Comparison of Shear Bond Strength of Orthodontic Brackets Bonded with Core Max II and Transbond XT in Fluorosed Teeth and Evaluation of Enamel Damage after Debonding

Orthodontic bracket bonding may encounter difficulties in fluorosed teeth. The aims of this study were to compare the shear bond strength (SBS) of brackets bonded to fluorosed teeth with Core Max II and Transbond XT and to assess the enamel damage after debonding. In this in-vitro study, 60 fluorosed (TFI=4 and 5) and non-fluorosed teeth were divided into two subgroups. The standard edgewise metallic brackets were bonded to the teeth with Transbond XT in the first and third groups, and with Core Max II in the remaining groups. After bonding, the SBS of the brackets was tested with a universal testing machine. The obtained data were analyzed by two-way ANOVA, post-hoc (LSD), Kruskal-Wallis, Wilcoxon, and paired samples tests. Fluorosis significantly reduced SBS (P =0.041). Core Max II significantly increased SBS (P =0.040). Teeth in group 4 (fluorosis and Transbond XT) had the lowest SBS (13.44±1.69 MPa); group 2 (fluorosis and Core Max II) showed the highest enamel damage. Core Max II is a good adhesive for orthodontic bracket bonding in fluorosed teeth but conservative debonding methods should be necessarily applied to decrease enamel damage.