If you break your adult tooth biting hard food, and the tooth is painful, ring your dentist to arrange an emergency appointment. Your dentist will check the tooth and at least help relieve the pain.
If the tooth isn't painful, ring your dentist as soon as possible to make a check-up appointment. Until that appointment, try to avoid eating on that tooth, and keep it clean with brushing and flossing.
If your tooth or your child's tooth is chipped or cracked in a sporting accident, keep any broken pieces of tooth. Place the pieces in a small container with milk, or in glad wrap, and take them with you to the emergency dental visit.