title: Effect of weathering and thickness on the superficial microhardness of acrylic resin and ocular button.
abstract: OBJECTIVE
  This study evaluated the effects of weathering (1008h) and thickness (1 and 3.5mm) on the superficial microhardness of the ocular button, using five colorless acrylic resins, and colorless buttons specific for ocular prosthesis.
  
  
  METHODS
  One-hundred-and-twenty specimens were made and distributed allocated to 12 groups. Microhardness analysis was carried out with a microdurometer (Shimadzu, Japan) before and after weathering for 1008h. Data were then analyzed statistically by ANOVA and the Tukey Test at 1% significance.
  
  
  RESULTS
  The data demonstrated that the ocular button and the QC 20 resin presented, respectively, the highest (22.9) and lowest (18.31) values of surface microhardness (Knoop), independently of the variable evaluated.
  
  
  CONCLUSIONS
  Thickness did not influence the property studied, and the specimens presented higher mean values of superficial microhardness after weathering for 1008h.
authors.affiliation: University of Brasília (UnB), Barsília/DF, Brazil.
authors.forename: Aline Ursula Rocha
authors.initials: AU
authors.lastname: Fernandes
authors.forename: Marcelo Coelho
authors.initials: MC
authors.lastname: Goiato
authors.forename: Daniela Micheline
authors.initials: DM
authors.lastname: dos Santos
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D003261:Contact Lenses; D019544:Equipment Failure Analysis; D006244:Hardness; D006245:Hardness Tests; D008422:Materials Testing
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials