Feeling confused about whether fluoride is a good thing or not? It seems like the great fluoride debate has been raging for decades. After all, who wants cavities if there is a preventive measure? But what about the possible detrimental effects? The newest recommendation may help to clarify the situation.

Health Canada has received a report from a panel of experts - and it recommends more stringent monitoring. The primary suggestion is to lower fluoride in drinking water, with an optimal level of 0.7 milligrams per litre. This concentration is thought to provide cavity protection while avoiding tooth staining due to fluorosis. The current maximum acceptable concentration is 1.5 milligrams per litre of drinking water.

Fluorides are natural compounds found in water, soil, most foods, and the atmosphere. Fish and tea leaves have particularly enriched natural levels. Other foods may have fluoride added during processing.

Many international health organizations support the use of fluoride for cavity prevention. Fluoride has several effects. Studies have found that fluoride strengthens tooth enamel, allowing it to stay intact when in contact with food acids. In addition, fluoride reduces bacterial growth and helps to repair early decay. When available during tooth formation and eruption, continual exposure builds stronger teeth. To this end, fluoridated toothpaste is available. Additionally, drinking water is supplemented in some areas.

One of the main arguments against fluoridation involved fluorosis. Young children under six- to seven-years-old who ingest high levels of fluoride can develop stained adult teeth. The most sensitive period is from about 2-3 years. Very high levels can go on to affect enamel formation, resulting in pain and chewing problems. Younger children often swallow significant amounts of fluoride in toothpaste. As a result of this risk, many organizations suggest non-fluoride toothpaste for young children or recommend tiny amounts of fluoride versions. For the same reason, fluoride supplements are no longer suggested.

Some concerns have centred on possible links between fluoride and health problems ranging from toxicity to cancer. Impaired intellectual, developmental, reproductive, and immune function have been implicated, partly due to laboratory animal studies. The current report found no support for a connection. However, it did recognize that excessive fluoride - 10 milligrams per day over many years - may lead to skeletal fluorosis. This progressive condition is marked by fluoride accumulation in bones, causing sore joints, bone brittleness, and deformation.

One remaining concern is the level of fluoride in infant formula. Since fluoride is added to powdered formulations, using fluoridated water may result in excessive levels overall.

Fluoridation of drinking water varies across different municipalities. About 40% of Canadians have fluoridated water, with an optimal concentration of 0.8 to 1.0 milligrams per litre. Vancouver does not add any fluoride. This may come as a nasty surprise for some parents, when junior develops that first little cavity after using non-fluoride toothpaste.

Some organizations actively oppose fluoridation, on the same bases examined in the Health Canada report. A 2006 review by the US National Research Council is focused on the US drinking water limit of 4 parts per million (ppm) - approximately 4 milligrams per litre - which is more than three times the allowable Canadian level. The variability of individual fluoride intake is the central issue, such that some people - including children or those with vulnerable health conditions - may be adversely affected by additional fluoridation.