title: Tooth sensitivity and bleaching effectiveness associated with use of a calcium-containing in-office bleaching gel.
abstract: BACKGROUND
  The authors conducted a study to evaluate tooth sensitivity (TS) and the bleaching effectiveness associated with use of a calcium-containing (CC) in-office bleaching gel.
  
  
  METHODS
  The authors used a 35 percent calcium-free (CF) hydrogen peroxide gel and a 35 percent CC hydrogen peroxide gel according to the manufacturer's instructions in 40 caries-free participants 18 years or older. They performed two bleaching sessions with a one-week interval between sessions. The authors registered the color at baseline and after the first and second bleaching sessions by using a shade guide and by gauging the participant's perception of TS as registered on a scale from 0 (none) to 4 (severe). The authors evaluated the bleaching effectiveness at each week's recall visit by means of the Friedman test, and they compared the groups at each assessment point by means of the Mann-Whitney test. They evaluated the percentage of participants with TS and the intensity of the TS by using the Fisher exact and Mann-Whitney tests.
  
  
  RESULTS
  Both groups demonstrated equivalent and significant tooth color enhancement compared with color values at baseline (P < .05), with an average bleaching of 7 to 8 shade guide units. Most of the participants from the CF group (80 percent) experienced sensitivity while undergoing the bleaching regimen, whereas only 40 percent of participants from the CC group reported experiencing TS (P = .02). The intensity of TS was significantly higher (P < .01) for the CF group during in-office dental bleaching.
  
  
  CONCLUSIONS
  The CC 35 percent hydrogen peroxide gel reduced the TS during in-office dental bleaching without jeopardizing the bleaching effectiveness.
  
  
  CONCLUSIONS
  The results of this study support the findings that a CC 35 percent hydrogen peroxide gel can reduce TS during in-office dental bleaching.
authors.affiliation: School of Dentistry, University Estadual de Ponta Grossa, Rua Carlos Cavalcanti, 4748, Bloco M, Sala 64-A, Uvaranas, Ponta Grossa, Paraná, Brazil 84030-900. stellakp@gmail.com
authors.forename: Stella
authors.initials: S
authors.lastname: Kossatz
authors.forename: Gislaine
authors.initials: G
authors.lastname: Martins
authors.forename: Alessandro Dourado
authors.initials: AD
authors.lastname: Loguercio
authors.forename: Alessandra
authors.initials: A
authors.lastname: Reis
mesh_terms: D000293:Adolescent; D000328:Adult; D002118:Calcium / Q000627:therapeutic use*; D002125:Calcium Gluconate / Q000627:therapeutic use; D003116:Color; D003807:Dentin Sensitivity / Q000209:etiology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000627:therapeutic use; D008297:Male; D014070:Tooth / Q000473:pathology; D014073:Tooth Bleaching / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000627:therapeutic use*; D014075:Tooth Discoloration / Q000188:drug therapy; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide; D002125:Calcium Gluconate; D002118:Calcium