Objective: The purpose of this study was to evaluate the shear bond strength of a new 7th generation self-etching primer iBOND (Heraeus Kulzer) on orthodontics brackets.
Methods: 30 non-carious and non-restored human molars were randomly divided into 2 groups of 15 each. Each tooth was mounted vertically in a self-cure acrylic, pumiced, washed and dried prior to bonding. Group 1 (control) used Transbond XT (3M Unitek) primer + 37% phosphoric acid and Group 2 used only the self-etching primer iBOND. The teeth were bonded with stainless steel buttons (GAC International) and Transbond XT adhesive paste (3M Unitek). After 24 hours incubation in 37°C de-ionized water, shear bond strength was measured using a Universal Testing machine (Zwick) with a crosshead speed of 0.5mm/min. The amount of adhesive resin left on the enamel after debonding was evaluated using the adhesive remnant index (ARI). Significant differences between the two groups were analyzed using the Student’s T-test. Chi-squared test was used to evaluate differences in the ARI scores between the groups.
Results: Transbond XT primer + 37% phosphoric acid (16.65±6.04MPa; cv=36%) had a significantly higher shear bond when compared to iBOND (9.32±3.18MPa; p<0.001; cv=34%). The results of the ARI chi-squared comparisons (χ2=10.754, p<0.05) indicated a significant difference between the two groups.
Conclusions: In vitro shear bond strength was significantly higher in the control Transbond XT primer + 37% phosphoric acid. However, shear bond strength for the new self-etching primer iBOND has the potential to bond orthodontic brackets successfully.