title: Assessment of changes in color and color parameters of light-cured composite resin after alternative polymerization methods.
abstract: OBJECTIVE
  To examine the amount of change in color and color parameters of a composite resin (Filtek P60) polymerized by five different polymerization methods.
  
  
  METHODS
  A Teflon mold (6mm in diameter, 2mm in height) was used to prepare the composite resin discs (n=10). G1: Polymerization with inlay oven; G2: Polymerization with HQTH and autoclave; G3: Polymerization with LED and autoclave; G4: Polymerization with HQTH; G5: Polymerization with LED. Colorimetric values of the specimens before and after polymerization were measured using a spectrophotometer. The CIE L*a*b color system was used for the determination of color difference. Analysis of variance (ANOVA) was used to analyze the data for significant differences. Tukey's HSD test and paired two-tailed tests were used to perform multiple comparisons (α=.05).
  
  
  RESULTS
  There were no significant differences in total color change (ΔE*ab) among the polymerization groups (P>.05). However, the lowest color change (ΔE*ab) value was 3.3 in LED and autoclave; the highest color change (ΔE*ab) value was 4.6 in HQTH. For all groups, CIE L*, C*ab and a*values decreased after polymerization (P<.05). The highest Δb* and ΔC*ab values were observed in specimens polymerized in an inlay oven (P<.05).
  
  
  CONCLUSIONS
  Composite resin material showed color changes above the clinically accepted value in all study groups (ΔE*ab⩾3.3). All specimens became darker during investigation (ΔL*< 0). Specimens polymerized with inlay oven presented the highest Δb* values which means less yellow color in specimens.
authors: Department of Restorative Dentistry, Faculty of Dentistry, Gaziantep University, Gaziantep, TURKIYE.
authors: Emine Sirin
authors: ES
authors: Karaarslan
authors: Mehmet
authors: M
authors: Bulbul
authors: Ertan
authors: E
authors: Ertas
authors: Mehmet Ata
authors: MA
authors: Cebe
authors: Aslihan
authors: A
authors: Usumez
keywords: Composite resin; color change; inlay oven; polymerization methods