Dra. Cléo Salustiano In this article
SummaryHow fluoride and sealants protect your teethIs fluoride bad for you? Safety, children and sealant upkeepFAQRead nextFluoride and Dental Sealants: What They Do, Who Needs Them and Are They Safe
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Fluoride strengthens enamel and helps prevent cavities, working mainly in contact with the teeth, which is why fluoride toothpaste is the foundation of prevention. Professional fluoride gel or varnish is recommended for people with higher cavity risk, including adults with exposed roots, sensitivity, dry mouth or braces. A sealant is a resin applied to the grooves of the back teeth, mainly recommended for children and teenagers, and it should be checked at routine visits. In the amounts used in dentistry, fluoride is considered safe; the precaution is keeping young children from swallowing too much toothpaste. In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients every day, from 8 a.m. to 10 p.m.
Fluoride strengthens enamel and helps prevent cavities: in contact with the teeth, it makes enamel more resistant to the acids produced by bacteria and supports the repair of very early lesions. A sealant is another form of prevention: a thin layer of resin applied to the grooves of the back teeth to "close" the fissures that a toothbrush cannot reach and where decay often starts. In the amounts used in dentistry, fluoride is considered safe; the main precaution is keeping young children from swallowing too much toothpaste.
In clinical practice, the most common questions are three: whether adults also need fluoride treatments, whether sealants are only for children and whether fluoride is bad for your health, a concern that comes up a lot online. The answers depend on each person's cavity risk, which the dentist assesses during the exam: diet, hygiene, saliva, history of cavities, fillings, and the presence of braces or exposed roots.
Dr. Cléo Salustiano (CRO-SP 170844), a dentist in Mooca, São Paulo, explains how fluoride works, when a professional application is recommended, how sealants are placed and what is known about safety.
This article comes from Dr. Cléo Salustiano's dental office in Mooca, São Paulo (care in English, Portuguese and Spanish). See the general dentistry page to learn how the treatment is done here and book your assessment.
How fluoride and sealants protect your teeth
Throughout the day, enamel goes through cycles: when we eat sugar, plaque bacteria produce acids that pull minerals out of the tooth (demineralization); afterwards, saliva helps put those minerals back (remineralization). A cavity forms when loss outweighs repair for a long time. Fluoride works mainly topically, that is, in contact with the tooth: it supports remineralization and builds enamel that resists acid better. That is why daily use in small amounts, as in toothpaste, is the foundation of prevention. To understand this process, see tooth decay: what it is and how it starts.
Everyday sources of fluoride are fluoride toothpaste, used twice a day or as advised; fluoridated tap water, present in many Brazilian cities, including São Paulo; and, in some cases, fluoride mouthwashes recommended by the dentist. A professional application, done at the office, uses more concentrated products in gel or varnish form; varnish is painted onto the teeth and stays attached for a few hours. Because it is more concentrated, it is recommended according to risk, not as a routine for everyone.
Fluoride treatment for adults: it is recommended when cavity risk is higher. Common situations are frequent cavities or white spots of early decay, roots exposed by gum recession, sensitivity, dry mouth (from medications, medical treatments or other causes), orthodontic braces, many fillings and difficulty cleaning. For people with sensitive teeth, varnish can help reduce discomfort; the article sensitive teeth: causes and treatment covers other options.
Dental sealants: molars and premolars have grooves and pits on the chewing surface that can be so narrow and deep that toothbrush bristles cannot get in. A sealant is a flowable resin applied to these grooves, which hardens with light and forms a barrier against plaque build-up. The procedure is usually quick and simple: the tooth is cleaned, kept dry, prepared with a gel, receives the sealant and is light-cured. It usually requires no anesthesia and no drilling. It is mainly recommended for children and teenagers, soon after the permanent molars come in, and may also suit adults with deep grooves and cavity risk.
