Enamel surface morphology after bracket debonding.

The purpose of this study was to evaluate the shear bond strength of brackets and the enamel morphology after using six methods for removal of adhesive after bracket debonding. A total of thirty-five recently extracted noncarious human premolars were used. The twin bracket Mini-Taurus was used with the Mono-Lok2 TM bonding system. Shear bond strength (MPa) was calculated. Immediately after the brackets were removed, the teeth were rinsed and dried, using an air-water syringe. The adhesive remnant index was calculated and the debonded teeth with residual adhesive material attached to the enamel surface were equally sorted in seven groups of five, as follows: Group 1. The residual adhesive was removed with a 12-blade tungsten carbide finishing bur in a high-speed handpiece, using water as the coolant. Group 2. The residual adhesive was removed with a 12-blade tungsten carbide finishing bur in a low-speed handpiece, using water as the coolant. Group 3. The residual adhesive was removed with an Arkansas stone: Dura-white stones for finishing composite in a high-speed handpiece using water as the coolant. Group 4. The residual adhesive was removed with an Arkansas stone: Dura-white stones for finishing composite in a low-speed handpiece, using water as the coolant. Group 5. The residual adhesive was removed with Sof-Lex aluminum oxide discs according to manufacturer's instructions in a low-speed handpiece, using water as the coolant. Group 6. The residual adhesive was removed with Enhance Composite Finishing Discs in a low-speed handpiece, using water as the coolant. In this group, the paste was not applied after the polishing discs. Group 7. The residual adhesive was removed with Enhance Composite Finishing Discs and Polishing Cups in a low-speed handpiece, using water as the coolant. Prisma-gloss polishing paste and ultrafine polishing paste were applied according to manufacturer's instructions. After removal of the adhesive, all teeth were evaluated with the scanning electron microscope. The results revealed a mean shear bond strength of 12.75 MPa. The higher the bond strength, the higher the percentage of ARI. The smoothest enamel surface was obtained when the Enhance system with the gloss polishing paste was used; the second smoothest enamel surface was obtained when using Sof-Lex discs. If the paste was not used with the Enhance system, the obtained surface was rougher than when using Sof-Lex discs.