Fluoride and Kids – What Works and How Much?

Dental caries rate in children and adolescents have generally not changed over the last 50 years. This is despite the widespread use of fluoride containing toothpastes and fluoridated water. Throughout this time there has been around a 700% increase in sugar consumption.

When looking at this issue, the question is where would we be without fluoride? Probably with a far higher caries rate than 1 in 2 children… This post will address fluoride use in dental practices.

Fluoride works post-eruptively by reducing the dissolution of enamel and remineralising enamel when there is less available calcium and phosphate ions. Essentially, it means that it makes teeth more resistant to acid attack and they can remineralise quicker.(1) In very high concentrations, fluoride is also antibacterial.

There have been numerous high-quality studies looking into the success and safety of fluoride and we won’t go into too much detail on this. What is relevant is what you should use in your practice and what you should recommend for children.

What About the Risk of Fluorosis?

Fluorosis, is the main concern for us and parents when prescribing a toothpaste. With fluoridated water at ~1.0ppm, approximately 10 - 15% of the population will develop fluorosis that is of a mild or very mild nature and not an aesthetic concern.(2)  As such, the reduction in caries rates, far outweighs these minor consequences.(2)

Cochrane 2015

When using a fluoride toothpaste on a young child, it is inevitable that they will ingest some fluoride. Below, you will find recommendations on dosages and strengths of toothpaste that should help to avoid any significant problems. Children should be supervised until at least 7 years of age with oral hygiene procedures. Also, as with all medications, fluoride toothpastes should be placed in a safe place where hungry children can’t get access to it.

What Strength Toothpaste Should You Use and How Much?

In Australia, there are a dizzying array of toothpastes available and it can be hard to know what to use. The strength of toothpaste to achieve a reasonable anti-cariogenic effect needs to be 1000ppm or above, with toothpastes containing 1450ppm found to be superior compared to 1000ppm.(3)

In Australia, most of the under 6yo children’s toothpastes contain 600ppm of fluoride or less. Interestingly, there is not a great deal of evidence this is more effective than a non-fluoridated toothpaste.(3) As such, in our practice we recommend that as soon as a tooth is present in the mouth a 1000ppm toothpaste should be used under supervision. Common commercial toothpastes with this that are not too ‘spicy’ include; Maclean’s Little Teeth (1000ppm) and Colgate’s Minion Toothpaste (1000ppm), amongst others.(3)

For children 0 – 3 years, this is where the most supervision is required as the permanent teeth are forming and at greatest risk of fluorosis. A grain of rice size of 1000ppm toothpaste is recommended.(3, 4)

For children 3 – 5 years, there is a progressively lower risk of fluorosis being an aesthetic concern. It is recommended to use a pea size amount of 1000ppm toothpaste.(3, 4) If the child had carious lesions, or is at high risk of caries, we would increase the strength to 1450ppm.

For Children 6 years and older, they are given the same instructions as adults. That is; 1450ppm toothpaste and slightly more than a pea size amount.(3, 4)

In extreme caries risk patients, or those with special health care needs, we may recommend a 5000ppm toothpaste. Interestingly, the jury is out if there is any substantial benefit of exceeding 2800ppm.(3, 4) However, if the child/adolescent/adult can spit we would still recommend its use.

What Professional Fluoride Should You Use?

Several Cochrane reviews have looked at the effectiveness of professional fluoride in children, adolescents and adults. In the case of varnishes, there was a reduction in caries of 43% in the permanent dentition and 37% in the primary dentition, when used at least twice per year. This is quite frankly amazing.(5, 6) When a combination of agents are used; such as varnish/gel and mouthrinse and toothpaste, there was a greater reduction in caries than one used by itself.(5, 6)

In children, it is not recommended and there is no good evidence for the use of gels or rinses. As such, fluoride varnish is the most appropriate to use in your practice. It can be applied 2 – 4 times per year depending upon the risk factors for the child.(4, 6)

We hope this summary has been of some help to you. We are happy to share with you the information sheets we have created to give to our parents. Please enter your details below and we will email these to you.

As always, we hope you are well

Cheers

Sarah and Tim

References

1.            Dawes C. What is the critical pH and why does a tooth dissolve in acid? J Can Dent Assoc 2003;69:722-724.

2.            Iheozor‐Ejiofor Z, Worthington HV, Walsh T, et al. Water fluoridation for the prevention of dental caries. Cochrane Database of Systematic Reviews 2015.

3.            Walsh T, Worthington HV, Glenny AM, Marinho VCC, Jeroncic A. Fluoride toothpastes of different concentrations for preventing dental caries. Cochrane Database of Systematic Reviews 2019.

4.            Toumba KJ, Twetman S, Splieth C, Parnell C, van Loveren C, Lygidakis NΑ. Guidelines on the use of fluoride for caries prevention in children: an updated EAPD policy document. European Archives of Paediatric Dentistry 2019.

5.            Marinho VCC, Worthington HV, Walsh T, Clarkson JE. Fluoride varnishes for preventing dental caries in children and adolescents. Cochrane Database of Systematic Reviews 2013.

6.            Marinho VCC, Worthington HV, Walsh T, Chong LY. Fluoride gels for preventing dental caries in children and adolescents. Cochrane Database of Systematic Reviews 2015.