Is Oral Health in the UK Getting Worse? Tooth Decay, Inequality and Your Dentistry Interview

Oral health in the UK is improving slowly for young children but getting worse for adults: 41% of adults in England now have obvious tooth decay, up from 28% in 2009. Five-year-olds in the poorest areas are more than twice as likely to have decay. For dentistry interviews, it's a hot topic and a common role-play theme.

I'm Dr Sonal Gandhi, a dentist and the dentistry admissions lead at TheUKCATPeople. This guide explains what the latest national surveys show, why the gap between richer and poorer areas matters, and how to use it in your dentistry interview, including stations where you advise a patient. Other current topics are in our NHS dentistry hot topics guide.

Is oral health in the UK getting worse?

For adults, yes. The Adult Oral Health Survey 2023, the first in England to examine adults' mouths since 2009, found obvious tooth decay in 41% of adults with natural teeth, up from 28%. That's a large rise in fourteen years, and it sits alongside the trouble people have had getting an NHS appointment.

For young children the picture is better but stuck. The national survey of 5-year-olds found decay in 22.4% of children in 2024, down from 30.9% in 2008. Most of that improvement came before 2015, and the figure then stayed between about 23% and 25% until 2022 before dipping slightly in the latest survey.

These are the key facts to know before an interview:

• Adults: obvious decay rose from 28% in 2009 to 41% in 2023, and 41% of adults with teeth had at least one gum pocket deeper than 3.5mm, a sign of gum disease.
• Five-year-olds: decay fell from 30.9% in 2008 to 22.4% in 2024, with those affected having an average of 3.5 decayed, missing or filled teeth.
• Inequality: 32.2% of 5-year-olds in the most deprived areas had decay, against 13.6% in the least deprived.
• Hospital: tooth decay remains the most common reason children aged 5 to 9 are admitted to hospital in England.
• Access: only 40% of adults in England saw an NHS dentist in the two years to March 2026, and 60% of children were seen in a year.

The table below is most of what you need:

Key Takeaway: Oral health is getting worse for adults and improving only slowly for young children, so the strongest answer separates the two groups and explains that access and deprivation sit behind both.

Why do children in poorer areas have more tooth decay?

Children in the most deprived areas have more decay because the things that protect teeth, such as fluoride toothpaste used twice a day, low-sugar diets, regular check-ups and fluoride in the water, are less common there. Decay is almost entirely preventable, which is why the gap between areas is treated as a health inequality and not bad luck.

The regional gap is wide too: in 2024, 28.7% of 5-year-olds in the North West had decay, compared with 17.5% in the East of England.

The barriers to good oral health that come up most often are:

• Diet: frequent sugary drinks and snacks, often cheaper and easier to buy than healthier options, including sugary drinks given in a bottle or at bedtime.
• Cost: NHS charges in England from April 2026 are £27.90 for a check-up, £76.60 for fillings and £332.10 for crowns or dentures unless a patient is exempt, as our guide to NHS dental bands explains.
• Access: many areas have very few NHS dentists taking on patients, and some people turn to DIY dentistry or treatment abroad instead.
• Knowledge and habits: families may not know that children need a parent to help them brush until about age seven, or that rinsing washes the fluoride away.
• Wider life: shift work, caring duties, dental anxiety and language barriers make appointments harder to keep.

When I talk about this with students, I ask them to link it to the wider idea of the social determinants of health, which our Marmot and health inequalities guide explains well. Tooth decay is one of the clearest examples you can give, because it's measurable, it's preventable and it follows deprivation very closely.

Key Takeaway: Decay follows deprivation because diet, cost, access and habits all stack up against the same families, so prevention has to be targeted where the need is greatest.

Why is tooth decay the top reason young children go into hospital?

Tooth decay is the most common reason children aged 5 to 9 are admitted to hospital in England, because badly decayed teeth often have to be taken out under general anaesthetic. In 2024/25 there were 33,976 decay-related extraction episodes in children and young people aged 0 to 19, up from 30,587 the year before.

Decay caused 86.5% of the extractions in 5 to 9 year olds and cost the NHS about £51.2 million for children and young people aged 0 to 19, and the rate in the most deprived areas was just over three times that in the least deprived.

I find this is the statistic that interviewers respond to most, because it turns a dental issue into a wider NHS one. A child having teeth removed under general anaesthetic misses school, a parent misses work, and a theatre slot is used for something that brushing with fluoride toothpaste and cutting down on sugar could usually have prevented.

Key Takeaway: Child extractions under general anaesthetic show the cost of preventable decay to children, families and hospitals, which makes them a strong example of why prevention matters.

What causes tooth decay, and what is the Stephan curve?

