Certain cheeses including Aged Cheddar, Swiss, and Monterey Jack, have been found to protect teeth from decay.
Why, you ask? Because eating cheese increases the production of alkaline saliva and neutralizes acid in the mouth. It also creates a protective layer around teeth that keeps any remaining acids from demineralizing them.
Research on this subject was carried out by the Academy of General Dentistry and results were published in their journal General Dentistry.