Permanent dentures, whether full or partial, are prosthetic devices designed to replace missing teeth and surrounding tissues. These dental restorations are custom-made to fit the patient’s mouth, restoring both function and appearance. A permanent denture is composed of two main structural parts: the gum-colored base, which rests on the soft tissues, and the artificial teeth secured into this base. The materials selected for each component determine the denture’s durability, fit, and aesthetic quality.
Materials Used for the Denture Base
The bulk of a conventional denture base is most commonly made from Poly(methyl methacrylate), or PMMA. This acrylic resin has been the standard material in dentistry since the 1940s. PMMA is inexpensive, lightweight, and easy for dental laboratories to mold and adjust.
The material is easily pigmented to match a patient’s natural gingival shade and is well-tolerated by the body’s tissues. However, traditional acrylic resin has lower impact strength and is prone to fracture if dropped. To enhance the material, some PMMA resins are now reinforced with fillers, such as polymers or ceramics, to improve mechanical properties.
For partial dentures, the base often incorporates a metal framework for strength and rigidity. These frameworks are typically cast from cobalt-chromium alloy, which is highly resistant to corrosion and possesses excellent mechanical strength. Although less aesthetic than the pink acrylic, the metal framework is strategically positioned to be minimally visible, offering a much thinner, stronger substructure.
Materials Used for the Denture Teeth
The artificial teeth embedded in the denture base must withstand chewing forces while maintaining a natural appearance. The most frequent choice is a specialized acrylic or plastic resin, which is lightweight, cost-effective, and easy to modify during fitting. Acrylic teeth are softer than natural enamel, which is beneficial because they cause less wear on any opposing natural teeth.
A second, more durable option is porcelain teeth, which offer superior aesthetics and are highly resistant to wear and staining. Porcelain is a harder, more brittle material, making it durable against chewing forces but prone to chipping or cracking if impacted. Because of their hardness, porcelain teeth are heavier and can accelerate the wear of opposing natural teeth.
Newer options include composite resins, a hybrid material designed to balance the properties of acrylic and porcelain. These composite teeth feature improved aesthetics and better wear resistance than standard acrylic. They remain lighter and easier to adjust than porcelain, offering a good compromise for enhanced durability and color stability.
Materials in Implant-Supported Dentures
Implant-supported dentures introduce a greater variety of materials because the prosthetic is anchored to dental implants. The implants themselves are small, screw-like posts primarily made from titanium, a highly biocompatible metal that fuses directly with the jawbone in a process called osseointegration. Zirconia is an increasingly popular alternative due to its tooth-colored appearance and metal-free composition.
The denture prosthetic requires a rigid framework, or substructure, typically fabricated from high-strength materials like milled titanium or cobalt-chromium alloys. Titanium frameworks are favored for their strength and lightness, often being created using Computer-Aided Design and Manufacturing (CAD/CAM) for a precise fit. For aesthetic full-arch fixed systems, the framework may be milled from monolithic zirconia, a ceramic material offering exceptional strength and a natural, white color.
The visible portion of the implant-supported denture—the base and teeth—is built upon this rigid framework. While acrylic and composite resins are still used for the teeth and gum tissue, these components are often reinforced or veneered onto the metal or zirconia substructure. This design creates a “hybrid” prosthesis, combining the strength of the underlying metal or ceramic with the aesthetics and ease of repair offered by the surface materials.