In vitro evaluation of color stability of non-pigmented maxillofacial silicone elastomer immersed in condiments

Maxillofacial silicone prostheses restore facial appearance, and those in the perioral region contact food that may affect their color. This study evaluated how common condiments influence the color stability of silicone elastomers.

Thirty-two non-pigmented silicone specimens were divided into four groups (n = 8) and immersed in water, ketchup, soy sauce, and vegetable sauce. A spectrophotometer measured color at baseline and after 7 and 14 days. ΔE₀₀ values were calculated using the CIEDE2000 formula, and data were analyzed statistically (α = 0.05).

At 14 days, ketchup caused the greatest discoloration (ΔE₀₀ = 8.11 ± 0.21), followed by vegetable sauce (2.27 ± 0.28), soy sauce (0.78 ± 0.17), and water (0.34 ± 0.16). The differences between groups were significant (P < 0.001). Ketchup caused more discoloration than the other condiments, while soy sauce and vegetable sauce differed only at 14 days. All condiments differed from water in relation to discoloration. Color changes included darkening and yellowing with ketchup, greenish-blue tinting with soy sauce, and darkening with vegetable sauce; water caused no change in color.

Pigments in condiments can affect the aesthetics of maxillofacial prostheses. Patients should thus receive dietary and hygiene guidance to extend the lifespan of prostheses.