title: Effect of organic solvents and ultrasound on the removal of orthodontic brackets.
abstract: OBJECTIVE
  To evaluate the effect of organic gel solvents (70% acetone and 90% ethanol) and ultrasound in the removal of metallic brackets.
  
  
  METHODS
  Metallic brackets were bonded with light-cured orthodontic composite (Transbond XT) in 120 human bicuspids and divided into 6 groups for the enamel etch-and-rinse adhesive system (XT) and 6 groups to self-etching system (SEPT) according to pretreatment to removal test: control, 70% acetone, 90% ethanol, ultrasound, 70% acetone+ultrasound, and 90% ethanol+ultrasound. The brackets were subjected to removal by shear testing and Adhesive Remnant Index (ARI) evaluation. Some specimens were prepared and its adhesive interface and etching ability observed by scanning electron microscopy (SEM).
  
  
  RESULTS
  Only the factor 'ultrasound' and its interaction with 'adhesive' were detected as a source of variance, with the SEPT/ultrasound showing the lowest shear strength than the other groups. Regardless the factor 'ultrasound', XT showed a higher ARI than SEPT; however, when the solvents were used, no differences were detected between XT and SEPT.
  
  
  CONCLUSIONS
  The organic solvents were not effective in reducing shear bond strength. The etch-and-rinse adhesive system showed a higher and more favorable ARI score than the self-etching primer. The behavior of the organic solvents on ARI showed to be better when associated with the self-etching primer. The ultrasound was effective in reducing the shear bond strength of the self-etching adhesive system but not in affecting the ARI of the adhesive systems.
authors.affiliation: Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
authors.forename: R M
authors.initials: RM
authors.lastname: Santana
authors.affiliation: Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
authors.forename: R N
authors.initials: RN
authors.lastname: Rached
authors.affiliation: Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
authors.forename: E M
authors.initials: EM
authors.lastname: Souza
authors.affiliation: Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
authors.forename: O
authors.initials: O
authors.lastname: Guariza-Filho
authors.affiliation: Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
authors.forename: E S
authors.initials: ES
authors.lastname: Camargo
authors.affiliation: Southwest Bahia State University - UESB, Bahia, Brazil.
authors.forename: M M
authors.initials: MM
authors.lastname: Pithon
authors.affiliation: Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
authors.forename: O M
authors.initials: OM
authors.lastname: Tanaka
mesh_terms: D000096:Acetone / Q000737:chemistry; D000268:Adhesiveness; D001641:Bicuspid; D057186:Comparative Effectiveness Research; D003738:Dental Cements / Q000737:chemistry*; D017005:Dental Debonding / Q000379:methods*; D003743:Dental Enamel / Q000293:injuries; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012997:Solvents / Q000737:chemistry*; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D003738:Dental Cements; D019279:Resin Cements; D012997:Solvents; C477790:Transbond XT; D000096:Acetone; D000431:Ethanol
keywords: acetone; dental bonding; ethanol; orthodontics; solvents; ultrasound