Just under half of the surfaces of your teeth can't be reached with a toothbrush - because they're the surfaces between your teeth and only dental floss can reach them!
Did you know..?
The Etruscans (who lived in what is now central and northern Italy) had dentures two and a half thousand years ago!
The tusks of many mammals alive today are actually elongated teeth - these include elephants, walruses and narwhals.
But in prehistoric times they were even longer...
Most people aren't born with teeth showing - but they're there - already forming under the gums just waiting to come through (erupt).
Tooth enamel (the surface of your teeth that you can see) is the hardest substance in the human body - even harder than bone!