When we have patients with an existing maxillary denture who want to transition to some type of implant prosthesis, there are many things to consider when we are treatment planning these types of cases. Number of implants, A/P spread, and vertical space are a few important clinical decisions that must be made. The decision to do a fixed or removable prosthesis, however, can be patient driven, meaning, most patients will want a fixed prosthesis if given the choice.
There are two things that I think are really important to consider, and often overlooked, when determining whether a fixed or removable implant prosthesis is best for these patients.
Number One: The Denture Flange
If they have an existing denture, we have to consider the importance of the denture flange and its role in providing facial support. How long has the patient been edentulous? Typically, the greater amount of ridge resorption, the greater need for the flange. When a patient transitions out of the denture to a fixed prosthesis, the denture flange will go away and that can be a very significant factor from an esthetic standpoint.
An effective way to test this out ahead of time is to duplicate their denture, cut the flange back to the crest of the ridge and try it in. Then, take some photographs with the full denture in place, and then with the modified duplicate denture in place. Looking at the photographs objectively helps the patient to see themselves differently. Also, have the patient look in the mirror so they can see the changes that will be made. Is the loss of the flange acceptable to them? (The same considerations apply to the mandibular denture flanges in providing facial support.)
Number Two: The Ability to Clean the Prothesis
The second factor that I think is really important to consider is the patient’s ability to clean the prosthesis. I have had patients who have rheumatoid arthritis and other dexterity challenges. Sometimes, the fixed prosthesis can be very difficult to clean, especially if the transition zone of where the prosthesis meets the implants is very high.
With the removable implant prosthesis, the patient can take the overdenture out and very easily clean around the bar. Acrylic fixed hybrid prostheses are even more difficult to clean because of the porosity of the acrylic harboring odors and bacteria.
Because of these two considerations, I tend to do more removable implant prostheses in the patient that presents with an existing maxillary denture. Learn more about proper denture considerations in Dr. Daxon's hand-on course, Keys for Predictably Fabricating Complete Dentures.