How to prevent tooth decay

The government’s oral health toolkit for dental teams describes tooth decay as very common in the UK and worldwide, and as largely preventable. Most of the habits below are everyday advice that UK guidance gives to everyone, and brushing takes about 2 minutes, twice a day.

How does tooth decay start?

Plaque is a sticky film of bacteria that coats your teeth. The toolkit explains that these bacteria break down sugars from what you eat and drink, and produce acids. Over time, the acids pull minerals out of the tooth enamel. Teeth can also take minerals back up, and the toolkit says decay can be reversed in its early stages. If the loss keeps outpacing the repair, the surface of the tooth breaks down and a hole, called a cavity, forms.

The toolkit lists the main risk factors you can change as having too much sugar too often and too little fluoride. The NHS adds not cleaning your teeth and gums regularly. Adults get decay too, because new decay can develop at any age. It may cause no symptoms at first, according to the NHS, so you cannot rely on feeling it.

Brush with fluoride toothpaste, twice a day

For preventing decay, the government toolkit says the fluoride in toothpaste is the most important part of brushing. A 2019 Cochrane review of 96 studies found that brushing with fluoride toothpaste reduces decay compared with toothpaste that has no fluoride. The reviewers add that evidence comparing different fluoride strengths is more limited. The NHS routine is:

• Brush for about 2 minutes, twice a day: last thing before bed, which the NHS says is important, and at one other time.
• Clean the inside, outside and chewing surfaces of all your teeth.
• Spit out the excess toothpaste and do not rinse with water straight away. Rinsing washes away the concentrated fluoride left on your teeth.
• Check the packaging for the fluoride level. The NHS says adults should use a toothpaste with at least 1,350 parts per million (ppm) fluoride, and that your dentist may advise a higher strength if you need it.

The toolkit warns that some toothpastes sold in the UK contain no fluoride, so it is worth reading the box rather than assuming. It also links brushing twice a day, rather than once, with less decay.

Manual or electric? The NHS says they are equally good, as long as you clean every surface and use fluoride toothpaste. The toolkit says powered brushes reduce plaque and gum inflammation more, but calls the clinical relevance unclear. It says teeth can be cleaned effectively with either type, and that there is no evidence on whether powered brushes prevent decay better.

Clean between your teeth

The NHS advises cleaning between your teeth every day with floss or interdental brushes. It says regular flossing may reduce gum disease, tooth decay and bad breath by removing plaque along the gum line. Interdental brushes, which should fit snugly between your teeth, are an alternative to floss, especially if you have gaps. The NHS advises against wooden toothpicks, which may damage your gums.

On decay specifically, the toolkit is more cautious. The trials behind interdental cleaning measured plaque and gum inflammation rather than decay. So it says there is no evidence either way on whether cleaning between the teeth reduces decay compared with brushing alone. It still recommends doing it daily, because healthy gums depend on removing plaque from those spaces. Your dentist or hygienist can show you which tool suits your teeth.

Sugar, medicines and other habits

The NHS advises against having too much sugary food and drink. Our guide to sugar and your teeth covers the UK daily limits and practical swaps.

Medicines can contain sugar too. The NHS advises using sugar-free medicines, so ask your pharmacist or GP whether a sugar-free version exists for a medicine you or your child take. Keep taking any prescribed medicine unless a pharmacist or doctor tells you to change it.

The NHS also lists not smoking, and not regularly drinking more than 14 units of alcohol a week, among its advice. Our guide to smoking and your mouth looks at the first.

Fluoride mouthwash and extra protection

A mouthwash containing fluoride can help prevent decay, the NHS says, but not straight after brushing, because it would wash away the fluoride left by the toothpaste. Choose a different time, such as after lunch, and avoid eating or drinking for 30 minutes afterwards. The toolkit says a daily fluoride mouthwash can be considered for people aged 8 and over.

Some people are more likely to get decay. The toolkit says past decay is a good predictor of future decay, and its higher-risk groups include some children, people with certain medical conditions or disabilities, and some older adults. It also says certain medicines can reduce the flow of saliva, which raises the risk, so ask your pharmacist or GP if you are unsure about a medicine you take. Our guide to dry mouth explains more.

For people at higher risk, the toolkit lists extra steps a dentist can consider. These are a daily fluoride mouthwash for anyone aged 8 and over, fluoride varnish put on by the dental team, and a higher-strength toothpaste on prescription. Whether any of these suits you is a conversation with your dentist.

What about children?

Young children need help with brushing. The NHS advises a smear of toothpaste under 3 and a pea-sized amount from 3 to 6. It says children need help or supervision until at least 7, and should not lick or eat toothpaste from the tube.

Check the fluoride level on the box. The NHS says children of any age can use family toothpaste with 1,350 to 1,500ppm fluoride. Children aged 3 and under who do not have decay can use a lower-strength children’s toothpaste, as long as it has at least 1,000ppm. Ask your dentist if you are unsure which toothpaste suits your child.

The toolkit also describes two treatments from the dental team. It strongly recommends fluoride varnish whenever a child visits the dentist. It also strongly recommends fissure sealants, a thin resin coating on the back teeth, for children their dentist judges to be at higher risk. Your dentist can tell you whether either suits your child. Our guide to oral health and your children is written for parents.

How often should you see a dentist?

The NHS says to have regular check-ups even if you have no problems. Many people assume every 6 months is the rule. The NHS says instead that your dentist should suggest your next visit, based on how healthy your teeth and gums are and your risk of future problems. The gap can be as short as 3 months or as long as 2 years, or up to 1 year if you are under 18.

The toolkit adds that there is no evidence that one particular interval changes how decay develops or progresses, and that the interval should be based on risk. At each check-up, the NHS says, your dentist should examine your teeth, gums and mouth, and advise on diet, smoking, alcohol and teeth cleaning.

When to see a dentist

A dental abscess is a build-up of pus caused by an infection, and decay is one cause. The NHS says to call 999 or go to A&E if you:

If you think you have a dental abscess, the NHS says to ask for an urgent dentist appointment or get help from NHS 111. Signs include intense pain, a swollen face or jaw, or a high temperature. The NHS says an abscess will not go away on its own. It also says not to go to a GP surgery, as they cannot give dental treatment.

Otherwise, the NHS says to see a dentist if any of these apply:

What we would do

If it has been a while, a new patient exam is the first step. We examine your teeth, gums and soft tissues, take small X-rays where needed to check for decay between teeth or below the gumline, and explain any options in plain language.

A dental hygiene appointment starts with an assessment of your gums. Then comes a clean and scale to remove trapped plaque, and a polish, with professional advice on your own brushing and flossing routine. If a check-up finds decay that has made a hole, a filling rebuilds the tooth with tooth-coloured composite, and treating decay early means a smaller filling and a simpler visit.

To talk through how to protect your own teeth, book an appointment at whichever of our five practices suits you.

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