title: Evaluation of an anatomic dual-laminate composite resin  shade guide.
abstract: BACKGROUND
  Color assessment in aesthetic dentistry is one of the most challenging steps for direct restorative treatment. Shade selection tools should be able to mimic closely the materials and layering technique used in the final restoration, hence the development of prefabricated anatomic dual-laminate shade guides.
  
  
  OBJECTIVE
  This study aims to compare different shade selection techniques and determine the suitability of a prefabricated anatomic dual-laminate shade guide and its best mode of use compared to a conventional guide and a layered custom guide.
  
  
  METHODS
  CIELab coordinates of different shade guides were assessed: Vitapan Classical (tab A2; Vita); Miris2 prefabricated anatomic dual-laminate shade guide, enamel WR tab on top of dentine S3 tab and nothing in-between (M2air) or glycerin gel (M2gly) or water (M2w); custom shade guide using prefabricated silicon moulds, Miris2 enamel WR composite resin moulded directly on dentine S3 pre-polymerised base (M2cus). The average values were obtained to calculate DE and compare the different shade selection techniques. Additional samples and measurements were made to compare Vitapan Classical shade tabs A1, A2 and A3 and all possible combinations of Miris2 and establish the closest matching shade (DE 3.3).
  
  
  RESULTS
  High DE values were found (6.51–9.11) when comparing M2air to Vita, M2gly M2w M2cus. Differences appeared acceptable (DE 2.09–2.99) between Vita, M2gly and M2w and M2cus. Seven combinations of M2 were found to match Vita tab A1 and A2 and three Miris2 combinations for Vita A3 (DE 3.3).
  
  
  CONCLUSIONS
  The use of Miris2 prefabricated anatomic dual-laminate shade guide with interposition of water or glycerin between the enamel–dentine tabs demonstrated acceptable DE values when compared to Vitapan Classical and custom guides. A chart for matching Vita shades with various combinations of Miris2 enamel/dentine shades was produced to assist the clinician in obtaining acceptable restorations.
  
  
  CONCLUSIONS
  The prefabricated anatomic dual-laminate shade guide is as efficient as a custom shade guide, facilitating clinical steps and saving material when doing compositeresin restorations.
authors.affiliation: Don and Sybil Harrington Professor of Esthetic Dentistry, Restorative Sciences, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA. magne@usc.edu
authors.forename: P
authors.initials: P
authors.lastname: Magne
authors.forename: G
authors.initials: G
authors.lastname: Bruzi
authors.forename: A O
authors.initials: AO
authors.lastname: Carvalho
authors.forename: M
authors.initials: M
authors.lastname: Giannini
authors.forename: H P
authors.initials: HP
authors.lastname: Maia
mesh_terms: D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D003743:Dental Enamel; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design / Q000295:instrumentation / Q000592:standards; D003804:Dentin; D006801:Humans; D017797:Prosthesis Coloring / Q000295:instrumentation* / Q000379:methods / Q000592:standards; D012015:Reference Standards; D013053:Spectrophotometry / Q000295:instrumentation; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003764:Dental Materials