Full-mouth varnish
All teeth painted, for children and decay-prone adults. Repeated every six months, or more often in high-risk cases.
£40
Preventive dentistry · Wimpole Street, Marylebone
Fluoride treatments in Marylebone: a five-minute varnish that hardens enamel and calms sensitivity
Enamel is constantly losing and regaining mineral. Acid from plaque bacteria and from what we eat and drink pulls calcium and phosphate out; saliva puts them back. Fluoride tips that balance towards repair: it draws mineral back into softened enamel, forms a harder, more acid-resistant surface and interferes with the bacteria themselves. Toothpaste supplies a low daily dose. A professional varnish supplies a far higher concentration, painted directly onto the teeth in a few minutes, where it sets on contact with saliva and releases fluoride for the rest of the day. At Wimpole Street a fluoride varnish application will be £40, usually given twice a year to children and to adults with a high decay rate, exposed roots or a dry mouth, and it is one of the few dental treatments with decades of trial evidence behind it.
- £40 per application
- About 5 minutes
- Usually twice a year
Suitability
Is it right for you?
A good fit when
- Children from around the age of three, and any child who has had decay in baby teeth.
- Adults who develop new cavities most years despite reasonable brushing.
- Exposed root surfaces from recession, which decay faster than enamel and are often sensitive.
- A dry mouth from medication, Sjögren’s or radiotherapy, where saliva’s natural protection is reduced.
- White spot lesions on the enamel, particularly after braces, which varnish can help harden and sometimes fade.
- Sensitivity to cold after whitening or hygiene treatment.
- Anyone wearing aligners or a fixed retainer, where plaque sits against enamel for long periods.
Think twice, or choose another route, when
- The rare individual with a known allergy to colophony, a resin in most varnishes; an alternative product is used.
- Patients with an active mouth ulcer or stomatitis on the day, where it is simply postponed.
- Cavities that have already broken through the enamel; varnish will not repair a hole, only a filling will.
- Anyone expecting a whitening effect; varnish may leave a slight yellowish tint for a few hours and does not change tooth colour.
The process
How it works at Wimpole Street
- 01
Assessment of risk
Decay history, diet, saliva flow, medications and existing recession are reviewed so the varnish is recommended where it will help rather than as a routine add-on.
- 02
Cleaning
Gross plaque is brushed off so the varnish contacts enamel rather than sitting on debris. This can be done immediately after a hygiene visit.
- 03
Drying
The teeth are wiped or gently air-dried so the varnish adheres. They do not need to be perfectly dry, which is what makes varnish suitable for young children.
- 04
Painting
A small brush applies a thin layer of varnish to all tooth surfaces, or to specific exposed roots and sensitive areas, in a couple of minutes.
- 05
Setting
The varnish hardens on contact with saliva into a thin film that stays on the teeth for several hours, releasing fluoride as it goes. You can leave straight away.
Choices
Options & materials
Targeted application
Varnish applied to specific exposed roots, sensitive teeth or white spots, often at the end of a hygiene or whitening appointment.
£40
High-fluoride toothpaste
A prescription-strength paste for daily home use in adults at very high risk, used alongside varnish rather than instead of it.
Prescribed at examination
Fees
What it costs
| Item | Fee |
|---|---|
Fluoride varnish Full mouth or targeted; about five minutes. | £40 |
Children’s examination Varnish is usually applied at the check-up. | £47.50 |
Hygiene appointment Varnish can be added at the end. | £89 |
Fissure sealants Often combined for children’s molars. | £65 per tooth |
Indicative Wimpole Street fees, the same as at South Kensington and St Paul's. A written plan with the exact figure is agreed before anything is started.
Outcomes
What the result looks like
Nothing looks different afterwards, which is rather the point. Over the following months the enamel surface becomes harder and more resistant to acid, early soft spots can re-harden, and sensitive root surfaces usually feel calmer within a few days. Large reviews of trials in children show that regular varnish applications cut new cavities by a substantial margin compared with no varnish, and the effect is greatest in those at highest risk.
Fluoride is a preventive measure, not a repair. It slows and can arrest early decay, but once enamel has cavitated the tooth needs a filling. Its benefit also depends on the rest of the picture: a varnish twice a year cannot compensate for frequent sugar or poor brushing in between.
Afterwards
Looking after the result
- Avoid eating for thirty minutes and hot drinks or alcohol for the rest of the day so the varnish stays on the teeth.
- Do not brush until the following morning; the film should be left to work overnight.
- A slight yellow tint or sticky feel for a few hours is normal and brushes off.
- Continue twice-daily brushing with a fluoride toothpaste, spitting rather than rinsing, so the low daily dose complements the varnish.
- Return at the interval advised, usually six months.
Informed consent
Risks and honest limitations
Every treatment has trade-offs. These are the ones we discuss at the consultation so that a decision is made with full information rather than after the fact.
- A temporary yellowish tinge and a slightly rough or sticky feeling on the teeth for the rest of the day.
- Nausea if a large amount is swallowed, which is why the quantity used in children is small and measured.
- Rare allergic reaction to colophony in the varnish, presenting as swelling or a rash; alternatives exist.
- Varnish does not prevent decay on its own and gives no protection to a tooth that is not being brushed.
- Mild fluorosis, a faint mottling of developing enamel, is associated with excessive fluoride ingestion in early childhood rather than with professionally applied varnish, but we mention it because parents ask.
FAQ
Questions patients ask
Yes, and it is recommended in UK guidance from around the age of three for all children, twice a year, and earlier for those at higher risk. The amount used is tiny and sets quickly, so very little is swallowed.
Toothpaste delivers a low dose every day, which is important. Varnish delivers a concentration many times higher in one application, which hardens enamel more deeply and is particularly useful for exposed roots and early lesions.
Often, yes. Varnish seals the tiny tubules in exposed dentine that transmit cold and sweet sensations. Relief usually appears within days and may need topping up.
It can arrest and partly re-harden very early decay that is still within the enamel. Once the surface has broken down into a hole, a filling is needed.
Adults at high risk of decay or with exposed roots benefit from twice-yearly applications. Adults at low risk with no sensitivity generally do not need it.
Yes, at South Kensington and St Paul’s now at the same £40 fee, with repeat applications in Marylebone from 1 October 2026.
Keep reading
Related treatments and guides
Marylebone, W1
Fluoride treatments at Wimpole Street from 1 October 2026
Register your interest and we will contact you as soon as the Marylebone diary is live. If you would rather start sooner, the same clinicians already see patients in South Kensington and at St Paul’s.
Opening 1 October 2026
Wimpole Street is not yet seeing patients. Until then, please book or call our South Kensington clinic on 020 7183 2362 or our St Paul's clinic on 020 7183 3709. Questions about the new clinic: wimpolestreet@md.co.uk.
Until we open
Need an appointment before 1 October 2026?
The same clinical team already works from two other Medical & Dental clinics. Book at either one now and, if you prefer, move your ongoing care to Wimpole Street once the doors open.
South Kensington
- 20 Old Brompton Road, London SW7 3DL
- Open seven days a week
- 020 7183 2362
St Paul's, City of London
- 5 Ave Maria Lane, London EC4M 7AQ
- Open Monday to Friday
- 020 7183 3709
