Make the Most of Your Mouth

Fluoride and Kids' Teeth: Ask the Dentist

Dentist Steven E. Roth, DMD, answers your additional questions about fluoride.

Question:

What is a cavity and what exactly causes it? How does fluoride prevent them?

Answer:

A cavity, or tooth decay, is caused by certain bacteria in the mouth. When a person eats sugar and other refined carbohydrates, these bacteria produce acid that removes minerals from the surface of the tooth. Fluoride helps to remineralize tooth surfaces and prevents cavities from continuing to form.

Question:

My city water has fluoride in it. Is drinking that enough for my kids or do they need more? They have several 8 ounce glasses of water a day.

Answer:

If you go to your municipality's web site, you can check on the fluoride levels. As a science-based organization, the ADA supports the Department of Health and Human Services' recommendation to set the level for optimally fluoridated water at 0.7 parts per million. This adjustment will provide an effective level of fluoride to reduce the incidence of tooth decay while minimizing the rate of fluorosis in the general population.

Question:

Why do children need fluoride?

Answer:

Fluoride hardens teeth and makes them less susceptible to tooth decay. About 50% of children have at least one cavity by age 5, so fluoride is an absolute necessity.

Question:

What is fluoride anyway? I heard that it is a byproduct of mining and can be poisonous!

Answer:

Nearly all naturally occurring water sources contain fluoride, a mineral that has been proven to prevent, and even reverse, tooth decay. Tooth decay is caused by certain bacteria in the mouth. When a person eats sugar and other refined carbohydrates, these bacteria produce acid that removes minerals from the surface of the tooth. Fluoride helps to remineralize tooth surfaces and prevents cavities from continuing to form.

Question:

Why is fluoride put in water? How can I tell if my city has water with fluoride in it?

Answer:

Fluoride is put in water at a low concentration to prevent and fight tooth decay. The CDC web site allows consumers in participating states to find basic information about their water system, including the number of people served by the system and the target fluoridation level.

Question:

What are the negative side effects of fluoride?

Answer:

The proper amount of fluoride helps prevent and control tooth decay in children and adults. Fluoride works both while the teeth are developing, and every day after the teeth have emerged through the gums. Fluoride consumed during tooth development can also result in a range of visible changes to the enamel surface of the tooth. These changes have been broadly termed dental fluorosis. That is probably fluoride's No. 1 negative aspect.

Question:

If I feed my kids healthy food, can they skip the fluoride?

Answer:

No. Although a healthy diet is very important, fluoride is necessary. Tooth decay is caused by certain bacteria in the mouth. When a person eats sugar and other refined carbohydrates, these bacteria produce acid that removes minerals from the surface of the tooth. Fluoride helps to remineralize tooth surfaces and prevents cavities from continuing to form.

Question:

Why can we swallow fluoride in our drinking water but not in toothpaste?

Answer:

It's due to the different concentration levels of the fluoride in drinking water and toothpaste. Drinking water has a low level of fluoride. Fluoride in toothpaste is much more concentrated and is not designed for ingestion.

Question:

Are there any fruits, vegetables, or other foods that contain fluoride and will substitute for dental products?

Answer:

Naturally occurring fluoride exists in water and many foods but not in high enough concentration to fight cavities. Drink the fluoridated water and use the products recommended by your dentist.

Question:

Do children need fluoride tablets? If so, what ages, and how do I use them?

Answer:

It is best to ask your pediatrician. In general, if you live in a location where the water is fluoridated, fluoride tablets are not necessary. You may have a child start using fluoride toothpaste at 2 to 3 years old.

Question:

Can young kids use regular toothpaste with fluoride?

Answer:

Waiting until a child is 2 to 3 years old is a good time to begin using fluoridated toothpaste. Be sure to supervise their brushing so they do not swallow the toothpaste.

Question:

Other than toothpaste, is the type of brush my child uses important? Manual or electric/battery powered? Hard or soft bristles? Adult or child size?

Answer:

Any product that makes it easy and fun is the best product. I like electric brushes because they remove plaque, and if kids are having fun while they brush, they are more likely to continue brushing.