| Measure | Purpose | Who usually benefits |
|---|---|---|
| Fluoride toothpaste | Daily enamel protection | Everyone, in an age-appropriate amount |
| Fluoridated water | Ongoing community-level protection | The general population |
| In-office fluoride gel or varnish | Extra protection for higher risk | Frequent cavities, exposed roots, sensitivity, dry mouth, braces |
| Fluoride mouthwash | Add-on in specific cases | As recommended by the dentist |
| Sealant | Closing deep grooves on back teeth | Children and teenagers after molars erupt; some adults |
Is fluoride bad for you? Safety, children and sealant upkeep
Is fluoride bad for you? In the amounts used for prevention, fluoride is considered safe by the main health and dental organizations. The issue is excess. In young children, while the permanent teeth are still forming, repeatedly swallowing too much fluoride can cause dental fluorosis, which usually shows as whitish spots or streaks on the enamel; in mild cases, it is a cosmetic issue. Swallowing a large amount at once, such as a child eating toothpaste from the tube or swallowing a professional product, can make them unwell and calls for medical care. That is why these products should be kept out of children's reach.
Care with children: an adult should supervise brushing, using a small amount of fluoride toothpaste. The most common guidance is a smear the size of a grain of rice for younger children who cannot spit yet, and a pea-sized amount once the child is able to spit, as advised by the dentist. The child should spit out the excess. Toothpastes without fluoride do not protect against decay in the same way and only make sense with professional advice. For children's oral health, see pediatric dentistry.
Sealant upkeep: a sealant can last for years, but not forever. It can wear down or partly come off with chewing, so it should be checked at routine visits and reapplied or repaired when needed. Sealants do not replace brushing, flossing or fluoride toothpaste: they protect only the chewing surface, and the surfaces between the teeth still depend on hygiene. As for bisphenol A (BPA), which sometimes comes up in discussions about sealants, dental organizations consider the exposure associated with the procedure to be very low and short-lived.
This content is for information only and does not replace an exam. Consult a dentist to find out your cavity risk and whether you or your child would benefit from fluoride treatment or sealants. In Mooca, Dr. Cléo Salustiano sees patients every day, from 8 a.m. to 10 p.m., including Sundays and holidays, for general dentistry and preventive dentistry in Mooca.
What does fluoride do for teeth?
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Fluoride makes enamel more resistant to the acids produced by plaque bacteria and helps replace lost minerals, which can even reverse very early cavities. It works mainly in contact with the tooth, which is why daily use of fluoride toothpaste is so important.
Do adults need fluoride treatments?
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Not all adults. A professional application is recommended when cavity risk is higher: frequent cavities, exposed roots, sensitivity, dry mouth, braces or many fillings. For people at low risk, fluoride toothpaste is usually enough. The dentist assesses this during the exam.
Is fluoride bad for your health?
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In the amounts used to prevent cavities, fluoride is considered safe by health organizations. The risk lies in excess: in young children, frequently swallowing toothpaste can cause fluorosis, which leaves white marks on the enamel. That is why the amount of toothpaste should suit the child's age and brushing should be supervised.
What is a dental sealant and how is it applied?
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It is a flowable resin applied to the grooves on the chewing surface of the back teeth, which hardens with light and forms a barrier against plaque. The tooth is cleaned, kept dry and prepared before application. It usually requires no anesthesia and no drilling.
Are sealants only for children?
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They are most often recommended for children and teenagers, soon after the permanent molars come in, when the grooves are most vulnerable. But adults with deep grooves, no decay and higher cavity risk can also benefit. The recommendation is individual.
How long do sealants last?
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They can last for years, but this varies with chewing, habits and the tooth surface. They can wear down or partly come off, so the dentist checks them at routine visits and reapplies or repairs them when needed. Even with sealants, brushing and flossing remain essential.
Where can I get fluoride treatment or sealants in Mooca?
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In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients at Rua Hipódromo, 1141, near Bresser-Mooca station, Monday to Sunday, from 8 a.m. to 10 p.m., including holidays. During the visit she assesses your cavity risk and recommends the preventive measures that suit you. Appointments via WhatsApp (11) 97409-7834, in Portuguese, English or Spanish.
