A permanent tooth knocked out whole is very urgent. If you can get to a dentist within 30 minutes, the tooth may be re-attached in the socket with a chance of lasting for years. Gently rinse the tooth of any debris and keep it from drying out - in water, saliva, or best of all, milk. Keeping the root surface as undisturbed as possible will maximize the chance of successful re-attachment.    More Information

A tooth pushed out of position by a blow is fairly urgent. It must be re-positioned by a dentist, and splinted to allow healing. You should be seeing your dentist as soon as possible for this.

A chipped or fractured tooth from trauma. Look closely:  if the pulp (the "nerve") is exposed, you'll see bleeding or pink tissue at the centre of the broken area. This needs treatment as soon as possible. If the tooth itself is not very sensitive, treatment is less urgent, but should be arranged promptly.

Any major tooth trauma can cause problems that are not immediately apparent. The root can be fractured without showing, or the blow can cause the tooth to die and eventually abscess - sometimes weeks or months later. Teeth should always be evaluated and radiographed (x-rayed) within a few days for hidden damage.

Localized swelling inside the mouth should be seen if it lasts more than a few days or increases steadily, especially if it's associated with a tooth.

Severe oral swelling that shows outside the mouth is urgent and requires prompt assessment.

Oral swelling that makes it hard to swallow or breathe is an emergency. Go to the hospital immediately.

Mild sensitivity to hot and cold should be checked by your dentist if it persists more than a few weeks.

Severe sensitivity to hot may indicate a tooth that is dying. Call your dentist for an appointment.

Sudden sharp pain on chewing can indicate a crack in the tooth. If left, the tooth may break - see your dentist within a few days.

A broken molar without pain may not be fractured close to the nerve - or the tooth may already be dead (so that there is no longer a nerve present. This should be seen within a few days.

Sensitivity to sweet may indicate that an old filling is starting to leak - letting the sweetness under the filling. Not urgent if there are no other symptoms, but have it checked within a few weeks if it persists.

Sensitivity to hot and cold after a new filling is fairly common (although much less so with the newer filling and bonding materials).  The degree of sensitivity, and how long it lasts, tends to vary with the size and depth of the filling. If it's gradually improving, time will normally solve the problem. If it's steadily increasing, the tooth may be starting to die - call your dentist.

Sensitivity to bite after a new filling is also common. Most often the numbness of local anaesthetic made it difficult for the patient - and the dentist - to get the bite exactly right on the filling, and it needs a simple adjustment. A high bite can make the tooth feel increasingly bruised after a few days, and become increasingly sensitive to bite and to temperature.

A permanent tooth coming behind the baby tooth, or the permanent tooth coming in without the baby tooth falling out, looks urgent but usually isn't. This is very common, and should be seen - but it can usually wait a few weeks.