title: Comparison of Shade of Ceramic with Three Different Zirconia Substructures using Spectrophotometer.
abstract: This study assessed how changing the Zirconia (Zr) substructure affected the color samples after they have been overlaid by the same shade of veneering ceramic.
  
  
  
  Three commercial Zr materials were tested in this study: Prettau(®) Zirconia (ZirKonZahn, Italy), Cercon (Dentsply, Germany) and InCoris ZI (Sirona, Germany). For each system, 15 disk-shaped specimens (10 × 1 mm) were fabricated. Three shades of A1, A2 and A3.5 of porcelain (IPS e.MaxCeram, IvoclarVivadent, USA) were used for layering the specimens. Five specimens from each type of Zr were layered with same shade of ceramic. Color measurements were recorderd by a spectrophotometer Color-Eye(®) 7000A (X-Rite, Grand Rapids, MI). Mean values of L, a, b color coordinates and ΔE were recorded and comparisons were made.
  
  
  
  Differences in the ΔE were recorded for the same porcelain shade with different Zr substructures and affected the color of the specimens (p < 0.01, ANOVA). The maximum difference between the ΔE values for the A1, A2 and A3.5 shades with three types of Zr substructures was found to be 1.59, 1.69 and 1.45 respectively. Multiple comparisons of the ΔE with PostHoc Tukey test revealed a statistically significant difference (p < 0.05) between the three types of Zr, except between Type 2 Zr and Type 3 Zr for the Shade A1. The mean values of L, a, b and ΔE for the Prettau(®) Zirconia substructure were found to be the least among the three types.
  
  
  
  The brand of Zr used influences the final color of the all ceramic Zr based restorations and this has clinical significance.
authors.affiliation: Assistant Professor, Department of Prosthodontics, College of Dentistry, King Saud University, Po Box-60169, King Abdullah Road, Riyadh 11545, Saudi Arabia, Phone: 0096614677441, e-mail: rashidhabib@hotmail.com.
authors.forename: Syed Rashid
authors.initials: SR
authors.lastname: Habib
authors.affiliation: Department of Prosthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Ibraheem F Al
authors.initials: IF
authors.lastname: Shiddi
mesh_terms: D003116:Color; D017076:Computer-Aided Design; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000295:instrumentation / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry*; D003801:Dental Veneers; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D013053:Spectrophotometry / Q000379:methods; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide
keywords: Zirconia color; Zirconia shade; Zirconia, Ceramic shade; Zirconia substructure