title: Illuminating light-dependent color shifts in core and veneer layers of dental all-ceramics.
abstract: The color of an object is perceived differently depending on the ambient light conditions. Since dental all-ceramic restorations are fabricated by building up several layers to reproduce the tooth shade, the optical properties of each layer should be optimized for successful shade reproduction. This study aimed to determine the separate contributions of the color shifts in each of the core and veneer layers of all-ceramics by switching the illuminating lights on the color shifts of layered ceramics. Specimens of seven kinds of core ceramics and the corresponding veneer ceramics for each core were fabricated with a layered thickness of 1.5 mm. A sintering ceramic was used as a reference core material. The Commission Internationale de l’Eclairage (CIE) color coordinates of core, veneer, and layered specimens were measured with a spectroradiometer under the CIE illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp) simulating lights. Color shifts of the layered specimens were primarily determined by the CIE a shifts (D65 to A switch) or by the CIE b shifts (D65 to F9 switch) of the veneer layer. The color coordinates shifts in the constituent layers differentially influenced those of the layered specimens by the kind of switched lights. Therefore, the optical properties of the constituent layers of all-ceramics should be controlled to reflect these findings.
authors.affiliation: Institute for Clinical Performance of Biomaterials (ICPB) and ETN Dental Clinic, 106-B101, 27 Heukseokhangang-ro, Dongjak-gu, Seoul 156-070, Republic of Korea.
authors.forename: Yong-Keun
authors.initials: YK
authors.lastname: Lee
authors.affiliation: University of Ulsan, College of Medicine, Department of Dentistry, Asan Medical Center, 388-1, Pungnap-2 dong, Songpa-gu, Seoul 138-736, Republic of Korea.
authors.forename: Hyun-Suk
authors.initials: HS
authors.lastname: Cha
authors.affiliation: Institute of Process Engineering, Chinese Academy of Sciences, State Key Laboratory of Multiphase Complex Systems, Beijing, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
mesh_terms: D002516:Ceramics / Q000737:chemistry*; D003116:Color; D008029:Lighting; D017797:Prosthesis Coloring; D013053:Spectrophotometry / Q000379:methods*