title: Rebonding of orthodontic brackets. Part II, an XPS and SEM study.
abstract: OBJECTIVE
  The hypothesis of this two-part study is that adhesive systems for bonding orthodontic brackets (ie, two self-etch primers [Transbond and M-Bond] and a conventional phosphoric acid etch [Rely-a-Bond]) would show a difference with respect to rebonded enamel surface morphology and chemical composition.
  
  
  METHODS
  This study examined the enamel surface before and after debonding with scanning electron microscopy and the enamel surface chemical composition for the elements Ca, P, O, F, Si, and C using x-ray photoelectron spectroscopy.
  
  
  RESULTS
  The etching of the two self-etch groups is less aggressive and less uniform than that of phosphoric acid. The change in the concentration of C indicated that the separation of the bracket from the enamel surface is at the resin-enamel interface for the phosphoric acid-etched adhesive and a mixed mode involving the enamel-resin-bracket interfaces for the self-etching systems. F release appears to occur for Transbond but not for M-Bond.
  
  
  CONCLUSIONS
  The results confirm the original hypothesis that differences in adhesive systems are manifested in less aggressive etches and less adhesive left on the enamel surface for the self-etching adhesive systems.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
authors.forename: Mona A
authors.initials: MA
authors.lastname: Montasser
authors.forename: James L
authors.initials: JL
authors.lastname: Drummond
authors.forename: John R
authors.initials: JR
authors.lastname: Roth
authors.forename: Lulwa
authors.initials: L
authors.lastname: Al-Turki
authors.forename: Carla A
authors.initials: CA
authors.lastname: Evans
mesh_terms: D000134:Acid Etching, Dental; D002118:Calcium / Q000032:analysis; D002244:Carbon / Q000032:analysis; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D017005:Dental Debonding; D003743:Dental Enamel / Q000737:chemistry / Q000648:ultrastructure*; D004577:Electron Probe Microanalysis; D005461:Fluorine / Q000032:analysis; D006801:Humans; D008422:Materials Testing; 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; D012825:Silicon / Q000032:analysis; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D010756:Phosphoric Acids; C097531:Rely a Bond system; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer; C516047:Transbond XT Light Cure Adhesive Primer; D010758:Phosphorus; D005461:Fluorine; D002244:Carbon; C030242:phosphoric acid; D010100:Oxygen; D002118:Calcium; D012825:Silicon