Available online 23 April 2025

Thresholds for perceptibility and acceptability varied between color measurement devices.

∆E*ab showed better visual-instrumental agreement than ∆E00 and ∆E94.

Device-specific thresholds are recommended for dental color quality assessment.

This study aimed to evaluate perceptibility (PT) and acceptability thresholds (AT) for multiple color measurement devices and assess the performance of three color difference equations (∆E*ab, ∆E00, and ∆E94) using a visual dataset from expert observers.

A visual dataset previously published was extended by adding the x-rite MetaVue spectrophotometer and ∆E94 to the analysis. Visual scaling was performed on 26 sample pairs of teeth using magnitude estimation. Observers answered PT and AT questions to determine thresholds. Threshold estimation was conducted using a model-free method, and device performance was analyzed using the standardized residual sum of squares (STRESS) index and visual instrument agreement scale (VIAS).

The PT and AT thresholds varied across devices and color difference equations. For ∆E00, STRESS values ranged from 23 to 32 (mean 29, sd 2.9), with VIAS scores between 68 % and 77 % (mean 71 %, sd 2.9). ∆E94 showed higher STRESS values (24–42, mean 34, sd 5.5) and lower VIAS scores (58–76 %, mean 66 %, sd 5.5). ∆E*ab demonstrated excellent visual-instrumental agreement with STRESS values from 18 to 36 (mean 24, sd 5.9) and lower VIAS scores (82–64 %, mean 76 %, sd 5.9) outperforming ∆E94 and ∆E00. The x-rite MetaVue achieved excellent results under controlled conditions but it is unsuitable for clinical research due to its design.

This study highlights the variability in PT and AT across devices, suggesting the need for device-specific thresholds. It also demonstrates the effectiveness of ∆E*ab in dental colorimetry compared to more complex color difference metrics

Tooth color measurement

Color difference equations

CIELAB

CIEDE2000

Visual thresholds

STRESS index

Visual scaling

Magnitude estimation

VIAS

© 2025 The Author(s). Published by Elsevier Inc. on behalf of The Academy of Dental Materials.