When I heard that there was a new study showing that tooth decay has worsened amongst Calgary’s children since the city removed fluoride from its water supply in 2011, I hastened to have a look at the paper. That’s what I often do when there’s a new piece of research in the news. But this one offered the priceless bonus of an opportunity to poke fun at Calgary.

The city council there seems to be about half clown at the best of times, and when it comes to child health, it’s worth remembering how the Calgary Flames jumped the queue for H1N1 flu vaccine in 2009, absconding with hundreds of doses from a star-struck clinic and having the paperwork fudged because hockey players are too important for socialized medicine. No, I am not one to resist a cheap shot at Calgary.

One reason I am like this, of course, is that Calgary is a nicer city than Edmonton in several obvious ways. And, of course, the tooth decay study from the journal Community Dentistry and Oral Epidemiology turns out to be a disappointment. Edmonton, which has kept the fluoride in its water, serves as the control in the study. The key finding is not that Calgary’s children have worse teeth than Edmonton’s as a consequence of the removal of the fluoride. It’s that their teeth were significantly better before, and they have now merely fallen to the same level as the less affluent, less educated Edmonton. Sigh.

The study is not quite the hammerblow to Calgary’s fluoridation policy that you might have expected, or been encouraged to expect by the headlines. The authors of the study looked at data on the teeth of a cross-section of grade 2 public-school kids in both cities. There was a “pre” sample of kids observed in the school year 2004-05, and a “post” sample taken in 2013-14, when the Calgarian children would have had up to three years of exposure to unfluoridated water. Hygienists went around to schools and basically counted decayed, filled, and extracted teeth.

The big change was that Calgary children had a lot less damage to their “primary” or baby teeth in ’04-’05. The two cities are now even; both got worse, but Calgary got … more worse. One notices, however, that the Calgary ’04-’05 sample is a lot smaller than the Edmonton one. The surveys were taken by hygienists hired by the old regional health boards, and Calgary’s approach was less aggressive. Only some schools were included in the sample, and the participation rate of the students in those schools was an unimpressive 60 per cent.