title: [Bonding of resin cement to bleached dental enamel].
abstract: OBJECTIVE
  The effects of bleaching times, types of etching agent and storage period of bleached bovine tooth on the shear bond strength of resin cement to the enamel were examined.
  
  
  METHODS
  Bovine teeth were repeatedly bleached 0, 1, 3, and 5 times then stored in 37 degrees C water for 1 week. The effect of bleaching number of the bovine tooth on the bond strength of resin cement to the enamel was investigated using 40% phosphoric acid (EG) etching technique. Next, the effects of types of etching agent and of storage period of bleached bovine tooth with three times in 37 degrees C water on the bond strength were studied using 10% citric acid-3% ferric chloride (10-3) or 10% citric acid (10-0) solution.
  
  
  RESULTS
  The bleaching of bovine tooth allowed for a dramatic decrease in the bond strength from 18.3 MPa to 9.8 MPa (1 time), and 3.9 MPa (3 times), even though the bovine enamel was etched by EG. However, when 10-3 or 10-0 solution was applied to the three times bleached enamel, bond strengths were 13.9 and 10.0 MPa, respectively. Furthermore, prolonging of the storage period of the three times bleached bovine tooth in water to 2 months resulted in a increase in the bond strength from 3.9 to 10.1 MPa, even if bovine enamel was etched by EG, and close to that obtained from the 10-3 etching.
  
  
  CONCLUSIONS
  To obtain the expected bond strength to bleached enamel, it is better to wait for 2 months for a restoration and use the 10-3 etching.
authors.affiliation: Department of Crown Bridge Prosthodontics, Nihon University School of Dentistry at Matsudo. wakami.masanobu@nihon-u.ac.jp
authors.forename: Masanobu
authors.initials: M
authors.lastname: Wakami
authors.forename: Mikiko
authors.initials: M
authors.lastname: Masuda
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kato
authors.forename: Naoko
authors.initials: N
authors.lastname: Tabei
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Watanabe
authors.forename: Juri
authors.initials: J
authors.lastname: Muramori
authors.forename: Takahiro
authors.initials: T
authors.lastname: Saikawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Aida
authors.forename: Norihiro
authors.initials: N
authors.lastname: Nishiyama
mesh_terms: D000818:Animals; D002417:Cattle; D002712:Chlorides; D019343:Citric Acid; D001840:Dental Bonding; D003738:Dental Cements; D003743:Dental Enamel; D045662:Dental Etching; D005290:Ferric Compounds; D033081:Shear Strength; D012996:Solutions; D014073:Tooth Bleaching
chemical_list: D002712:Chlorides; D003738:Dental Cements; D005290:Ferric Compounds; D012996:Solutions; D019343:Citric Acid; C024555:ferric chloride