Colour parameters and shade correspondence of CAD-CAM ceramic systems

Alvaro Della Bona; Oscar E Pecho; Razvan Ghinea; Juan C Cardona; María M Pérez

doi:10.1016/j.jdent.2015.02.015

Colour parameters and shade correspondence of CAD-CAM ceramic systems

J Dent. 2015 Jun;43(6):726-34. doi: 10.1016/j.jdent.2015.02.015. Epub 2015 Mar 6.

Authors

Alvaro Della Bona¹, Oscar E Pecho², Razvan Ghinea³, Juan C Cardona⁴, María M Pérez³

Affiliations

¹ Post-graduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil. Electronic address: dbona@upf.br.
² Post-graduate Program in Dentistry, Dental School, University of Passo Fundo, Brazil; Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n, 18071 Granada, Spain.
³ Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n, 18071 Granada, Spain; Houston Center for Biomaterials and Biomimetics, Department of Restorative Dentistry and Prosthodontics, University of Texas, School of Dentistry, 7500 Cambridge St., Houston, TX 77054, USA.
⁴ Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n, 18071 Granada, Spain.

PMID: 25748670
DOI: 10.1016/j.jdent.2015.02.015

Abstract

Objectives: To evaluate colour differences between (1) CAD-CAM ceramic systems considering shades A1, A2 and A3 and the corresponding nominal shade of VC (Vita Classical shade guide) and (2) shades A1-A2, A2-A3 and A1, A2 and A3 within the same ceramic system.

Methods: Samples of shades A1, A2 and A3 were fabricated (n=5) from CAD-CAM ceramic blocks (IPS e.max(®) CAD LT and HT, IPS Empress(®) CAD LT and HT, Paradigm™ C, and VITABLOCS(®) Mark II) and polished to 1.0±0.01mm in thickness. Spectral reflectance and colour coordinates were measured using a spectroradiometer inside a viewing booth using the CIE D65 illuminant and the d/0° geometry. Spectral reflectance curves were compared using VAF coefficient and were statistically analyzed using Kruskal-Wallis and the Mann-Whitney U test (α=0.05). Colour coordinates were statistically analyzed using one-way ANOVA, Tukey's test with Bonferroni correction (α=0.001). All colour differences (ΔEab(*) and ΔE00) were analyzed through comparisons with the PT - perceptibility and AT - acceptability thresholds for dental ceramics.

Results: ΔE between ceramic systems and its corresponding shade ranged from 6.32 to 13.42 (ΔEab(*)) and 4.48 to 9.30 (ΔE00). ΔE between shades A1-A2, A2-A3 and A1, A2 and A3 ranged, respectively, 1.93-4.82, 1.22-5.59 and 3.63-8.84 (ΔEab(*)); 1.54-3.87, 1.03-3.90 and 2.95-6.51 (ΔE00).

Conclusions: Considering the corresponding nominal shade from VC, none of the ceramic systems showed colour differences below the AT. In addition, some ceramic systems showed colour differences below AT (shades A1-A2 and A2-A3) and below PT (shades A2-A3).

Clinical significance: Careful adjustments should be made to the final shade of CAD-CAM ceramic restorations to reach a clinically acceptable shade match.

Keywords: Colour; Dental ceramics; Reflectance.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ceramics / chemistry*
Color
Colorimetry / instrumentation
Colorimetry / methods
Composite Resins / chemistry*
Computer-Aided Design*
Dental Materials / chemistry*
Dental Porcelain / chemistry
Dental Prosthesis Design
Prosthesis Coloring*
Surface Properties

Substances

Composite Resins
Dental Materials
Dental Porcelain