Tooth decay, or dental caries, happens when bacteria in plaque turn sugars into acid, and that acid dissolves minerals out of the enamel and then the dentine underneath. Early decay can be reversed when saliva and fluoride put minerals back, but once a cavity forms the tooth needs a filling or, if it's badly damaged, an extraction.

The Stephan curve, described by Robert Stephan in 1944, plots plaque pH after a sugary food or drink. The pH falls within minutes, and below a critical level of about 5.5 enamel starts to dissolve. Saliva then neutralises the acid, and the pH recovers over roughly 30 to 60 minutes.

The main lesson of the curve is that how often you eat sugar matters as much as how much, because every snack or sip starts a new acid attack. Five small sugary drinks spread across the day keep teeth below the critical pH for far longer than the same sugar taken with one meal.

If you're asked to explain the curve to a patient, I'd suggest dropping the word pH altogether. You could say that every time they have something sugary, their teeth are under attack for about half an hour while the mouth recovers, so keeping sweet things to mealtimes gives their teeth time to repair in between.

Key Takeaway: Decay is acid from plaque bacteria dissolving enamel, and the Stephan curve shows why the frequency of sugar matters as much as the amount.

What are gum disease and tooth erosion?

Gum disease starts as gingivitis, where plaque at the gumline makes the gums red, swollen and likely to bleed when brushed, and it can be reversed with good cleaning. If it continues, it can become periodontitis, where the bone and tissue holding the teeth are lost, pockets form around the teeth and teeth can eventually loosen.

Gum disease matters beyond the mouth. People with diabetes have more gum disease, and a 2022 Cochrane review found that treating gum disease lowered long-term blood sugar (HbA1c) by about 0.4 percentage points after three to four months. Links with heart disease are reported too, but the evidence that gum treatment prevents heart problems is still inconclusive.

Tooth erosion is different from decay because no bacteria are involved: acid from fizzy drinks, squash, fruit juice or stomach reflux dissolves the enamel directly. In the last national children's survey in 2013, about a third of 5-year-olds had wear on the outer surfaces of their front baby teeth, mostly from erosion.

Dentists also check for mouth cancer at every examination, because smoking or chewing tobacco, heavy drinking and HPV infection all raise the risk.

Key Takeaway: Gum disease, erosion and mouth cancer show that a dental check-up is about the whole mouth and links to general health, especially diabetes.

What does Delivering Better Oral Health advise?

Delivering Better Oral Health is the national, evidence-based toolkit that tells dental teams in England what prevention advice to give. Its summary guidance tables are the source for the advice below, and they are what you would be expected to give in a patient role play.

The rest of the advice is the same for almost everyone:

• Brush twice a day: including last thing at night, for about two minutes, reaching every surface and the gumline.
• Spit, do not rinse: so the fluoride from the toothpaste stays on the teeth for longer.
• Cut down on sugar: both the amount and how often, and keep sugary food and drinks away from bedtime.
• Fluoride varnish: applied by the dental team twice a year from age 3, and two or more times a year for children at higher risk.
• Start early: the NHS advises taking children to the dentist when their first milk teeth appear, and certainly before their first birthday.

Parents often ask me whether fruit juice and smoothies are healthy for teeth. They contain free sugars and acid, so keep them to mealtimes and give water or milk between meals.

Key Takeaway: Fluoride toothpaste twice a day, spitting without rinsing, less frequent sugar and regular varnish are the core of evidence-based prevention, and they are what a patient role play expects you to explain.

What is being done to improve oral health in the UK?

The main programme in England is supervised toothbrushing, announced in March 2025 with £11 million for 3 to 5 year olds in nurseries and schools in the most deprived areas. It aims to reach up to 600,000 children a year, and the government estimates that every £1 spent saves £3.

Scotland has run supervised toothbrushing in nurseries for much longer as part of its Childsmile programme. A 2015 evaluation found that the cost of treating decay in 5-year-olds fell by 54% between 2001/02 and 2009/10, which is a useful piece of evidence that prevention can save money as well as teeth.

You can also mention the Soft Drinks Industry Levy from 2018, which one study linked to 12.1% fewer decay-related extractions than expected (an association, with no control group), the 2026 NHS dental contract reforms, which pay better for fissure sealants and fluoride varnish for children, and water fluoridation, which is being expanded in the North East of England.

Key Takeaway: Prevention programmes such as supervised toothbrushing, the sugar levy and fluoridation have good evidence behind them, but access to NHS dentists still limits progress, especially for adults.

How can I talk about oral health in my dentistry interview?

Oral health comes up in two ways: as a discussion question about the state of NHS dentistry, and as a role play or practical station where you advise a patient or explain something in everyday words.

