Then take both eggs and put them in separate jars containing vinegar. Have students observe the immediate difference in bubbling or reactivity of the two different eggs. Take both eggs out of the jar and examine them. The egg shell soaked in the fluoride will be hard. The purpose of this activity is to help students understand the need for flossing.
Materials needed include thick tempera paint, a toothbrush, and yarn.
Cover your hand with thick tempra paint. Using a toothbrush, clean off the paint while holding fingers tightly together. Show the students that the brush will not remove the paint from between the fingers. Discuss where plaque accumulates on the teeth and why flossing along with brushing is important for maintaining healthy teeth. Distribute 12-inch pieces of yarn to the students.