title: Effect of calcium hydroxide dressing on microleakage of composite restorations in endodontically treated teeth subsequent to bleaching.
abstract: OBJECTIVE
  This study evaluates the effect of calcium hydroxide dressing on microleakage of composite restorations following non-vital bleaching.
  
  
  METHODS
  A total of 45 sound extracted human maxillary central incisors underwent endodontic treatment. The teeth were randomly divided into three groups (n=15). In group 1, access cavities were restored with composite. In group 2, the teeth underwent a bleaching procedure for one week before being restored with composite. In group 3, following a bleaching procedure, calcium hydroxide paste was placed in the pulp chamber for one week. The teeth were then restored with composite. The specimens were subjected to a dye leakage test. The data was analyzed using Kruskal-Wallis and Mann-Whitney U tests.
  
  
  RESULTS
  There were significant differences between the groups (P<0.0005). No statistically significant differences were found between groups 2 and 3, while the differences between other groups were significant.
  
  
  CONCLUSIONS
  The bleaching agent increased microleakage of composite restorations in non-vital bleaching, whereas microleakage was not found to be increased by calcium hydroxide.
authors.affiliation: Department of Endodontics, School of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Rahimi
authors.forename: Shahriar
authors.initials: S
authors.lastname: Shahi
authors.forename: Soodabeh
authors.initials: S
authors.lastname: Kimyai
authors.forename: Lali
authors.initials: L
authors.lastname: Khayyam
authors.forename: Majid
authors.initials: M
authors.lastname: Abdolrahimi
mesh_terms: D001458:Bandages; D002126:Calcium Hydroxide / Q000494:pharmacology*; D003763:Dental Leakage / Q000139:chemically induced*; D006801:Humans; D014073:Tooth Bleaching; D019553:Tooth, Nonvital
chemical_list: D002126:Calcium Hydroxide