While bridges and crowns can last a lifetime, they sometimes to unseal and fall. One of the best ways to ensure the longevity of your bridge or your crown is to have good oral hygiene. A bridge can lose his seat if the teeth or bones that keep them in place are affected by dental or periodontal disease. Keep gums and teeth healthy by brushing with fluoride toothpaste twice a day and using dental floss daily. Consult your dentist regularly for an audit and professional cleaning. To avoid damaging your new bridge or your new crown, avoid chewing hard foods, ice or other hard objects.