dr. Wendy stuart

It's 98 degrees outside, the AC is bathing you in cool air, and music from the ice cream truck is filtering down the street. Your first instinct is to grab your wallet, hail the ice cream truck and sink your teeth into a luscious, cold treat. Then you remember that cold foods send you rocketing up to the ceiling. Or maybe cold doesn't bother you, but you wince in pain when you drink a hot or acidic beverage, or when you eat hot or acidic foods. If so, you may have a condition called sensitive teeth.

If either scene describes you, you are not alone. According to Delta Dental Insurance Company, an estimated 45 million people in the US suffer from sensitive teeth. The good news is that sensitive teeth are treatable.

Sensitive teeth typically occur sporadically when you feel a sudden, sharp pain in the tooth or a mild tingling sensation. However, if you experience extreme, constant sensitivity or pain for more than a few days, you may have a more serious condition that needs an immediate call to your dentist. Let's first explore the more typical, non-serious condition called "dentinal sensitivity."

Dentinal sensitivity is not serious and is treatable: As you can see in the illustration, your tooth is composed of layers of material. The outside layer, enamel, is the strongest substance in your body and protects the exposed surface (crown) of your tooth. The next layer, dentine, covers the innermost, center portion of the tooth, the pulp. Pulp is made up of numerous blood vessels and nerves.

Dentine contains thousands of tiny hollow canals that lead from the outermost portion of the dentine down to the pulp. Each canal has a nerve branch in it. Tooth sensitivity occurs when the cementum is worn down and exposes those little canals or tubules and its tiny nerve branch. The tubules provide a pathway for hot, cold or acid foods to stimulate the nerve inside the tubule, race down the nerve into the nerves in the pulp and cause you to wince in momentary pain.

Getting to the root of the problem: To stop the sensitivity, you first have to determine the cause. Here are several common causes of dentinal sensitivity:

Aggressive brushing: Look at your toothbrush. If the bristles go in several different directions, you're brushing too hard. This can wear away your tooth's enamel and cementum. Brushing too vigorously can also wear away your gums and expose the tooth root.

The wrong brush, the wrong way: You should only use a soft-bristle brush held at a 45 degree angle to your gums. Using a hard-bristle brush with a strong-armed brushing technique only makes the problem worse. Brushing horizontally, or in a sawing motion, can wear away tooth enamel, too.

Brushing too quickly: According to the Academy of General Dentistry , most people brush only half as long as they should. You should brush for two to three minutes, and don't forget to floss. Poor hygiene can lead to tooth decay. Poor hygiene can also lead to periodontal disease which will cause the gum to recede and expose the sensitive root.

Bruxism: Constant and forceful clenching and grinding of the teeth puts pressure on the entire tooth structure and can result in cracks and fractures in the teeth. Once the enamel is fractured or worn away, the dentine layer, which houses the outer portion of those hollow canals, is exposed.

Quick fix: A broken or leaking filling lets food seep into the nerves.

Too much of a good thing: Excessive tooth whitening and use of whitening toothpastes with baking soda and peroxide can be a culprit.

Acid burner: Highly acidic foods like citrus fruits, tomatoes, diet colas, and tea can feed the problem. Some mouthwashes are high in acid and may do more damage to the dentine layer.

Now What?: Once you and your dentist have ruled out a more serious problem like an abscess, cavity, or a problem that requires a root canal, there are ways to relieve the pain.

Read the label: Switch to desensitizing toothpaste. Look for one that is approved by the American Dental Association. There are two ingredients you should also look for: potassium nitrate, which can help reduce sensitivity, or strontium chloride, which encourages the minerals in your saliva to crystallize and cover up the canals in your exposed roots.

On guard: Talk to your dentist about getting a nightguard. A nightguard reduces the clenching and grinding pressure.

Rinse away: Your dentist may prescribe a high fluoride mouthwash that will reduce the sensitivity.

Agents of change: Your dentist may apply a "bonding agent" that will close the canals of the tooth root, or rub an "oxalate" compound on the root to reduce the sensitivity.

Lay it on: Your dentist may decide that a crown, filling, inlay, or bonding will be the best solution to the problem. When it comes to sensitive teeth, you don't have to grin and bear it. If you take some simple steps like make sure you're using the proper brushing technique, use a desensitizing toothpaste, go easy on the mouthwash, and wear a nightguard, your teeth should toughen up in no time. Just remember to look both ways when you chase down the ice cream truck.