Why so sensitive? Inside the pain of tooth sensitivity

Nothing can turn you off food like a sharp jolt of tooth pain as you chomp into something hot or cold. So what causes sensitive teeth, and how can you treat it?

Tooth sensitivity refers to a short, sharp stab of pain through one or more of your teeth in response to something hot or cold, explains Dr Michael Foley, of the Australian Dental Association.

“It’s usually pretty quick, pretty sharp then it goes away and returns the next time you eat ice cream or drink a cold can of coke,” he says.

What causes sensitive teeth

Teeth are made up of several layers, designed to protect the nerves that run down the middle of the crown of the tooth to the roots.

“Our root surface, when looked at under a microscope, is entirely covered with pores and channels called dentinal tubules,” says Dr Anna Chau, principal dentist and owner at dhealth Dentistry in Melbourne.

“These dentinal tubules are connected to our nerves living in the centre of each of our teeth.”

Protecting the dentinal tubules is a layer of enamel on the outside of the tooth.

“Mostly your teeth should not be sensitive because they’re protected by that enamel,” says Dr Foley.

“But if that enamel is disrupted, once you lose that outer protection to the teeth you’re much more likely to get sensitivity.”

How does tooth enamel become weak?

There are a number of possible contributors to weakened tooth enamel, says Dr Foley.

Excessive brushing, certain food and drinks (particularly those that are acidic), a cracked or chip tooth, or a tooth cavity can penetrate the enamel in your tooth and expose the nerves to extreme temperatures.

Dr Foley says drinks such as soft drink, beer, wine, or juice can gradually wear away the enamel.

“Most of these drinks are really acidic and they soften the tooth enamel, and over many years it just dissolves.”

Once the enamel is gone it cannot regenerate, but Dr Foley says you can stop it from getting any worse.

Treatments for sensitive teeth

Dr Foley recommends looking at your lifestyle to assess what might be causing the weakening of your tooth enamel.

For example, cut back on acidic or sugary food and drinks, don’t brush too hard, and avoid potential triggers such as cold or hot foods or drink.

The good news is that sensitive teeth can usually be treated fairly easily with sensitive toothpaste.

“There’s a lot of toothpaste designed for sensitive teeth, and they’re all fairly effective,” says Dr Foley.

Dr Chau says sensitive toothpastes have invisible tiny particles that bind and cover the pores or entrances of the dentinal tubules.

“This only offers a short-term relief as the particles fall out with time because of brushing,” he says.

“However, most people use this type of toothpaste long-term to prolong its effectiveness.”

For recurring tooth sensitivity, some dentists offer laser treatment.

“Certain dental lasers can be used to block the patency of the dentinal tubules at the neck of the tooth,” says Dr Chau.

“It is because laser, at a particular wavelength and intensity, creates a thermal effect to ‘melt’ the most superficial surface of our dentine, forming a ‘blanket’ over the rest of the tubules.

“This procedure is done without any local anaesthetics.”

If sensitivity persists, Dr Foley recommends seeing a dentist to investigate more serious causes such as a chipped tooth, worn filling, decay or gum disease.

Written by Claire Burke.