WHY MY DENTURES (DON'T) SUCK PT II

Part 2
Options for Final Impressions

by Drake's on-staff Dentist - Larry R. Holt, DDS, FICD

WELCOME BACK!

Hopefully by now you have a good understanding of critical edentulous anatomy. This entry will focus on selecting the correct tray to use for capturing said anatomy.  

We all remember dental school and the initial alginate impression with over extended borders; sending that to the lab and having a custom tray fabricated.  This is still a sound method to having an appropriate tray to use, probably the gold standard.  Be sure when you use this work flow that you take some time and draw in your desired borders for the custom tray that is to be fabricated on your overextended model.  I like to have these borders slightly short so there is room to do some border molding.

A relatively recent innovation on the market is heat malleable stock trays that are specifically made for edentulous arches.  There are multiple manufacturers of these trays.  I have used several of them with success.  When a patient has an existing denture, it’s easy enough to take some lab putty and make a putty model by placing putty into the intaglio of their old denture.  Once the putty model is set, the tray selection can be done on that model and not in the patient’s mouth.  You can heat the tray in a water bath and adjust it to further customize its shape.  Once you have a tray that fits the putty model, you can border mold that tray in the mouth with some fast set heavy body PVS material.  

BE SURE TO USE ADHESIVE WHEN ADDING PVS TO ANY IMPRESSION TRAY.

^Figure 1 stock edentulous tray with putty model of intaglio of patient's existing denture

^Figure 2 heating the tray in water bath

^Figure 3 Adjusting heat malleable edentulous tray

^Figure 4 border molding and stops placed with heavy body PVS

IF YOU DON'T OWN A WATER BATH, THEY CAN BE EXPENSIVE.  You can purchase a small deep fryer that will serve the same purpose.  Just check the temperature and use a low setting.

Check with your supply vendor to explore the options for these stock trays.  They may not be the gold standard of a custom tray, however they serve a good purpose.  There are those times when you need the final impression today and not two appointments from now.  I consider these trays one more option in a fully equipped office.

Next time we will explore another option for edentulous impression taking.

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'till then!

-Larry