Despite the success and predictability of dental implants, they may still be cost-prohibitive for our patients. Removable partial dentures (RPDs) are still a part of my practice, although I’m not doing a lot of them these days.
These patients are using older dental technology to replace their missing teeth but they expect it to look like modern dental technology and will hold your work to a high esthetic standard. This means we really have to be up to date with our RPD knowledge.
If you’re like me, when it comes time to design an RPD, I often have this reaction:
Uh... Aker's clasp, RPI, T-bar?
My apologies to my former professors in removable prosthodontics, but I just can’t recall a lot of that information about clasp design because I use it so rarely.
Rather than just letting the lab design it for you, it think a preferable solution is to speak with the lab and design the case together. You may only do one a year, but a lab has 100 dentists that only do one a year, so they’re doing 100 RPDs a year. Much more experience to tap into! Start a dialogue.
You have probably heard of manufacturers that use a flexible material in place of hard acrylic and metal. Cu-Sil (silicone rubber) and Valplast (nylon resin) are two of the most popular on the market. These have a great track record but they do come with some drawbacks:
(1) Difficult to adjust
(2) Difficult to reline
(3) More prone to fracture
Maxillary RPD made from flexible material.
The materials used in these flexible prostheses does not handle like regular hard acrylic. It typically becomes rough and stringy upon adjustment. They are also usually contraindicated for patients with heacy occlusal forces, like bruxers.
My solution is to make a traditional acrylic and metal RPD but use flexible claps in the esthetic zone.
Maxillary RPD made from base metal and acrylic with a flexible clasp on the canine.
This hybrid RPD will be as strong and easy to adjust and reline as a traditional metal and acrylic prosthesis. We’re only using the flexible materials in the areas we absolutely need them for maximum esthetics.
If you break open your old removable prosthodontic textbook from dental school and look up esthetic clasp design, you’ll see discussions of T-bars and other infra-bulge clasps that try to snake the metal around so that it is concealed from the eye. In today’s world where esthetics is a factor for almost every patient, we must rely on newer materials and designs.