Adhesion of mesh-base direct-bonding brackets.

The bond strength of mesh-base and metal-base brackets to human enamel was investigated for different adhesive systems. The bond strengths were determined by means of tension, shear, and torsion tests. The data were statistically analyzed and the following conclusions were drawn: 1. An adhesive system (bracket base and adhesive) cannot be selected on the basis of one test (tension, shear, or torque) alone. The various systems generally ranked differently, depending upon the test method utilized. 2. Mesh-base brackets were more retentive than the metal-base brackets in tension, while metal-base brackets were more retentive in shear. 3. For the metal-base brackets, Bond-Eze was the most retentive material, Adaptic and Orthomite followed narrowly behind, and Genie was the least retentive. 4. For the mesh-base bracket in tension and shear, Bond-Eze, Adaptic, and Solo-Tach were the most retentive materials when used with the 60-mesh base, and Genie was the least retentive. Torsion values were not useful because of a large number of bracket wing failures.