Sources of Fluoride

"Estimation of the amount of fluoride ingested from all environmental and dietary sources is important so that rational and scientifically sound decisions can be made when guidelines for the use of fluorides are reviewed periodically and modified." (Journal of Dental Research 1992)

Dental Products

Dental products are a major source of fluoride exposure, particularly for children. Fluoridated dental products include toothpastes, mouth rinses, fluoride gels, fluoride varnishes, and fluoride supplements.

How Much Fluoride Are in these Products?

Fluoride Toothpastes (1,000 to 1,500 ppm)

• Over 95% of toothpastes now contain fluoride.
• A single strip of toothpaste covering the length of a child’s brush contains between 0.75 to 1.5 mg of fluoride. This exceeds the amount of fluoride in most prescription fluoride supplements (0.25 to 1.0 mg).
• Many young children swallow over 50% of the paste added to their brush, particularly if they use candy-flavored varieties and if they are not supervised during brushing to ensure they spit and fully rinse. Research has shown that some children swallow more fluoride from toothpaste alone than is recommended from all sources combined.
• Although dentists now recommend that children only use “a pea-sized amount” of toothpaste, many children use more than this, particularly when the toothpaste has bubble gum and watermelon flavors.
• Ingesting toothpaste during childhood is a major risk factor for dental fluorosis, and can also cause symptoms of acute fluoride toxicity (e.g., stomach pain, etc).
• The FDA now requires a poison warning on all fluoride toothpastes sold in the U.S.

Fluoride Mouthrinses (230 ppm)

• Some mouth rinses now contain fluoride.
• A single mL of fluoride mouthrinse contains roughly 0.25 mg of fluoride.
• Between 5 to 15 mL are generally used per rinse, which equates to 1.25 to 3.75 mg of fluoride.
• Little data is available to show how much of the rinse is ingested.

Fluoride Gels (Self-Applied) (5,000 ppm)

• Dentists prescribe self-applied gels to those at high-risk of tooth decay.
• Each mL of gel contains 5 mg of fluoride.
• Without taking extraordinary precaution to limit the amount of gel that is applied and reduce the amount of gel that is ingested, self-application can result in dangerously high fluoride exposures.

Fluoride Gels (Professionally Applied) (12,300 ppm)

• A single mL of gel contains 12.3 mg of fluoride.
• Dentists are now recommended to apply no more than 4 mL when treating children (=49 mg of fluoride), and no more than 8 mL when treating adults (=98 mg of fluoride).
• The highly acidic nature of the gel greatly increases saliva flow, which makes it largely impossible to avoid swallowing large amounts of it. While few measures were used in the past to limit the amount of fluoride ingested, dentists are now advised to use suction devices and to encourage the child to fully rinse and spit at the end of the treatment.
• Even when precautionary measures are taken, children swallow an average of 7.7 mg per treatment
• Adults swallow an average of 10.3 mg per treatment.
• Symptoms of acute fluoride toxicity (e.g., nausea and vomiting) are common in children receiving fluoride gels.
• Although dental researchers only recommend topical fluoride gels for patients with high risk for cavities, surveys have shown that dentists routinely apply gels to most of their patients.

Fluoride Varnishes (22,600 ppm)

• A single mL contains 22.6 mg of fluoride. Dentists apply 0.5 to 1 mL per treatment.
• Since the varnish eventually wears off the teeth, all of the fluoride that is applied (=11.3 to 22.6 mg) is ingested.
• Dentists apply varnishes up to 4 times a year in children with high risk for cavities.

Fluoride Supplements 

• Supplements contain between 0.25 to 1 mg of fluoride per drop, tablet, or lozenge. The amount depends on the age of the child.
• Supplements are available by prescription only. Unlike dietary supplements, fluoride supplements cannot be purchased over the counter.
• Despite being prescribed for over 50 years, the FDA has never approved fluoride supplements as safe or effective.
• The ADA no longer recommends for infants under 6 months of age.
• Supplements were designed to only be used in non-fluoridated areas as a substitute for fluoridated water. Surveys have repeatedly found, however, that some dentists prescribe supplements to children living in fluoridated areas as well.
• Current supplement use greatly increases a child’s risk of developing dental fluorosis, while doing little to prevent tooth decay.