You need to systematically go round all the surfaces of your teeth with fluoride toothpaste, for at least two minutes, twice a day. Unfortunately, we live such busy lives that putting two minutes aside feels like a lifetime for some people.

Your teeth tend to be a bit softer just after eating, so wait at least half an hour. Then brush all along the gum line with a little scrubbing action. Don’t press too hard, or to be too light.

It is very important that you remove the bacteria – the dental plaque – from your teeth. If you don’t remove that, your gums will get irritated, then bleed. Some people think this means they need to let them heal, but all that happens is the bacteria stay on your teeth. If you want to be sure you’re doing it effectively, buy some plaque-disclosing tablets from the chemist, which will stain the bacteria that remain.

There is some evidence that small-headed electric toothbrushes tend to be a bit better than manual brushes – but make sure you still use them in a systematic way.

Brushing your teeth fights gum disease; fluoride toothpaste stops the decay. Spit the toothpaste out but don’t rinse out. Mouthwash by itself is not going to do the job that brushing with toothpaste does. If you do want to use mouthwash, again spit rather than rinse.

Ask your dentist or hygienist about flossing. For most people, good brushing will be enough. Others may be more susceptible to gum disease and have to do more, such as using interdental brushes (for gaps between teeth) and floss (where your teeth have tight contact).

Prof Damien Walmsley is a scientific adviser to the British Dental Association. He was talking to Emine Saner