Effect of polymerization and accelerated aging on iris color stability of ocular prosthesis

Abstract 

Purpose

The purpose of this study was to investigate color change of irises obtained by both printed digital image and painted with gouache, acrylic and oil paints, after polymerization and accelerated aging.

Materials and methods

Eight samples simulating ocular prostheses were fabricated. Each sample was constituted by one disc of N1 colored acrylic resin and one disc of colorless acrylic resin with the iris interposed between the discs. The irises in brown and blue color were obtained by painting or by digital image. The specimens’ colors were measured with a spectrophotometer using the CIE L*a*b* system, at baseline (B), after polymerization (P), and after 504h (A₁) and 1008h (A₂) of accelerated aging. The data were evaluated by 2-way repeated-measures ANOVA and the Tukey's HSD test (α=.05).

Results

Color change was observed in all samples both after polymerization and after accelerated aging. The different periods of accelerated aging did not influence on color change for the irises painted with blue oil paint. The polymerization promoted a statistical significant effect on the iris color stability for all painting techniques in comparison to all accelerated aging periods.

Conclusion

After accelerated aging the oil painting technique showed the greatest color stability while the printed digital images technique the worst.

Keywords: Artificial eye, Color stability, Digital image, Ultraviolet rays