Learning Activity: Teeth Discoloration Experiment
•5 paper cups with lids
•Paintbrushes – 1 for every student
•Brown and yellow food coloring
A. 20 mL of water and 2 drops of yellow food coloring
B. 20 mL of water and 2 drops of brown food coloring
C. 20 mL of water
D. 20 mL of water and 5 drops of brown food coloring
E. 20 mL of water and 5 drops of yellow food coloring
2. Label the cups with their corresponding letter as listed above in bold.
Note to Teacher: Test the solutions on paper before doing the experiment. Slight differences in food coloring may change the amounts needed to create an easy-to-see continuum of “stains.” See the Results Table for descriptions of what color each solution should be when applied to paper.
Discuss the following questions with the students. Which teeth are the most stained and why? How could someone avoid staining their teeth like this? If Ann only used tobacco for a short time, why are her teeth yellow? Explain to the students that Denisha’s teeth are the darkest and most stained from smoking cigarettes and that not smoking is the best defense against discolored teeth. Highlight that Ann’s teeth are slightly yellow because any tobacco use, no matter how little, can yellow teeth. Stains get worse over time, but the stains begin to form right after the start of tobacco use.
Light/Early tobacco use
Moderate tobacco use
Long, moderate tobacco use
Heavy tobacco use
No tobacco use