How to Take a Pickup Impression for a Locator Reline

00:00 Introduction
In this video we'll go over the steps for using an existing denture to do a pickup impression over Zest Locator abutments. This will allow the denture to be relined with the Locator housings.

00:18 Order the appropriate abutment
But first, it's important to order the appropriate Locator abutment. When choosing a Locator abutment, you need to first measure the depth of the tissue from the highest point, to the top of the implant. Then, you simply order the abutment with a collar height that matches that measurement. This will ensure that when the abutment is seated, the top portion of it is completely supragingival. And this is crucial for ensuring that the housing can completely seat over that abutment and provide the intended retention.

00:49 Take bite, seat abutments, verify adequate height
Before you seat any of your Locator abutments however, you'll first want to take a bite with the denture in place.

Once that's done, you can seat the Locator abutments to the implants and then verify that the retentive area of each abutment is supragingival. The retentive area is everything above the cuff, starting where the abutment diameter shifts in slightly.

If any part of the retentive area is subgingival, you'll need to either order a replacement Locator with an increased collar height or do a gingivectomy in that area.

01:25 Torque specs
When torquing a Locator abutment in to place, you can typically use the torque value that's recommended by that implant manufacturer, but never more than 30Ncm, and only 20Ncm if the implant has threads smaller than 1.4mm.

01:45 Grind out intaglio of denture
Ok, so with the Locators torqued in, the next step is to grind out the intaglio of the denture in the areas where it's going to seat over the Locator abutments. You want to make sure that there's a passive fit of that denture over those abutments. Additionally, you may want to grind away a shallow amount of the entire intaglio surface to ensure there's enough space for adequate thickness of the impression material.

02:05 Pickup impression
With that complete, you can apply tray adhesive followed by a light wash.

Inject impression material around the locator abutments, like you would a crown prep.

Place the denture in the mouth and using the bite registration that was made earlier, have the patient come just to a close. It's important that the patient does not close heavy.

Once the impression material has set up, you can remove the denture and send it to the lab.

02:35 Lab steps
In the lab, we'll place locator analogs in the denture so that we can pour up a model. We'll flask the denture, remove the impression material, and replace with acrylic. Finally, we'll get it trimmed and polished for delivery back to your office in a day or two.

Alex Rugh, CDT
O'Brien Dental Lab
www.obriendentallab.com