The results of a £50,000 study into fluoridating water supplies should be finished later this year.
Health officials have been working with water companies since early 2008 on the costs and practicalities of adding fluoride to public water supplies.
They are now deciding whether the benefits of fluoridation would outweigh the cost – which would be borne by health trusts.
Supporters of fluoridation said it was necessary to reduce tooth decay.
Critics said it might harm people’s health and was not effective enough to justify the cost.
The study is being led by officials at NHS Nottingham City on behalf of all nine primary care trusts in the East Midlands.
Alison Challenger, a consultant in public health who is involved in the study, said: “The technical assessment work is done. This looks at how and where fluoride might be added to water.
“We have had to look at the cost of setting up plants, where they would be and the cost of ongoing maintenance.
“Each primary care trust area is different and some may decide they do not want to fluoridate supplies.
“It may be that it is decided health promotion is more cost-effective. Those decisions will be down to individual trusts.
“The feasibility study will produce a report for each area so that it can discussed and debated locally.”
Philip Martin, a dentist in Braunstone and chairman of Leicestershire local dental committee, said: “The dental profession is very keen on the idea of fluoridation of water supplies as a method which would benefit patients and prevent the early loss of teeth and other problems.
“I’m disappointed that it didn’t happen years ago.”
The National Pure Water Association campaigns against fluoridation.
A spokesman said: “There is no high-quality scientific evidence that fluoridation makes a difference. American research shows that for disease control fluoride has to be applied to the tooth surface and that doesn’t happen with drinking water.
“It should also be remembered that fluoride is a toxin.”
The British Dental Health Foundation website said studies carried out for the Government by York University and the Medical Research Council failed to find any evidence that fluoride added to water caused harmful side effects.
It said: “Opponents of fluoridation claim they have firm evidence that fluoride added to water is harmful.
“Scientific analysis has not supported their claims.”
Worldwide, more than 300 million people drink fluoridated water supplies which has “led to improved levels of dental health”, it said.
A spokesman for Severn Trent Water said: “All decisions on whether to fluoridate are made by strategic health authorities and fluoridation can only happen under their direction. Water companies are obliged to fluoridate if directed to do so.”
He added that it was possible to fluoridate only parts of a county’s water supply.
To read the Medical Research Council’s report, go to: www.mrc.ac.uk