We then did an experiment.
Tooth's enamel surface is similar to an egg shell.
So we hard boiled two eggs. We placed one in Coke and one in a colored punch.
We then soaked them for several days. See below what happened to the eggshells.
We used toothpaste and a toothbrush to try to clean the eggshells' discoloration.
It was a lot of hard work but it was clear to see that the eggshell helps to protect the inside of the egg.
We have learnt that even if tooth enamel protects our teeth we still need to brush them everyday to keep them strong.