For the discussion, think back to your work experience: a dentist explaining brushing to a child, a patient who hadn't been seen for years, or a prevention leaflet in the waiting room. You can also use a part-time job or volunteering where you explained something to someone younger.

A simple way to structure a discussion answer is:

1. Say what the problem is in one sentence, for example that decay is falling slowly in children but rising in adults.
2. Give one or two figures, such as the deprivation gap or child hospital extractions.
3. Explain the causes, linking diet, fluoride, cost and access.
4. Weigh what is being done, including prevention schemes and the contract reforms, and say what you think would help most.
5. Finish with what it means for you as a future dentist, such as a focus on prevention and communication.

For a patient role play, the same advice applies whether the patient is an adult with bleeding gums or a parent worried about a child with decay:

• Ask before you advise: find out what they already do, what they eat and drink, and what worries them, before giving any advice.
• Use plain words: say 'germs' or 'plaque' and 'acid attacks', and check they understand by asking them to tell you their plan.
• Stay kind: avoid blaming a parent or patient, and give one or two realistic changes instead of a long list.
• Know your limits: as a student, say you would check with the dentist or supervisor before making any clinical decision.

For a station with a graph or table of decay rates, the techniques in our data interpretation guide apply directly. If you want to practise these role plays out loud, our dentistry interview tutors run them as mock stations.

Interviewers are usually looking for:

• Whether you understand prevention and why it matters more than treatment.
• Whether you can explain a scientific idea to a patient without jargon.
• Whether you can talk about inequality sensitively and without judging people.
• Whether you know your limits as a student and put the patient first, in line with the GDC standards.

Key Takeaway: Treat oral health as both a discussion topic and a communication test, and practise explaining decay and brushing to a child, a parent and an adult.

Example interview questions on oral health

You are unlikely to be asked any of these word for word, and you do not need a prepared answer to each one. Use them to check your understanding: if you could speak for a minute on most of them, you know this topic well enough for whatever the interviewer actually asks.

Questions to get you thinking

1. Is oral health in the UK getting better or worse?
2. Why do children in deprived areas have more tooth decay?
3. How would you explain tooth decay to a seven-year-old?
4. A patient says their gums bleed when they brush. What advice would you give?
5. What did you learn about prevention during your work experience?
6. How would you plan a short talk about teeth for a class of young children?

Harder questions to stretch you

1. Should the NHS spend more on prevention, even if it means less money for treatment?
2. A parent is upset that their child needs teeth taken out. Who is responsible for a child’s oral health?
3. Describe this graph of plaque pH after a sugary drink, and explain what it means for a patient.
4. Why might adult tooth decay have risen since 2009?

Model answer: "A parent brings in their six-year-old, who has several decayed teeth. How would you approach this?"

"First, I'd remember that as a dental student I'd be working under a supervising dentist, so I'd make sure they were involved in any decisions about treatment. My priority would be the child's comfort, so I'd check whether they were in any pain and make sure that was dealt with.

Then I'd want to understand the situation before giving any advice. I'd ask the parent, calmly and without judging, about the child's brushing routine, their toothpaste, what the child usually eats and drinks, and whether anything had made it hard to come to the dentist. Many parents feel guilty here, so I'd want them to feel supported.

Next, I'd explain in plain words that decay comes from sugar turning into acid on the teeth, and that how often sugary things are eaten matters a lot. Then I'd agree one or two realistic changes, such as brushing twice a day with a pea-sized amount of family fluoride toothpaste, spitting without rinsing, and keeping sweet drinks to mealtimes.

I'd check they understood by asking them to tell me their plan, and I'd mention that the dental team can apply fluoride varnish to help protect the teeth. Finally, I'd make sure a follow-up appointment was booked so we could see how things were going."

Why this answer works:

• It puts the child first and recognises the limits of a dental student’s role.
• It listens before advising, which is how the best patient conversations work.
• It uses accurate, evidence-based advice from Delivering Better Oral Health, explained without jargon.
• It treats the parent with empathy and plans follow-up, showing long-term care.

Key Takeaway: In a role play, listen first, explain in plain words, agree small realistic changes and plan follow-up, all within your role as a student.

What's the one thing to remember about UK oral health?

If you remember one thing, make it this: tooth decay is largely preventable, yet it's rising in adults and still sends tens of thousands of children to hospital, mostly in the poorest areas, so prevention and access are the two levers that matter most.

Related topics: the 9 GDC principles and our 230 dentistry interview questions will help you practise this topic alongside the rest of NHS dentistry.

Key Takeaway: Decay is preventable but unequal, and a future dentist should care about prevention and access as much as treatment.