**11. Methods and materials: Part II**

#### **11.1 Sample preparation**

One hundred human premolar teeth were collected from various oral surgery practices located in southeast Michigan. Only premolars presenting a healthy facial enamel surface were included. All teeth were assigned randomly to five equal groups of 20 teeth. One of the groups had brackets bonded with Aegis-Ortho resin cement while the remaining groups were bonded with Transbond XT. Of the four Transbond XT groups, one served as a control, another received Vanish (3M, Espe, MN) fluoride varnish, another received MI Paste and the final received a coat of Pro-seal as adjunctive treatments.
