What is fluoride?
Is fluoride good or bad?
Fluoride is also beneficial after teeth come through. The surface enamel of teeth is weakened and dissolved by acid attacks which occur after consuming sugary or acidic food and drinks. However, enamel can remineralise, or repair, itself by taking in minerals from sailva. Low levels of fluoride present in saliva and dental plaque encourage remineralisation and therefore make it less likely that a cavity will be formed. The fluoride also becomes incorporated into the enamel surface making it stronger and more resistant to acid attack.
So what’s the problem with fluoride?
The amount of fluoride in drinking water varies greatly. The level of fluoride in freshwater, for example rivers and lakes, is usually low. However as water seeps through soil and rocks it becomes contaminated with various naturally occurring substances or pollutants. These contaminants also become more concentrated where the groundwater level dips.
India has become increasingly dependent on groundwater, from wells or bore-wells, to meet demands for drinking water and in some areas, this contains much higher than the recommended level of fluoride.
The optimum level of fluoride in drinking water – to provide dental health benefits and minimise side effects – is 1mg per litre. In India, the permissible level is up to 1.5 mg/l.
The Indian Department of Drinking Water Supply reported that 203 out of 593 districts have higher than permissible levels of fluoride in water.
As this map shows,almost all states in India have districts where groundwater contains excessive levels of fluoride. Even in Bangalore, the level of fluoride varies between different areas and during different seasons. As water quality is not well regulated, it is not always easy to know the levels of fluoride in a particular area.
In the second part we will look at how fluoride can be used safely to benefit dental health.