Fluoride’s Importance to the Teeth
Enamel, the outer layer of the crown of a tooth, is made of closely packed mineral crystals. Every day, minerals are lost and gained from inside the enamel crystals. Losing minerals is called demineralization. Gaining them back is called remineralization.
Demineralization begins with the bacteria in the plaque on your teeth. They feed on sugar and other carbohydrates in your mouth and produce acids. The acids dissolve crystals in tooth enamel. The loss of enamel is balanced by remineralization. In this process, minerals in the saliva, such as fluoride, calcium and phosphate, are deposited back into the enamel. Too much loss of minerals without enough replacement leads to tooth decay.
Fluoride helps teeth in two ways. When children eat or drink fluoride in small doses, it enters the bloodstream and becomes part of their developing permanent teeth. Swallowed fluorides also become part of the saliva and strengthen teeth from the outside. Acids are less able to damage tooth enamel strengthened by fluoride.
In addition, people apply fluoride directly to their teeth when they use a fluoride toothpaste or rinse. Both children and adults also can receive fluoride treatments from the dentist. Fluoride applied to the outside of the teeth helps to speed remineralization. Fluoride treatments, applied in the dental office, also are strong enough to disrupt the production of acids by bacteria.
Fluoride in foods, supplements and water enters the bloodstream through the stomach. From there, it is absorbed into the body. In children, the fluoride then becomes available to the teeth that are developing in the jaw. Swallowed fluorides do not add fluoride to the teeth in someone older than age 16.
Topical fluoride products are applied directly to the teeth. They include toothpaste, mouth rinses and professionally applied fluoride treatments. Topical fluoride treatments are in the mouth for only a short time. However, fluoride levels in the mouth remain higher for several hours afterward.
Professional fluoride treatments are given in a dental office. They are applied as a gel, foam or varnish. The fluoride used for these treatments has a higher strength than over-the-counter or prescription mouthwashes or toothpastes.
Fluoride supplements also are available by prescription. They usually are reserved for children who live in areas where the water supply does not contain enough fluoride. Children who need supplements receive them from ages 6 months to 16 years.
Fluoride Supplements: Who Needs Them?
Children between 6 months and 16 years old who do not drink fluoridated water should take fluoride supplements. They are available as liquids for younger children and tablets for older children. Either your pediatrician or your dentist can prescribe them.
If your child has had cavities or is at high risk of tooth decay, he or she should use extra fluoride. This will promote remineralization. Fluoride mouth rinses are recommended for children over the age of 6. They are found in the mouthwash section of most stores.
Your dentist can prescribe fluoride rinses and gels if your child needs a higher level of fluoride. Carefully supervise your children when they use any fluoride product. Keep fluoride out of reach of young children.
Can Fluoride Cause Harm?
Fluoride is safe and effective when used properly. All water-fluoridation systems are checked daily to maintain safe fluoride levels for drinking. Parents should supervise the use of all fluoride products in the home.
Fluoride-supplement tablets should be stored safely away from young children. These supplements are taken each day in small quantities. The dose can range from 0.25 to 1 milligram per day based on the child’s age and the amount of fluoride in the water.
Dentists limit the amount of tablets they prescribe at one time to reduce the risk of overdose. To avoid any chance of overdose, do not stock up on fluoride tablets in your home. If you have any questions regarding fluoride risks, talk to your dentist or physician.
Toxic fluoride doses are based on weight. For example, the toxic dose of fluoride for a 2-year-old child weighing 22 pounds is 320 milligrams. For an 8-year-old child weighing 45 pounds, the toxic dose is 655 milligrams.
In comparison, an 8-ounce glass of water fluoridated to 1 part per million contains 0.25 milligrams of fluoride. Since these fluoride products are used in such small amounts, it is very difficult to receive toxic doses when using fluoride products at home.
All children should use fluoridated toothpaste. If your children are younger than 6, be cautious about how they use it, however. Young children are more likely to swallow toothpaste after brushing instead of spitting it out. Use only a pea-sized amount of toothpaste when they brush. Encourage them to spit out as much as possible. Avoid flavored toothpastes that might encourage swallowing.
Swallowing toothpaste while teeth are developing can cause a cosmetic defect known as fluorosis. Mild fluorosis appears as white specks on the tooth. For many people this is not noticeable. Swallowing larger amounts of fluoride can cause “mottled” brown enamel. This is unusual and occurs mainly in areas that have naturally high levels of fluoride in the water.