Fluoride is a chemical compound based on fluorine. The fluorine (gas) is hardly presented in a pure form. It connects very quickly with other elements. If fluorine connected with another element, it called fluoride with giving the name of partner element. For example, when fluorine connects with sodium, this compound name is sodium fluoride.
As a natural component of our body, fluoride plays an important role in the construction and maintenance of bones and teeth. Tooth enamel is the hardest substance in the human body. the enamel contains a micro-fine crystal (hydroxyapatite) which embeds inorganic substances, eg: magnesium, sodium, and potassium. When acids attack the tooth, these substances are released, and tooth enamel surface became porous and a favorable place for bacteria colonization and metabolism which can cause dental caries. Fluoride can counteract this process.
It is not a recent discovery. In 1802, a researcher found that human teeth contain a fluoride. In 1823, it was discovered as part of bottled water. Since 1850, we know that fluoridated enamel is acid resistant and it can reduce the risk of dental caries. In 1874, the fluoride is recommended as the correct way to prevent dental caries.
Dental Caries Progress & Development
Dental caries also known as tooth decay is the destruction of tooth enamels by acids produced by oral bacteria. The oral cavity is a digestive organ that contains millions of bacteria, most of them are beneficial and help in digestion. But there are some harmful bacteria such as “streptococcus mutans”. These bacteria metabolize sugar, including fructose, glucose and produce acids in the oral cavity which decrease the oral pH and create an acidic environment. Dental caries bacteria start its activity when oral pH is below 5.5. This disturbs the harmony and the equilibrium in the oral cavity. (pH is a measure of the acidic or basic character of an aqueous solution. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic).
The acids dissolve the hydroxyapatite crystals in enamel and release minerals especially calcium and phosphate. This process called demineralization(minerals are removed from tooth enamel). After bacteria completing the “digestion process”, the acidity in the mouth drops again. The saliva contains water and minerals (mainly calcium and phosphate). These minerals are taken up by the enamel – almost like a sponge. Tooth enamel becomes solid and dense again. This process is called remineralization (minerals are absorbed by tooth enamel).
Ideally, there is a balance between demineralization and remineralization. If acids are produced very often, or acids levels are high, because of the increased frequency of food consumption especially, sweets. The demineralization process will occur more than the remineralization process, the tooth enamel won’t get enough minerals (calcium and phosphate) from the saliva, and dental caries will begin.
How Does Fluoride Work?
Fluoride protects our teeth in various ways against dental caries bacteria and acid produced by them. This include:
- It supports the remineralization process. It accelerates the incorporation of calcium and phosphate from saliva into tooth enamel. So, it lowers the risk of dental caries.
- It is also incorporated into the tooth enamel, just like calcium and phosphate. If the demineralization process begins by acid, It immediately speeds up the remineralization process and helps to neutralize the harmful acid.
- Fluoride, which is applied directly on teeth such as toothpaste or varnish, forms a protective layer around the tooth enamel. This layer protects teeth against bacterial acid attack.
- It interferes with bacterial metabolism and inhibits acid production.
- It should be used in children when permanent teeth have not yet erupted. It incorporates into the tooth enamel during tooth formation, from food or tablets via the bloodstream. So, it creates a stable tooth microstructure and the tooth becomes more resistant to destruction by acids.
- The increasing use of fluoride-containing toothpaste has led to a significant decrease of dental caries in children and adolescents.
Community Water Fluoridation
Water fluoridation is the addition of fluoride to drinking water to decrease the level of dental caries in general population. The fluoridation of drinking water is introduced in some cities in the United States in 1945 and has been widely used since 1950. The optimal level of drinking water fluoridation is .5 – 1.5 ppm (parts-per-million) according to the suggestion of World Health Organization and .7 – 1.2 ppm according to U.S Department of Health and Human Services (HHS).
Fluoride in Water and Food
You can find the fluoride in mineral water, fish, shellfish, spinach, carrots, orange juice, and tea. Its concentration is usually very low, and not enough for a sufficient accumulation in the tooth enamel and prevention of dental caries. Therefore, the fluoridation of enamel surface by toothpaste, gel, or varnish is important for healthy teeth.
Prophylaxis with Fluoride
Fluoride plays an important role in the prevention of dental caries (prophylaxis). So, dentists recommend the regular use of fluoridated toothpaste, mouthwash, or salt. Also, fluoride gel, foam, or varnish can be applied to teeth in the dental office for the prevention of dental caries. If these measures are not sufficient, the dentist may prescribe fluoride tablets.
- Fluoridated salt: it is an inexpensive and effective way to prevent dental caries. Commercially fluoridated salt is combined with iodine (for the prevention of goiter).
- Fluoride toothpaste: From the first milk tooth to the eruption of the first permanent tooth, children should use a toothpaste with low fluoride concentration (maximum 500 ppm). ppm means parts-per-million. Until 2 years of age, teeth should be cleaned once daily with a small amount of fluoridated toothpaste (about the size of a pea). After the eruption of the first permanent teeth (about 6 years), teeth can be cleaned with an adult toothpaste (1000 to 1500 ppm) at least twice daily.
- Fluoride gel: It contains a higher concentration of fluoride than a toothpaste and is used by patients with high caries risk and after a dental procedure when a special protection of teeth is necessary for a short term. The gel is applied on the surface of teeth for 4 minutes by a dental professional, and you should not rinse, eat, drink, or smoke for 30 minutes after application. So, the gel remains on teeth surfaces and can be absorbed by tooth enamel. It can be used by adults and school age children. Discuss the using of gel with your dentist.
- Fluoride varnish: it is a highly concentrated form of fluoride (approximately 50,000 ppm) that can be used to prevent dental caries or treat teeth hypersensitivity. It is effective against dental caries in both primary and permanent dentition. Discuss the using of varnish with your dentist.
- Dental fluorosis: the dose determines whether a substance is good or bad for health. If too much of fluoride is ingested over a long period, It creates a so-called “dental fluorosis”. It comes with white to brownish-yellow spots on teeth and enamel damage. Children under seven years, growing in areas where the fluoride concentration exceeds the value of 1.5 mg per liter of water, are at the risk of dental fluorosis. Also, It can cause pain and damage to bone and joints “skeletal fluorosis”.
- Fluoride poisoning: in rare cases, it occurs when young children swallow a large amount of fluoride. Its symptoms include nausea, vomiting, diarrhea and stomach pain. The symptoms can occur from a dose of 3-5 mg/kg of body weight. 20 kg child would swallow 60-100 mg to show symptoms of fluoride poisoning. In mild cases, children act hyperactive.
How Do I Know If I’m Getting The Optimal Amount of Fluoride?
If the drinking water in your city is fluoridated (1 ppm is optimal) and you brush your teeth regularly with fluoride toothpaste. It is considered sufficient for the prevention of dental caries in both children and adult. You can call your water company to know if drinking water is fluoridated or not. If it is not fluoridated, discuss the alternatives with your dentist.