Healing of the dento-epithelial junction following the use of dental floss.

The healing of the dento-epithelial junction following the use of dental floss was studied on 28 first premolars in seven children who were under orthodontic treatment. On the mesial surfaces the floss was brought to the depth of the pocket and moved back and forth three to five times, while being pressed against the tooth surface. After observation periods varying between 15 min and 3 weeks, the teeth were extracted and stained in a 1% solution of Water Blue and examined under the stereomicroscope. All the distal surface (control) were found to be covered with a more or less continuous layer of junctional epithelial cells, whereas on the mesial surface (experimental), these cells were absent after 15 min and 24 h, i.e. they had been detached by the floss. New epithelial cells were found to reattach to the enamel after 3 days, and after 2 weeks and more, the cell population on the experimental surfaces could not be distinguished from that on the control surfaces. In one patient in whom the floss had been used daily for 3 1/2 months, there had for obvious reasons been no reattachment of junctional epithelial cells to the enamel, but there was nothing to indicate that the flossing had had unfavorable consequences.