I would not use dental floss unless things changed the floss has wax on it. That could come off in a wound. Strongly recommend if your(anyone) itching to do stiches on someone then buy real sutures. There is a lot of stuff you have to do before giving someone stitches like getting the wound clean and as sanitary as possible. Your better off just putting a band aid on the wound and transport the patient back to base station for treatment in a fairly sanitary setting.
P.S.
If you want to improvise with stiches, then use monofilament fishing line, the smaller the better. I think ice fishing line is the smallest.