In vitro enamel remineralization at orthodontic band margins cemented with glass ionomer cement.

Demineralization adjacent to orthodontic bands remains a clinical concern. The release of fluoride from glass ionomer cement has been shown to inhibit demineralization. The purpose of this study was to examine the remineralization effects of a glass ionomer cement adjacent to orthodontic bands. Forty extracted molars were painted with an acid-protective varnish, excluding a 2 x 6 mm window on the buccal surfaces. Artificial caries-like lesions were created in the exposed enamel with an acidified gel. Half the lesion on each tooth was then painted with an acid-protective varnish. An orthodontic band was cemented with a glass ionomer cement or zinc phosphate cement, the gingival margin of the band located at the level of the artificial carious lesion. The teeth were placed in separate closed environments of a nonfluoridated artificial saliva for 3 months. The teeth were then sectioned and photographed with polarized light microscopy in imbibition medias of water and Thoulet's (R.I.: 1.41, 1.47), representing a minimum of 5%, 10%, and 25% pore volume, respectively. With a sonic digitizer, the area of the body of the lesion was measured in each imbibition media, comparing the maintained varnished out lesions to the lesions exposed to the cement. Results demonstrated a statistically significant reduction in the body of the lesions (p < 0.005) for those exposed to the glass ionomer cement.