Assessment of Enamel Demineralization Following the Use of Different Orthodontic Bracket Materials, Etchants, and Adhesive Systems: An In Vitro Study

The aim of this study was to assess enamel demineralization depth following the use of different bracket materials, etchants, and adhesive systems. Ninety-nine extracted human premolars were assigned to nine groups (eight experimental and one control), each including 11 specimens. The experimental groups were bonded to either metal or ceramic brackets and prepared using a total-or self-etchant with a pre-coated or flash-free adhesive system. All specimens were immersed in an artificial demineralization solution for 7 days at pH 4.5 and 37 °C. The brackets were debonded, and the specimens were sectioned buccolingually at the right and left sides of the bracket base margins. Scanning electron microscopy was used to assess the demineralization depth using ImageJ software. Significantly deeper enamel demineralization was observed in all bonded teeth compared to non-bonded teeth (p < 0.001). The adhesive system had no significant effect on the demineralization depth. Metal brackets caused significantly deeper enamel demineralization than ceramic brackets (p <0.005). The use of the total-etch surface treatment caused deeper demineralization compared to that of the self-etch treatment. In conclusion, bonded teeth exhibit deeper enamel demineralization than non-bonded teeth. Metal brackets contribute to deeper demineralization than ceramic brackets. The total-etch surface treatment caused deeper demineralization than self-etch when combined with metal brackets and a pre-coated adhesive system.