New Crown Under Existing Partial Denture Workflow
Need to get a new crown under a patient's existing partial denture using traditional impression materials? We can help with this workflow.
Index
Overview for this Workflow
When a patient requires a new crown under an existing partial denture, the ideal treatment option is to first place the crown before fabricating a new partial denture, but the cost can be a barrier for some patients who may already have a clinically acceptable partial denture. In these cases, retrofitting a crown under the existing partial denture may be the preferred choice. Fabricating a crown under an existing partial placement can be time-consuming and requires careful attention to detail to ensure proper seating and retention.
This workflow is for those clinicians still using traditional impressions. If you’re looking for the digital version, please see this link.
Clinical and Lab Goals
Indications & Contraindications
Setting Patient Expectations
There are two basic options for this traditional impression workflow:
- You are able to capture a pre-operative impression of the clinical crown in addition to other impressions needed for this case. If this is the case, the patient may keep the partial after the impression process. RDL will provide a copy of the clinical crown, including any rest seats or preps that might be on the tooth surface to support the partial.
- You are unable to capture a pre-operative impression. In this case, the patient’s partial should be captured in place in the impression and not removed prior to sending it to the lab. Impressions should be taken with appropriate PVS or other impression materials that are stable without moisture.
The key component is the ability to capture that impression of the crown as it supports the partial before committing the preparation. This will save you valuable chair time.
First Clinical Visit
In this visit, you will capture the key diagnostic impressions needed to complete the case
Diagnostic Materials to Deliver to Russellville Dental Lab
Option 1 – Preliminary Impression
- Prescription, including Shade
- Bite Registration
- Preliminary Impression (critical component)
- Opposing Arch Impression
- Tradtional Impression of the Tooth to be Restored with clearly defined margins
Option 2 – No Preliminary Impression
- Prescription, including Shade
- Bite Registration
- Opposing Arch Impression
- Impression of the Parital Denture in Place, over the prepared tooth (soft body injection)
Laboratory Procedures
After arriving at Russellville Dental Lab, the impressions will be poured, trimmed, and mounted. If your case involves an impression in place, we will carefully pour the case and slowly expose the margin of the crown while maintaining the positive seat of the partial on the model.
The lab will be on the lookout for errors in the impression that might limit the clinical outcomes. Typical complications in this workflow are most likely to be improperly seated partials in the impression. We can usually see this immediately when pouring up, as the poor seat will lead to stone over the partial surfaces.
If all is well, we will scan and design the crown, and after milling and sintering the crown will be placed as either a “Copy Crown” mimicking the natural tooth, or it will be adjusted to fit under the partial if there was no preliminary impression.
The Lab Will Return:
- The Patient’s New Crown
- The Patient’s Existing Partial
Final Clinical Visit
Delivery
Following this workflow will help the clinician and lab get those calibrated, consistent results you expect from your Dental Lab.
This procedure traditionally has a higher-than-average need for chairside adjustments at delivery compared to traditional crowns, but not more than what would be needed to fine-tune a rest prep proposed by the lab for an immediate partial denture.
