"Effect of grape seed and green tea on shear bond strength of brackets bonded to bleached enamel with and without Lase Peroxide Lite" - An study.

OBJECTIVE

To investigate the effect of antioxidants on shear bond strength of brackets bonded to bleached enamel with and without titanium dioxide nanoparticles (Lase Peroxide Lite).

MATERIALS AND METHODS

One hundred and five human maxillary premolars were randomly divided into seven groups ( = 15). Group I served as control, in group II-A bleaching was performed with Opalescent Boost. In group II-B and C, bleaching was performed with Opalescent Boost followed by application of 5% grape seed and 10% green tea extracts, respectively. Group III-A bleaching was performed with Lase Peroxide Lite. Group III-B and III-C bleaching was performed with Lase Peroxide Lite followed by application of 5% grape seed and 10% green tea extracts, respectively. Brackets were bonded with composite resin and cured with light emitting diode (LED) light. Shear bond strength of brackets was tested with a Universal testing machine.

RESULTS

There was statistically significant difference in the shear bond strength among the seven groups included in the study. There is a statistically significant decrease in shear bond strength in group II-A (8.2 ± 1.6 Mpa), group III-A (8.6 ± 2.1 Mpa) when compared with group I-A (15.9 ± 1.4 Mpa). Among all experimental groups, group II-A showed the lowest mean shear bond-strength values (8.2 ± 1.6 Mpa) ( < 0.005). Group III-C (14.9 ± 2.2 Mpa) has significantly higher shear bond strength.

CONCLUSION

Bleaching reduced the shear bond strength of brackets below acceptable level while application of grape seed and green tea extracts has recovered the shear bond strength.