PORTLAND, Ore. -- It's a dental story told so often it borders on cliche.
When someone moves to Portland from another state -- and that's most people you meet in this city of transplants -- their new dentist takes one look at their excellent teeth and concludes they must have been raised elsewhere, a place that puts fluoride in its drinking water.
The tale is also told from the perspective of native Portlanders.
"I have had several dentists comment on my and my children's teeth, saying: 'Oh, I can see you grew up in Portland,'" Mary Lou Hennrich said. And that's no compliment, she added.
Portland is the largest city in the U.S. that has yet to approve fluoridation to combat tooth decay, a distinction that could change at Wednesday's city council meeting. Mayor Sam Adams and two city commissioners have announced their support, ensuring a majority on the five-member panel.
Fluoridation has been an emotional topic in communities across the country for more than 50 years, and continues to be in cities ranging from conservative Wichita, Kan., to a place whose unofficial motto is "Keep Portland Weird."
Portland is considered one of the nation's most liberal, and the issue presents a clash between two progressive positions: the desire to improve the dental health of low-income children and the impulse to avoid putting anything unnecessary in the air, food or water.
"The fact that Portland stands out as the largest U.S. city without fluoridation is not the kind of weird we should be," the mayor said. "This is causing pain to kids."
Many in Portland and the state have long opposed public fluoridation, saying it's unsafe and violates an individual's right to consent to medication. While 73 percent of the U.S. population drinks water treated with fluoride, the rate is less than 25 percent in Oregon.
Portland voters twice rejected fluoride before approving it in 1978. They overturned their decision before it was ever added to the water.
The issue re-emerged last month, when a coalition of health and other organizations that had been lobbying the council for more than a year gained the public support of Commissioner Randy Leonard.
Opponents criticized the council for rushing into action without a public vote, and plan to collect signatures to force a referendum on it in May 2014. More than 225 people signed up to testify at a public hearing last week that ran 6 ½ hours. Sixty-one percent opposed fluoridation.
"Barnyard animals are force medicated, not human beings," said Mike Smith, a member of the Occupy Portland movement.
Portland's drinking water already contains naturally occurring fluoride, though not at levels considered to be effective at fighting cavities.
A 2007 report from the state Department of Human Services said 35 percent of Oregon first-through-third graders had untreated dental decay, a higher percentage than in neighboring states with more fluoridation, such as Washington (19 percent) and Idaho (27 percent). Dentists describe a health care crisis, with their offices and clinics inundated with cavity-ravaged youngsters.
"A lot of these kids will have such severe problems that they need to be hospitalized in order to have their dental care done," said Lisa Bozzetti, dental director at the Virginia Garcia Memorial Health Clinic.
Fluoride opponents, however, say the dental benefits of the mineral are small (better diets would have greater impact) and don't outweigh the negatives.
The Internet is rife with warnings about fluoridation, and residents with thyroid issues, kidney disease and multiple chemical sensitivity worry it will make their lives worse. Others say it reduces IQ and can cause autism, memory loss, attention deficit hyperactivity disorder and other problems.
Rick North, the former executive vice president of the American Cancer Society in Oregon, said he figured fluoride was OK until he started researching the issue several years ago and spotted many red flags. Supporters, he said, believe it is a "silver bullet" to fight cavities and won't hurt anyone else.
"But you can't put a drug into the water supply and expect that it's not going to have side effects," he said.
Commissioner Nick Fish, who co-sponsored the plan, said more than 200 million Americans drink water with added fluoride, and it doesn't appear to have caused great harm. Most mainstream health organizations, such as the American Medical Association and American Dental Association, endorse it as safe.
"Over the last 50 years, as we have fluoridated more water, the overall IQ of Americans has gone up," he said. "I don't suggest a cause-and-effect, but I also think it shows the reverse isn't true."
The ordinance to be voted on Wednesday calls for the water to be fluoridated by March 2014 at a projected upfront cost of $5 million.
Mayor Adams, who is not seeking re-election, said he planned to take time before the vote to research how people with the health conditions described at the public hearing live in cities that fluoridate. But he has yet to hear anything persuasive enough to change his opinion that it is a safe and effective way to help children born into families that can't afford dentists or don't stress dental health.
"Science is about the preponderance of evidence," he said. "There are very few proofs in this world."