title: Clinical acceptability of two self-etch adhesive resins for the bonding of orthodontic brackets to enamel.
abstract: OBJECTIVE
  To determine whether two self-adhesive resin cements, Clearfil SA and RelyX, can be used to successfully bond orthodontic brackets to enamel.
  
  
  METHODS
  Seventy extracted premolars were custom mounted, cleaned and randomly divided into three groups. In group 1 (control), orthodontic brackets were bonded to 25 premolars using the Transbond Plus and Transbond XT two step adhesive systerm adhesive. In group 2, brackets were bonded to 25 premolars using Clearfil SA. In group 3, brackets were bonded to 20 premolars using RelyX. The brackets were debonded using a universal testing machine and shear bond strengths recorded. After debonding, each tooth was examined under 20× magnification to evaluate the residual adhesive remaining. An ANOVA with Duncan's Multiple Range Test was used to determine whether there were significant differences in shear bond strength between the groups. A Kruskal-Wallis Test and a Bonferroni multiple comparison procedure were used to compare the bond failure modes (adhesive remnant index scores) between the groups.
  
  
  RESULTS
  The mean shear bond strengths for the brackets bonded using Clearfil SA and RelyX were 5·930±1·840 and 3·334±1·953 MPa, respectively. Both were significantly lower than that for the brackets bonded using Transbond (7·875±3·611 MPa). Both self-etch adhesive resin cement groups showed a greater incidence of bracket failure at the enamel/adhesive interface while the Transbond group showed a higher incidence at the bracket/adhesive interface.
  
  
  CONCLUSIONS
  The shear bond strengths of the self-etch adhesive resin cements may be inadequate to successfully bond orthodontic brackets to enamel.
authors.affiliation: Montefiore Medical Center/Albert Einstein College of Medicine Bronx, New York, USA.
authors.forename: Bradley
authors.initials: B
authors.lastname: Schnebel
authors.forename: Scott
authors.initials: S
authors.lastname: Mateer
authors.forename: Anthony Louis
authors.initials: AL
authors.lastname: Maganzini
authors.forename: Katherine
authors.initials: K
authors.lastname: Freeman
mesh_terms: D000268:Adhesiveness; D001641:Bicuspid; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: C581302:Clearfil SA; D003722:Dental Alloys; C483701:Rely X Unicem; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer; C477790:Transbond XT; D013193:Stainless Steel