Question:

If a person NEVER has fluoride, what will happen to their teeth?

Answer:

That depends on their body's ability to fight off infection.  Some people will be fine, while others will experience rapid tooth decay. 

Question:

Can you overdose on fluoride? What if my kid eats a tube of toothpaste?

Answer:

Yes, eating toothpaste can be fatal. Call your local Poison Control Center and 911 if your child eats a lot of toothpaste.

Question:

I saw a new "once-a-week" toothpaste. Is this safe for children? Do you have to use regular toothpaste the rest of the week?

Answer:

Most people need to brush at least 2 times per day. The "once-a-week" toothpastes are designed to be used in addition to the 2 times per day type of toothpaste.

Question:

There are so many choices! What are the ingredients kids absolutely need in toothpaste?

Answer:

Fluoride for cavity protection is the most important ingredient. Please refer to the American Academy of Pediatric Dentistry and the American Dental Association web sites for more information.

Question:

What are risk factors for kids that could lead them to have cavities?

Answer:

Factors that can increase risk for cavity development include a diet high in refined sugar and fructose, obesity, poor manual dexterity, lack of access to dental care and fluoride treatments, lack of fluoride in the water supply, genetics, and consuming sweets, juices, and sodas -- especially right before bedtime without tooth brushing and flossing. Nighttime is a very dangerous time for the formation of tooth decay.

Question:

How can I keep my child from swallowing toothpaste?

Answer:

Only use a small pea-size amount of paste to prevent swallowing until your child is over the age of 6. Children under 6 years old have weak swallowing reflexes, so they must be supervised.

Question:

My 5-year-old's adult teeth are coming in with white spots. I've heard this is caused by too much fluoride. How can I treat the spots? They are very, very noticeable.

Answer:

Ask a pediatric dentist to evaluate the spots to see if they are caused by dental fluorosis. There are several available dental treatments that can minimize the discoloration.

Question:

Is flossing safe for kids under 3?

Answer:

Only if flossing is done by a parent. Floss, like many other stringy items, should not be left with small children.

Question:

My son uses an asthma inhaler. Could this harm his teeth? Does he need to take any extra dental care steps?

Answer:

According to research, there is nothing in the medication that can specifically cause a tooth problem, but there is possible danger of decay from a dry mouth. Use a mouth rinse right after using the inhaler, and have professional checkups regularly.

Question:

What is a fluoride treatment? Can children have a fluoride treatment or is it just for adults? Are there home treatments available, or do I have to have a dentist do it?

Answer:

A fluoride treatment is the application of a more concentrated topical fluoride to a patient's teeth after their teeth have been professionally cleaned. Fluoride is not available without a prescription, so do not do it at home.  A professional fluoride treatment is safe for children as well as adults.

Question:

My daughter’s dentist wants to apply a protective sealant once her molars have grown in. What is that? Does it mean she doesn't need to use fluoride?

Answer:

Fluoride is always necessary. Dental sealants act as a barrier, protecting the teeth against decay-causing bacteria. The sealants are usually applied to the chewing surfaces of the back teeth (premolars and molars) where decay occurs most often.

Question:

Our water is from a well and has no added fluoride. Is using fluoride toothpaste enough?

Answer:

If there is no fluoride in your well water, you will probably need fluoride treatments from your dentist at your cleaning visits, and a supplemental fluoride mouth rinse to use at home. Ask your dentist what is best.

Question:

Does my water filter take out the fluoride out of the water?

Answer:

If that's your goal, you would have to use a dedicated fluoride filter designed specifically for that purpose. A regular water filter will not remove fluoride.

Question:

How can I know if my children are brushing their teeth enough? How long should they brush?

Answer:

Brushing for two minutes is best -- a bit on every tooth. There are some fun brushing timers available to use for kids to help encourage these habits.

Thank you for joining us for Ask the Dentist. Be sure to check in on Sept. 8 at 1 p.m. ET when we'll discuss what's in your dental care products. Sign up if you'd like an email reminder the day before the event.