title: Influence of artificial accelerated ageing on the colour stability of paints used for ocular prosthesis iris painting.
abstract: OBJECTIVE
  To evaluate the colour stability of paints used for ocular prosthesis iris painting submitted for accelerated artificial ageing (AAA).
  
  
  METHODS
  Forty specimens of acrylic resin for sclera (16 × 2 mm) were made and separated into eight groups (n = 10) according to the type of paint (gouache, GP; oil, OP; acrylic AP; and composite resin for characterisation, CR) and the colours used (blue/brown). After drying (72 h), a new layer of colourless acrylic resin was applied and the initial colour readout was performed (Spectrophotometer PCB 6807). New colour readouts were performed after AAA, and ΔE was calculated.
  
  
  RESULTS
  Statistical analysis (two-way anova-Bonferroni, p < 0.05) demonstrated that the brown colour showed lower ΔE means in comparison with the blue colour, with statistically significant difference for AP only. Blue colour showed no statistically significant difference with regard to the type of paint used. Brown AP showed lower ΔE than the other groups, with significant difference for OP and GP. GP showed greater alteration in ΔE for the brown colour, being statistically similar only to OP.
  
  
  CONCLUSIONS
  Only the AP group for brown pigment shows clinically acceptable values for colour stability after AAA.
authors: Department of Dental Materials and Prosthodontics, Ribeirao Preto Dental School, São Paulo University, Ribeirao Preto, SP, Brazil.
authors: Fabrício M
authors: FM
authors: Mundim
authors: Pedro L
authors: PL
authors: Antunes
authors: Ana Beatriz S
authors: AB
authors: Sousa
authors: Lucas F R
authors: LF
authors: Garcia
authors: Fernanda C P
authors: FC
authors: Pires-de-Souza
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D003116:Color; D004396:Coloring Agents / Q000737:chemistry* / Q000528:radiation effects; D003188:Composite Resins / Q000737:chemistry; D005137:Eye, Artificial; D006801:Humans; D007498:Iris; D008422:Materials Testing; D010150:Paint / Q000145:classification / Q000528:radiation effects; D017797:Prosthesis Coloring / Q000379:methods*; D011474:Prosthesis Design / Q000379:methods; D013053:Spectrophotometry / Q000295:instrumentation; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D000180:Acrylic Resins; D004396:Coloring Agents; D003188:Composite Resins; C539101:vipi cril