What are the Topical Sources of Fluoride?

Topical sources of fluoride can either be given at the dentist or by yourself at home. In the dental surgery, they must be more carefully applied and monitored because dentist fluorides are more highly concentrated.

  • Dentist Fluorides (20-40% less dental caries). There are a few different types of gels, solutions, foams, and varnishes available at the dentist; each containing different amounts of fluoride and suitable for slightly different situations.

(i) Prophy paste- The standard polishing pastes used at the dentist to polish your teeth have concentrations of fluoride ranging from 4000- 20,000 ppm, (much higher than a standard toothpaste) but they serve in more of a polishing role for stain removal, than as a topical fluoride application.

(ii) Fluoride gels and foams- A fluoride application in a foam tray often contains 12,300 PPM that is 8-10 times stronger than toothpaste. This is routinely given to patients following a scale and polish and has the most benefit in children and those with moderate to high caries risk. This coats all the teeth and is not rinsed off for half an hour- which means nothing to eat or drink!

(iii) Fluoride varnishes- A high fluoride varnish such as duraphat contains 23,000 PPM (pretty high!) and this may be used in areas of early caries to help remineralisation, or to put into the pits and fissures of vulnerable developing back teeth if, that is, moisture control is too difficult to place a dental sealant well. It is also good on exposed roots at risk of caries. Because of the very high concentration it should only be used directly in areas of problems or potential problems and care is needed in young children.

  • Topical fluoride gels for application by you- the patient. If you are very high risk for dental caries, then your dentist may advise topical applications in your own custom-made trays. Impressions are made of your teeth and the stone casts that result are used to make custom fitting trays very similar to the ones you would use for teeth bleaching. Fluoride can be put in these trays and they can be worn over night a few nights a week. Your dentist will be able to advise you on the best fluoride to put in the trays and how often to do it. Options tend to be:

(i) Sodium fluoride (5000ppm F-)

(ii) Acidulated phosphate fluoride (5000ppm F-)

(iii) Stannous Fluoride (1000ppm F-)

These can be particularly useful for:

- Orthodontic braces

- Rampant caries -rapidly progressing dental caries

- Xerostomia due to salivary gland disease or head and neck radiotherapy

- Root caries

- Continuing caries- where despite best efforts, other less intense forms of fluoride application haven’t been successful.

  • Mouthwashes- (15-50% less dental caries)

(i) These should be avoided in children under seven because the chance is too high, that they will forget to spit it out and thus swallow it.

(ii) The daily rinses are probably the most effective and contain about 0.05% fluoride (230ppm). Weekly or fortnightly mouth rinses at 0.2% (900ppm) are also available.

(iii) Fluoride rinses probably only have a significant effect if you are at an increased risk of dental caries and certainly should not be substituted for brushing with a fluoride toothpaste- you need to do both.

They are useful for:

- Orthodontic patients- as a good alternative (or supplement) to foam tray applications if you are having orthodontic treatment.

- Moderate to high caries risk

- Patients at risk of root caries

- Early enamel caries- - If you have evidence of caries that is confined to the enamel which you are attempting arrest.

- Partial denture wearers

- Patients with xerostomia

It is most useful to use mouthwash when the permanent premolars and molars erupt, usually between the ages of 10 and 13.


(i) Rinse with 10ml for one minute and spit out- do not swallow!

(ii) When rinsing with a fluoride mouth wash, try and swish it in and around all your teeth paying particular attention to forcing it in between your teeth . It is best used away from tooth brushing, where possible. Certainly don’t swallow it and as always with any type of fluoride application, try to wait 30 minutes before eating and drinking to get the maximum benefit.

The amount of fluoride that stays in the mouth following rinsing is unlikely to cause fluorosis, though it does depend on the other sources of fluoride you are having and the total amount that is taken in.

I prefer mouth rinses without alcohol ,so if available I would recommend choosing this option.

  • Fillings
Glass ionomer cements are one of our white filling materials that are able to act like a fluoride reservoir; storing fluoride when it's in the mouth and releasing it slowly over a long period. They allow fluoride to be absorbed into the surrounding tooth and whilst they don't provide the most aesthetic (good looking) restoration, they are very useful in preventing decay in areas not critical to your smile. They are useful in treating root caries, cementing in crowns and some other restorations, as they prevent dental caries occurring around the margins.

  • Chewing gum
In certain countries, chewing gums containing fluoride are available. I know they are available in Sweden but I personally haven’t seen any in Australia or the UK. Assuming that they contain appropriate concentrations and are not chewed for extended periods, some good benefits are likely to be found for moderate to high risk patients, adding fluoride to the extra saliva that chewing stimulates.

  • Floss
Floss impregnated with fluoride is great if you can get it- unfortunately it's not always readily available. An alternative, in the mean time, a good substitution is to simply wipe a bit of fluoride toothpaste on to your floss. This gets fluoride to where it is needed most; in-between your teeth. If I find on bitewing radiographs that a patient has numerous early enamel-confined caries lesions, this is one of the first things I will recommend.

  • Toothpastes (15-30%)
Toothpastes have several benefits, perhaps the biggest and most important is that they contain fluoride and when you brush you're massaging this gently, (or not so gently for some of you) into the surface of your teeth.

They are the main reason we have less dental caries today than 30 years ago. The effect on reducing caries is about 15% in fluoridated areas, that’s half the effect it has compared to non-fluoridated areas where the extra benefit is clear.

Studies have shown that rinsing straight after brushing will actually reduce the benefits of fluoride on stopping decay. So spit away, but if rinsing- it is best to re-apply a fresh bit of toothpaste after.

There's really no firm evidence to recommend one type of fluoride toothpaste over another- except for the different concentrations they come in. Tooth pastes come in four basic fluoride concentrations:

(i) Babies (Children under two)- no fluoride toothpastes

(ii) Child- Child preparations with low fluoride are available (under 500 ppm) in case the child swallows any paste and to reduce the risk of mottling in the developing teeth. Some evidence suggests that these concentrations are less effective than 1000pm and as such should be saved for children who are at low caries risk- instead drink fluoridated water or take the appropriate supplements.

(iii) Adult- Adult tooth pastes contain 1000-1450ppm. Even though they say adult, these toothpastes should be used by all children over the age of 6.

(iv) High Fluoride- More concentrated fluorides over 1500ppm are available for high caries risk patients on the advice of their dentist.