Do cities really save $38 for every $1 they spend on fluoridation?

The Portland City Council is set to vote early next month on whether to fluoridate the city’s drinking water -- and a ‘yes’ vote looks all but certain. City Commissioner Nick Fish said as much in a statement that started bluntly "I believe it is time to add fluoride to Portland’s drinking water."

Part of his rationale, he explained in the statement, are the potential savings fluoridation offers.

"In fact, cities save an estimated $38 in dental costs for every $1 invested in fluoridation," he wrote.

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We thought the topic was timely enough that we ought to do a quick check on this would-be fact. (Full disclosure: The Oregonian used the same fact in a Page 1 article on the subject of fluoridation.)

We called Fish’s office and spoke with Emily York, one of the commissioner’s policy coordinators. She sent us a fact sheet from the Everyone Deserves Healthy Teeth Coalition that laid out the economic case in favor of fluoridation, including the $38 figure that Fish used.

The figure, the fact sheet noted, came from a 2001 study published in the Journal of Public Health Dentistry by Susan Griffin, Karl Jones and Scott Tomar.

It took some time, but we were able to get our hands on a copy of the study. A quick read revealed that the authors had indeed found significant savings from fewer instances of tooth decay and resulting dental care when communities fluoridated their water supplies. (PolitiFact Oregon recognizes that fluoridation has strong opponents who raise other issues -- but our purpose here is simply to examine the possible cost savings.)

To get to the $38 figure, you need to do a little math. For a large community like Portland, the study’s authors estimated that fluoridation costs about 50 cents per person. Then it goes on to give a range of possible dental cost savings per person --  from $2.99 to $56.07, with a most likely savings (base case in financial jargon) of $19.12 per person for the 50 cents spent

Just double the $19.12 in savings -- because that’s how much you get for half a dollar -- and you wind up with $38 in savings for each $1 spent. That’s a pretty decent return, to be sure.

Now, there are a few caveats here. The study explicitly states that it does not take into account overhead costs of fluoridation or possible health issues that stem from fluoridation, such as dental fluorosis, which the study says "are negligible."

We contacted one of the study’s authors, Scott Tomar, who teaches at the College of Dentistry at the University of Florida. In an e-mail he said the bottom line of the decade-old study was that "that community water fluoridation saves money under almost any scenario. It is actually one of extremely few public health initiatives that can make such a claim.  Based on our analyses, an 18 to 1 return on investment is a reasonable estimate for Portland."

We wanted something a little more specific, however, so we took a look at the actual numbers Portland would be facing. The figures are a little different for the Portland area because it’ll cost more than the estimated 50 cents per person to fluoridate. According to early estimates, it’ll cost the city about $5 million to get the project started and then about $575,000 annually from there on to fluoridate water for about 900,000 people.

We worked the math and that means in the first year, Portland area residents would save about $3 in dental costs for every $1 invested. After that, it’d cost closer to 64 cents per person to fluoridate the water, meaning a savings of about $30 for each $1 spent.

Fish was measured in his comments. He said that "cities save an estimated $38 in dental costs for every $1 invested in fluoridation" and, indeed, that was the estimate of one article that appeared in a peer-reviewed medical journal. Furthermore, the findings of this article are highlighted by the Centers for Disease Control and Prevention on its website on the subject.

The savings for Portland, however, are slimmer, and we think that’s important context that is missing.

We find this statement Mostly True.