There are many common dental causes of toothaches -- dental abscess, gum disease, irritation of the tooth root -- but by far the most common is the cavity.

Dental Cavities

Dental cavities are basically holes in the hard outer layers of the tooth called the enamel and the dentin.

These two layers do not have any feeling (for the most part) but when a hole gets eaten or worn through them, the inner pulp is exposed.

There is plenty of "feeling" in the pulp, as anyone who has suffered a toothache can tell you.  Without the protection of the enamel certain bacteria in the mouth can "attack" the pulp when the convert simple sugars into acid.

Small shallow cavities that do not sink deep into the pulp may not cause pain and may be unnoticed by the patient. In fact most of us have several "worn" spots at any given time.

But the larger, deeper cavities can can allow the pulp to become irritated by bacterial toxins or by foods that are cold, hot, sour, or sweet.

Toothache from cavities is the most common reason for visits to dentists.

What Can be Done to Ease the Pain of a Toothache?

Treatment of these cavities can range from a dental filling for the smaller and shallower ones to an onlay or crown for the larger ones to even a root canal for the really deep ones that have injured the pulp.

Until you can get proper medical help, you can ease the pain by taking away the source.  In most cases the pain of a toothache is caused by trapped food being converted to acid by bacteria.

So to ease the pain you can wash away the food and bacteria and/or kill the bacteria.

It's not as difficult -- or gross -- as it sounds.  You do it every day.