Journal List > J Korean Acad Conserv Dent > v.28(5) > 1056074

Park, Hwang, Kim, Oh, and Hwang: Metamerism in composite resins under five standard illuminants - D65, A, C, FCW and TL84

Abstract

This study was done to present a criterion in selection of the most proper light sources and materials by measuring metamerism index(MI) of the light curing composite resins with spectrocolorimeter. Metamerism is defined when two objects appear to be the same color in one illuminant but different in another. This is due to the fact that they have different spectral curves that fail to match under the second illuminant.
In this study, A1 & A3 shade of five light curing composite resins (Esthet-X, Filteck Z250, Filteck A110, Charisma, Vitalescence) were chosen based on Vita shade. Five samples were made for shade of each product with Teflon mold (diameter: 15mm, thickness: 2mm).
Metamerism index of each samples on a Barium sulfate plate (L*=96.54, a*=0.19, b*=0.01) prepared for sample fixation were measured with spectrocolorimeter(Miniscan XE plus, Model 4000s, Hunter Lab, USA) by applying standard light source D65, C, Fcw, TL84 and A. Standardization was done with reference standard (X=80.8, Y=85.7, Z=90.8) and light trap. The results were as follows.
  1. Different resins with same Vita shade showed recognizable color difference(ΔE*>2).

  2. All composites had MI below accepted value 0.5 between standard illuminant(D65, C, & A) and below 1.5 under fluorescent condition (Fcw & TL84).

  3. MI value between D65 and A showed higher value than MI value between other source of light(p<0.01).

  4. All resins except Z250 showed MI value that A3 is higher than A1 between D65 and A(p<0.05).

Figures and Tables

Fig. 1
L* and C* value of the tested composite resins.
jkacd-28-402-g001
Fig. 2
a* and b* value of the tested composite resins.
jkacd-28-402-g002
Fig. 3
Metamerism.
jkacd-28-402-g003
Fig. 4
Spectral Distribution of CIE standard illuminants.
jkacd-28-402-g004
Table 1
Products, shade, and manufacturers of tested composite resins
jkacd-28-402-i001
Table 2
CIE L*a*b* and C* values of 5 composite resins under D65
jkacd-28-402-i002
Table 3
Metamerism index (MI) of the tested composite resins measured under combination of illuminants with D65
jkacd-28-402-i003

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