Whilst I do use dental floss for general oral health and for removing bits of food that are stuck between teeth there are many other things it can be used for and is well worth taking on a trip.
Armed with the needle your dental floss becomes a sewing thread that is extremely strong and can be used for repairs on backpacks (including stitching through the teeth of a zip that were fraying from the zip itself), clothing, shoes, tents and more. If you need a finer thread most floss can be untwisted to create three strands.
Make temporary shoe laces from it.
Fasten your hair back.
Use it to fasten the tops of bags.
If there is no lock on your room door you may be able to run a thread from the door handle to something in the room to secure it.
Tie baggage to something secure or yourself when on public transport.
Repair broken jewellery or even make your own jewellery with it.
ALWAYS REMEMBER IT IS SO STRONG YOU WILL NEED EITHER THE CUTTING BLADE ON THE DISPENSER OR SCISSORS TO CUT IT.
Feel free to fill in comments if you know of any other really good uses.
This has to be one of the bargains of the year in terms of value, usability, size and weight - why travel without it?