Influence of cement shade and water storage on the final color of leucite-reinforced ceramics

Abstract

Leucite-reinforced ceramics have a translucent structure, which may have an advantage when fabricating esthetic restorations. However, the different shades of cement and water storage may adversely affect the final color of translucent restorations. Over time, the final color of a restoration may be significantly affected by the specimens. The color of the ceramic specimens was measured with a colorimeter. All disks were gently removed from the tooth surfaces, and 10 specimens (Group A1) were luted to the buccal surfaces of teeth using a dual-polymerizing resin composite cement (Vita A1, Rely X ARC), while the remaining 10 specimens (Group A3) were luted to the lingual surfaces of the teeth with a different shade (Vita A3, Rely X ARC) of the same cement. The final color of the specimens was measured immediately after cementation and at 3-, 30- and 90-day intervals after cementation. Color coordinates L*, a*, b* were recorded. The teeth were stored in 37°C saline solution during measurement intervals. The Mann-Whitney U-test (post-hoc test) was performed to compare the results (α=0.05). The color difference of specimens luted with the two cements with different shades was not perceivable (ΔE<3.7) for AC (after cementation), AC/3, AC/30 and AC/90 measurements. The color alteration between baseline and immediately after cementation (AC) was not perceivable for each cement group. However, after water storage, color differences between the baseline and AC/3, AC/30 and AC/90 were above this limit in both cement groups. The shade of the luted 0.8 mm IPS Empress porcelain specimens became darker after cementation, particularly on the third day, regardless of the cement shade tested. When the final color of ceramics luted with cements in two different shades was compared, it was observed that the final color differences were not perceivable for each measurement session.