ADDING fluoride to the water supply of two-thirds of Southampton's residents could condemn thousands of youngsters to a lifetime of paying for expensive dental treatment.

That is the fear raised by campaigners arguing against fluoridation who say it will mean one in eight children will grow up to experience discoloured or mottled teeth.

Southampton residents will get the chance to have their say on adding fluoride to the city's water supply when a public consultation starts on September 8 - but campaigners are already out in force.

City health chiefs want fluoride introduced in a bid to improve chronic dental health amongst children in more deprived areas.

But those against topping up levels of the chemical say there is no proof it actually helps reduce tooth decay - and it leads to negative side effects such as bone cancer, thyroid problems, brain damage, fertility complications and fluorosis.

Tony Lees, dental adviser to UK Councils Against Fluoridation, said the most comprehensive study into the practice, the York Review, estimated 12.5 per cent of people in fluoridated areas would develop fluorosis.

"That breaks down to three or four children in every class in all schools," he said.

"The Secretary of State for Health, Alan Johnson, claims that fluoridation is giving poor kids rich kids' teeth'.

"In fact it does the opposite - it actually condemns one in eight of the population to a lifetime of paying for completely avoidable cosmetic dentistry."

Dr Lees said veneers to hide dental fluorosis cost about £400 per tooth.

But Southampton City Primary Care Trust (PCT) claims most fluorosis is minor and many sufferers remain unaware of it.

"It is possible that a very small proportion of children may experience mild fluorosis following the introduction of a fluoridation scheme," said a PCT spokesman. "But this has to be set against their significantly lower risk of tooth decay and their lower risk of needing teeth filled or extracted under a general anaesthetic.

"Usually, the fluorosis appears as pearly white marks, often making the affected part of the tooth seem whiter than the rest.

"Severe mottling, where the marks are brown rather than white, is associated with very high natural fluoride levels in water in hot climates. This would not apply to the proposed scheme for Southampton and surrounding areas."

South Central Strategic Health Authority (SHA) is launching a public consultation on fluoridation which will run until December 19. Events offering people the chance to talk to experts about fluoridation will take place across the region and a document setting out information will be published. Anyone wishing to express views about the move can email fluoridation@southcentral.nhs.uk. A final decision will be made early next year.