FLUORIDE; Topical versus Systemic


Fluoride is a mineral that is found naturally in soil, water, and foods.  It's concentration in seawater is about 1.3 ppm (parts per million), and typically in freshwater ranges from 0.01 to 0.3 ppm.  Outside of the United States in some area of the world, naturally occurring fluoride is much higher.  Fluoride can also be made in laboratories, which is then commonly added to drinking water, toothpaste, and other various products.


According to the American Dental Association (ADA), American Academy of Pediatric Dentistry (AAPD) and Center for Disease Control (CDC) water fluoridation is the single most effective public health measure to prevent tooth decay.  In the early 1930s, scientists found that people who were brought up in areas with naturally fluoridated water had up to two-thirds fewer cavities compared to those who lived in areas where the water was not fluoridated.  Today, several studies show that water fluoridation reduces tooth decay by 20-40%, even with exposure to other fluoride-containing products, such as fluoride toothpaste. 

If you suspect the water you consume has lower than optimum concentration of fluoride, for example, if you use well water, filters that remove fluoride, or only use non-fluoridated bottled water, fluoride supplementation may be indicated.  Fluoride supplements can be prescribed for at-risk children as drops, lozenges or tablets, with the dose varying with the level of fluoride contained in your water supply and age of the child.  The use of fluoride supplements by pregnant women does not result in any benefit for the baby.


Fluoride is said to protect the teeth in two ways:

  • Protection from demineralization - when bacteria in the mouth combine with sugars they produce acid. This acid can erode tooth enamel and damage our teeth. Fluoride can protect teeth from demineralization that is caused by the acid.

  • Remineralization - if there is already some damage to teeth caused by acid, fluoride accumulates in the demineralized areas and begins strengthening the enamel, a process called remineralization.

According to the National Health Service, fluoride disrupts the process of tooth decay by:

  • altering the structure of the developing enamel so that it is more resistant to acid attack. These structural changes occur as a child's enamel develops (before he/she is seven years old).
  • providing an environment where better quality enamel is formed, which is much more resistant to acid attack
  • reducing the bacteria's (bacteria in plaque) ability to produce acid, a major cause of tooth decay


Almost all public health authorities and medical associations agree that children and adults both can benefit from fluoride.  Systemic Fluoride, which is the fluoride in water and foods, and is ingested, helps in proper development of teeth that are not yet erupted.   Topical fluoride, on the other hand, is the fluoride in tooth paste and fluoride applied to teeth by a dental professional.  Topical fluoride affects the teeth that are already in the mouth.  For children, AAPD (American Academy of Pediatric Dentistry) recommends in-office fluoride application 2-4 times per year, frequency determined based on each child's caries risk assessment.

Several people, especially those at higher risk of tooth decay, benefit from fluoride treatment. This includes individuals who have:

  • A history of tooth decay (cavities)
  • Inadequate oral hygiene
  • Diets that are high in sugars/carbohydrates
  • Snacking habits
  • Bridges, crowns, braces, and appliances
  • Special needs individuals
  • Patients who are on certain medications which affect the oral conditions/flora
  • Certain systemic conditions that directly or indirectly affect the mouth, i.e., acid reflux
  • Patients born prematurely with dental and/or medical implications
  • Individuals with eating disorder
  • Enamel defect
  • Defective restorations
  • exposed roots
  • Familial high caries rate
One example of fluoride varnish with its applicator.

One example of fluoride varnish with its applicator.

In-office Topical Fluorides

In-office fluorides are available as varnishes, gels, foams, and rinses.  They differ by type of fluoride, concentration, and method and length of application.  The selection, use and frequency of use is based on individual patient's caries risk level, assessed by your pediatric dentist who will be able to discuss your child's caries risk level, ADA and AAPD recommendations, product efficacy, clinical support and safety, ease of use and patient preference/tolerance for maximum results.  Fluoride varnishes are becoming more and more popular not only in dental offices but also in pediatric and general medical practices.  Varnishes contain higher fluoride level than other forms of in-office fluorides.  It is of great importance to evaluate all factors involved before applying varnishes to ensure best results attained from the procedure, but most importantly to minimize ingestion which may contribute to fluorosis of permanent teeth amongst other health issues.  These factors are determined through a complete history taking and a thorough evaluation of your child's teeth, diet and home dental care routine.  Once fluoride treatment is indicated by your dentist, a trained personnel can apply the varnish, using dosage guidelines and proper technique.