Bonding of precoated bracket on a composite restoration needs adhesion between two exisiting polimerized materials. Composite restorations are usually polished by using rubber cups before bonding. The aim of this study was to evaluate the influence of a composite resin surface polishing on the adhesion to precoated brackets.
Specimens of Filtek Z250 and enamel were polished with rubber cups according to different protocols; precoated brackets were bonded with Transbond XT to the specimens. The shear bond strength of brackets was evaluated and measured data were statistically analysed.
The results highlight low adhesion forces between composite resin and brackets used, demonstrating an unsatisfactory bonding from a clinical point of view. Therefore, different surface polishing techniques have to be chosen before bonding precoated brackets on composite restorations
