title: Effect of nightguard vital bleaching gel on the color stability of provisional restorative materials.
abstract: OBJECTIVE
  To assess the hypothesis that there was no difference in effect of 10% and 15% tooth bleaching agents on color stability of materials used for provisional fixed dental prosthesis.
  
  
  METHODS
  Fifteen samples from two materials used for provisional fixed dental prosthesis: methacrylate-based and composite-based materials and 15 preformed polycarbonate crowns soaked in bleaching gel or distilled water. Spectrophotometer recorded color of specimens at baseline, after 3, 7, and 14 days. Data were statistically analyzed using two-factor ANOVA test to compare the color stability of tested materials.
  
  
  RESULTS
  Methyl-based provisional material exhibited statistically higher color change when exposed to 10% and 15% bleaching gel (delta EFNx01: 9.0 and 11.1, respectively) as compared to distilled water (delta EFNx01: 2.9). Delta EFNx01 of composite-based material specimens exposed to distilled water was statistically higher (6.3) than specimens exposed to 10% and 15% bleaching gel (1.5 and 1.1, respectively). Polycarbonate crowns showed a statistically lower color change when exposed to 15% (0.9) than to 10% bleaching gel (5.1) or distilled water (5.5).
  
  
  CONCLUSIONS
  Composite-based provisional material showed highest color stability when exposed to vital tooth bleaching gel, whereas methacrylate-based material was the least color stable. Polycarbonate crowns were more color stable when exposed to 15% bleaching gel as opposed to 10% bleaching gel.
authors.affiliation: Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Salwa Omar
authors.initials: SO
authors.lastname: Bajunaid
mesh_terms: D003116:Color; D003188:Composite Resins; D003833:Denture, Partial, Temporary; D006801:Humans; D008689:Methacrylates; D013053:Spectrophotometry; D014073:Tooth Bleaching / Q000009:adverse effects / Q000379:methods; D058205:Tooth Bleaching Agents / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D003188:Composite Resins; D008689:Methacrylates; D058205:Tooth Bleaching Agents