title: Effect of several bleaching agents on teeth stained with a resin-based sealer.
abstract: OBJECTIVE
  To evaluate the effect of peroxide-based bleaching agents on teeth stained with AH26 sealer (Dentsply De Trey, Konstanz, Germany), using digital images and computer analysis.
  
  
  METHODS
  Thirty-five maxillary central incisors were root filled, and the internal walls of the access cavity were coated with AH26 sealer. Internal bleaching commenced 4 months after the root fillings. In three experimental groups (n = 10), the teeth were bleached for 21 days using 45% carbamide peroxide (CP) gel, 45% sodium perborate + carbamide peroxide (SP + CP) or sodium perborate + distilled water (SP + W). No bleaching was undertaken in the control group. Digital images of each specimen were made before treatment, 4 months after endodontic treatment and 2 weeks after bleaching. Colour differences (∆E) were calculated by determining L*a*b* values using digital images and imaging software. Differences between the original colour and sealer-stained teeth, between sealer-stained and bleached teeth and between original colour and bleached teeth were calculated. Data were analysed using one-way anova and Duncan tests (α = 0.05).
  
  
  RESULTS
  Colour differences between baseline and sealer staining were in the range of 8.1-9.9, but differences between the groups were not significant. After bleaching, the degree of lightening was essentially identical for the carbamide peroxide and sodium perborate + carbamide peroxide groups, but was significantly greater (P < 0.05) in these two groups than in the sodium perborate + water group.
  
  
  CONCLUSIONS
  For bleaching AH26 sealer-stained teeth, carbamide peroxide gel and carbamide peroxide gel mixed with sodium perborate were equally effective and significantly better than sodium perborate mixed with water.
authors: Torabinejad Dental Research Center, Department of Operative Dentistry, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors: A
authors: A
authors: Feiz
authors: B
authors: B
authors: Barekatain
authors: S
authors: S
authors: Khalesi
authors: N
authors: N
authors: Khalighinejad
authors: H
authors: H
authors: Badrian
authors: E J
authors: EJ
authors: Swift
mesh_terms: D006801:Humans; D010895:Pit and Fissure Sealants; D012117:Resins, Synthetic; D014073:Tooth Bleaching / Q000379:methods*; D014075:Tooth Discoloration / Q000628:therapy*
chemical_list: D010895:Pit and Fissure Sealants; D012117:Resins, Synthetic
keywords: carbamide peroxide; discoloration; endodontic sealer; intracoronal bleaching; sodium perborate