title: Color stability of white mineral trioxide aggregate.
abstract: OBJECTIVE
  This study aims to evaluate the color stability of white mineral trioxide aggregate (WMTA) after irradiation with three different curing lights and with a fluorescent lamp in an oxygen-free environment.
  
  
  METHODS
  Thirty samples of WMTA were divided into four experimental groups (three curing light and one fluorescent lamp) and one negative control group. The samples in the curing light groups were immersed in glycerine and were irradiated for 20, 60, and 120 s with a curing light. The samples in the fluorescent lamp group were immersed in glycerine and left on a laboratory shelf below a fluorescent lamp, whereas the negative control group was irradiated with a curing light without immersion in glycerine. A spectrophotometer was used to determine the color of each specimen before and after each light exposure and after 5 days. Data were analyzed using analysis of variance and Fisher's least significant difference test.
  
  
  RESULTS
  All the groups showed discoloration except for the negative control group. At 20, 60, and 120 s, there were no significant differences between the Optilux and Bluephase groups (which were the darkest). The Demi group was the curing light experimental group that showed the lowest degree of discoloration (P = 0.0001). No differences were observed between the fluorescent lamp and the negative control groups. After 5 days, the fluorescent lamp group also showed darkening of the sample surface and there were no significant differences between this group and the other three experimental groups (P > 0.05).
  
  
  CONCLUSIONS
  WMTA showed dark discoloration after irradiation with a curing light or fluorescent lamp in an oxygen-free environment.
  
  
  CONCLUSIONS
  WMTA may cause tooth discoloration when it is used in a coronal position.
authors: Department of Restorative Dentistry and Endodontics, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Barcelona, Spain.
authors: Marta
authors: M
authors: Vallés
authors: Montserrat
authors: M
authors: Mercadé
authors: Fernando
authors: F
authors: Duran-Sindreu
authors: Jose Luis
authors: JL
authors: Bourdelande
authors: Miguel
authors: M
authors: Roig
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry* / Q000528:radiation effects*; D000704:Analysis of Variance; D017610:Calcium Compounds / Q000737:chemistry* / Q000528:radiation effects*; D016009:Chi-Square Distribution; D003116:Color; D055117:Curing Lights, Dental; D004338:Drug Combinations; D005453:Fluorescence; D005990:Glycerol; D010087:Oxides / Q000737:chemistry* / Q000528:radiation effects*; D010100:Oxygen; D012387:Root Canal Filling Materials / Q000737:chemistry* / Q000528:radiation effects*; D017640:Silicates / Q000737:chemistry* / Q000528:radiation effects*; D013053:Spectrophotometry
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D005990:Glycerol; D010100:Oxygen