title: Measurement of opalescence of tooth enamel.
abstract: OBJECTIVE
  Opalescent dental esthetic restoratives look natural and esthetic in any light, react to light in the same manner as the natural tooth and show improved masking effect. The objective of this study was to determine the opalescence of tooth enamel with reflection spectrophotometers.
  
  
  METHODS
  Color of intact bovine and human enamel was measured in the reflectance and transmittance modes. Two kinds of spectrophotometers were used for bovine and one kind was used for human enamel. The opalescence parameter (OP) was calculated as the difference in yellow-blue color coordinate (CIE Deltab(*)) and red-green color coordinate (CIE Deltaa(*)) between the reflected and transmitted colors.
  
  
  RESULTS
  Mean OP value of bovine enamel was 10.6 (+/-1.4) to 19.0 (+/-2.1), and varied by the configuration of spectrophotometers. Mean OP value of human enamel was 22.9 (+/-1.9).
  
  
  CONCLUSIONS
  Opalescence varied by the configuration of measuring spectrophotometer and the species of enamel. These values could be used in the development of esthetic restorative materials.
authors.affiliation: Department of Dental Biomaterials Science and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea. ykleedm@snu.ac.kr
authors.forename: Yong-Keun
authors.initials: YK
authors.lastname: Lee
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
mesh_terms: D000818:Animals; D002417:Cattle; D003116:Color; D003743:Dental Enamel / Q000737:chemistry*; D006801:Humans; D013053:Spectrophotometry / Q000295:instrumentation