FIG. 1 is a front elevational view of a dental floss holder showing our new design;

FIG. 2 is a left side view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

Elements shown in dotted are environmental only, and form no part of the claimed design.