Related Experiment Video
Updated: Feb 8, 2026

Author Spotlight: 3D Movement Assessment of Maxillary Posterior Teeth in Clear Aligner Treatment
Published on: February 23, 2024
Evaluation of colorimetric indices for the assessment of tooth whiteness
Qianqian Pan1, Stephen Westland1, Roger Ellwood2
1School of Design, University of Leeds, Leeds, LS2 9JT, United Kingdom.
Objectives:
To evaluate the performance of existing equations that measure perceptual whiteness of teeth.
Methods:
Three new psychophysical experiments were conducted and combined with two previously published experiments to form a large set of data to test performance of whiteness indices. Three whiteness indices (WIC, WIO, WID,) were compared with regard to their ability to measure perceived whiteness. Coefficient of determination (r2) and '% wrong decisions' were used as measures of performance. One of the new experiments involved 500 participants across five different countries to explore the effect of gender, age and culture on whiteness perception.
Results:
Equations (WIO and WID) that have been optimized for use with tooth whiteness better correlated with visual perceptions of changes in tooth whiteness than the more general CIE whiteness index (WIC). The best performance was given by WIO (in terms of both r2 and % wrong decisions). No effect of age, gender or culture was found on whiteness perception.
Conclusions:
WIO is a robust method for assessing whiteness of human teeth.
Related Concept Videos
Indicators
Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
Mechanical Ventilation I: Indication and Settings
Bioequivalence of Drugs: Drugs with Multiple Indications
Cardiovascular Drugs: Classification based on Therapeutic Indications

