HAVING four grandchildren, and another due any day now, it would be nice to think that their teeth could be protected by a perfectly safe water additive.

Dr Fisher, Red Rose Dental Group, replying to my recent letter, says, categorically, that fluoride is not a poison. Yet my dictionary describes fluorosis, as fluoride poisoning. I'm confused!

He also says dental fluorosis -- brown mottling of teeth -- is "most likely" caused by ingesting fluoride toothpaste, rather than fluoride in the water. I'm even more confused!

If this was the case, surely sufferers would be more evenly spread across the country, not concentrated in fluoridated areas, where up to a third of children are said to have brown mottled teeth. But at least the doctor admits that fluoride, from one source or the other, is responsible for dental fluorosis. He couldn't deny it.

But after 36 years of fluoridation in this country, we really should be getting clearer answers from these experts. "Most likely" just isn't good enough. And if the doctor is right in his assessment, then maybe we should have health warnings on fluoride toothpaste.

Brian Derbyshire

Ribchester Grove

Bolton