Fluoride, an important mineral, is incorporated in toothpastes and mouthwashes to prevent cavities. However, exposure to excess fluoride has more unhealthy results than benefits. Fluorides are commonly present in drinking water, underground, borewell, and packaged water. It is also present in other sources such as medicinal supplements, tea, milk, and salt.
“In India, the ideal concentration of fluoride in water or any other source is around 0.7 ppm. When a child consumes high levels of fluoride (more than 1 ppm) it results in dental fluorosis,” says Dr Teenu Thomas, assistant professor in the Department of Public Health Dentistry, Mahe Institute of Dental Sciences, Mahe, Puducherry. Dental fluorosis is a condition that affects the teeth due to increased intake of fluoridated water.
The hidden reason for dental fluorosis
“My teeth had brown stains since childhood. Earlier, I was not aware of the cause as none of my family members had it,” Jothi S, 20, receptionist at a hospital, Theni, Tamil Nadu, shares her experience about growing up consuming borewell water. She adds that she tried using whitening toothpastes, but nothing worked.
After consulting a dentist, she learnt that the excess fluoride present in water was the sole cause for the discolouration. Since she had fluorosis, the dentist suggested capping (crown) of the affected teeth.
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“In some parts of India, the water is fluoridated more than the recommended level. Hence, it affects the entire population residing in that area,” says Dr Dhivya P, consultant endodontist, Bengaluru.
If young children consume this water before or during the developmental stage of permanent teeth, it disrupts the enamel formation, she adds.
The symptoms can be as mild as small white spot lesions or severe as pitting (minor holes in the tooth surface) over the enamel. Moreover, the teeth can have discolouration (light to dark brown or dark yellow) with structural changes.
Time-linked causes of dental fluorosis
Dr Thomas says that the structural changes in the teeth occur in adults due to fluoride exposure in childhood. If children are exposed to high levels of fluoride through diet or water till the age of seven, they have a higher chance of getting fluorosis.
“All the permanent teeth including the second molar may get effected. Their third molars (wisdom teeth) may also be involved if the child is exposed to affected water till the age of eight,” adds Dr Thomas.
Benefits and risks
“Since fluoride is an anticavity agent, a few people with fluorosis do not get cavities. However, if there are rough pits on the surface of enamel due to severe fluorosis, there is a chance of food entrapment which further leads to cavities,” says Dr Dhivya. In addition, the enamel becomes weak and brittle making the teeth prone to chipping and breaking.
A 2022 study published in The science of the total environment shows that excess fluoride intake can affect the bones, muscles, and joints of the body. Moreover, too much ingestion of fluoride can damage the vital organs including the heart, kidney, liver, blood vessels, and nerves.
“Accidental swallowing of fluoridated toothpaste in children while brushing causes systemic conditions later in life,” adds Dr Dhivya.
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A 2023 study published in the National Centre for Biotechnology Information and Dr Dhivya suggest the following measures to prevent fluorosis:
- Healthcare providers must educate about the importance of optimal intake of fluoride, especially in rural areas.
- Limit consuming the borewell or underground water that has excess fluoride.
- People consuming fluoridated water should avoid the intake of fluoride supplements and limit the use of fluoridated toothpastes and mouthwashes.
- Parents should supervise children while brushing and make them spit the toothpaste without swallowing.
- Children should not use toothpaste and mouthwashes meant for adults as those have different levels of fluoride.
Dr Dhivya says that the treatment of fluorosis is expensive and involves cosmetic correction. “The surface stains are removed using whitening procedures and severely affected teeth are covered with composite fillings (white fillings), veneers (white-coloured teeth coverings), or crowns (capping),” she adds.
Even though treatment is always an option, Dr Dhivya recommends preventive measure for better oral health.