In our study, the effects of acidic drinks on the enamel of bonded teeth during fixed orthodontic treatment was evaluated. 45 non-carious first premolars that were to be orthodontically extracted have been used in each of the invivo and invitro groups. The teeth in both groups were divided into subgroups of 15 that were treated with Sprite. Coke and controls. Brackets were placed on the vestibule surfaces of the teeth with adhesives and an apparatus was formed to create an artificial oral condition. In the first division of the apparatus, acidic drinks were kept in room temperature, in the second division, artificial saliva was kept at 37°C with the help of a ther-mostate. The teeth in the Coke and Sprite groups were kept in the acidic drinks 3 times for 5 minutes spending the rest of the 24 hours in artificial saliva for 4 months, while the teeth in the control group were kept in only artificial saliva for 4 months. In the invivo group 45 teeth that were to be extracted for orthodontic reasons, were bonded with adhesives before treatment and the patients were divided into 3 groups. The patients in the first group were told to drink Coke for 3 times daily, the second group were told to drink Sprite and the patients in the third group were told to stay away from acidic drinks. At the end of 4 months these teeth were extracted carefully without damaging the brackets. The enamel around the brackets in invivo and invitro groups were evaluated with SEM. Areas of defect due to demineralization were observed on the enamel surface around the brackets in consistence with the effects of acidic drinks, both in the invitro and in the invivo groups.

Keywords: Fixed orthodontic treatment, Acidic drinks, SEM