Preventing tooth decay 

Maintaining good oral hygiene through brushing and flossing your teeth is one of the most effective ways to prevent tooth decay.

Some simple changes your diet can also help.


Brush your teeth for at least two minutes last thing at night before you go to bed and on one other occasion every day. Apart from bedtime, it doesn't really matter when the other time you brush your teeth is – providing it's at least an hour after you last ate.

Don't brush your teeth straight after a meal as it can damage your teeth, especially if you've had fruit, fizzy drinks, wine or any other food that contains acid. Leaving an hour will give your saliva a chance to neutralise the acid.

It is also important you brush your teeth in the right way. The following advice may help:

  • Place the head of your toothbrush against your teeth, then tilt the bristle tips to a 45 degree angle against the gum line. Move the brush in small circular movements, several times, on all the surfaces of every tooth.
  • Brush the outer surfaces of each tooth, upper and lower, keeping the bristles angled against the gum line.
  • Use the same method on the inside surfaces of all your teeth.
  • Brush the chewing surfaces of the teeth.
  • To clean the inside surfaces of the front teeth, tilt the brush vertically and make several small circular strokes with the front part of the brush.
  • Brushing your tongue will freshen your breath and clean your mouth by removing bacteria.
  • Do not rinse your mouth with water or mouthwash after brushing as this washes the protective toothpaste away. Just spit out excess toothpaste.
  • Try not to eat or drink anything for 30 minutes after brushing.

It is important to replace your toothbrush on a regular basis because they wear out and become less effective in removing plaque. Most toothbrushes need to be replaced every two to three months.

It doesn't matter whether you use an electric or manual toothbrush. They're both equally as good, providing you brush with them properly. However, some people find it easier to clean their teeth thoroughly with an electric toothbrush.


Flossing is an important part of oral hygiene. It removes plaque and food particles from between your teeth and under the gum line, where a toothbrush cannot always reach.

You should ideally clean between your teeth at least once a day with floss. This can be done before or after brushing your teeth at night.

Your dentist or hygienist can advise you on flossing techniques, but the following tips may help:

  • Take 12-18 inches (30-45cm) of floss and grasp it so you have a couple of inches of floss taut between your hands.
  • Slip the floss gently between the teeth and into the area between your teeth and gums, as far as it will go.
  • Floss with 8-10 strokes, up and down between each tooth, to dislodge food and plaque.

You can use interdental brushes instead of flossing, especially if your teeth are very close together and you find it difficult to manoeuvre dental floss through the gap.


Using an alcohol-free dental mouthwash that contains fluoride can also help prevent tooth decay.

However, this should not be used directly after brushing your teeth. Choose a separate time to use mouthwash, such as after lunch. Do not eat or drink for 30 minutes after using a fluoride mouthwash.


Limiting the amount of sugar you eat and drink is important to prevent tooth decay and also has wider benefits for your general health. Have sugary food and drink only at mealtimes and don't eat sugary snacks between meals.

Most of the sugars we eat and drink are contained in processed and ready-made food and drinks. These include:

  • sweets, chocolate, cakes and biscuits
  • buns, pastries and fruit pies
  • sponge puddings and other puddings
  • table sugar added to food or drinks, such as tea
  • sugary breakfast cereals
  • jams, marmalades and honey
  • ice cream
  • dried fruit or fruit in syrup
  • syrups and sweet sauces
  • sugary drinks, including soft drinks, fizzy drinks, milkshakes, alcoholic drinks and fruit juice

Healthier alternatives for snacks and drinks include cheese, fruit and vegetables, and unsweetened tea or coffee. Some artificial sweeteners have been shown not to contribute to toothy decay, so they may be a good alternative if you like to add sugar to any foods or drinks.

Chewing sugar-free gum after you have eaten may also help prevent tooth decay. When you chew gum, your mouth produces saliva, which neutralises the acid in your mouth before it can damage your teeth.

Some medicines can contain sugar too, so you should ideally use sugar-free alternatives whenever possible. Your GP or pharmacist should be able to advise you about this.

Read more about lifestyle tips for healthy teeth.

Checking food labels

Check labels on foods to see how much sugar they contain. Sugar comes in many forms, so look out for the following ingredients:

  • glucose
  • sucrose
  • honey
  • dextrose
  • maltose
  • fructose
  • hydrolysed starch or syrup

Ingredients are usually listed in order of the amount used, with the main ingredient listed first. If sugar, or one of the ingredients above, is near the top of the ingredients list, it may mean the food is high in sugar.

Some products also use the traffic light system as part of their labelling to indicate whether they are high or low in sugar, where a red light indicates a high amount of sugar and a green light indicates a low amount of sugar.

In general, high in sugar means more than 15g of sugar for every 100g of product and low in sugar means less than 5g of sugar for every 100g.

Read more about eating a healthy, balanced diet and reading food labels.

Page last reviewed: 30/05/2014

Next review due: 30/05/2016