title: Surface and interfacial analysis of sandblasted and acid-etched enamel for bonding orthodontic adhesives.
abstract: BACKGROUND
  The purposes of this study were to characterize enamel surfaces treated with sandblasting, acid etching, or sandblasting followed by acid etching for bonding of orthodontic adhesives and to evaluate the enamel-adhesive interfaces.
  
  
  METHODS
  Buccal premolar surfaces were sandblasted, acid etched, sandblasted and subsequently acid etched, or left intact. For 2 treatments (acid etching and sandblasting plus acid etching), orthodontic brackets were bonded for resin infiltration assessment. Surface roughness and enamel loss were evaluated by optical profilometry, and surface morphology and elemental composition were examined by low-vacuum scanning electron microscope/energy dispersive x-ray analysis, whereas interfacial resin infiltration was assessed by high-vacuum scanning electron microscopy. Differences were statistically analyzed by 1-way analysis of variance and Tukey-Kramer multiple comparison tests or t tests (α = 0.05).
  
  
  RESULTS
  The sandblasted and sandblasted-plus-acid-etched groups showed higher surface roughness values than the acid-etched group. Sandblasting plus acid etching removed more enamel than did sandblasting or acid etching alone. Sandblasting plus acid etching demonstrated a more uniform type I etching pattern, without alumina particles implanted in the enamel, unlike sandblasting. No difference was found in the extent of resin infiltration between the bonded acid-etched and sandblasted-plus-acid-etched groups, although the latter showed improved infiltration characteristics.
  
  
  CONCLUSIONS
  Sandblasting-plus-acid-etching treatment creates a rough enamel surface, typical of type I etching, with the greatest extent of enamel loss, free of alumina interferences, demonstrating the same extent of resin infiltration as acid etching, but exhibiting improved infiltration quality.
authors.affiliation: Senior research and teaching associate, Department of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland. Electronic address: raphael.patcas@zzm.uzh.ch.
authors.forename: Raphael
authors.initials: R
authors.lastname: Patcas
authors.affiliation: Assistant professor, Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece.
authors.forename: Spiros
authors.initials: S
authors.lastname: Zinelis
authors.affiliation: Professor and director, Department of Biomaterials, School of Dentistry, University of Athens, Athens, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Eliades
authors.affiliation: Professor and director, Department of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Theodore
authors.initials: T
authors.lastname: Eliades
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000537:Aluminum Oxide / Q000737:chemistry*; D002118:Calcium / Q000032:analysis; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D045662:Dental Etching / Q000295:instrumentation / Q000379:methods*; D004577:Electron Probe Microanalysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D055115:Light-Curing of Dental Adhesives; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D010100:Oxygen / Q000032:analysis; D010756:Phosphoric Acids / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis; D019279:Resin Cements / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D010756:Phosphoric Acids; D019279:Resin Cements; C477790:Transbond XT; C516047:Transbond XT Light Cure Adhesive Primer; D010758:Phosphorus; C030242:phosphoric acid; D000537:Aluminum Oxide; D010100:Oxygen; D002118:Calcium