Fluoride: Too Much of a Good Thing May Mottle Children's Teeth

Water fluoridation has been hailed as one of the 10 greatest public health achievements in the 20th century, significantly reducing the occurrence of cavities in young children. However, although the risk for cavities has been lowered, another problem has emerged - mottled teeth from too much fluoride ingestion.

Although merely a cosmetic problem, researchers in a recent study suggest that children should receive fluoride based on their needs, and a reevaluation is warranted to determine whether fluoride concentrations in public water need to be reduced.

What Is Fluoride?

The fluoride ion comes from the element fluorine. Fluoride, either applied topically to erupted teeth, or ingested orally (called systemic fluoride) during tooth development, helps to prevent tooth decay, strengthen tooth enamel, and reduce the harmful effects of plaque. Fluoride also makes the entire tooth structure more resistant to decay and promotes remineralization, which aids in repairing early decay before the damage is even visible. Fluoride prevents tooth decay in two ways, according to the Centers for Disease Control and Prevention (CDC):

• through direct contact with teeth
  
  
• through drinking it in the water supply during tooth-forming years and later

According to the CDC, water fluoridation reduces tooth decay in children by 18 to 40 percent.

What Is Enamel Fluorosis?

The condition, called enamel fluorosis, is a developmental defect of the tooth enamel caused by too much fluoride. The mildest form of fluorosis is characterized by light spots on the teeth that can be detected only by a dentist or dental hygienist. The more severe form of fluorosis may cause spotting, pitting, or staining. The condition is considered a cosmetic problem, with no harmful effects to a person's health.

In a recent study, published in the Journal of the American Dental Association, researchers compared enamel fluorosis data collected by the National Institute of Dental Research (NIDR) on school children in the 1980s with data collected by H. Trendley Dean in the 1930s. In addition, the researchers looked at where the children lived, categorizing their residences by levels of fluoride in the water:

• optimal fluoride (OF) - adjusted fluoride concentrations between 0.7 and 1.2 ppm
  
  
• natural fluoride (NF) - naturally occurring fluoride between 0.7 and 4.0 ppm
  
  
• suboptimal fluoride (SF) - water systems not reported in the census, suggesting levels of fluoride less than 0.7 ppm

(You can find out the fluoride levels in your public drinking water by calling your local water department, your local health department, or by visiting the CDC Web site.

According to the NIDR data:

• 55 percent of children live in SF communities
  
  
• 38 percent of children live in OF communities
  
  
• 6 percent of children live in NF communities

The prevalence of enamel fluorosis ranging from mild to severe varied across the communities:

• 38 percent in the NF group
• 26 percent in the OF group
• 15.5 percent in the SF group

The prevalence of moderate to severe fluorosis based on fluoride levels was the following:

• 8.6 percent in the NF group
• 1.5 percent in the OF group
• 0.6 percent in the SF group

In the Dean study (in the 1930s), the prevalence of enamel fluorosis ranged from 6.5 percent to 48 percent among communities with fluoride levels between 0.7 and 1.9 ppm. However, Dean observed no severe fluorosis, not even in communities with fluoride levels of 1.9 ppm.

Always consult your physician for more information.

please go to page two
for more on this story...