Shear Bond Strength of a Mechanically Retained Ceramic Bracket

Abstract The failure under shear loading of mechanically retained ceramic brackets bonded to enamel was investigated. One light-activated dual-cure and two no-mix self-cure adhesives were compared to au Adhesive Pre-coated hracket (APC). The results indicated that the ceramic bracket bonded with the light-activated dual-cure adhesive had a significantly higher mean shear bond strength than the other adhesive systems. All adhesive systems usually failed cohesively with adhesive remaining attached to the bracket and enamel surfaces. There was no significant difference in failure site. There was a significant difference in the amount of adhesive remaining attached to the enamel surface. The light-activated dual-cure adhesive and Adhesive Pre-coated brackets failed in 50% and 80% of instances respectively, with less than 10% of the adhesive remaining attached to the enamel surface. Self-cure adhesives failed usually with 10-90% of the adhesive remaining attached to the enamel surface. There were no instances of enamel damage. Three cases of bracket fracture occurred, one of these being associated with the highest recorded bond strength.