title: Color stability and colorant effect on maxillofacial elastomers. Part III: weathering effect on color.
abstract: BACKGROUND
  Maxillofacial prostheses are serviceable for approximately 6 months, after which they need to be refabricated because of the deterioration of color and physical properties.
  
  
  OBJECTIVE
  This third article in a 3-part series evaluated the color stability of commonly used colorant-elastomer combinations as a result of exposure to weathering.
  
  
  METHODS
  Fifteen specimens were fabricated for each of the 3 elastomers (Silastic medical adhesive type A, Silastic 4-4210, and Silicone A-2186) and 6 colorants (dry earth pigments, rayon fiber flocking, artist's oil paints, kaolin, liquid cosmetics, and no colorant) for a total of 270 specimens (18 groups of 15 specimens). The 15 specimens of each elastomer-colorant combination were separated into 3 test condition groups (control, time passage, and natural weathering) of 5 specimens per test condition group. Control specimens were evaluated within 1 month of fabrication. The time passage group was sealed in glass containers and kept in the dark for 6 months before testing. The natural weathering groups were placed on the roof of the dental school for 6 months and exposed to sunlight and weathering. Color and optical density data for each elastomer-colorant combination were subjected to a 1-way analysis of variance to examine effects among test conditions (control, time passage, and weathering). When significant differences were observed, the Student-Newman-Keuls multiple range test was performed to identify differences in elastomer-colorant combinations among each test condition at a significance level of .05.
  
  
  RESULTS
  Changes in color, as a result of weathering, were noted in many of the colorant-elastomer combinations. Also, color change occurred not only to the colored, but also to uncolored materials over time without exposure to weathering.
  
  
  CONCLUSIONS
  Clinically, the addition of colorants could have a stabilizing effect on the elastomer color when it is exposed to weathering.
authors: Indiana University School of Dentistry, Indianapolis, Ind.46202, USA. SPHAUG@IUSD.IUPUI.EDU
authors: S P
authors: SP
authors: Haug
authors: C J
authors: CJ
authors: Andres
authors: B K
authors: BK
authors: Moore
mesh_terms: D000704:Analysis of Variance; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003116:Color; D004396:Coloring Agents / Q000737:chemistry*; D004355:Drug Stability; D006801:Humans; D008422:Materials Testing / Q000379:methods / Q000706:statistics & numerical data; D008447:Maxillofacial Prosthesis / Q000706:statistics & numerical data; D017797:Prosthesis Coloring / Q000706:statistics & numerical data; D011474:Prosthesis Design / Q000379:methods / Q000706:statistics & numerical data; D012826:Silicone Elastomers / Q000737:chemistry*; D014887:Weather
chemical_list: D004396:Coloring Agents; D012826:Silicone Elastomers