Fluoride is a naturally occurring mineral that has been proven several times to safely prevent cavities in children and adults. To understand how fluoride prevents cavities, it is helpful to understand the dental caries (cavities) process.
We all have bacteria in our mouth, most of it is harmless, however a few species of bacteria are responsible for dental caries. Whenever these cavity causing bacteria are exposed to carbohydrate (food, and sugared drinks), they eat the carbohydrates and produce an acid. This acid breaks down enamel and dentin of teeth.
The breakdown of tooth structure eventually leads to a hole (cavity) in the tooth. Because of its special properties, fluoride can be absorbed into enamel and dentin of teeth. When a tooth is exposed to fluoride, it absorbs the fluoride and becomes more resistant to cavities.
Also, once a cavity starts in a tooth, fluoride will incorporate into the weakened enamel and make it even more resistant to future decay. There are a few strategies that are used to expose teeth to fluoride.
1. Ingesting fluoride (through community drinking water) allows for the incorporation of fluoride into the dentin and enamel of unerupted teeth. This makes the teeth better able to resist cavities once they erupt into the mouth. Ingested fluoride is also found in saliva and will provide a constant source of fluoride as saliva is secreted into the mouth covering the teeth. Communal fluoridated water is the most effective method of reducing cavities in the general population. Most studies show a reduction of dental decay by 50%
2. Fluoride toothpaste allows for the application of fluoride when the teeth are brushed. The American Academy of Pediatric Dentistry recommends that children under 3 should use a smear or rice sized amount of fluoridated toothpaste, and children older than 3 a pea sized amount.
3. The periodic professional topical application of more concentrated fluoride is very beneficial in the prevention of cavities. After teeth have been professionally cleaned is the optimal time to apply a fluoride varnish because all the dental plaque and debris has been removed. We recommend a fluoride application after every dental cleaning to maximize fluoride uptake by the teeth. If we note a high risk for dental decay we may recommend a fluoride varnish application every 2-3 months.