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Illuminant effect on the coverage error of a gingiva-colored composite resin shade guide
Rafat S Amer1, Indumathi Chandrasekaran1, William M Johnston2
1Assistant Professor, Division of General Practice and Materials Science, The Ohio State University, Columbus, Ohio.
The Journal of Prosthetic Dentistry
|June 18, 2016
Summary
The gingiva-colored composite resin shade guide showed significant coverage errors under different lighting conditions, indicating metamerism. Color differences exceeded clinically acceptable ranges, challenging shade selection for dental clinicians.
Area of Science:
- Dental Materials Science
- Color Science in Dentistry
- Optical Properties of Tissues
Background:
- Dental clinicians struggle to select appropriate gingiva-colored composite resins.
- Accurate shade matching is crucial for aesthetic dental restorations.
Purpose of the Study:
- To evaluate the coverage error (CE) of a gingiva-colored composite resin shade guide.
- To assess shade guide performance under two different Commission Internationale de l'Eclairage (CIE) illuminants (A and D65).
Main Methods:
- Measured spectral reflectance of 12 gingiva-colored composite resin shade tabs (Amaris gingiva).
- Measured optical characteristics of the attached gingiva in 120 participants using spectroradiometry.
- Calculated CIELab values and CIEDE2000 color differences under CIE illuminants A and D65.
Main Results:
- Average coverage error was 4.0 for CIE illuminant D65 and 5.8 for CIE illuminant A.
- Significant differences in CE were observed between the two illuminants.
- The shade guide exhibited metamerism, with varying color differences under different lighting.
Conclusions:
- The tested gingiva-colored shade guide demonstrated metamerism.
- Color differences (ΔE) exceeded the clinically acceptable range for both illuminants.
- This highlights challenges in achieving accurate gingival shade matching in clinical practice.
