Effect of luting cement colour on all-ceramic restorations

Objectives: The aim of this study was to investigate the effects of various composite resins on the restorations' shade and if it is affected by composite resins' color or different thickness of ceramic restorations. Methods: Four different composite resin systems (Variolink II, Bifix DC, RelyX-ARC, Nexus II) in two different shades were used for cementation of 192 IPS Empress specimens on polyethylene plates. The ceramic samples were prepared in two different thicnesses (0,8mm and 1,0mm). The shade differences of the Empress surfaces were examined spectrophotometrically (X-Rite, Smartscan MA60) in two stages; before and after the cementation. Results: The results of the statistical analysis (ANOVA) showed that the differences related with the kind of composite resin, the colour of the composite resin and the thickness of the ceramic specimens found to be significant (p<0.05). The shade difference of Variolink II composite resin was significantly greater, and the difference caused by Bifix DC was found to be significant than those of Rely X ARC and Variolink II. (Bonferroni, p<0.05). Conclusions: Because the luting cement colour affects the final shade of all-ceramic restorations, the enhanced knowledge on colour charesteristics of composite cements is required to achieve superior esthetics.