Effect of Cement, Porcelain Thickness to Color of All Ceramics

Objectives: The metal ceramic crown has been used in dentistry for more than 45 years. However, metal ceramic restorations have numerous undesirable characteristics; one of them is the opaque nature of the metal substructure does not simulate natural translucency. All ceramic restorations, having no metal structure, allow superior translusency and can be used where esthetics are paramount. The esthetic success of ceramic restorations depends on a good color match between the tooth and the restorative material. The color stability of both porcelain and luting materials is also very important for the esthetics of laminate veneers and full ceramic crowns. The purpose of this study is to determine the effect of resin-based luting cement and the thickness of all ceramic restorations to the final color of the restorations. Methods: One resin based light polymerized direct composite with two different shades (RelyX ARC, 3M, ESPE, Seefeld, Germany) and one dental porcelain(IPS Empress 2, Ivoclar, Schaan, Liechtenstein) with different thicknesses were selected for this study. 50 disks; 10 mm in diameter and each five specimen were different in thickness (0,4mm,1 mm, 2mm, 3mm and 5 mm respectively). Initial specimen color parameters were determined in the Commission International de l'Eclairage Lab(CIELAB) color order system with a colorimeter (Minolta CR321,Japan).Color changes were calculated between baseline color measurements and measurements after cementation. Color difference data were statistically analysed by repeated measurements of ANOVA and paired t test. Results: It was found that the color of the luting cement effects the final color of the restoration p<0.05 and the thickness of the ceramic layer has a significant role on this situation. Conclusions: Cement shade and thickness of the ceramic effect the final color the restoration.