Which is a New Crown?
Mr. Chen is a Cambodian refugee. He grew up in an environment where oral care was unavailable. Although he has had a lot of cavities, they are under control. He keeps good oral hygiene. Recently a new crown is added to his front teeth. There are two old crowns. Can you guess which is the new among the three (Fig.1: 1,2,3)? What is your basis for guessing?
Here is the answer.
Xin Wei, DDS, PhD, MS 1st edition 06/14/2012, last revision 06/14/2012