The aim of this in vitro study was to evaluate the effects of substrate colors, different
levels of ceramic thickness and translucency, and cement shades on the color difference
from a reference color of lithium-disilicate crowns.A premolar tooth preparation was
made on a study model for 1.0 and 1.5 mm thick full-ceramic crowns. Digital impressions
were taken (3Shape TRIOS) and crowns designed in a CAD program (DentalDesigner). Shade
A1 crowns were milled (Everest, Kavo) from high-translucency (HT) and low-translucency
IPS e.max (Ivoclar Vivadent) blocks. Twelve substrates were made of different colors
and materials (Natural Die Material, Co-Cr, zirconia, and gold-colored alloy). Three
different shades of try-in pastes were used to simulate the effect of cements (Variolink
Esthetic try-in paste; Ivoclar). Shade measurement was done three times for each crown
by a spectrophotometer (VITA Easyshade Advance); averages were compared to a reference
crown (A1, HT, 1.5 mm, ND2 abutment, neutral try-in paste) with ΔE00 (CIEDE2000, according
to the CIE latest standard) calculated.All the examined parameters influenced the
ΔE00 of the crowns. The weakest effect was exerted by the try-in paste.All examined
parameters influenced the final color of e.max CAD lithium-disilicate ceramic crowns.Matching
the shade of ceramic crowns to the natural tooth color is a great challenge in dentistry.
To meet patients' increasing esthetical expectations, CAD/CAM methods are very popular
for full-ceramic crowns. However, several factors such as the shade of the abutment,
luting cement color, ceramic thickness, and translucency may influence the final color.
Our objective was to measure the optical effect of these factors on the final shade
of CAD/CAM lithium-disilicate ceramic crowns.