AYER — The American Dental Association promotes Children’s Dental Health Month every February, and the idea sparked action at Lura A. White School.
A dental hygienist visited classrooms and explained to the children the importance of brushing their teeth and how dental health affects overall health. Some teachers took it upon themselves to do additional activities on the subject.
Third-grade teacher Kristen Lynch had her students submerge eggs and eggshells in five substances — vinegar, water, a power drink, tea and soda — and leave them there overnight. Eggs were used because their shells are similar to tooth enamel. Both are made of calcium carbonate and have thin shells and pores.
The students made educated guesses as to what they thought would happen to each of the eggs and shells, but they had to wait patiently to see the results for themselves. Hannah Leahy said she thought the power drink would permeate the shells and stain teeth, but water and vinegar would not. Melissa Bird agreed, but made an observation that the shells looked “bubbly” in the vinegar container.
The next day the students brushed the shells to find out if the power drink stains would come off. They were curious to see if the shells had changed in composition at all.
The students found that even though the soda was the darkest in color of all the liquids, it was the most easily brushed off.
The power drink turned the shell a slightly pink color. But more interestingly, it left a grayish film on the shell that Lynch said is similar to plaque build up.
The tea stained the shell almost as much as the soda did, but it did not come off during the brushing process.
Lastly, the vinegar provided the most exciting results. The half eggshells had completely dissolved. The whole egg didn’t have a shell on it. It was held intact by a thin membrane around the yolk. When it was cut into, it burst like a water balloon- much to delight of the onlookers.
Lynch emphasized to her students the importance of caring for their teeth. She asked the students to write about the “egg-speriment” using descriptive language.
“I am so proud of my students,” she said. “They used good reasoning skills and amazing descriptive language during this project.”