J Korean Acad Conserv Dent JKACD Journal of Korean Academy of Conservative Dentistry 1225-0864 2093-8179 The Korean Academy of Conservative Dentistry 10.5395/JKACD.2008.33.4.352 Original Article Evaluating the reliability and repeatability of the digital color analysis system for dentistry Jeong Joong-Jae Park Su-Jung Cho Hyun-Gu Hwang Yun-Chan Oh Won-Mann Hwang In-Nam Department of Conservative Dentistry, School of Dentistry, DSRI, Chonnam National University, Korea. Corresponding Author: In-Nam Hwang. Department of Conservative Dentistry, School of Dentistry, Chonnam National University 5 Hak-dong, Dong-gu, Gwangju, 501-757, Korea. Tel: 82-62-220-4443, Fax: 82-62-225-8387, hinso@jnu.ac.kr 07 2008 31 07 2008 33 4 352 368 22 04 2008 26 05 2008 29 05 2008 Copyright © 2008 The Korean Academy of Conservative Dentistry 2008

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

This study was done to evaluate the reliability of the digital color analysis system (ShadeScan, CYNOVAD, Montreal, Canada) for dentistry.

Sixteen tooth models were made by injecting the A2 shade chemical cured resin for temporary crown into the impression acquired from 16 adults. Surfaces of the model teeth were polished with resin polishing cloth. The window of the ShadeScan handpiece was placed on the labial surface of tooth and tooth images were captured, and each tooth shade was analyzed with the ShadeScan software. Captured images were selected in groups, and compared one another.

Two models were selected to evaluate repeatability of ShadeScan, and shade analysis was performed 10 times for each tooth.

And, to ascertain the color difference of same shade code analyzed by ShadeScan, CIE L*a*b*values of shade guide of Gradia Direct (GC, Tokyo, Japan) were measured on the white and black background using the Spectrolino (GretagMacbeth, USA), and Shade map of each shade guide was captured using the ShadeScan.

There were no teeth that were analyzed as A2 shade and unique shade. And shade mapping analyses of the same tooth revealed similar shade and distribution except incisal third.

Color difference (ΔE*) among the Shade map which analyzed as same shade by ShadeScan were above 3.

Within the limits of this study, digital color analysis instrument for dentistry has relatively high repeatability, but has controversial in accuracy.

