Egg Experiment in Year 4

In their science lessons, Year 4 have been investigating whether sugar causes tooth decay. They placed eggs in cups of drinks with different amounts of sugar in, with the shell of the egg acting like the enamel on their teeth. After observing them daily for 2 weeks, they found out that orange juice, which has a high sugar content, made the shell disintegrate, whilst the eggs in milk and water were nearly the same as when they went in.