There is no denying the benefits of fluoride toothpaste. However, overusing it can do harm, especially in areas where the water is polluted with fluoride.
Regarded as one of the top 10 public health achievements of the 20th century, fluoride is best known as an ingredient in something we all use every day: toothpaste.
A double-edged sword
According to the scientific literature, fluoride plays many important roles in the body: it helps prevent tooth decay, forms part of the structure of bones and ligaments, stimulates collagen production in the early stage of healing a broken bone, and stimulates bone cells to increase bone mass, which is used in the treatment of osteoporosis.
Tooth enamel is the hardest tissue in the body, and it is made up mainly of apatite. Fluoride can be absorbed into the enamel and form fluorapatite, which makes teeth harder and less easily worn away by acid, and so helps prevent tooth decay. None of these effects can be denied. However, Assoc. Prof. Dr. Nguyễn Đình Hòe of the University of Science says that every substance has its benefits and its harms. It is only truly useful when used within the permitted limits.
Assoc. Prof. Hòe says that under Vietnamese standards, a fluoride level of 0.5 to 1 mg/l is safe; using more than this limit leads to brittle bones and fractures.
This has been clearly shown in Phú Yên and Khánh Hòa, areas whose water is contaminated with fluoride and which have been called “the land without smiles”. As a scientist who has researched fluoride pollution in the water in these areas, Assoc. Prof. Hòe warns: in areas with fluoride pollution, using fluoride toothpaste is no different from smearing extra poison on your teeth.
Warnings are needed
The fact is that manufacturers have issued almost no warnings about which areas people should not use fluoride toothpaste in. The advertising in the mass media simply leads people to assume that toothpaste must contain fluoride, and that toothpaste with fluoride is the best.
On top of that, ads showing a toothbrush loaded with toothpaste lead consumers to assume that you need that much to get your teeth clean. “That is not entirely true,” says Assoc. Prof. Dr. Nguyễn Đình Hòe.
Dr. Nguyễn Hữu Hoan believes that children aged 1 to 6 should not use fluoride toothpaste. For adults, a thin layer on the surface of the brush is enough; there is no need for a thick layer like in the ads. “Quite apart from the harm of too much fluoride, using a lot of toothpaste is also very wasteful,” says Dr. Nguyễn Hữu Hoan. Assoc. Prof. Dr. Nguyễn Đình Hòe gives this advice: if you brush twice a day, brush once with fluoride toothpaste and once with diluted salt water. Note that in areas with fluoride pollution, you should never use fluoride toothpaste.
Assoc. Prof. Hòe also says that in other countries, two kinds of toothpaste are made, with and without fluoride, so consumers can choose. Manufacturers also advise who should use fluoride toothpaste and publish clear standards. In Vietnam, on the other hand, it seems to be taken for granted that toothpaste must contain fluoride, regardless of whether the local water is contaminated with fluoride or not.
Dr. Nguyễn Hữu Hoan of the Institute of Industrial Chemistry agrees with this view. Dr. Hoan says that fluorine itself is an extremely toxic chemical. Even a tiny amount of pure fluorine on a fingernail is enough to make the nail crumble. Adding fluoride to toothpaste is necessary, but it must be tightly controlled, and people should be advised to use it in moderation.