By John Woolfolk

By a 53-vote margin, voters in Santa Cruz apparently said no Tuesday to fluoride in their water. But nearly 300 uncounted ballots could either bolster that win or shatter it.

Voters won't know until Friday at the earliest. Although 50.3 percent of voters -- 4,274 to 4,221 -- endorsed the ban, nearly 204 absentee ballots remain to be counted, along with 79 that must be checked for eligibility.

The turnout was nearly 23 percent of the 37,224 registered voters.

``We won't call it tonight,'' said Santa Cruz County elections coordinator Diane Moore.

With the surprisingly strong show of support for a ban, voters in this iconoclastic coastal town displayed their trademark maverick streak against a dental health practice widely embraced elsewhere.

Still, the results were a blow to dentists and health advocates who have been flabbergasted by the controversy surrounding fluoridation, a practice widely embraced for half a century to prevent tooth decay. Measure N opponents had raised six times as much funding as its supporters and were expecting it to be soundly defeated, based on phone surveys.

``I would say this is a triumph of disinformation, even the fact that it's close,'' said Santa Cruz City Councilwoman Cynthia Mathews, the council's lone fluoride supporter.

Measure supporters, though also hoping for a decisive victory, said the close election shows residents are ambivalent about fluoride.

``We're glad to go to sleep winners, even though the count is not final,'' said Theodora Kerry, a Measure N supporter. ``This has been an educational campaign.''

If Measure N passes, Santa Cruz voters will become the first in the state to defy a 1995 state mandate for fluoridation.

A ban on the additive is likely to provoke a court fight with the state. The Attorney General's Office will probably seek a ruling on whether the state law supersedes the local measure, said Dr. David Nelson, a dentist and fluoridation specialist with the state Department of Health Services.

If the ban fails, it may not be the final word on fluoride. A city ordinance requires an affirmative vote for the additive; Measure N bans all water additives intended to affect water consumers.

While growing numbers of communities have embraced fluoridation, critics found fertile ground for resistance in Santa Cruz.

A year ago, the Santa Cruz City Council became the first to formally challenge the state mandate, voting 6 to 1 to require voter approval for fluoridation. Residents cheered in support while dentists shook their heads in dismay and state officials vowed a court battle.

In the 1950s, Santa Cruz was among several cities that rejected fluoridation when conservatives likened it to socialized medicine and called it a communist plot.

Though the citizenry in this university town is decidedly more liberal today -- environmental, political, peace, health and other activists abound -- many still greet fluoridation with suspicion. In a town with more organic groceries than supermarkets, fluoridation is seen by many to be as artificially sinister as irradiated produce. Many resent the idea of having it forced on them by the state.

``People in this community have trusted in the fact that it should be an individual choice,'' said Jeff Green, a San Diego management consultant who has organized opposition to fluoride around the state. ``Whether you call that independence or what, it's a strength.''

Dentists and other health advocates have been stunned by the continued controversy over fluoride. Since being introduced after World War II, it has been endorsed by virtually every health organization as safe and effective in fighting cavities.

``This is not some newfangled idea,'' said state Sen. Jackie Speier, D-San Mateo, who as an assemblywoman introduced the law requiring water districts with 10,000 or more customers to fluoridate. ``When you look at all the data, all the research, there's no dispute.''

While nearly two-thirds of Americans and nine in 10 Bay Area residents drink fluoridated water, only 17 percent of California communities are fluoridated. The issue was hotly debated in the Legislature before the law was adopted.

``When I introduced the bill I was warned, `You have no idea what you're getting into,' '' Speier recalled. ``I got voodoo dolls in the mail.''

Despite lingering controversy, most communities have embraced fluoridation in the wake of the state law. In November, Mountain View voters overwhelmingly endorsed fluoridation in an advisory measure. City officials in Sacramento, Los Angeles and several other cities have recently voted to fluoridate as well. And fluoridation foes failed to gather enough signatures last year to qualify a statewide ballot measure against it.

Fluoride critics, however, seized the momentum of last year's Santa Cruz council action, gathering 12,000 signatures to put Measure N on the city ballot.

If approved, Measure N would replace the council's action with a fluoridation ban that could be reversed only by voters, City Attorney John Barisone said.

If Measure N failed, the council's action would still stand, requiring voter approval for fluoridation, Barisone said.