Spectrophotometric analysis of tooth color reproduction on anterior all-ceramic crowns: Part 1: analysis and interpretation of tooth color.
Color matching of a natural maxillary central incisor is one of the most difficult challenges in clinical dentistry. Accurate color determination and interpretation of tooth color information in ceramic work is an important step in achieving success in ideal color reproduction. In this case study, factors that influence tooth color determination were analyzed, and the process of interpretation of tooth color information was assessed based on scientific color data using a novel dental spectrophotometer system. An all-ceramic crown for a maxillary right central incisor was the subject of this color assessment. The contralateral incisor was an intact natural tooth that was bleached and then used as the target shade for an all-ceramic crown. The dental spectrophotometer (Crystaleye, Olympus, Tokyo, Japan) was used for tooth color measurement and analysis. The target tooth, prepared tooth, maxillary arch, and face images were captured for color information. Tooth color stabilization related to tooth bleaching and tooth dehydration was assessed. Based on tooth color data obtained by the dental spectrophotometer, color was analyzed in several different areas of a tooth using CIELAB (Commission Internationale de l'Eclarirage) color coordinates L*, a*, b*, and color difference Delta E. Interpretation of the tooth color information was made in each of porcelain layers on a blue map, and its intensions for color reproduction were described. Throughout this spectrophotometric assessment, the process of stabilized tooth color determination, tooth color analysis, interpretations, and fabrication of a blue map for porcelain work was clarified with color data as scientific evidence.


CONCLUSIONS
The use of a dedicated dental spectrophotometer allows the evaluation and measurement of the color of a bleached tooth. This allows the laboratory technician to more precisely understand the bleached tooth shade as well as when the bleached tooth color has become stable enough to match to a contralateral all-ceramic crown restoration.
Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA 02115, USA. shigemi_nagai@hsdm.harvard.edu
Shigemi
S
Ishikawa-Nagai
Aki
A
Yoshida
John D
JD
Da Silva
Lloyd
L
Miller
D000328:Adult; D003442:Crowns; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D006801:Humans; D007180:Incisor; D008297:Male; D008437:Maxilla; D017797:Prosthesis Coloring / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D013053:Spectrophotometry / Q000295:instrumentation; D019228:Tooth Crown
D003776:Dental Porcelain