As Portlanders debate adding fluoride to the city water supply, figures from a statewide survey indicate children’s dental health in Oregon and Multnomah County has made marked improvements during the last five years.

Though a full report based on the Oregon Smile Survey, initially expected in February, has not been released, the state has reported some of the numbers to the federal government.

According to the survey, the percent of first, second and third graders in Multnomah County who reported having had a cavity dropped to 50.8 percent in 2012 from 56.3 percent in 2007, the last time the survey was conducted. That’s a 10 percent decline overall.

That drop, though significant, is outshone by the state as a whole, which saw a 19 percent decline: 52 percent of 1st through 3rd graders said they had a cavity in 2012 as opposed to 64 percent in 2007.

Other parts of the state saw well over 50 percent improvement, said Shanie Mason, oral health unit manager for the Oregon Health Authority.

The report doesn’t examine why cavity rates have dropped, but it’s likely due to multiple factors. Those may include increased awareness programs about the importance of brushing and flossing, the state’s dental sealant program and similar efforts, and possibly the expansion of Healthy Kids, which extended dental coverage to thousands of youths.

Mason cautioned against looking solely at the overall percentages given that the final report would offer other health indicators, including the percent of respondents with untreated tooth decay and various community breakdowns.

“What is really important, and we’re working on with the analysis now, is when you start to break down by some of the demographic data,” Mason said.

The report, which could offer voters significant context, may not be issued before the May 21 election, despite earlier indications it would be released in February, if not earlier. Ballots should be mailed about May 3.

Researchers are still analyzing data, according to Mason, who cited her small staff as one reason the report isn’t finished. She also said that the February deadline was never a strict deadline, but rather her best case scenario. She still doesn’t know when the report will be available in its final form.

Kristen Robison, campaign manager for Clean Water Portland, which opposes fluoridation, said the fact that this data was available but that the report still has not been released, is problematic.

“It is concerning that we have a state agency that has delayed for months releasing data showing that Oregon cavity rates have dropped by such a significant amount,” she said in a prepared statement. “This data disproves fluoridation advocates’ claims that Oregon is having a dental health crisis caused by lack of fluoridation and highlights how effective alternatives to fluoridation can be.”

She also noted that if you compare this data to the most recent federal data for other states reporting cavity rates, “Oregon now has some of the lowest cavity rates in the country.”

Healthy Kids, Healthy Portland, the group advocating for fluoridation, had a different take on the figures.

“This data is incomplete,” campaign manager Evyn Mitchell wrote in an email. “But what it does tell us is that we’re still in a crisis situation, and that we have an urgent need for water fluoridation. Over half of our 1st, 2nd and 3rd graders have cavities. … That’s still far too many kids in pain.”

Mitchell made her own comparison, stacking Multnomah County against Washington’s King County. “Their rates are still much lower than ours. In 2010, 39.7 percent of screened children (kindergartners and 3rd graders) were experiencing cavities.”

— Janie Har of The Oregonian contributed to this report.