Abstract: Objective To study the color stability of prosthesis silicone elastomer covered by nano-TiO2 membrane caps coated by silica alumina at different thickness, and to explore the effectiveness of this method on improving the color stability of facial prostheses silicone rubber, as well as to provide a theoretical basis. Methods Using MDX4-4210 silicone elastomer as substrate, nano-TiO2 coated with Si and Al as masking agent, and cadmium red oil paint as coloring agent, L*a*b* values of nano-TiO2 membrane cap specimen coated by silica alumina at different thickness (0, 0.5, 1.0 mm) before and after aging were observed. Results 0.1% silica-alumina-coated nano-TiO2 membrane cap specimen ΔE, Δa gradually decreased as the thickness increased (P＜0.05), while ΔL, Δb gradually increased as thickness increased (P＜0.05). Conclusion Coating nano-TiO2 membrane caps with silica alumina at different thickness played a role in delaying the fading of prosthesis silicone elastomer, which provided inspiration for improving the color stability of silicone elastomer prosthesis.

Key words: silicone elastomer, prosthesis, opacifiers , nano-TiO2