title: The effect of at-home bleaching and toothbrushing on removal of coffee and cigarette smoke stains and color stability of enamel.
abstract: BACKGROUND
  The authors conducted a study to evaluate the stain removal ability of tooth bleaching and simulated toothbrushing after coffee and cigarette smoke staining and to determine the enamel susceptibility to restaining.
  
  
  METHODS
  The authors used a colorimeter to determine the baseline color of 40 bovine labial enamel surfaces according to the Commission Internationale de l'Eclairage L*a*b* coordinates. They immersed one-half of the specimens in coffee and exposed one-half to cigarette smoke in a smoking machine. They took color measurements again and determined the color change from baseline (ΔE1) for each group. The authors divided each group into two subgroups and subjected the specimens to at-home bleaching (one hour per day for 21 days) or simulated toothbrushing (120 cycles per day for 21 days), followed by another color measurement (ΔE2). The authors repeated both staining procedures (that is, cigarette smoke and coffee) and followed them with a third color measurement (ΔE3). They analyzed the data by using a two-way analysis of variance and the Tukey test (α = 5 percent).
  
  
  RESULTS
  Both staining procedures resulted in similar values for ΔE1. The specimens stained with coffee and cigarette smoke exhibited a significant reduction in color change after bleaching (P < .05). However, toothbrushing resulted in a significantly reduced color change only for cigarette smoke-stained specimens (P < .001). The discoloration in coffee-stained specimens increased after restaining, irrespective of the stain removal method (P < .05).
  
  
  CONCLUSIONS
  The study results show that at-home bleaching removed both coffee and cigarette smoke staining. The restaining potential was greater for specimens stained with coffee than for those stained with cigarette smoke, regardless of the removal method used.
  
  
  CONCLUSIONS
  Six percent hydrogen peroxide at-home bleaching was effective in removing stains caused by coffee or cigarette smoke. However, continued frequent consumption of coffee can increase the staining susceptibility of enamel.
authors.affiliation: Pontifical Catholic University of Paraná, Curitiba, Paraná, Brazil.
authors.forename: Juliana Zavala
authors.initials: JZ
authors.lastname: Bazzi
authors.forename: Marcio José Fraxino
authors.initials: MJ
authors.lastname: Bindo
authors.forename: Rodrigo Nunes
authors.initials: RN
authors.lastname: Rached
authors.forename: Rui Fernando
authors.initials: RF
authors.lastname: Mazur
authors.forename: Sergio
authors.initials: S
authors.lastname: Vieira
authors.forename: Evelise Machado
authors.initials: EM
authors.lastname: de Souza
mesh_terms: D000818:Animals; D002417:Cattle; D003069:Coffee / Q000009:adverse effects*; D003124:Colorimetry; D003743:Dental Enamel; D006699:Home Care Services; D006861:Hydrogen Peroxide / Q000627:therapeutic use; D012008:Recurrence; D012907:Smoking / Q000009:adverse effects*; D014073:Tooth Bleaching / Q000379:methods; D058205:Tooth Bleaching Agents / Q000627:therapeutic use; D014075:Tooth Discoloration / Q000209:etiology / Q000628:therapy*; D014099:Toothbrushing
chemical_list: D003069:Coffee; D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide