Quote:
Originally Posted by sepiagal  A short period of time? How could that be? How did they gather the data to know that tooth decay dropped significantly AND in a short period of time? |
Of course they can gather data to show that tooth decay dropped significantly and in a short period of time, simply by looking at dental records before and after.
I had answered a post about fluoride in another thread and remembered seeing this one somewhere, and came looking for it.
If you believe fluoride in water is poisonous or otherwise bad for you, then you can avoid it. But attacking fluoride in water as being ineffective in cavity prevention weakens the argument, because scientific studies comparing the same populations before and after fluoridation consistently have found a significant decrease in cavities after fluoridation. It was highly obvious in the 1950s and 1960s when most of the fluoridation was going on.
You can't compare two separate populations, or populations in different countries. It has to be the same community, and within a relatively short time frame, to control for widespread changes in lifestyle in the community that take place over many years.