title: Color stability of heat-activated and chemically activated fluid resin acrylics.
abstract: OBJECTIVE
  Heat- and chemically activated acrylics processed by compression molding or fluid resin matrix techniques for fabrication of partial dentures were evaluated for color stability by reflection spectrophotometry after accelerated aging.
  
  
  METHODS
  Samples of heat-activated (L199, PDON, SB) and chemically activated (PR, PVAR, SC) denture base acrylics were polymerized according to manufacturers' instructions. Samples were aged in an artificial aging chamber, and color was measured by CIE L*a*b* on a reflection spectrophotometer at baseline and after each of three aging cycles.
  
  
  RESULTS
  At 450 kJ/m2, color changes of two chemically activated acrylics (PR and SC) were perceptible. PR became less red, whereas SC became darker and more yellow. The most color-stable acrylics were a heat-activated resin (SB) and one chemically activated acrylic (PVAR).
  
  
  CONCLUSIONS
  The three heat-activated acrylics tested were more color-stable than two of the chemically activated acrylics, but one chemically activated acrylic (PVAR) recommended for a fluid resin matrix technique was color-stable.
authors.affiliation: Department of Prosthodontics, Beijing Medical University, Dental School, People's Republic of China.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: J M
authors.initials: JM
authors.lastname: Powers
authors.forename: M E
authors.initials: ME
authors.lastname: Connelly
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000704:Analysis of Variance; D003116:Color; D003819:Denture Bases; D005069:Evaluation Studies as Topic; D006358:Hot Temperature; D011108:Polymers / Q000737:chemistry; D017797:Prosthesis Coloring; D013997:Time Factors
chemical_list: D000180:Acrylic Resins; D011108:Polymers