Illuminant metamerism between natural teeth and zirconia restorations evaluated with a chromatic adaptation transform

Sascha Hein; Stephen Westland

doi:10.1016/j.prosdent.2023.07.035

Illuminant metamerism between natural teeth and zirconia restorations evaluated with a chromatic adaptation transform

J Prosthet Dent. 2023 Sep 9:S0022-3913(23)00542-5. doi: 10.1016/j.prosdent.2023.07.035. Online ahead of print.

Authors

Sascha Hein¹, Stephen Westland²

Affiliations

¹ Postgraduate Researcher, Graduate School of Color Science and Technology, School of Design, University of Leeds, Leeds, England, UK. Electronic address: sdsch@leeds.ac.uk.
² Professor, Color Science and Technology, Graduate School of Color Science and Technology, School of Design, University of Leeds, Leeds, England, UK.

PMID: 37696745
DOI: 10.1016/j.prosdent.2023.07.035

Abstract

Statement of problem: Little is known about the effect of illuminant metamerism between natural teeth and zirconia restorations, despite their increasing clinical popularity.

Purpose: The purpose of this in vitro study was to compare illuminant metamerism between pairs of natural teeth and layered zirconia restorations and pairs of natural teeth and monolithic zirconia restorations under 10 different illuminants and analyze their metameric potential.

Material and methods: Spectral reflectance factors were obtained from 10 pairs of extracted natural teeth and layered zirconia restorations and 28 pairs of extracted natural teeth and monolithic multilayer zirconia restorations. Each pair showed a color match that was within the visual threshold for clinical acceptability (CIEDE2000≤1.8). A special index of metamerism for the change of illuminant (M_ilm) was calculated from the CIEDE2000 color difference equation. Descriptive statistics and the one-sample t test were used to analyze the results for the M_ilm and for both groups of layered and monolithic zirconia restorations (α=.05).

Results: Layered zirconia restorations reached a mean ±standard deviation value for M_ilm=0.3 ±0.2 and M_ilm=0.5 ±0.4 for monolithic zirconia restorations (P<.01).

Conclusions: The effect of illuminant metamerism between natural teeth and zirconia crowns was weak and generally within the clinical acceptability limit.