Shear bond strength of orthodontic brackets after adding silver nanoparticles to a nano-bond adhesive at different thermal cycles and cyclic loading- An study.

OBJECTIVE

To evaluate the effects of silver nano particles (AgNPs) added on Nano-Bond adhesive system (NBA) and its effect on shear bond strength (SBS) of orthodontic brackets attached to enamel at different thermal cycles and cyclic loading.

MATERIALS AND METHODS

Forty extracted premolar teeth for orthodontic reasons were divided randomly into two main groups (20 teeth in each group). Group A: the brackets were bonded by NBA without additives. Group B: the brackets were bonded by NBA containing AgNPs with concentration 0.05%. Every group was further subdivided into 4 subgroups according to teeth subjected or not subjected to thermocycling and cyclic loading. SBS was tested using Lloyd universal testing machine. One-way analysis of variance (ANOVA) was used for testing the significance between the means of tested groups.

RESULTS

Shear bond strength of Nano-Bond adhesive system with AgNPs showed significantly highest mean SBS (20.25 MPa) than Nano-Bond adhesive system without additives (15.64 MPa, = 0.001). The SBS increased in Group B with AgNPs compared to Group A in all the conditions tested. Group A1 and B1 with zero thermal cycling and cyclic loading exhibited highest mean SBS.

CONCLUSIONS

These results indicate addition of AgNPs significantly increased the shear bond strength of Nano-Bond adhesive system.