Abstract
Purpose: The aim of this study was to evaluate and compare the total color difference (E) between natural teeth and fabricated crowns from three ceramic systems with different thicknesses.
Materials and Methods: The color of ninety maxillary central incisors was measured from the middle third of the labial surface with a Vita Easyshade spectrophotometer. All-ceramic crown preparations with different thicknesses (0.8, 1.2, 1.5 mm) were done on selected teeth (n = 30). Prepared teeth were randomly divided into three equal groups to fabricate ceramic crowns from three ceramic systems, Duceram LFC (DLFC), In-Ceram SPINELL (ICS), and IPS Empress (IPSE). Colors of cemented crowns were measured and compared with their corresponding measurements before preparations. Data were statistically analyzed using two-way ANOVA at 5% significance level.
Results: A significant difference of E was detected between natural teeth and different thicknesses of crowns constructed from the all-ceramic materials investigated. Comparing the three materials at 0.8 mm thickness revealed that the lowest E was recorded for DLFC, which was significantly different from the other ceramic systems while IPSE showed the highest E. At higher thicknesses there was no difference between natural tooth shade and crowns constructed from different ceramic materials.
Conclusions: Reinforcement of ceramics by alumina for In-Ceram and leucite for Empress decreases color production. Level of acceptance between the different ceramic materials and thicknesses varied. DLFC showed the highest color matching at all thicknesses followed by ICS and IPSE in descending order. In general, increasing the thickness of fabricated crowns enhances color match.