title: Color stability of adhesive resin cements after immersion in coffee.
abstract: OBJECTIVE
  Marginal discoloration of luting cement may affect the appearance of esthetic restorations. This study evaluated the color stability of current adhesive resin cements after immersion in coffee.
  
  
  METHODS
  Four dual-cured resin cements (Clearfil SA cement Automix Universal, Maxcem Elite Clear, Maxcem Elite Yellow, and RelyX Unicem2 Automix A2) and two chemical-cured resin cements (Super-Bond C&B Clear and Super-Bond C&B Esthetic) were examined. The CIE L*a*b* of 2.0-mm-thick disc-shaped specimens was measured using a spectrophotometer on a white background (n = 6). The color differences (∆E) after 1-day and 1-week immersion in 37 °C water or coffee were analyzed by two-way ANOVA by selecting immersion solution and product as main factors, followed by Tukey's HSD test (α = 0.05). Water sorption and solubility were also evaluated.
  
  
  RESULTS
  The two-way ANOVA of the ∆Es suggested that the two main factors and their interaction were significant. The ∆Es after coffee immersion were significantly greater than those after water immersion, except for Super-Bond C&B Esthetic. The ∆Es after water immersion were not significantly different among the products; those of Maxcem Elite Clear and Maxcem Elite Yellow after coffee immersion were significantly greater than the others. The water sorption and solubility significantly correlated with the ∆Es.
  
  
  CONCLUSIONS
  The ∆Es of the adhesive resin cements examined after 1-week coffee immersion were significantly different among the products. The product showing greater water sorption and solubility displayed greater color change.
  
  
  CONCLUSIONS
  Adhesive resin cements should be carefully selected when the marginal appearance of the ceramic restoration is important.
authors.affiliation: Removable Partial Prosthodontics, Department of Masticatory Function Rehabilitation, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
authors.forename: Maho
authors.initials: M
authors.lastname: Shiozawa
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Yuya
authors.initials: Y
authors.lastname: Asakawa
authors.forename: Naohiko
authors.initials: N
authors.lastname: Iwasaki
mesh_terms: D003069:Coffee; D003116:Color; D012995:Solubility
chemical_list: D003069:Coffee