title: Effect of brand and shade of resin cements on the final color of lithium disilicate ceramic.
abstract: BACKGROUND
  Resin cements are available in various shades from different manufacturers. However, there is no standard for the optical properties of these cements, which may result in differences in the color of translucent ceramic restorations.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to evaluate the effects of different shades and brands of resin cements on the color of a lithium disilicate ceramic.
  
  
  METHODS
  Ten ceramic disks (11×1.5 mm, shade A2) were fabricated from lithium disilicate high-translucency blocks. Eighty cement disks (11×0.2 mm) were fabricated from 4 brands (Maxcem; Variolink; Clearfil; and RelyX) of resin cements in translucent and universal (shade A2) shades. Color measurements of ceramic specimens were made without (control) and with each brand/shade of resin cement material (test) with a spectrophotometer, and International Commission on Illumination Lab (CIELab) color coordinates were recorded. Color differences (ΔE00) between the control and test groups were calculated. ΔE00results were analyzed by 2-way ANOVA and subsequent pairwise testing. Comparisons were performed using the Student t test, and then all P values were corrected with the step-down Bonferroni procedure (α=.05).
  
  
  RESULTS
  The effect on the ΔE00values (P<.001) of the brand and shade of resin cement materials was significant. Both shades of RelyX cement groups had significantly lower and Variolink_translucent cement group had significantly higher ΔE00results than other brands (P<.05). Only RelyX_translucent and RelyX_universal were significantly different from each other for comparisons within brands (P<.05). The effect of RelyX_universal cement on the ceramic was not visually perceptible (ΔE00≤1.30). Clinically unacceptable results (ΔE00>2.25) were observed only for Variolink_translucent cement (2.36).
  
  
  CONCLUSIONS
  Same-shade resin cements from different manufacturers had different effects on the color of lithium disilicate ceramic. The effects of different shades of resin cements from the same manufacturer on the color of lithium disilicate ceramic were statistically different for only RelyX, which may also be considered clinically different based on clinical acceptability thresholds for color difference values (ΔE00). Accordingly, this effect may be considered clinically different for Variolink but not clinically different for Maxcem and Clearfil.
authors.affiliation: Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Ordu University, Ordu, Turkey.
authors.forename: Doğu Ömür
authors.initials: DÖ
authors.lastname: Dede
authors.affiliation: Professor, Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
authors.forename: Gözlem
authors.initials: G
authors.lastname: Ceylan
authors.affiliation: Associate Professor, Division of Restorative Science and Prosthodontics, The Ohio State University, College of Dentistry, Columbus, Ohio. Electronic address: yilmaz.16@osu.edu.
authors.forename: Burak
authors.initials: B
authors.lastname: Yilmaz
mesh_terms: D003776:Dental Porcelain; D006801:Humans; D066298:In Vitro Techniques; D017797:Prosthesis Coloring; D019279:Resin Cements; D013053:Spectrophotometry
chemical_list: C029849:Clearfil Bonding Agent; C515955:Maxcem; C528569:Rely-X; D019279:Resin Cements; C493120:lithia disilicate; D003776:Dental Porcelain