The increased use of bottled water in the United States has been controversial for many groups. Environmentalists are understandably concerned about the impact that the plastic has on the environment, and some cities are upset at the waste that it causes. These groups have a perhaps unexpected ally in the United States – dentists, who worry that the overreliance on bottled water is bad for our teeth. They say that the effect is particularly pronounced in children.

The use of fluoride in water has perhaps been even more controversial than water bottles, particularly in English-speaking countries. (Continental Europe does not add fluoride in water, instead choosing to fluoridate table salt.) Some argue that the addition of it into the water supply is an ethical issue and that its health benefits do not justify the costs. In the 1950's and 1960's, some argued that its use was a communist plot to undermine public health. Nevertheless, fluoridated water is used in most states and municipalities in the United States and the English-speaking world.

But despite the use of fluoride in tap water, dentists are seeing a significant uptick in children with severe dental problems. Dr. Burton Edelstein, president of the Children's Dental Health Project in Washington, D.C. and a professor of dentistry and health policy and management at New York City's Columbia University, said to HealthDay that the number of young children with prominent tooth decay is alarming. One in 10 two-year-olds, one in five three-year-olds, one in three four-year-olds, and nearly half of five-year-olds have evidence of tooth decay.

So why do dentists blame bottled water? Americans drink 8.4 billion gallons of bottled water every year. Unlike municipalities, bottled water manufacturers do not need to have fluoride in their containers, and do not need to report if they have it or not. Most manufacturers do not put it in their bottled beverages. Researchers do acknowledge that the link between bottled water and tooth decay has not yet been definitively proven.

Parents cite convenience, taste, smell and a fear of public water contamination as reasons that they prefer giving their children bottled water. But it is important to note that, with few exceptions, tap water is perfectly safe. Perhaps, in a compromise between bottled water and tap water, parents should invest in water filters and reusable water bottles.