Why are my teeth sensitive?

Having sensitive teeth is more than a minor inconvenience. When cold or sweet foods have an ‘ouch’ factor, it’s time to tell your dentist. Tooth sensitivity may be an initial sign of something more serious.

Sensitivity occurs when the protective enamel shell on the outside of a tooth is damaged, or when receding gums expose the root surface of a tooth to the oral cavity. The root of a tooth does not have the protective enamel layer and is porous, allowing irritants like cold, sweet, stimulation by brushing, etc. to reach the nerve of the tooth which interprets all sensations as pain.

If the enamel of a tooth is damaged through trauma or a habit of clenching and/or grinding your teeth, the underlying material called dentin is exposed to the mouth. Dentin is also porous like the root of a tooth and has the same symptoms mentioned above.

Once you have seen your dentist and the other possible causes ruled out, such as cavities, there are several ways to relieve the discomfort.

Brushing regularly with desensitizing toothpaste is often enough. These toothpastes are designed to plug the porosities in tooth surfaces to prevent irritants from reaching the nerve of the tooth, but they have to be used regularly and you have to avoid foods that undo their protective effect, like acidic and sugary foods.

A fluoride gel applied professionally, or a fluoride rinse used at home will also help as fluoride is able to provide relief similar to the desensitizing toothpastes mentioned, however the protective effect can also be undone by eating acidic and sugary foods.

Another option available that your dentist may recommend is a fluoride varnish, a thick paste with a high concentration of fluoride that’s applied to sensitive teeth every two or three months.

Bonding is a more permanent fix where an insulating layer of tooth-coloured composite resin (filling material) is applied to exposed, sensitive roots. This can provide long-lasting protection from tooth sensitivity provided you use a soft toothbrush, warm water and gentle brushing.

If grinding your teeth at night has caused tooth enamel to wear away, your dentist might suggest making you a close-fitting, thermoplastic night guard to protect your teeth while you sleep.