Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded With Nano-Filled Composites

Objectives: the purpose of this study was to evaluate the shear bond strength (sbs) of orthodontic brackets bonded with two types of nano-composites in com-parison to a conventional orthodontic composite.materials and methods: sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. in group i, a conventional ortho-dontic composite (transbond xt) was used to bond the brackets, while two nano-composites (filtek tm supreme xt and aelite aesthetic enamel) were used in groups ii and iii respectively. the teeth were stored in distilled water at 37°c for 24 hours, thermocycled in distilled water and debonded with a universal testing machine at a crosshead speed of 1 mm/min. the adhesive remnant index (ari) was also evaluated using a stereomicroscope.results: aelite aesthetic enamel nano-composite revealed a sbs value of 8.44±2.09 mpa, which was higher than transbond xt (6.91± 2.13) and filtek tm supreme xt (6.04± 2.01). statistical analysis revealed a significant difference be-tween groups ii and iii (p < 0.05). no significant difference was found between groups i and iii, and between groups i and ii (p > 0.05). evaluation of ari showed that transbond xt left fewer adhesive remains on teeth after debonding. conclusion: results of this study indicate that the aforementioned nano-composites can be successfully used for bonding orthodontic brackets.