title: Effect of firing on the color stability of a light-cured ceramic stain.
abstract: OBJECTIVE
  This study evaluated the color stability of four stains of a light-cured porcelain stain system between the light-cured and fired stages.
  
  
  METHODS
  Thirty-six ceramometal discs 20 mm in diameter and 2 mm in thickness were cast to provide the substrate on which Ceramco II porcelain was applied. The porcelain was polished to a uniform thickness of 2 mm, and the samples were divided into four groups and assigned a color (yellow, orange, green, or blue). Orbit LC stain was applied in a thin layer and light-cured for 40 seconds. After light-curing, three color readings were made with a Minolta Chroma Meter II. The porcelain discs were then fired in a porcelain oven and three color measurements were again made. The pre- and postfired Commission Internationale de I'Eclairage L*a*b* values were recorded and the color difference (delta E) was calculated for each specimen. The clinical significance for the computed delta E ratings was completed according to previously modified criteria.
  
  
  RESULTS
  The results show that the mean delta E between the light-cured and fired stages of Orbit LC are clinically acceptable. No statistically significant differences (p < .05) were observed between any of the four groups.
  
  
  CONCLUSIONS
  A light-cured porcelain stain system was evaluated for color stability between light-cured and fired stages. Within the conditions of this study, the following conclusions can be made: (1) There was no clinically significant color difference between light-cured and fired stages for the stain colors evaluated; and (2) the final color of the restorations altered with light-cured stains can be predicted before firing.
authors.affiliation: Unigranno University, Department of Dental Materials, Dtopue de Caxias, R.J. Brazil.
authors.forename: R S
authors.initials: RS
authors.lastname: Reis
authors.forename: G F
authors.initials: GF
authors.lastname: Neiva
authors.forename: P
authors.initials: P
authors.lastname: Yaman
authors.forename: M E
authors.initials: ME
authors.lastname: Razzoog
mesh_terms: D000704:Analysis of Variance; D004396:Coloring Agents / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D006358:Hot Temperature; D008027:Light; D008422:Materials Testing; D017797:Prosthesis Coloring
chemical_list: D004396:Coloring Agents; D003776:Dental Porcelain