Effect of varying core thicknesses and artificial aging on the color difference of different all-ceramic materials

Abstract

Objective. Clinicians should reserve all-ceramics with high translucency for clinical applications in which high-level esthetics are required. Furthermore, it is unclear whether a correlation exists between core thickness and color change. The aim of this study was to examine the effects of different core thicknesses and artificial aging on the color stability of three all-ceramic systems. Materials and methods. Ninety disc-shaped cores with different thicknesses (0.5 mm, 0.8 mm and 1.0 mm) were prepared from three all-ceramic systems, In-Ceram Alumina (IC), IPS e.max Press (EM) and Katana (K). The colors of the samples were measured with a spectrophotometer and the color parameters (L*, a*, b*, ΔE) were calculated according to the CIE L*a*b* (Commission Internationale de L'Eclairage) color system before and after aging. Results. The effects of aging on color parameters were statistically significant (p < 0.001), regardless of core thickness. For all systems, the CIE a* values increased as the thickness of the core increased. Conversely, such increases in core porcelain thickness were correlated with decreasing CIE L* and b* values. Core thickness had a statistically significant effect on color change among the groups. Conclusions. Different core thicknesses (from 1.0–0.5 mm) and artificial aging affected color stability of the all-ceramic materials tested.

Key Words::

• all-ceramic
• color
• core thickness
• aging

Acknowledgments

This study (project number AR-2010/28) was supported by Gulhane Military Medical Academy Scientific Research Commission, Ankara, Turkey. The authors would like to thank the manufacturers for supplying the materials tested.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.