The in vitro shear and tensile strength of four enamel adhesives was investigated. The materials examined were System 1⁺, Vitrebond, C & B Metabond and Panavia-Ex (original version). The mode of failure of each material was also investigated under a scanning electron microscope. Edgewise mesh-backed brackets were bonded to the buccal surface of extracted premolar teeth and forces applied with an Instron 1011 testing machine.

Results indicated that Panavia-Ex (with sandblasted brackets) had the highest tensile strength when compared to the other materials (P<0.01). Panavia-Ex had the highest...

The in vitro shear and tensile strength of four enamel adhesives was investigated. The materials examined were System 1⁺, Vitrebond, C & B Metabond and Panavia-Ex (original version). The mode of failure of each material was also investigated under a scanning electron microscope. Edgewise mesh-backed brackets were bonded to the buccal surface of extracted premolar teeth and forces applied with an Instron 1011 testing machine.

Results indicated that Panavia-Ex (with sandblasted brackets) had the highest tensile strength when compared to the other materials (P<0.01). Panavia-Ex had the highest shear strength when compared to C ' B Metabond (P<0.05) and to the other materials (P<0.01). C & B Metabond had the highest shear and tensile strength of the other adhesives (P<0.01). No significant differences were found for System 1⁺ when compared to Vitrebond for tensile strength, but System 1^& was stronger for shear strength (P<0.01). Analysis of failure shows that 50% of the samples failed at the adhesive-enamel interface, 25% failed in a combined mode and the remaining 25% failed either adhesively to metal or cohesively.