Creating Your Ideal Workflow
Scanning, software, milling, and printing all offer advantages for dentures
Nate Farley, DDS, MS, FACP
Various digital tools offer advantages related to precision, efficiency, and cost in denture design and fabrication. My preferred workflow starts with digitizing either analog impressions or an existing denture. We then design the teeth and base, and the software combines them. We 3D print the try-in, which is quick and inexpensive; we can easily make changes and print another if necessary. Once we have finalized the design, our in-house laboratory mills a final monolithic prosthesis from tooth-colored PMMA, and we add pink composite on the facial surface to create a realistic gingiva. Patients typically do not mind the lingual side being tooth-colored, but if they prefer, then we can add pink to that as well.
What are the advantages of printing and milling?
A printed try-in is not only easy and affordable to make, but it is also durable enough to allow the patient to wear it home for a couple weeks to eat with it and smile with it. With teeth set in wax, that was not possible. For the final denture, millable discs can provide a translucency gradient for the teeth without the necessity of stain and glaze. Milling from a monolithic disc also gives us a significantly stronger, more durable denture. Our practice is geared toward full-arch, all-on-X-type prosthetics, which involve a conversion process; a monolithic denture allows us to sleep at night, because we no longer have patients returning with teeth debonding from the base, which was a frequent occurrence with our traditional conversion dentures.
Have you reaped the benefits yet of having digital files stored?
Yes. More often than patients losing or breaking a denture, we have had patients who simply realized they did not like the esthetics after wearing their dentures for a few days or weeks. They are frustrated with themselves for not having realized exactly what they wanted, so it is comforting for us to be able to tell them not to worry because we can fabricate a new one relatively easily. With analog processes, if a patient did not like a denture after living with it for some time, we had to start over almost from scratch. Now, there is still time and money involved, but not nearly as much.
Can you scan an edentulous arch?
I have scanned edentulous arches for immediate dentures. For a final denture, however, we feel that border molding is a necessity. We need to capture the movements of the tissues that will occur in the patient's everyday life, and that cannot be done with an intraoral scanner. Different tactics have been attempted over the years, but nobody has been able to capture movable tissue that way. In our practice, we either take analog impressions and scan them, or we scan an existing denture outside the mouth, 3D print a copy, and reline it, which gives us the opportunity to border mold.
So many workflow options are possible with the various tools at our disposal. Obviously, we can all debate which options are best, but each dental professional needs to develop a workflow that works best for them.
Nate Farley, DDS, MS, FACP, is a board-certified prosthodontist and co-founder of Infodontics, LLC.
He maintains a private practice in Mesa, Arizona.