Evaluation of color and translucency of colored and pre-colored monolithic zirconia ceramics

Aim:The presentin vitrostudy evaluated the Color and Translucency of Colored and Pre-colored MonolithicZirconia ceramics. Materials and methods:Twenty disks of Monolithic Zirconia with a diameter of 10 mm and a thickness of1.5 mm were milled from White and Pre-colored Blanks. The disks milled from the White blanks were subjectedto immersion in Coloring liquid. The disks were divided into Group I Colored Zirconia and Group II Pre-coloredZirconia. Twenty Co-Cr disks of diameter of 10◦mm and thickness of 2.5◦mm with a superficial hollow spacer of8◦mm diameter and 0.1◦mm thickness were used in this study to serve as metallic substrates for the Zirconiadisks. Using a Color Spectrophotometer, Color coordinates were observed. Color difference (AE) was measuredover a white backdrop, metal substrate before, and metal substrate after cementation. The Translucency Parameter(TP) was measured over a white and black backdrop. Independent ‘t-test and Mann WhitneyUtest were used toanalyze the Color difference and Translucency Parameter data, respectively. Results:The Mean Color difference between Colored Zirconia and Pre-colored Zirconia against a white backdropand metal substrate before cementation was 12.32 and 10.37, respectively. The Mean Color difference betweenColored Zirconia and Pre-colored Zirconia against a white- backdrop and metal substrate after cementation was2.48 and 3.41, respectively. The mean color difference between Colored and Pre-colored Zirconia against metalsubstrate before and after cementation was 8.37 and 9.13, respectively. Pre-colored Zirconia showed a statisticallysignificantly higher color difference than Colored Zirconia (P◦<◦0.05). The mean Translucency parameter forColored Zirconia and Pre-colored Zirconia was 7.73 and 8.83, respectively. The mean Translucency parameterfor Colored Zirconia and Pre-colored Zirconia over metal substrate was 0.52 and 0.57, respectively. Conclusion:On comparison of Colored and Pre-colored Zirconia from a white background to the metal substratebefore and after cementation, the Colored Zirconia showed lower color difference than the Pre-colored Zirconia,which suggests that Colored Zirconia has better masking ability than Pre-colored Zirconia. However, comparingthese two materials for Translucency, the Pre-colored Zirconia material demonstrated higher translucency than theColored Zirconia material before and after cementation over the metal substrate.