systemic fluoride

Fluoride is the most valuable mineral in the field of dentistry. It is naturally found in the environment and reaches water sources by the process of leaching from the rocks and soils. Clinically, fluoride can be delivered both topically and systemically. Topical fluorides consist of manufactured products in the form of fluoride gel, toothpaste, or mouthwash. These formulations are applied or used directly on the tooth surface.

Systemic fluoride compounds are supplied through a process of fluoridation in water, milk, or salt. Systemic fluoride is usually ingested and incorporated into forming tooth structures during the developmental stages. While both the forms of fluoride may differ in some ways, they equally benefit the health of the teeth. Today’s article will highlight the types of topical and systemic fluoride. Moreover, we will also take a close look at the differences between the two forms.

What is fluoride?

Fluoride is typically an ionic form of fluorine, which is a natural mineral found in water, air, and soil. This compound selectively acts on the hard tissues of the body, such as the bones and teeth. Fluoride in the field of dentistry is popularly known for its preventive and protective properties against dental caries and cavity formation.

Tooth decay is a multifactorial process that occurs over time by demineralization of the tooth enamel. Plaque, bacterial acids, and a high sugar diet are considered as the prime factors to initiate the process of dental caries in the mouth.

Typically, fluoride can be delivered systemically through water fluoridation or topically in the form of toothpaste or gel. In both cases, fluoride helps to remineralize the tooth enamel and make it resistant to acid attack. Furthermore, it slows down the progression of caries and protects the tooth from cavity formation.  (1)

What do you mean by topical fluoride?

Topical fluoride, as the name suggests, is used in direct contact with the tooth surface. It strengthens the tooth and contributes to the reduction of caries incidence. Typically, topical fluoride can be delivered in the following ways –

Self-applied forms

Self-applied forms are commercial fluoride products that can be used at home. Some of them include –

  • Fluoride toothpaste – fluoride toothpaste is the most commonly used oral health product. It acts with the tooth enamel to make it resistant to bacterial acids. Moreover, it reduces plaque formation and growth of harmful bacteria in the mouth. Usually, fluoride toothpaste consists of 1000-1500 ppm of fluoride, which his optimal for caries prevention. (2)
  • Fluoride gel or mouth rinse – fluoride mouth rinse is a concentrated solution that contains around 0.05-0.2% of sodium fluoride compound. Fluoride mouth rinse shares similar protective properties as compared to the toothpaste. It is usually recommended for adults and children above the age of six years. (3)

At-home fluoride kits come in the form of a gel and tray system. In this process, the tray containing the fluoride gel is placed in contact with the teeth on both the arches for 4-5 minutes.

Professionally – applied forms

Professionally applied fluoride formulations come in the form of fluoride gel, foam, or varnish. These formulations contain a high concentration of fluoride as compared to self-applied products (5000-19000 ppm). A dentist or a dental hygienist usually performs fluoride treatments.

Typically, professionally applied fluoride can be used in the form of sodium fluoride or acidulated phosphate fluoride. Fluoride gel and foam can be applied directly or with the help of a disposable tray. The formulation is placed in contact with the teeth for at least four to five minutes. (4) Unlike other formulations, fluoride varnish is painted on the tooth surface and left for one to four minutes.

What is systemic fluoride?

Systemic fluoride is usually ingested by mouth through a community drinking water supply or dietary fluoride supplements. Systemic fluoride mainly helps in forming the tooth structure. However, when present in saliva, it can topically assist in the protection of tooth enamel. Typically, systemic fluoride can be categorized into the following –

Community/school water fluoridation

Water fluoridation usually involves a controlled addition of fluoride into the water supply up to an optimal level that may help in caries prevention. Community water fluoridation slightly differs from the school water fluoridation. Usually, the optimal level of fluoride in community water supply must be within 0.7 – 1.2 parts per million. Keeping the optimal level constant in the community and water supply, fluoride is said to reduce the risk of caries by 40-70% in children and 20-40% in adults. (5)

School water fluoridation requires a higher than average amount of fluoride – about 4.5 times more fluoride in areas where community water fluoridation is not feasible. School water fluoridation accounts for 25-40% decrease in the incidence of dental caries among children.

Salt fluoridation

Salt fluoridation is a process of controlled addition of fluoride in the salt. Usually, two forms of fluoride, namely Sodium or Potassium fluoride, are used in this process. In developed countries, the reduction of dental caries caused by salt fluoridation is parallel to that of water fluoridation.

Milk fluoridation

Like any other fluoridation process, milk fluoridation involves the addition of a measured quantity of fluoride to packages or bottled milk supply. The level of ionized fluoride is relatively low in milk, which is sufficient in protecting the teeth from caries and cavity. (6)

Fluoride supplements

Fluoride supplements come in a wide variety of forms, such as fluoride tablets, drops, and lozenges. These supplements are mainly given to children who are not exposed to other means of systemic fluoride supply.

What is the difference between topical and systemic fluoride?

Now that you are familiar with the two forms of fluoride let us look at some of the differences between them –

  • Systemic fluoride has a continuous effect on the teeth throughout life, while topical fluoride acts only for a shorter duration of time.
  • Systemic fluorides play a role in forming stable tooth structures, while topical fluorides only help in protecting the teeth from acid attack.
  • Usually, a person may not realize the amount of fluoride ingested per day, which can increase the chances of dental fluorosis. Topical fluoride, on the other hand, is used in controlled amounts, which is beneficial for tooth protection only. (7)
  • Professional fluoride treatments require a great deal of patient co-operation and compliance, which is not the case in systemic fluoride supply.
  • Topical fluorides are generally recommended for patients at moderate to high risk of dental caries.
  • Topical fluoride products and treatments are expensive as compared to systemic water fluoridation techniques.

Take away message

Fluoride is an essential mineral that is found naturally in water sources. There is no doubt that fluoride has beneficial properties that protect the teeth and strengthen the enamel increasing the longevity of the tooth in the mouth. Fluoride can be delivered in two forms – systemic and topical fluoride. Systemic fluoride usually has a global distribution in the form of community water fluoridation, salt, and milk fluoridation and dietary fluoride supplements.

Topical fluoride can be delivered in the form of self-applied toothpaste, gel, or mouth rinse. Moreover, professional fluoride treatments are also beneficial in preventing the incidence of dental caries. Although both the forms of fluoride may be equally beneficial to the tooth, there differ in a few aspects. It is best to always keep a check on the daily fluoride intake. Also, follow routine dental check-ups to be aware of the risk of dental caries.