Once a week, elementary school children throughout Paterson swish fluoride rinse in their mouths for one full minute before spitting it into a cup.

Pupils at seven schools around Bergen County also rinse with fluoride, and beginning this fall, so will youngsters in Passaic.

It’s the only way health officials know for certain the children are getting the cavity-fighting mineral. They surely aren’t getting it in their drinking water.

More than half a century after U.S. cities and towns began adding fluoride to public water supplies to reduce cavities, most New Jerseyans have yet to benefit. Only about 16 percent of the state’s residents — none in Bergen or Passaic counties — have fluoridated public water.

Many New Jerseyans mistakenly assume their water contains fluoride, state health officials and dentists say.

But the Garden State falls third-to-last among the 50 states in the percentage of residents whose public water is fluoridated, ahead of only Utah and Hawaii. By next year, when parts of Utah will begin fluoridation, New Jersey will slip yet another rung, federal health officials said.

Lack of fluoridation is just one way the state lags in ensuring oral health among residents, health experts say. It’s also in the bottom tier of states in its reimbursements to dentists serving low-income people.

“It’s such an embarrassment because New Jersey is touted as one of the wealthiest states in the nation,” said Mary Moskal, director of dental care programs for the New Jersey Dental Association.

Now, there’s a stirring for change.

A diverse coalition of government health officials, dentists, and insurers will meet at the state’s first oral health summit Wednesday to consider proposals for promoting better dental health.

Organizers said they hope the conference will spark a campaign promoting fluoridation or at least increase awareness of the lack of it.

“I hope some communities will be alerted to the problem,” said Dr. Kevin Heaney, dentistry chairman at Hackensack University Medical Center.

Home rule is one reason why New Jersey trails in fluoridation 56 years after Grand Rapids, Mich., became the first U.S. city adding the mineral to its water supply.

With no state mandate for communities to fluoridate, each of New Jersey’s 566 municipalities has a say. United Water Resources, for example, the major supplier in Bergen and Hudson counties, says it will add fluoride only if each of the 60 communities it serves signs on.

The state also has a vocal and active anti-fluoride group, New Jersey Citizens Opposing Forced Fluoridation, which since its formation in 1956 has fought local and state initiatives to use the additive, President Nancy Browne Coleman said.

The group helped to defeat a proposal at referendum last fall to fluoridate the water supply in Pequannock.

“Fluoridation is basically medicating people through their water supply for a non-lethal disease,” Coleman said.

The federal Centers for Disease Control and Prevention, however, calls fluoridation one of the great public health achievements of the last century.

Initially, studies showed adding fluoride to water reduced cavities up to 60 percent. Recent estimates indicate a less dramatic impact of up to 40 percent fewer cavities. That is because in the past 50 years, people have been getting fluoride from other sources — primarily toothpastes and food, sodas, and juices made in areas with treated water, a federal report says.

Fluoridating water supplies is still the most cost-effective way to prevent dental decay, said Dr. William R. Maas, oral health director for the CDC.

Low-income families benefit the most, he said, as they are less likely to have the education or structure in their lives necessary to maintaining regular brushing, flossing, and dentist visits. They are also more likely to lack dental insurance.

But fluoridation helps everyone, Maas and others said.

“It doesn’t care whether you’re rich or poor,” said Bryon Roshong, a Dumont dentist who will speak at Wednesday’s conference. “It’s the greatest leveler in preventive dentistry.”

Drinking fluoridated water works two ways: internally, by strengthening gums, and topically, by concentrating in saliva and in plaque. There, it serves to discourage bacteria growth and strengthen teeth under the plaque.

“It’s like putting a spray on top of your furniture,” said Dr. Allen Finkelstein, dental director of AmeriChoice Corp., an HMO serving low-income New Jerseyans on Medicaid and state-funded health insurance.

Finkelstein said he sees the effects of fluoride in the different rates of dental work required for AmeriChoice clients in New York City, which is fluoridated, and in New Jersey.

“I have more rampant decay in New Jersey than I have in New York,” he said.

Though fluoride benefits adults and children, it’s most vital for youngsters under 6 whose tooth enamel is developing, the federal report states.

Tooth decay can begin early.

One recent unpublished survey of 3- and 4-year-olds in Newark, where water is unfluoridated, found that about half had decay, said Dr. Milton Houpt, pediatric dentistry chairman at the University of Medicine and Dentistry-New Jersey Dental School.

