Learning the "tooth"

Sometimes it is the simple things that make the greatest impact.  The students marveled at our model of a tooth, which was simply a hard boiled egg. The shell of the egg related to the enamel on our teeth, which we want to keep clean. We even tried to brush it!

How did it get to be so dirty?  The egg on the left was left in juice for about 12 hours, the middle egg in coca cola and the last one on the right is just a simple hard

boiled egg.  The students were amazed that the coca cola would stain the egg so quickly.  They learned that if they did not brush their teeth, the germ would attach themselves and create plaque that could lead to cavities.  We could not really get that egg clean even with toothpaste!  

In the second 'eggs'periment, a hard boiled egg was left in a bowl with vinegar overnight.

The students again were amazed that the vinegar broke down the shell enough that they could 'squish' it with their fingers.  Vinegar is acidic and this reminds the students that acidic foods must be brushed off our teeth just like sugary foods.  They learned that the enamel on our teeth is the hardest substance in our bodies, even harder than our bones, but that the enamel still needs our help to keep it clean and healthy so that we can keep our teeth for our lifetime!