Application of digital imaging in tooth whitening randomized controlled trials

Area of Science:

• Dental materials science
• Biophotonics and imaging
• Clinical research methodology

Background:

• Novel peroxide-based bleaching systems necessitate accurate clinical evaluation methods.
• Digital imaging technology offers potential for objective tooth color assessment.
• Previous methods for plaque quantification inform tooth color measurement techniques.

Purpose of the Study:

• To establish the reproducibility of an objective, digital imaging method for assessing tooth color.
• To evaluate the reliability of this method in both in vitro and in vivo settings.
• To support the clinical assessment of tooth whitening efficacy.

Main Methods:

• Reproducibility assessed in vitro using digital images of 16 standard shade guide tabs over 2 days.
• Clinical reproducibility assessed in vivo using digital images of 14 volunteers' anterior teeth over 2 days.
• Color values (L*, a*, b*) derived from images; variability analyzed using ANOVA and reliability using intra-class correlation coefficients (ICCs).

Main Results:

• In vitro: High reproducibility with ICCs of 0.998 (L*), 0.996 (a*), and 0.998 (b*).
• In vivo: High clinical reproducibility with ICCs of 0.970 (L*), 0.979 (a*), and 0.989 (b*).
• Both studies confirmed the reliability of digital imaging for tooth color measurement.

Conclusions:

• Objective digital imaging is a highly reproducible method for measuring tooth color.
• This technique provides reliable data for evaluating tooth whitening treatments.
• The method is suitable for both laboratory standardization and clinical application.