Have you ever suffered from a niggling - or perhaps not so niggling - health complaint, such as constant headache or neck pain, for which you have never identified the cause?

If so, and you have tried conventional diagnoses, the answer could be right under your nose - in the fillings in your teeth.

The amalgam in traditional fillings contain up to 50 per cent mercury, an element long known to be poisonous. Now after 150 years as a mainstay of dentistry, a new breed of "alternative" dentists to use it.

John Roberts is amongst thousands of dentists worldwide reporting beneficial health effects for patients. Roberts, who runs a one-man practice in Rochdale, Lancashire, has not used mercury-based amalgam since 1994.

He says: "The only places we are permitted to put mercury are down the drain in special leak-proof containers collected by licensed people, or in our patients' mouths."

Holistic dentists believe mercury used in radical root canal work may adversely affect the body's energetic system, known to acupuncturists as "meridians".

I am a typical case study. I had been suffering tinnitus - a constant ringing in my ears - for some time.

John Roberts told me that the cocktail of metals which dentists line our mouths produces an electric charge.

A test on one of my teeth held in place by root canal work an alarming charge of half a volt, enough to power a small light bulb. Hardly a surprise that I had been hearing things. He took out my tooth and my tinnitus was extracted with it.

Roberts says: "I have treated hundreds, and know of thousands, of people that have benefited from alternative dentistry.

His US counterpart Dr Mark Breiner cites numerous dramatic cures in his book "Whole Body Dentistry". There was Josephine, 65, whose crippling arthritis disappeared after the removal of a root canal tooth and two other dead teeth, and Jack, an executive, whose sudden dramatic hair loss was halted - and in fact his hair grew back - when he had his fillings replaced with a non-toxic alternative.

Mercury poisoning is linked to many diseases including Alzheimer's. So it does not surprise me that my father, a dentist, died from this harrowing disease. The poison is able to cross the barrier between mother and unborn child and is a suspected cause of infant autism. It does not act dramatically like cyanide would, but is absorbed by our entire bodies.

In susceptible people - and not everyone is - this can result in an immediate but more likely a slow, deterioration in health. Roberts cannot explain why British dentists are not taking heed of the many scientific reports linking mercury poisoning to ill health.

Breiner sums up the dental dilemma: "You have to wonder why we are arguing over whether a poison is a poison."

For more information, visit: www.holistic-dentistry.com