Effects of orthodontic bands on microbiologic and clinical parameters.

The aim of this study was to evaluate the effect of placement of orthodontic bands on the gingival tissues and the microbial composition of dental plaque. Ten subjects undergoing orthodontic treatment completed the study. In each subject four sites were examined: two test sites with orthodontic bands and two control sites free of bands. Clinical and bacterial examinations were performed before the beginning of the treatment and 5, 7, 47, 72, and 90 days after placement of the orthodontic appliances. Plaque index (Pl I) and bleeding scores increased significantly on banded teeth as compared with control sites. Probing depth remained within normal values for both test and control groups. The composition of dental plaque determined by dark-field microscopy showed significant shifts in the test sites after banding. Changes consisted of an increase in the percentage of spirochetes, motile rods, filaments, and fusiforms; conversely, a decrease in cocci was noted. During the same period no significant changes in the bacterial distribution were observed in the control group.