copings (also known as impression posts, impression pins or implant transfers) are inserted into the implants. Once installed, these copings extend above the gums, and special facets indicate the rotational position of the hex inside the implant.
Each implant type requires a specific impression coping, customized to fit securely and accurately transfer data. Watersedge provides impression copings to our dental partners based on the surgical report provided to us.
Closed Tray Technique
Impression material is injected around the coping and the adjacent teeth. Simultaneously, an assistant prepares a crown and bridge impression tray. The loaded tray is then introduced into the patient’s mouth. When the material has set, the impression is removed, leaving the impression coping securely in place.
The impression exposes the cavity formed by the coping, clearly revealing the flat facets. At this time, it is imperative to confirm that the impression material properly conforms to the coping. Any air pockets will affect how the coping fits back into the impression. If this is the case, the impression must be performed again.
The impression, along with the impression coping, is then sent to Watersedge, where we create accurate models and fabricate precise restorations tailored to the patient’s specific needs.
Open Tray Impressions
Open tray impressions ensure accurate impressions using custom trays and uniquely designed impression copings.
When to Use Open Tray Technique
The decision to use the open tray method depends on factors such as implant stability, accessibility, and patient comfort. It is best to use the open tray technique when faced with challenging implant angulations or difficult implant positions, for example, multiple implants with varying orientations.
Attaching impression copings to implants at varying angles in the mouth and introducing a loaded closed impression tray could result in the impression becoming fixed in place, which all clinicians strive to prevent. In such cases, the open tray technique is preferred.
Open Tray Impression Copings
Unlike closed tray copings, open tray copings incorporate flanges specifically engineered to interact with the impression material. These flanges serve a crucial role in securing the coping within the impression and preventing any movement or dislodgement during the impression-taking process.
Watersedge provides the required open tray impression copings to our dental partners based on the surgical report. We also design custom trays with windows that precisely align with the open tray impression copings.
Open Tray Technique
Like the closed tray procedure, healing abutments are removed, and impression copings (with flanges) are attached to the implants.
Impression material is injected around the copings
and surrounding teeth while an assistant loads a custom tray as well. The tray (with strategically placed openings) is then inserted into the patient’s mouth.
During the open tray impression technique, every effort is made to ensure the screw heads of the copings remain clear while the impression material sets. After it has set, the copings are unscrewed from the implants. Upon removal of the impression from the patient’s mouth, the impression copings remain embedded in the impression material, firmly held in place by the flanges, ensuring both vertical and rotational stability.
This process must be meticulously performed to avoid common pitfalls. Any air pockets around the coping flanges can compromise the accuracy of the impression. If mobility in the copings is detected, the impression should be redone to ensure optimal results.
The impression with embedded copings and screws is then sent to Watersedge. With this information and other relevant data, we meticulously create models and produce customized restorations that address the unique requirements of each patient.
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Dental Implant Materials
Light body impression material, commonly used for capturing fine detail in tooth impressions, is not the best choice for implant impressions. Instead, opt for a medium body impression material—we prefer it to be the same material the tray is loaded with.
Polyvinyl siloxane (PVS) is widely regarded as one of the best materials for implant impressions due to its stability, reliability and durability. Polyether, if you are familiar with it, is also a good choice.
Note: Alginate impression material, commonly used for study records, is unsuitable for implant impressions. Alginate lacks the strength required to hold impression copings in place securely and has a high shrinkage rate as the water evaporates, leading to inaccuracies in the impression.
Dental Implant Impression Process
If digital scans are deemed insufficient, we help our dental partners determine the optimal impression technique.
To begin the process, Watersedge requires:
- The study model or alginate impression of healing abutments.
- A copy of the surgical sheet and any relevant notes.
- An implant-based prescription. (Experienced doctors only. New doctors are encouraged to send the case and request a phone call for guidance.)
With this information, Watersedge will:
- Analyze the study model and surgical report.
- Confirm or suggest an open or closed tray impression technique.
- Provide the required impression copings for the implants.
- Provide a custom tray to obtain accurate impressions.
- Inquire if a loan of specialized installation tools (i.e. screwdrivers and torque drivers) is required. This service is available to local clinicians only.
At this juncture, the clinician is equipped with everything required and can proceed with the chosen implant impression technique. However, should any questions arise, the team at Watersedge is available for support and guidance.
After a successful implant impression is performed, the following is sent to Watersedge:
- The master impression.
- The opposing model or impression.
- The bite registration.
Following these steps ensures a smooth and accurate implant impression process, allowing Watersedge to craft models and precise restorations.
Implant Model Verification Jig
For complex implant cases involving implant bars or four or more implants, Watersedge often provides clinicians with an implant model verification jig—a tool to validate the accuracy of the record.
Clinicians are invited to try the plastic device onto the implants in the patient’s mouth, and if any discrepancies arise, it signals the need to retake the impression. To support this process, Watersedge sends the original impression copings and custom tray to the dentist with the verification jig.
This extra step prioritizes predictability and ensures fit on the day of delivery.
Implant Impression FAQs
Can I modify stock trays to create open trays for impression-taking?
Yes, you can convert stock trays into open trays for impression-taking. However, most of our dental partners prefer using custom trays provided by our laboratory, as they offer a more reliable and tailored solution for impression-taking. If you choose to create open trays, several steps are involved. First, since stock trays come in various sizes, you must try multiple trays to find one that comfortably fits the patient and allows space to accommodate the added impression copings. Additionally, drilling holes in the trays creates an inconvenient and unwanted mess chairside.
Should I link impression copings together to strengthen them?
No, it is not recommended to link impression copings together in an attempt to make them stronger. Doing so can create tension between the impression copings, which alters their angles within the impression material. Therefore, splinting them together compromises the accuracy of the impressions.
My implant case is more complicated than I initially thought. Is Watersedge available to speak with patients directly?
Yes, absolutely. In cases where the complexity of a patient’s treatment plan exceeds initial expectations, direct communication with the patient can be highly beneficial. We are happy to address any concerns over the phone or offer in-lab patient visits, where we provide personalized insights and recommendations utilizing models of their teeth.
I do not have the necessary tools to perform the planned implant system. Can you provide them to me?
Certainly, we maintain many implant toolkits at our laboratory for this purpose and would be happy to loan them to you. To ensure seamless coordination, we will verify the timing of your patient’s appointment and dispatch the final restoration plus toolkit accordingly. This service is exclusive to our local clients. (Note: In the event the tools are not returned within one week’s time, an invoice for $800 will be issued.)
Trust Watersedge for Guidance and Expertise
Education and collaboration are the cornerstones of success in implant dentistry, and the team at Watersedge Dental Lab is ready to support you every step of the way.
Whether you’re seeking guidance about open tray vs. closed tray impression techniques, material selection, or treatment planning, our team is available for a consultation. Additionally, we’re happy to communicate with patients directly when requested, send a technician to assist with impression-taking or provide guidance during restoration delivery.
How can Watersedge help you deliver exceptional care today?