What a facial prosthesis is made of
Silicone elastomers and acrylic resins dominate today. Behind them is a long trail of porcelain, leather, rubber and gelatin, and a problem that no material has yet solved: aging.
A face moves, flushes, sweats and sheds oil. A replacement for part of it has to sit against skin all day, bend with the expression around it, and look like skin from arm's length. For most of history nothing met that brief for long. Today two families of material do most of the work, and both are still being improved. This page looks at what they are, why one of them is favored for soft parts of the face, and what research says about how they wear out.
The two families in use
A review of implant-retained craniofacial prostheses lists the materials tried over the long history of the craft: porcelain, natural rubber, gelatin and latex among them. Of these, the author says, two have established themselves: methacrylates and silicones. Methacrylates (acrylic resins) are more durable but relatively hard. Silicones are soft and flexible and keep body temperature, and hair and skin features such as pigmentation can be built in. Their edges can be stretched thin enough to become transparent, which helps the join between prosthesis and skin disappear.
The International Journal of Dentistry review of the field adds that acrylic resins are used for intraoral prostheses such as obturators and for ocular prostheses, which can be heat-cured in a water bath or self-curing. Silicones and acrylics are the most used materials for maxillofacial reconstruction, while the current list also includes vinyl plastisol, polyurethanes and latex.
| Material | Where it is used | Strengths noted | Limits noted |
|---|---|---|---|
| Silicone elastomer | External facial prostheses such as ear, nose, orbit | Soft, flexible, can be given thin translucent edges and built-in color | Color change, tearing, aging; lifespans of a few months to about 2 years reported |
| Acrylic resin (methacrylate) | Obturators, ocular prostheses, frameworks | Durable, can be shaped to fit a socket | Relatively hard compared with silicone |
Why silicone became the default for the face
A 2024 review in the journal Materials says polydimethylsiloxane, the common silicone polymer, has been the most widely used maxillofacial prosthetic material since the 1960s. It credits skin-like flexibility, intrinsic transparency, light weight, ease of processing and good aesthetics. The International Journal of Dentistry review names two processing types, room-temperature vulcanizing and high-temperature vulcanizing, and lists chemical inertness, strength, durability and ease of manipulation among the advantages.
The same review gives the cost of those advantages. Silicone polymers suffer color degradation and instability from ultraviolet rays, air pollution, temperature variation and humidity. In its words, silicones still need improvement because they last for short periods, in one cited case about 6 months, and need frequent replacement.
What came before
The same history review traces a procession of attempts. Prostheses in the 16th century were made from materials such as papier-mache, leather, ivory, gold and silver. In the 19th century, some were made of nitrated cellulose, which the review says turned brown and caught fire for smokers. Vulcanite arrived at the end of the 19th century and was frequently used during the First World War. A mixture of gelatin and glycerin gave good results when new but lasted only days, or a week at most. Between the world wars researchers worked on materials such as prevulcanized latex. A review in Frontiers in Bioengineering and Biotechnology lists wax, parchment, wood, gold, silver, copper and hard rubber for noses, eyes and palates in the 16th century. The timeline places these materials in the wider story.
How silicone ages
The 2024 review in Materials sets out why a facial prosthesis does not last. It reports that prostheses have shown serious changes over time, giving an average lifespan of approximately 2 years, and that the main reason for replacement is discoloration and mismatch with the surrounding tissues. Other causes listed are poor maintenance and tearing. Separation of the silicone from an acrylic base accounted for about 12 percent of replacements in a study the review cites. The review also names lack of reparability and the peeling or fading of surface colors as drawbacks.
Several things drive the change. Ultraviolet exposure transforms organic pigments chemically, and the review notes that ceramic pigments are generally recognized as ensuring greater color stability than organic pigments or external makeup. The effect of cigarette smoke on silicone has been studied very little, it says, though smoke and beverages are accepted as staining factors. Microbes play a part too. The review mentions a fungus of the genus Penicillium isolated from worn nasal prostheses that showed black discoloration. A hospital such as Cambridge University Hospitals tells patients in practical terms that its silicone prostheses should last 12 to 18 months, because ultraviolet light and skin oils fade the colors. Figures vary between centers and studies, and they depend on the prosthesis, the site and how it is worn and cleaned.
Molds matter as well
A review of soft-tissue prosthetics from Queensland University of Technology points out that some materials can be processed at room temperature in low-cost dental stone, acrylic or epoxy molds, while others cure at higher temperatures and need more expensive metal molds. The same authors note a downside of stone molds: they leave rough surfaces on which microorganisms can colonize, which matters because biofilm can penetrate the prosthetic material itself. Detail on the making is on how a facial prosthesis is made, and on how color is built into the material on colour matching.
What research is trying to improve
The 2024 review's closing lists are blunt about what is missing. Materials considered safe by standards are used according to manufacturers' indications, but their long-term side effects are generally not verified in common practice, the authors write. They call for materials with better resistance to microbial growth and to weathering and wear, to be compared with the commercial products now in use. The history review points to biocompatibility, cleaning protocols, pigment incorporation and bonding efficiency as active areas. How cleaning itself changes the material is covered on care and cleaning.
None of this is advice about any one prosthesis. The material your own prosthetist chooses depends on the site, the way it will be held in place and your circumstances, and their guidance on wear and care comes first.
In brief
Silicone elastomers are favored for soft external parts of the face because they are flexible, can be thinned to transparent edges and take color well, while acrylic resin is used where hardness is useful. Neither lasts indefinitely, and reviews report lifespans from months to around two years, mostly limited by color change and wear. Better, safer and longer-lived materials are an open research question.