shear bond strength of orthodontic brackets bonded with a self-adhering composite in dry and saliva-contaminated conditions

Objectives: the purpose of this study was to evaluate the effect of saliva contamination on shear bond strength (sbs) of orthodontic brackets bonded by a self-adhering composite compared with a conventional adhesive. materials and methods: this in vitro, experimental study investigated 40 human premolars. the teeth were randomly divided into four groups based on the adhesive type and bonding condition: (i) vertise flow composite without saliva contamination (vf), (ii) vertise flow composite with saliva contamination (vf/s), (iii) transbond xt composite without saliva contamination (txt), and (iv) transbond xt composite with saliva contamination (txt/s). after the preparation step, brackets were bonded to the buccal surface of the teeth, and samples were mounted in acrylic blocks, incubated at 37°c for 24 hours, and underwent thermocycling between 5- 55°c. next, the sbs was measured by a universal testing machine. data were analyzed by anova and tukey’s test. p<0.05 was considered statistically significant. results: anova showed a significant difference in sbs among the groups (p<0.001). the highest sbs was achieved in the txt group (26.63±9.09 mpa), followed by txt/s (13.69±4.23 mpa), vf/s (3.68±1.49 mpa), and vf (3.04±1.73 mpa). conclusion: saliva contamination did not have a significant effect on sbs of brackets bonded with vertise flow. however, it did not provide acceptable bond strength for orthodontic bracket bonding in the clinical setting.