title: Changes in color and color coordinates of an indirect resin composite during curing cycle.
abstract: OBJECTIVE
  To measure the color changes of indirect resin composites during curing cycle and to determine the influence of shade group on these changes.
  
  
  METHODS
  One brand (belleGlass NG), divided into three shade groups (EN, OD and TL), was investigated. Resin composite was packed into a mold (BC) and was cured with a light-curing unit (C1). Secondary curing was performed in the proprietary curing chamber (C2). Color was measured at BC, C1 and C2 conditions. Changes in color and color coordinates were calculated and repeated measures three-way ANOVA was performed. Each pair of compared-condition in the curing cycle was set as a repeated variable.
  
  
  RESULTS
  Net curing color change (C2-BC) was in the range of 1.0-10.1DeltaEab* units. Based on ANOVA for the color changes, DeltaEab* was influenced by the compared-condition, the shade group and the shade designation (p<0.01). Changes in color coordinates varied by the shade group.
  
  
  CONCLUSIONS
  Changes in color during curing cycle were perceptible in several shades by the condition (DeltaEab*>3.7); therefore, clinical practice of shade matching should consider these color changes.
authors.affiliation: Department of Dental Biomaterials Science and Dental Research Institute, School of Dentistry, Seoul National University, 28 Yeongeon-dong, Jongro-gu, Seoul, Republic of Korea.
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Yong-Keun
authors.initials: YK
authors.lastname: Lee
mesh_terms: D003116:Color; D003124:Colorimetry; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects; D006801:Humans; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects; D011108:Polymers / Q000737:chemistry / Q000528:radiation effects; D011829:Radiation Dosage; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D011108:Polymers; C110370:belleGlass