Dentures can break or become damaged for many reasons, including being dropped on hard surfaces and general wear and tear. Additionally, according to the American Dental Association, partial dentures can get damaged if you bite down to fit them into place. Biting down could break or bend the clasps.
If your false teeth do break, your dentist is the only person who can fix them. Over-the-counter glues can contain harmful chemicals, and you should stay away from them. Incorrectly fixing dentures can also lead to mouth sores or general irritation in your mouth, which can need days of oral maintenance on your part. Meanwhile, a dentist can often fix your dentures in just a day or so.