Before you get that permanent tooth filling you should read this...

http://www.naturalnews.com/042204_cavities_natural_healing_tooth_decay.html#

So, apparently teeth heal themselves naturally and tooth decay hardly relies on the stuff in your mouth, but the stuff you digest in your stomach. Your teeth are alive. You probably have noticed how some people have very good teeth and others not so much, well this is due to nutrition and genetics but hardly oral hygiene. Like how the people in America that drink fluorinated water have exactly the same oral health as people in Europe. Of course oral hygiene does play a role in tooth health, it plays a much smaller role than dentists and governments want you to think. So basically fluoride in toothpaste and water proves even more useless, as if digesting fluoride wasn't useless enough. The government wants you to believe that your teeth are fragile and need extreme hygiene, they teach this to the dentists and teachers, who teach it to us. Stay healthy.