Generally speaking, pain is a protective response that ranges from minor sensitivity to severe pain and informs the body that something is wrong. As for tooth pain, it is caused by a reaction of the nerves inside a tooth's pulp chamber with the severity dependent upon the type and degree of the stimulus. What follows are some examples of symptoms you may be feeling and their possible causes.
1) Symptom
Sensitivity to hot or cold foods and liquids.
Possible problem:
If discomfort lasts only moments, sensitivity generally does not signal a serious problem. It may be caused by; a small area of decay in a tooth, a loose filling or an exposed root surface resulting from gum recession and possibly toothbrush abrasion.
What to do:
If a root surface is sensitive, keep it clean and free of dental bacterial plaque. Use a soft toothbrush, cleaning very gently at the gum line, and brush no more than twice daily. Try using fluoride-containing toothpaste made for sensitive teeth. You can even try using toothpaste like an ointment, rubbing it into the root surface for ten minutes or so at a time. If the sensitivity continues, see your dentist.
2) Symptom:
Sensitivity to hot or cold foods after dental treatment.
Possible problem:
Dental work may result in tooth sensitivity due to inflammation of the pulp tissues inside a tooth.
What to do: This sensitivity should last no longer then a few days; however, if decay has recently been removed or a filling or crown recently has been placed, a tooth may take a week or two to settle. Mild pain relievers like acetaminophen, aspirin or ibuprofen should help. If the pain persists or worsens, see your dentist.
3) Symptom:
Sharp pain when biting down on food.
Possible problem:
Decay, a loose filling and/or a cracked tooth are possible causes.
What to do: See a dentist to diagnose the problem before the pain worsens. Decay will need to be removed, and a loose filling replaced by your dentist. If the pain is caused by pulp tissue damage, your dentist may send you to an endodontist (“endo” – inside; “dont” – tooth), a specialist who will perform a root canal treatment to clean out the damaged pulp, disinfect the root canal and fill and seal the remaining space to save the tooth. A cracked tooth may be difficult to treat not only if it involves the pulp, but also depending on the location and depth of the crack
4) Symptom:
Lingering pain after eating hot or cold foods and liquids.
Possible problem:
This probably means the pulp is inflamed and/or dying, and may be irreversibly damaged usually as a result of deep decay or physical trauma.
What to do: See your dentist or endodontist to diagnose the problem before the pain becomes severe due to the development of an abscess. The tooth will likely need root canal treatment to remove the dying or dead pulp tissue to save the tooth.
5) Symptom:
Dull ache and pressure in the upper teeth and sinus area of one or both sides.
Possible problem:
Pain felt in the sinus area of the face is often associated with the upper back teeth because they share the same nerves. The origin of this “referred” pain consequently may be difficult to determine. Therefore, sinus pain can feel like tooth pain and vice versa. That's why sinus congestion from a cold or flu can cause pain in the upper teeth. Additionally it's also important to determine if clenching or grinding is a factor, as they too cause similar symptoms.
What to do: See your dentist or endodontist to find out if the symptoms are dentally related; otherwise, you may need to see your family physician. However, don't wait until the pain worsens.