Perspectives

COLOR MEASUREMENT SYMPOSIUM 2003

leaching has become a mainstay B of esthetic dentistry. Since the introduction of at-home bleaching in 1989, the profession has moved beyond the question of whether at-home bleaching works and has moved into other need-to-know topics. In addition to the popularity of at-home bleaching techniques, numerous other bleaching methods have either resurged or newly emerged. Categories of bleaching techniques now include at-home bleaching, in-office bleaching with and without various thermocatalytic lights, and over-the-counter bleach- ing products in a variety of delivery options and material concentrations.

Currently the profession is seeking to compare how well one product in a similar category compares with another, as well as how different categories compare in terms of effi- cacy. Classically, these comparisons have been made using a standard Vita shade guide (Vitapan@, Vita Zahnfabrik, Bad Sackingen, Germany). But, these determina- tions of color measurements present many difficulties. Previous color science sought to match porcelain or composite colors to tooth color. Now the profession needs ways to

more accurately measure incremen- tal differences between shades of teeth prior to and following various bleaching treatments.

A number of methods for determin- ing tooth color have been used in dentistry. These include shade tab matching, colorirneters, spectro- photometers, and digital or 35 mm single lens reflex photography. Each of these methods has certain pro- cedures that must be followed to achieve maximum accuracy. Even when these protocols are followed, there are certain advantages, dis- advantages, and limitations to each technique.

To address these and other issues, a scientific symposium was con- ducted in August 2003 at the Medical College of Georgia in Augusta, GA, USA. The purpose of the one-day event was to discuss the various options for color mea- surement of teeth, their relative accuracy, and the advantages and disadvantages of each, and to pro- pose some general guidelines for color measurement that would lend clinical relevance to research and clinical bleaching trials. The pro- ceedings are published in this sup-

plement of the ]ournal of Esthetic and Restorative Dentistry in a series of peer-reviewed papers.

Following the scientific presenta- tions, extensive discussion among speakers and invited topic experts resulted in the development of a list of consensus statements. These statements are intended not only to reflect the current state of the art relative to color-measurement tech- niques, but also to suggest existing areas of concern and new directions for color-measurement research.

The following are consensus state- ments from the Color Measurement Symposium:

1. All current methods that are used to assess tooth whitening (shade guide, spectrophotome- ter, colorimeter, and digital photography) seek to match the perception of the human visual system.

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2. Methods used to compare the efficacy of tooth-whitening products should be available for scientific replication.

3. Color-measurement techniques, whether shade tabs or instru- mentation, are not valid for interval-scale comparisons because of the nonlinear nature of hue, value, and chroma.

4. Universally accepted standards by which the results of instru- ment-based methodologies can be used for comparison between studies of the clinical effective- ness of tooth-whitening agents have not yet been established. In the absence of these standards, the use of such methods for establishing comparative effi- cacy claims should be consistent with the determination of visu- ally detectable differences in

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tooth shade. Statistically signifi- cant differences may not always be visually perceptible. Since all methods for assessing tooth color have limitations, further development of more accurate, reproducible, and clin- ically relevant methodologies must continue.

Additional recommendations of the symposium are as follows:

1. In the dental environment, the use of L”c*h* values instead of L*a’bb* values should be con- sidered, because they may be more relevant to clinical research.

2. Correction of delta values in accordance with standard color difference equations (such as CIEDED 2000) should be considered.

3 . Shade tabs and guides should become more representative of natural and bleached tooth colors to facilitate the needs of clinical research and communi- cation with patients.

It is hoped that the information presented in this supplement of the Journaf will provide the standard against which current publications are assessed and the springboard to support further color-measurement research. The end result of this endeavor is that the dental profes- sion will better understand and evaluate bleaching claims of prod- ucts and processes.

Van B. Haywood, DMD Moderator

02003 BC Decker lnc

Note: The Color Measurement Symposium and this supplement were funded by the Colgate-Palmolive Company. The opinions expressed in this Perspectives feature are those of the author and do not neces- sarily reflect those of theJourna1 or its staff.

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