title: A laboratory investigation of colour changes in two contemporary resin composites on exposure to spices.
abstract: BACKGROUND
  The aim of this study was to evaluate colour stability upon exposure to spices of a nano-filled and a micro-hybrid resin composite finished either with Sof-Lex™ discs (SLD) or against plastic strips (PS).
  
  
  METHODS
  Forty cylindrical specimens of 3 mm thickness were fabricated from Filtek Supreme XT ™ (FS) and Gradia Direct X™ (GD). The top surface of each specimen was polished with SLD while the bottom surface was finished against PS. All samples were immersed in staining solutions (0.1% weight turmeric, paprika and tamarind) and distilled water at 37 °C. Colour after 0, 24, 72 and 168 hours of immersion was recorded with a reflection spectrophotometer using CIE L*a*b* parameters and the results were statistically analysed with repeated measures of ANOVA and Bonferroni post hoc tests.
  
  
  RESULTS
  Among all the staining solutions tested, the highest colour deviation was obtained in the turmeric group. FS finished against PS showed significantly more colour changes compared to specimens polished with SLD, while GD finished against PS were found to be more resistant to colour changes.
  
  
  CONCLUSIONS
  Within the limitations of this study all the spices tested have the potential to stain resin composites with turmeric causing the most significant discolouration. Micro-hybrid and nano-filled resin composites appeared to respond differently to staining by spices when either finished with PS or polished with SLD.
authors: Department of Operative Dentistry, Faculty of Dentistry, Universiti Kebangsaan Malaysia, Malaysia.
authors: H Z
authors: HZ
authors: Yew
authors: T L
authors: TL
authors: Berekally
authors: L C
authors: LC
authors: Richards
mesh_terms: D002212:Capsicum; D003116:Color; D003188:Composite Resins; D030024:Curcuma; D010860:Pigments, Biological; D013053:Spectrophotometry; D017365:Spices; D029861:Tamarindus
chemical_list: D003188:Composite Resins; C474035:Filtek Supreme; C470230:Gradia; D010860:Pigments, Biological
keywords: Colour stability; micro-hybrid; nano-filled; resin composite; spices