Teddy Bear Hamsters Cage Bedding
The floor of your hamster cage should always be covered with a substantial layer of soft bedding. Your hamster may move it around and dig in it, and it will also get soiled with time.
You should replace visibly soiled bedding daily, and completely change the bedding once a week.
As for your choice of bedding, look for good-quality hamster bedding from a reliable source. Never use any kind of "homemade" bedding such as sawdust, sand or shredded newspaper. Don't be tempted to use your cat's litter either - these materials were not designed with hamsters in mind, and may be harmful to your little teddy bear hamster.
Once you find commercial bedding that's labeled as suitable for small animals, you should still carefully read and see what it's made of. Some types of bedding use cedar or pine trees as their base material. Both can become toxic to hamsters with use, so avoid these types.