Diet

Eating food and drink high in carbohydrates, particularly between meals, will increase your risk of tooth decay.

Tooth decay is often associated with sweet and sticky food and drink, such as chocolate, sweets, sugar and fizzy drinks. Starchy food, such as crisps, white bread, pretzels and biscuits also contain high levels of carbohydrates.

Poor oral hygiene

If you do not regularly brush your teeth, you are at a higher risk of tooth decay. You should brush your teeth at least twice a day.

Smoking

Smokers have a higher chance of developing tooth decay as tobacco smoke interferes with production of saliva, which helps keep the surface of your teeth clean. Studies have also shown passive smoking can be a risk factor, particularly for children.

Dry mouth

People who have lower levels of saliva in their mouth are at higher risk of developing tooth decay, because saliva helps to keep the surface of your teeth clean.

A number of medicines and medical treatments can lower the amount of saliva in your mouth. For example:

• tricyclic antidepressants
• antihistamines (used in the treatment of allergies)
• some antiepileptic medicines
• some antipsychotic medicines
• beta-blockers (used to treat a number of heart conditions)
• radiotherapy 

If you are taking a medicine or receiving treatment known to cause dry mouth, take frequent sips of still, unflavoured water and make sure you have a good oral hygiene routine.