Reno Dental Office May Trivia Question by pastrell | May 22, 2017 | Dental Trivia | Reno Dental Office Fun! We are enjoying playing this trivia game each month. Hope you are too! First person to email the correct answer to email@example.com wins a $10 Starbucks gift card! Question: In the Middle Ages, what did people use to make a mouth rinse to prevent tooth decay?