Introduction: Like other aspects of health care, dental products containing fluoride have been in existence for so long that they are rarely challenged by health professionals. Over 35,000 articles have been published on various modalities and effects of fluoride, making fluoride well studied but frequently dull. It works; let’s move on is how dentistry and drugs mostly view it. However, when the popular media, internet, or individuals raise questions, it may be good to have a brief reference manual accessible. Several good resources can be found and listed in the appendix, but here’s a quick and dirty overview of fluoride when you will need a quick fact. Just be sure that you combine it with another contentious substance – Caffeine.
History: Fluoride has a colorful history that began in Colorado Springs in 1901. A young dentist, Dr. McKay, moved into town and discovered two things that alerted him. One, everyone in Colorado Springs had brown mottled teeth. Second, virtually no dental decay existed. In a time when dental decay was uncontrolled back east, this really was a remarkable finding. He was able to attract the eye of a prominent dental researcher who then found other regions in the nation where the condition has been replicated. Soon the correlation between brownish stains and lack of caries was established.
Later the cause of the staining was found to be elevated levels of fluoride in several water sources. The director of NIH at the time, Dr. Trendley Dean, then made the intuitive leap that aspirin at low enough levels may reduce corrosion levels but not create unsightly brown staining. In a feat of epidemiological research, he found the intersection that hastens caries prevention while minimizing fluorosis. Dean’s fluoride level of 1ppm was later tested in Grand Rapids Michigan in 1944. Eleven years later caries rates were proven to be reduced by 60% without significant side effects. The era of fluoridation was firstborn. In 1964, Stanly Kubrick’s Dr. Stangelove made water fluoridation a communist plot. In 1967 Crest introduced fluoride toothpaste. The rest is history…
Mechanism of Action: Fluoride includes two modes of action. When ingested, roughly 50 percent of fluoride is deposited in the teeth and bones, 50% is excreted. In bones, fluoride moves in and out as bones remodel. In teeth, fluoride integrates into the enamel and does not remodel once it is formed. As the tooth, if shaped and calcifies, fluoride is incorporated into the crystal structure of the tooth along the protein scaffolding laid down by specialized cells called ameloblasts. At 1 ppm, fluoride doesn’t interrupt the crystal creation of the tooth, but at levels over that, a few disruptions in crystal formation start to occur. In 2ppm, visible disruptions in tooth arrangement can occur, and at 4ppm and over, ameloblast cell alteration causes considerable amounts of the protein matrix that is disrupted.
The enamel structure warps lose its translucence and can chip and pick up food stains. This illness, coined Fluorosis runs a spectrum of seriousness but does not make the tooth more susceptible to decay. Fluoride only works systemically while the teeth are forming. Fluoride does not cross the placental barrier and is a trace element in breast milk, so rarely are primary teeth influenced, Permanent teeth start calcifying at dawn for first molars, about 2 years for central incisors, and about 4-6 years to get second premolars. Introduction of systemic fluoride at various ages and respective levels then accounts for the amount of caries resistance and fluorosis seen from the adult dentition. Often ingestion of fluoride toothpaste during the toddler years affects the front permanent teeth esthetics. In the early studies from Grand Rapids, it is evident systemic fluoride plays a crucial part in caries resistance. However, in this day and age when water fluoridation is available to about 60 percent of their US and fluoride toothpaste is ubiquitous, significant debate exists about how much systemic fluoride performs in modern-day caries resistance.
The second mode of activity is Topical. Topical fluoride describes the fluoride ion being present in the mouth and accessible to tooth surfaces. On the tooth surface a constant demineralization is occurring due to plaque acid and to a lesser extent acidic foods (which are often well buffered by the saliva). In these areas, the negatively charged fluoride ion is drawn and catalyzes to start remineralization of tooth arrangement with salivary calcium and phosphates. Enamel is shaped of hydroxyapatite crystals, but in the presence of fluoride ion, the hydroxy ion is substituted along a fluorapatite crystal is formed on the outer enamel. The fluorapatite crystal is less soluble and more acid resistant, thereby getting more caries resistant. The more frequently fluoride is present in the saliva, the more caries resistant teeth become. This is especially true of recently erupted teeth that have not yet reached full mineral content. These teeth are especially vulnerable to decay, but reap the most from benzoyl peroxide. Read more about Sunset dental.
Topical fluoride comes in many types. Water fluoridated at 1ppm will increase salivary fluoride 100 to 1000 times and remain high for 1 -2 hours. The more water washing over the teeth the longer the balance is tipped to remineralization. The identical action to a much larger salivary concentration happens with regular use of toothpaste, mouthwashes, or professionally applied fluorides. While higher dosed fluoride modalities will aim and help reverse hypo mineralized enamel structure or”white stains,” frequency of fluoride exposure will lessen caries rate most radically.