Toothache
Tooth pain can indicate a range of dental problems and its cause should be identified so that it can be addressed. It is often described as one of the worst pains imaginable. When tooth pain comes on suddenly, is progressively getting worse, or is intense, it is especially important to see an emergency dentist. 

Fractured or Cracked teeth
Chips and cracks in the teeth can happen when biting down on hard objects, using teeth to do things besides biting and chewing, or because of an accident. People who grind or clench their teeth are also more susceptible to chipping or cracking teeth.
Any tooth fragments should be rinsed, preserved in a glass of milk or water, and brought to your emergency dental appointment.
If a tooth is loose, it is important to try and keep that tooth in its socket to prevent it from falling out. This can be accomplished by gently biting down on the tooth to hold it in place.
If a tooth has been knocked out, it is important to try to locate the missing tooth. If the missing tooth is located, it should only be handled by the crown and rinsed. You can preserve a missing tooth by doing one of two things: first, you can place it back in the socket and bite down like you would for a loose tooth. Second, you can store it in a glass of milk or water, like you would for tooth fragments from a chipped tooth. 

Missing or Loose Dental Restoration
Both permanent and temporary restorations can become loose or fall out,
Some restoration and crowns  maybe recemented and refixed back in place. Therefore it is useful if you can find the lost restoration to bring it in with you.