title: Shear bond strength of precoated and uncoated brackets using a self-etching primer.
abstract: OBJECTIVE
  To test the hypothesis that there are no significant differences in the shear bond strength or the adhesive remaining on the tooth after debonding between precoated and uncoated brackets using a self-etching primer.
  
  
  METHODS
  APC Plus precoated brackets and uncoated brackets were bonded with Transbond XT adhesive using the self-etching primer Transbond Plus Self-Etching Primer (TPSEP). The brackets were bonded to extracted human premolars and categorized into two groups: (1) TPSEP/Transbond XT and (2) TPSEP/APC Plus. Shear bond strength was measured with a universal testing machine. The adhesive remnant on each tooth after debonding was quantified with image analysis equipment. Scanning electron microscope (SEM) observations of enamel surfaces treated with TPSEP were also carried out.
  
  
  RESULTS
  No significant differences were observed in the shear bond strengths for the two groups evaluated (P < .05). TPSEP/APC Plus left significantly less adhesive on the tooth after debonding than did TPSEP/Transbond XT (P < .05). It was observed that SEM left a porous and potentially retentive surface.
  
  
  CONCLUSIONS
  There was no significant difference in the bond strength of the two systems tested, but there was a significant difference in the percentage of area of adhesive remaining on the tooth.
authors.affiliation: Docent Unit of Orthodontic Dental Clínic, University of Murcia, Hospital Morales Meseguer, 2a planta, C/Marqués de los Vélez s/n, Murcia 30008, Spain. ascenvi@um.es
authors.forename: Ascensión
authors.initials: A
authors.lastname: Vicente
authors.forename: Luis Alberto
authors.initials: LA
authors.lastname: Bravo
mesh_terms: D020099:Coated Materials, Biocompatible; D001840:Dental Bonding / Q000379:methods*; D017005:Dental Debonding; D003743:Dental Enamel / Q000648:ultrastructure*; D045662:Dental Etching / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016910:Orthodontic Brackets; D033081:Shear Strength; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D020099:Coated Materials, Biocompatible