title: In vitro bracket bond strength to acid-etched or air-abraded enamel.
abstract: OBJECTIVE
  This study evaluated, in vitro, the capacity of a dentin bonding agent to improve the bond strength of orthodontic brackets using air abrasion enamel preparation.
  
  
  METHODS
  Each of the enamel surfaces received a different treatment prior to bonding procedures. Group 1 received acid-etched with 38% phosphoric acid for 30 seconds. Group 2 received acid-etched with 38% phosphoric acid for 30 seconds, dentin bonding agent (Scotchbond MultiPurpose) applied after rinse completed. Group 3 received abrasion-etched (particle size 50 microns, 120 psi). Group 4 received abrasion-etched, dentin bonding agent applied after etching completed. Unfilled adhesive resin (Ormco light cured sealant) was applied followed by a premolar bracket (Ormco meshed mini-twin) with adhesive (Ormco light cured adhesive) placed on the back. Shear bond strengths were measured using an INSTRON machine and the site of bond failure was determined under 3X magnification.
  
  
  RESULTS
  The shear bond strength obtained with a traditional acid-etch, in vitro, was not improved significantly by the use of a dentin bonding agent. Air abraded surfaces showed very low bond strengths with all treatments.
  
  
  CONCLUSIONS
  Tested in vitro, air-abraded surfaces provide clinically unacceptable bond strength when compared to acid-etched enamel surfaces.
authors.affiliation: University of California, Los Angeles, USA.
authors.forename: K
authors.initials: K
authors.lastname: Mulcahey
authors.forename: A A
authors.initials: AA
authors.lastname: Caputo
authors.forename: D F
authors.initials: DF
authors.lastname: Duperon
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods* / Q000706:statistics & numerical data; D000388:Air; D000704:Analysis of Variance; D001641:Bicuspid; D001840:Dental Bonding / Q000379:methods* / Q000706:statistics & numerical data; D017220:Dentin-Bonding Agents / Q000737:chemistry; D019243:Enamel Microabrasion / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D066298:In Vitro Techniques; D008963:Molar; D016910:Orthodontic Brackets / Q000706:statistics & numerical data; D013718:Tensile Strength
chemical_list: D017220:Dentin-Bonding Agents