title: Evaluation of the color stability of two techniques for reproducing artificial irides after microwave polymerization.
abstract: The use of ocular prostheses for ophthalmic patients aims to rebuild facial aesthetics and provide an artificial substitute to the visual organ. Natural intemperate conditions promote discoloration of artificial irides and many studies have attempted to produce irides with greater chromatic paint durability using different paint materials.
  
  
  OBJECTIVE
  The present study evaluated the color stability of artificial irides obtained with two techniques (oil painting and digital image) and submitted to microwave polymerization.
  
  
  METHODS
  Forty samples were fabricated simulating ocular prostheses. each sample was constituted by one disc of acrylic resin N1 and one disc of colorless acrylic resin with the iris interposed between the discs. The irides in brown and blue color were obtained by oil painting or digital image. The color stability was determined by a reflection spectrophotometer and measurements were taken before and after microwave polymerization. Statistical analysis of the techniques for reproducing artificial irides was performed by applying the normal data distribution test followed by 2-way ANOVA and Tukey HSD test (α=.05).
  
  
  RESULTS
  Chromatic alterations occurred in all specimens and statistically significant differences were observed between the oil-painted samples and those obtained by digital imaging. There was no statistical difference between the brown and blue colors. Independently of technique, all samples suffered color alterations after microwave polymerization.
  
  
  CONCLUSIONS
  The digital imaging technique for reproducing irides presented better color stability after microwave polymerization.
authors.affiliation: Department of Dental Materials and Prosthodontics, Araçatuba Dental School, São Paulo State University, Araçatuba, SP, Brazil. goiato@foa.unesp.br
authors.forename: Marcelo Coelho
authors.initials: MC
authors.lastname: Goiato
authors.forename: Daniela Micheline dos
authors.initials: DM
authors.lastname: Santos
authors.forename: Amália
authors.initials: A
authors.lastname: Moreno
authors.forename: Humberto
authors.initials: H
authors.lastname: Gennari-Filho
authors.forename: Eduardo Piza
authors.initials: EP
authors.lastname: Pellizzer
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000704:Analysis of Variance; D003116:Color; D005137:Eye, Artificial; D007498:Iris; D008422:Materials Testing; D008872:Microwaves; D010150:Paint; D058105:Polymerization; D017797:Prosthesis Coloring / Q000379:methods*; D013053:Spectrophotometry; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D000180:Acrylic Resins