Spectrophotometric evaluation of color match of three different porcelain systems for all-ceramic zirconia-based restorations.
OBJECTIVE
To determine by a spectrophotometric analysis the variations in color between the intended and the fabricated shades of three different porcelain systems when applied in a standardized thickness on a zirconia core.


METHODS
Three porcelain systems for zirconia based restorations, Ivoclar IPS e.max Ceram, VITA VM9, and Creation Zi-F were tested. Nine disc-shaped (15 mm diameter, 0.5 mm thickness) specimens of VITA YZ zirconia core per group were made comprising a total of 27 discs. Three different shades (A2, A3, A4) of the Vitapan Classical shade guide were investigated. The porcelain veneer total thickness was set at 1.0 mm in all groups. The porcelain stratification was made by applying calibrated layers of porcelain. Thicknesses of single porcelain layers were calculated from drawings retrieved from the manufacturers' instructions. Color parameters (L*, a*, b*) of veneered specimens were measured by a clinical spectrophotometer. Color differences (deltaE) were calculated using a color difference formula. Two-way ANOVA and Tukey's test were used to analyze the data.


RESULTS
The mean color differences for the three ceramic systems, Ivoclar IPS e.max Ceram, VITA VM9 and Creation Zi-F were respectively 4.1, 2.7 and 3.2, regardless of the shades. VITA VM9 resulted in the best average shade matching among the porcelain systems, even if results with shade A3 were considerably worse than shades with A2 and A4 (P<0.05). Color matching appeared not to be shade dependent (P>0.05) among the tested shades.
Tuscan School of Dental Medicine, Department of Dental Materials and Fixed Prosthodontics of Siena, University of Florence and Siena, Italy. alessandrovichi1@gmail.com
Alessandro
A
Vichi
Giovanni
G
Fazi
Michele
M
Carrabba
Gabriele
G
Corciolani
Chris
C
Louca
Marco
M
Ferrari
D000704:Analysis of Variance; D003116:Color / Q000592:standards*; D003124:Colorimetry; D003442:Crowns; D003776:Dental Porcelain; D003801:Dental Veneers; D003830:Denture, Partial, Fixed; D008422:Materials Testing; D016876:Metal Ceramic Alloys; D017797:Prosthesis Coloring; D013053:Spectrophotometry; D015040:Zirconium
D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide