I don’t remember the punchline and it’s probably gonna come back to bite me. 
Placing the tooth in milk instead of water helps preserve the tooth – cells within the tooth’s root surface will swell and burst in water, but not in milk. Milk contains proteins, antibacterial substances, and sugars that help save the tooth.
Did you know that the teeth are the only part of the body that can’t fully heal themselves? While they may heal to a certain extent, teeth lack the cells necessary to rebuild enamel. Another reason why you should take care of your teeth!