Other studies of New Jersey schoolchildren have shown higher rates of cavities than in the United States as a whole, Houpt said.

Children can always take fluoride supplements, as the American Dental Association recommends beginning in infancy. But some pediatricians fail to prescribe the supplements and some parents neglect to get them, dentists said.

The children who miss out are also more likely to be among those failing to get regular dental care, dentists said.

Though the rate of cavities has sharply declined nationally in the past 30 years, decay is still prevalent among some groups — particularly the uninsured, low-income, and poorly educated, the federal report and health officials said.

Research shows 80 percent of all cavities in children ages 5 to 17 occur among 25 percent of youngsters in that age group.

The elderly are vulnerable to poor oral health, too, experts say, because Medicare does not cover dental work.

A surgeon general’s report on oral health last year summed up the disparity: “A silent epidemic of oral diseases is affecting our most vulnerable citizens — poor children, the elderly, and many members of racial and ethnic minority groups,” it said.

The disparities exist nationwide, but New Jersey isn’t doing enough to erase them, dental experts said.

“There’s minimal state leadership on this particular issue,” said Dr. Jan Goldsmith, regional dental consultant for the federal Health Resources and Services Administration. Goldsmith helped late last year to start the New Jersey Oral Health Coalition, which is holding Wednesday’s conference.

One example: New Jersey has had no state dental director since the early 1990s, when the position was lost to budget cuts.

The last dental director, Wilson Baker, was also the last state official to campaign for water fluoridation, state officials said.

Goldsmith said the state needs to expand its school-based dental health efforts, such as the fluoride rinse program it has sponsored since 1986.

Another glaring problem, he and others said, is that New Jersey has among the lowest reimbursement rates in the nation for dentists treating patients on Medicaid and the state insurance program for the working poor, Family Care.

In New York, dentists who give a patient on Medicaid a sealant, a plastic film painted on children’s molars to prevent decay, get $39 from the state, said Finkelstein of AmeriChoice. New Jersey pays $6 for the same treatment.

“Most of the fees don’t begin to cover dental overhead,” said Dr. Sidney Whitman, a Trenton pediatric dentist who heads the state dental association’s Medicaid committee.

So dentists don’t participate. Only between 1,000 and 1,700 dentists — 14 percent to 25 percent of the 7,000 in the state — accept any of the 800,000 patients on Medicaid or Family Care.

Though the state raised reimbursement rates last year and plans to do so again in 2002, it recognizes it must do more to attract dentists.

“We have a long way to go,” said Celeste Wood, head of the state Division of Family Health Services.

Hackensack University Medical Center’s dental clinic has a 12-month waiting list for appointments. The backlog grew more severe over the past 15 years as clinics at two other hospitals in the county and at the now-defunct dental school at Fairleigh Dickinson University closed.

“Right now, there is no one else in Bergen County who is doing this,” treating large numbers of uninsured, Medicaid, and Family Care patients, said Heaney, the hospital’s dentistry chairman.

At Paterson Community Health Center last week, a familiar plea from a parent was heard over the phone.

“I have a 7-year-old who stayed home from school today because she has a toothache,” a mother told the receptionist over the conference phone. Could she get an appointment that day?

Not possible, the receptionist told her. “Maybe tomorrow.”

Dr. Omar Cockey, the clinic’s dental director, shook his head: “We get this all day long.”

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Tips for protecting your child’s teeth if your water lacks fluoride, from the American Academy of Pediatric Dentistry (www.aapd.org).

* Children should make their first trip to the dentist when the first tooth appears, or no later than their first birthday, to determine the risk of decay and evaluate fluoride needs. (This also goes for children with fluoridated water.)

* All children between 6 months and 16 years old should take fluoride supplements if they regularly drink unfluoridated water, whether the water is bottled, from wells, or from a public water supply. Most bottled water brands don’t contain enough fluoride to prevent tooth decay.

* Be careful of getting too much fluoride. It can cause a harmless discoloration of teeth called fluorosis.

* Regardless of whether water is fluoridated, children should brush with a pea-sized amount of fluoridated toothpaste twice a day, after breakfast and before bed. Parents need to supervise brushing until age 8.

* Parents should be cautious about using toothpaste with children under 2, who tend to swallow it. That could lead to their taking in too much fluoride.