Fluoride Action Network

Fluoridation puts Edmonton ahead of Calgary in child dental health, study finds

Source: Edmonton Journal | February 17th, 2016 | By Keith Gerein
Location: Canada, Alberta

Rates of childhood tooth decay have increased faster in Calgary than in Edmonton the past decade, says a new provincewide study in which researchers link the disparity to Calgary’s decision to stop fluoridating its water.

“Our results show that even after a relatively short period of time, we have seen a negative effect of removing fluoride from the drinking water,” said Lindsay McLaren, a public health researcher at the University of Calgary and lead author of the study. “It’s one piece of information that was not available when the decision was being made.”

Fluoridation was at one time widely used across much of Canada, but increased aversion to chemical additives and concerns about potential health risks in recent years prompted some communities to stop the practice.

Still, McLaren said, few studies have focused on the long-term effects of cessation, which is why Calgary’s move in 2011 to stop fluoridating provided a good opportunity for comparisons with Edmonton. The capital has had fluoride in its water since 1967.

The study, jointly conducted with researchers from the University of Alberta and Alberta Health Services, required open mouth exams of about 5,000 Grade 2 students in the two major cities. Investigators counted the number of tooth surfaces with signs of decay.

Those results, collected during the 2013-14 school year, were then compared with similar data gathered in 2004-05 to look for any changes over time.

Neither city fared well in the analysis, each recording increased rates of tooth deterioration. However, the worst results were in Calgary, where the number of surfaces with decay increased an average of 3.8 over the time frame of the study. In Edmonton, the increase was 2.1 surfaces.

A Grade 2 student has about 20 teeth — both baby and permanent teeth — with about four or five surfaces per tooth.

Steven Patterson, a professor of dentistry at the U of A who served as one of the study’s investigators, said the worsening trend in both cities is consistent with anecdotal evidence reported by dentists.

He said it is still unclear why dental health has been declining, especially since many products, such as toothpaste, contain fluoride.

Poorer nutrition is likely the biggest contributor, along with increased consumption of bottled water that contains little or no fluoride, he said.

“It’s also possible more people are not able to access dental care for some reason,” he said. “It’s hard to know definitively. But I suspect the big impact is related to what people choose to eat.”

As for the disparity between Edmonton and Calgary, Patterson said fluoridation is the most likely cause since little else has changed in the two cities in the past decade.

“Out of everything we looked at, it seemed to be the difference in fluoridation that made that greater negative impact in Calgary.”

McLaren said she hopes further studies can be done to see if the trend continues.

The team’s study is published in the February edition of Community Dentistry and Oral Epidemiology.

Fluoride, which has been shown to strengthen tooth enamel, began being added to municipal drinking water supplies in the 1940s. The Centers for Disease Control and Prevention in the United States has listed fluoridation as one of the greatest public health achievements of the 20th century.

As of 2012, about one-third of the Canadian public was believed to be exposed to fluoridated water systems.

Tooth decay is listed as the most common infectious disease in Canadian children and is a leading reason for day surgery.