Bottled water leads to tooth decay

Is your child spending too much time in the dental chair?  Based on scientific data, they may not be alone.  Statistics have shown that dental caries, better known as tooth decay or cavities, is on the rise in children aged two to five years, and has been on the increase for the past two decades.

Tooth decay is by far the most common of all the chronic childhood diseases, affecting five times more Canadian children than asthma.  While childhood tooth decay is readily treatable, it does potentially lead to undesirable outcomes such as discomfort, dental anxiety or phobia, time lost from school and significant financial burden to families.

Although many different risk factors have been implicated for developing tooth decay, the four essential ingredients are a tooth surface, decay-causing bacteria, fermentable carbohydrates (such as sugar) and time. What makes some children more prone to cavities than others are factors such as the hardness of the enamel, the anatomy of the teeth, and the buffering capacity of the saliva.

Modifiable factors include the sugar content of the diet, brushing and flossing habits, regular preventive dental visits and exposure to or avoidance of fluoride containing products.  The value of fluoride in reducing or eliminating tooth decay has been well established for over 60 years.  However, excessive exposure to fluoride is not good either, and can cause fluorosis, which can negatively affect the appearance of the teeth, and potentially lead to other health problems.

Optimal benefit from community water fluoridation programs has been shown to take place at one part per million in municipal water supply.  This has been the fluoridation level in Toronto’s drinking water since 1959.  In spite of this, media focus on the undesirable effects of excessive fluoride intake has unfortunately led to the rise of an ‘anti-fluoride’ movement.

Bottled water in plastic bottles began to gain popularity in the 1980s, in part because of widespread concern about the safety of tap water.  Bottled water is usually either obtained from natural springs, or produced by treating tap water with a chemical process known as reverse osmosis.  This process is designed to remove unwanted impurities from tap water, but unfortunately it also removes most or all of the fluoride from the water.

Dentists have long speculated that mass consumption of bottled water would lead to significant increase in the prevalence of tooth decay.  Recently, a number of studies have proven this speculation to be valid.  Researchers in a number of centres have studied two groups of children from the same community over a period of two to three years, one group drinking exclusively tap water, and the other only bottled water. In each community studied, the group of children drinking bottled water had significantly more tooth decay.  The only variable the researchers could identify to distinguish the two groups was the presence or absence of fluoride in their drinking water.

Based on these findings, most dentists recommend tap water over bottled water, particularly in young children.  Parents of young children should be encouraged to carefully consider the health effects before choosing bottled water over municipal tap water.

Dr. Allan Katchky is a dentist who practises in the East End

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