title: Effect of enamel pretreatment on shear bond strength of brackets bonded with resin-modified glass-ionomer cement.
abstract: OBJECTIVE
  To evaluate the shear bond strength of brackets bonded with resin-modified glass-ionomer cement (RMGIC) using various methods of enamel conditioning.
  
  
  METHODS
  Forty-five human premolars were randomly divided into five groups. The roots of these teeth were fixed in acrylic resin cylinders, and brackets were bonded to the teeth's crowns using the following material combinations: RMGIC only; RMGIC and corresponding primer; RMGIC, acid etching, and Scotchbond Multipurpose; RMGIC and two-step self-etching primer; and RMGIC and one-step primer. All specimens were submitted to pH cycling for 14 days before shear bond strength was assessed in a universal test machine.
  
  
  RESULTS
  The medians and standard deviations (in MPa) were RMGIC only = 8.34 ± 1.11; RMGIC and corresponding primer = 7.05 ± 2.24; RMGIC, acid etching, and Scotchbond Multipurpose = 7.00 ± 4.79; RMGIC and two-step self-etching primer = 0.54 ± 0.30; and RMGIC and one-step primer = 10.61 ± 4.58. The value for RMGIC and two-step self-etching primer was significantly lower than all other values.
  
  
  CONCLUSIONS
  It can be concluded that the tested RMGIC is suitable for bonding orthodontic brackets, even when used by itself. Different enamel preparations do not improve its performance. However, they can worsen its bonding capacity as the combination with the two-step primer system clearly shows.
authors.affiliation: São Leopoldo Mandic School of Dentistry and Research Center, Campinas, SP, Brasil.
authors.forename: Ricardo Oliveira
authors.initials: RO
authors.lastname: Chicri
authors.forename: Robson Tetsuo
authors.initials: RT
authors.lastname: Sasaki
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Carvalho
authors.forename: Paulo Roberto Aranha
authors.initials: PR
authors.lastname: Nouer
authors.forename: Ynara B O
authors.initials: YB
authors.lastname: Lima-Arsati
mesh_terms: D000085:Acetates / Q000737:chemistry; D000134:Acid Etching, Dental / Q000379:methods; D002021:Buffers; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D058105:Polymerization; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D000085:Acetates; D002021:Buffers; D003188:Composite Resins; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; C408584:Prompt L-Pop; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C084550:Vitremer; C030242:phosphoric acid