title: Effect of coffee and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching.
abstract: There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching.
  
  
  OBJECTIVE
  To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching.
  
  
  METHODS
  Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max) and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO) before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD) at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E) and lightness (∆L) variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (p<0.05).
  
  
  RESULTS
  Significant differences were observed between groups for both the ∆L and ∆E values (p<0.001). All specimens presented a decrease in brightness (negative ∆L). The highest ∆E values were observed for teeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively). Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times.
  
  
  CONCLUSIONS
  The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching.
authors: aff01.
authors: Rodrigo
authors: R
authors: Pirolo
authors: Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors: Rafael Francisco Lia
authors: RF
authors: Mondelli
authors: Graduate Program in Dentistry, Positivo University, Curitiba, PR, Brazil.
authors: Gisele Maria
authors: GM
authors: Correr
authors: Graduate Program in Dentistry, Positivo University, Curitiba, PR, Brazil.
authors: Carla Castiglia
authors: CC
authors: Gonzaga
authors: Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
authors: Adilson Yoshio
authors: AY
authors: Furuse
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002253:Carbonated Beverages; D002417:Cattle; D003069:Coffee / Q000737:chemistry*; D030221:Cola / Q000737:chemistry*; D003116:Color; D006861:Hydrogen Peroxide / Q000737:chemistry; D010858:Pigmentation / Q000187:drug effects*; D012016:Reference Values; D013053:Spectrophotometry; D013499:Surface Properties / Q000187:drug effects; D013997:Time Factors; D014070:Tooth / Q000187:drug effects*; D014073:Tooth Bleaching / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000737:chemistry; D014075:Tooth Discoloration
chemical_list: D003069:Coffee; D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide