Accelerated color change in a maxillofacial elastomer with and without pigmentation

Maxillofacial prostheses often require frequent replacement due to material and color degradation. Prior research has shown that elastomers used in these prostheses are susceptible to environmental factors. It was already known that sunlight exposure can alter polymer properties. However, no prior work had resolved how specific pigments affect color stability. This gap motivated the need to assess whether color changes are predictable with different pigments. Existing studies have focused on general degradation patterns. That uncertainty drove the current investigation into three specific pigments. No comprehensive data existed on how these pigments interact with a specific silicone elastomer under real-world conditions.

This study aimed to evaluate how three pigments influence color changes in a specific silicone elastomer. The specific problem addressed was whether color changes are predictable when pigments are added. The motivation stemmed from the need to improve prosthesis longevity. The researchers propose that pigment type and location affect degradation rates. The goal was to test if documented ASTM methods could provide reliable baseline data. The study focused on comparing unpigmented and pigmented groups in different climates. The researchers propose that environmental variables like sunlight exposure influence outcomes. This study sought to establish a reproducible framework for future research.

The study involved an RTV elastomer and three pigments: burnt sienna, Hansa yellow, and alizarin red. Eight groups of 10 polymerized specimens were created. Groups 1 and 2 served as unpigmented controls. Groups 3–4 included burnt sienna; groups 5–6, Hansa yellow; and groups 7–8, alizarin red. Odd-numbered groups were placed in Miami, while even-numbered groups went to Phoenix. Outdoor weathering followed ASTM methods. Spectrophotometric measurements tracked L* a* b* color parameters before and after exposure. The study used a controlled experimental design to isolate pigment effects. The researchers propose that this method provides a valid baseline for future work.

Arizona specimens showed larger mean color changes than Florida specimens. The unpigmented control groups had differences ranging from 0.4 to 2.36 DeltaE* units. Significant differences were observed in unpigmented (P=.001), burnt sienna (P=.006), and Hansa yellow groups (P=.001). Alizarin red groups had the smallest DeltaE* change of 0.4 units. Miami specimens received 1305.7 MJ/m2 sunlight exposure. Phoenix specimens received 1310.2 MJ/m2 sunlight exposure. The researchers propose that these values reflect real-world degradation patterns. These findings suggest that pigment type and location influence color stability.

The study suggests that color changes in maxillofacial prostheses depend on pigment type and environmental conditions. The authors propose that Arizona's climate produces larger color shifts than Florida's. The researchers propose that unpigmented and Hansa yellow groups showed statistically significant changes. The authors propose that alizarin red had the smallest measurable impact. The study suggests that ASTM methods provide a valid baseline for further research. The authors propose that these findings may inform material selection for prostheses. The researchers propose that outdoor weathering tests are essential for predicting real-world outcomes. The study suggests that future work should explore additional pigments and climates.