Top 4 Removable Partial Dentures (RPD) Framework Materials

The removable partial dentures (RPDs) framework material used plays a vital role in the success and longevity of the prosthesis.

Which framework material to select for an RPD depends on several factors, including patient preference, esthetic concerns, and the required support. Cast metal frameworks remain the most popular choice, while PEEK and Acetal resin frameworks are newer and offer excellent esthetic and mechanical properties. Titanium frameworks are also a strong and biocompatible option but can be more expensive.

Top RPD Framework Materials

Here is a quick breakdown of the most common materials used for RPD framework fabrication, identifying their unique fabrication methods and their main pros and cons.

Cast Metal

Traditional cast metal frameworks are the most used. The most popular alloy used for RPD fabrication is cobalt-chromium (CoCr), which offers high strength and excellent biocompatibility.

Fabrication:

The process involves waxing, investing, and casting.

Pros:

The fabrication process produces high-quality, strong, durable frameworks. 

Cons:

The process is time-consuming. Also, there is the unesthetic appearance of the clasps, mainly due to the metallic color. (Many resin products have been developed to overcome this issue.)

Titanium

Titanium frameworks are strong, biocompatible, and lightweight, with excellent mechanical properties.

Fabrication:

The process involves CAD/CAM technology, where a digital impression of the patient's mouth creates a 3D model.

Pros:

Titanium frameworks have the advantage of being strong, durable, and biocompatible.​

Cons:

Relatively expensive compared to other materials. Also, as with the cast metal option, a disadvantage is the unesthetic appearance of the clasps, which, again, can be overcome with the use of resin products that have been developed.

Polyetheretherketone (PEEK)

This is a newer thermoplastic polymer material used for RPD frameworks. The material is biocompatible, lightweight, and has excellent mechanical properties.

Fabrication:

PEEK frameworks are fabricated using CAD/CAM technology, where a digital impression of the patient's mouth is used to create a 3D model.

Pros:

Highly esthetic and easily modified.​

Cons:

Relatively expensive compared to other materials. It’s also prone to staining with chemicals and stains.

Acetal Resin

Acetal resin frameworks are also a popular choice for RPD fabrication. Acetal resin is a thermoplastic material that is biocompatible, lightweight, and easily modified.

Fabrication:

Resin is molded and shaped based on models provided.

Cons:

Acetal resin is more prone to fracture than metal frameworks. It can also wear down over time, particularly if the patient has a habit of grinding their teeth or biting down on hard objects. And like PEEK, acetal resin can be challenging to adjust or modify once fabricated, making it difficult to achieve an ideal fit.

For a more comprehensive discussion on RPD framework materials please see my online course, “A 3D View of RPD Fundamentals."

Ahmed Mahrous, D.D.S., is a practicing prosthodontist and an Arizona School of Dentistry faculty member.