Objectives: The present study was carried out to compare the shear bond strength of metallic brackets bonded with single Bond and Assure bonding agents under dry and saliva contamination conditions.
Materials and Methods: A total 60 sound premolar teeth were selected for the purpose of this in vitro study and stainless steel brackets were bonded on enamel surfaces with single bond and assure bonding agents under a dry condition or with salivary contamination. The shear bond strength values of the brackets were measured in a universal testing machine. The adhesive remnant index (ARI) scores were determined after debonding of the brackets under a stereomicroscope. One-way ANOVA was used to analyze bond strength. Two-by-two comparisons were made with post hoc Tukey tests (P < 0.001). The frequencies of ARI scores were analyzed with Kruskal-Wallis test.
Results: The bond strength values of brackets to tooth structure were 9.29 ± 8.56 and 21.25 ± 8.93 MPa with the use of Assure resin bonding agent under saliva contamination and dry conditions, respectively. These values were 10.13 ± 6.69 and 14.09 ± 6.6 MPa, respectively, under the same conditions with the use of single bond adhesive. Contamination with saliva resulted in a significant decrease in the bond strength of brackets to tooth structure with the application of Assure adhesive resin (P < 0.001). There were no significant differences in the ARI scores between the different study groups.
Conclusions: Application of single bond and assure bonding agents resulted in adequate bond strength of brackets to tooth structures. Contamination with saliva significantly decreased the bond strength of Assure bonding agent compared to dry conditions.