title: Color stability of silicone or acrylic denture liners: an in vitro investigation.
abstract: OBJECTIVE
  The aim of this study was to compare the color stability of three acrylic based hard liners (Ufi gel hard, Dura-Liner II, Tokuso Rebase) and two silicone based soft liners (Ufi gel permanent, Molloplast B) by using the colorimeter.
  
  
  METHODS
  Sixty disc-shaped samples, with uniform size of 10 mm diameter and 2 mm in thickness were fabricated for each material. Thirty samples were made as control group in distilled water and the remaining thirty samples were weathered in accelerated aging chamber. Color measurements were made before and after distilled water and aging. Data were statistically analyzed using nonparametric Kruskal-Wallis and Mann-Whitney U tests.
  
  
  RESULTS
  Data showed that there are significant differences among materials in both after distilled water and aging treatments (P<.001). These results indicated that the most discolored liner material was Dura Liner II after aging (DeltaE*=16.30) and the least discolored material was Ufi gel permanent after distilled water (DeltaE*=0.41).
  
  
  CONCLUSIONS
  Based on the results of this study, silicone based liner materials are considered to be more color stable than acrylic based liner materials.
authors.affiliation: Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Türkiye.
authors.forename: Gulfem
authors.initials: G
authors.lastname: Ergun
authors.forename: Isil Cekic
authors.initials: IC
authors.lastname: Nagas