Effects of etchants and primers on shear bond strength of a self-ligating esthetic orthodontic bracket.
BACKGROUND
Damon 3 orthodontic brackets (Ormco, Orange, Calif), combining a self-ligating bracket with a composite bracket pad were the subject of an in-vitro bonding study to determine the shear bond strength to enamel and adhesive remaining on the teeth with various enamel and bracket preparation procedures.


METHODS
A 3 x 2 factorial design was selected with the following factors as variations of the enamel preparation: liquid phosphoric acid etchant followed by primer (Ortho Solo; Ormco), gel phosphoric acid etchant followed by primer, and self-etching primer (Transbond Plus; 3M Unitek, Monrovia, Calif). The second factor was a primer (Ortho Solo) either applied to the bracket pad or absent as a control.


RESULTS
No statistically significant differences were observed in shear bond strengths, with group average estimates ranging from 14.5 to 16.6 MPa. Debonding predominantly occurred at the bracket-pad interface with no significant differences in adhesive remaining on the teeth.


CONCLUSIONS
This in-vitro study indicated that self-etching primer, gel etchant, and liquid etchant produce equal and sufficient bond strengths. Furthermore, application of primer to the bracket pad does not improve bond strength.
Chalgren
Robert
R
School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
Combe
Edward C
EC
Wahl
Andrew J
AJ
D000134:Acid Etching, Dental; D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents; D004955:Esthetics, Dental; D006801:Humans; D008964:Molar, Third; D016910:Orthodontic Brackets; D019279:Resin Cements; D033081:Shear Strength
C522883:Blugloo; D017220:Dentin-Bonding Agents; C508972:OrthoSolo; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer