Effect of Quaternary Ammonium Salt on Shear Bond Strength of Orthodontic Brackets to Enamel

Objectives This study sought to assess the effect of quaternary ammonium salt (QAS) on shear bond strength of orthodontic brackets to enamel. Materials and Methods In this in vitro experimental study, 0, 10, 20 and 30% concentrations of QAS were added to Transbond XT primer. Brackets were bonded to 60 premolar teeth using the afore-mentioned adhesive mixtures, and the shear bond strength of the four groups (n=15) was measured using a universal testing machine. After debonding, the adhesive remnant index (ARI) score was determined under a stereomicroscope. Data were analyzed using one-way ANOVA. Results The mean and standard deviation of shear bond strength of the control and 10%, 20% and 30% groups were 23.54±6.31, 21.81±2.82, 20.83±8.35 and 22.91±5.66 MPa, respectively. No significant difference was noted in shear bond strength of the groups (P=0.83). Study groups were not different in terms of ARI scores (P=0.80). Conclusions The results showed that addition of QAS to Transbond XT primer had no adverse effect on shear bond strength of orthodontic brackets.