 Tooth color Digital color Color analysis Color repeatability ShadeScan Sproull RC Color matching in dentistry. Part II: Practical applications of the organization of color J Prosthet Dent 1973 29 556 566 Paravina RD Power JM Fay RM Color comparison of two shade guides Int J Prosthodont 2002 15 73 78 Hwang IN Oh WM Colorimetric Analysis of Extracted Human Teeth and Five Shade Guides J Korean Acad Conserv Dent 1997 22 769 781 Preston JD Current status of shade selection and color matching Quintessence Int 1985 16 47 58 Grajower R Revah A Sorin S Reflectance spectra of natural and acrylic resin teeth J Prosthet Dent 1976 36 570 579 Bell AM Kurzeja R Gemberg MG Ceramometal crowns and bridges: focus on failures Dent Clin North Am 1985 29 763 778 O'Brien WJ Boenke KM Groh CL Coverage errors of two shade guides Int J Prosthodont 1991 4 45 50 Cernavin I Effect of chlorine-containing disinfecting compounds on shade guides made of acrylic resin J Prosthet Dent 1996 75 574 Sykora O Fabrication of a posterior shade guide for removable partial dentures J Prosthet Dent 1983 50 287 288 Lemire PA Burk B Color in dentistry 1975 Hartford, CT J.M Ney Co. Grajower R Revah A Sorin S Reflectance spectra of natural and acrylic teeth J Prosthet Dent 1976 36 570 579 Macentee M Lakowski R Instrumental color measurement of vital and extracted teeth J Oral Rehabil 1981 8 203 208 Goodkind RJ Schwabacher WB Use of a fiber-optic colorimeter for in vivo color measurements of 2830 anterior teeth J Prosthet Dent 1987 58 535 542 Park HK Jeong JH A Study on the Color of Korean Natural Teeth J Korean Acad Prosthodont 1988 26 185 195 Cho KM Shin DH Color Analysis of the Natural Teeth with a Modified Intraoral Spectrophotometer J Korean Acad Conserv Dent 1998 23 223 235 Freedman G Communicating color Dent Today 2001 20 78 80 Chu SJ Tarnow DP Digital shade analysis and verification: A case report and discussion Pract Proced Aesthet Dent 2001 13 129 136 Chu SJ Precision shade technology: Contemporary strategies in shade selection Pract Proced Aesthet Dent 2002 14 79 83 Paravina RD Powers JM Esthetic color training in dentistry 2004 St. Louis, Missouri Mosby Inc. 165 174 Clark EB An analysis of tooth color J Am Dent Assoc 1931 18 2093 2103 Clark EB Tooth color selection J Am Dent Assoc 1933 20 1065 1073 Miller LL Shade matching J Esthet Dent 1993 5 143 153 Miller LL Organizing color in dentistry J Am Dent Assoc 1987 12 Spec No 26E 40E Hayashi T Medical color standard. V. Tooth crown 1967 Tokyo Japan Color Research Institute Goodkind RJ Loupe MJ Teaching of color in predoctoral and postdoctoral dental education in 1988 J Prosthet Dent 1992 67 713 717 O'Brien WJ Groh CL Boenke KM A one-dimensional color order system for dental shade guides Dent Mater 1989 5 371 374 Seghi RR Hewlett ER Kim J Visual and instrumental colorimetric assessments of small color differences on translucent dental porcelain J Dent Res 1989 68 1760 1764 Gross MD Moser JB A colorimetric study of coffee and tee staining of four composite resins J Oral Rehabil 1977 4 311 322 Hwang IN Lee KW Translucency of Light Cured Composite Resins Depends on Thickness & its Influence on Color of Restorations J Korean Acad Conserv Dent 1999 24 604 613 Johnston WM Kao EC Assessment of appearance match by visual observation and clinical colorimeter J Dent Res 1989 68 819 822 Goodkind RJ Keenan KM Schwabacher WB A comparison of Chromascan and spectrophotometric color measurement of 100 natural teeth J Prosthet Dent 1985 53 105 109 Schwabacher WB Goodkind RJ Three-dimensional color coordinates of natural teeth compared with three shade guide J Prosthet Dent 1990 64 425 431 Yeh CL Powers JM Miyagawa Y Color of selected shades of composites by reflection spectrophotometry J Dent Res 1982 61 1176 1179 Robertson AR Colorimetry Rep Prog Phys 1978 41 471 510 Thornton WA How strong metamerism disturbs color spaces Color Res Appl 1998 23 402 407 Park EJ The basis of color molding 1996 2nd ed Seoul Mijinsa 56 194 Park DY Practical Chromatics 1992 Revised ed Seoul Bando publisher 99 120 The Korean Industrial Standard. KS A 0065

Shade Map of the maxillary central incisors.

Shade Map of the maxillary lateral incisors.

Shade Map of the maxillary canines.

Shade Map of the maxillary first premolars.

Shade Map of the maxillary second premolars.

Repeated measurement of a central incisor.

Repeated measurement of a canine.

Shade Map of A1 shade guide on the black background (upper) and white background (below) according to thickness.

Shade Map of A3 shade guide on the black background (upper) and white background (below) according to thickness.

Vita shade-guide colors (O'Brien et al.26, 1989)

CIE L*a*b* value of shade guides measured on the black background and white background

Color difference (ΔE*) of 3 mm thickness shade guide between measured on the black background and white background

Color difference (ΔE*) among shade guides that analysed as same Vita code

A1 (1W) : 1 mm A1 shade guide analysed on white background

B3 (1B) : 1 mm B3 shade guide analysed on black background